Journal of Lasers in Medical Sciences
Volume:13 Issue: 1, Winter 2022

Stem cell activities have different effects on tissue response and its outcomes. Low-level laser therapy (LLLT) can be considered a trigger to modify stem cell activities. The objective of the present experimental investigation was to study the effects of two protocols of LLLT on the proliferation and differentiation of human dental pulp stem cells (hDPSCs) cultured on sandblasted titanium discs.

Cells obtained from human dental pulp were seeded/cultured on titanium discs and were set in 2 main groups: (i) Radiated cells using the gallium-aluminium-arsenide (GaAlAs) diode laser at a continuous wavelength of 808 nm at 3 J/cm2 for 12 sec or 5 J/cm2 for 20 seconds, and (ii) Non-irradiated cells serving as control groups. The impact of LLLTs on hDPSC-proliferation and viability was investigated using the MTT assay after 24, 72 and 96 hours. The alkaline phosphatase activity was studied with p-nitrophenylphosphate after 14 and 28 days. The ability of hDPSCs to express osteocalcin was investigated using real-time polymerase chain reaction after 28 days, while their attachment was observed under a scanning electron microscope (SEM) after 14 and 28 days.

Our study showed that LLLTs caused maximum cell proliferation in 96 hours (P < 0.001) with 3 J/cm2 resulting in a higher proliferation rate. The highest activity of alkaline phosphatase and osteocalcin expression was observed in the laser radiation groups after 28 days.

The outcomes of the current study showed that cultured hDPSCs on sandblasted titanium discs had a tendency towards increased cellular activity in response to LLLTs. Thus, LLLTs could regulate the activities of hDPSCs on bone repair surrounding the sandblasted titanium discs.

Bichectomy consists of the partial removal of the Bichat ball (BB) of its buccal extension and smoothing the facial contour. The objective of this study is to present, by means of a clinical case, bichectomy surgery with the use of a high-power diode laser and cold scalpel on different sides of the same patient, analyzing the trans-surgical phase and the pain and edema like consequence operative of each technique and 6-month follow-up.

A 20-year-old female patient reported the occurrence of involuntary trauma to the cheek mucosa and rounded facial appearance. After anamnesis and clinical examination, bichectomy was proposed. For comparison, on the right side, an incision was made using a laser, while on the left side, with a cold scalpel. To assess and measure the progression of treatment, photographs and facial measurements were repeated before the procedure, 7, 14, and 28 days after the procedure, and 2, 3, and 6 months after the procedure.

The high-power diode laser showed excellent applicability for bichectomy due to its hemostatic properties in the trans-surgical phase. In addition, it promoted greater patient comfort, with less edema and pain on the side of the face where it was used.

The present study aimed to describe parameters used with 808- to 980-nm wavelength diode lasers for managing dentin hypersensitivity and analyze their results.

The inclusion criteria were based on randomized controlled clinical trials using diode lasers at an 808-980 nm wavelength range in patients with dentine hypersensitivity with a minimum of 1-month follow-up. An electronic search for articles on Medline, PubMed, and Cochrane databases was performed. The risk of bias was assessed with the Cochrane collaboration tool.

Our electronic search resulted in 130 papers, of which 11 articles met the inclusion criteria. A majority of the studies assessed dentine hypersensitivity using the Visual Analogue Scale, which ranged between 2.3 and 8.8 before treatment and significantly reduced to a mean value of 0.45-3.7 after diode laser application. The power settings ranged between 1.5 mW and 3 W with an emission mode of continuous wave, except for 2 authors who used chopped mode. The energy density varied from 2.5 to 128 J/cm2, and the exposure time was between 10 and 120 seconds. The authors applied a minimum of 1 to 4 treatment sessions with a 2-day to 1-week interval between them. Most of the studies mentioned the tooth surface as the treatment site but without describing the specific irradiation points.

Despite the heterogeneity of the analyzed variables, a statistically significant improvement in all laser groups as described. However, they cannot be compared homogenously.

the Er,Cr:YSGG laser has a suitable wavelength for the ablation of both hard and soft tissues of the periodontium and can be considered as a potential tool in periodontal surgeries. The current study aimed at evaluating the application of this laser versus conventional instruments in periodontal pocket reduction flap surgery.

Eight patients (16 dental arches) requiring periodontal surgery were included (Trial registration number: IRCT201711129014N199). Using a split-mouth study design, two posterior sextants of a dental arch were randomly allocated into either a test group, open flap debridementperiodontal surgery using the Er,Cr:YSGG laser or a control group using the conventional method. Laser parameter settings of a 2780 nm wavelength, H mode (60 μs pulse duration), 25-50 Hz, 2-3.5 W output powers and Air-20%, Water-60-80% were applied and adjusted individually for each step of the flap surgery procedure. Baseline, 1 and 3-month measurements of plaque index (PI), Gingival Index (GI), gingival recession (GR), probing depth (PD) and clinical attachment level (CAL) were recorded for comparisons. Data were analyzed by a linear model for correlated data using the generalized estimating equations (GEE) method and the least significant difference (LSD).

In both treatment groups, reductions in PI and GI were observed in the 3-month follow-up period. These indices were significantly lower in the laser-treated sides compared to the conventional group (P < 0.05). The Mean PD and CAL were lower at 1 month and3 months compared to the baseline in both groups (P < 0.05). However, these parameters were not statistically different in the treatment groups during these follow-up timelines. An increase in GR was observed from the baseline to 1 month and 3 months with less recession in the laser-treated sides (P = 0.016).

Based on the results of the present study, the Er,Cr:YSGG laser assisted periodontal flap surgery resulted in similar treatment outcomes to the conventional method and may be considered as a safe and effective treatment modality.

Staphylococcus aureus is one of the critical pathological bacteria. This bacterium had developed a variety of genetic mutations that made it resistant to drugs and more harmful to humans. In addition, all attempts to design a specific vaccine against S. aureus have failed. Therefore, this experiment was designed as a trial for vaccine production, by using a photodynamic treatment (PDT) through partial biological inhibition. The PDT of bacteria mainly focused on reducing the activity of staphylocoagulase (SC), which has a protective feature for bacteria. This study aimed to examine the photodynamic effect of combining a specific wavelength of a laser and a certain dilution photosensitizer, methylene blue (MB) dye. The possible PDT effect on the inhibition of pathogenic enzymatic activity was predicted. This study also aimed to evaluate the inhibitory effect of PDT on the total bacterial account (viability) simultaneously with SC assay.

A 650nm wavelength diode laser was used with 100 mW output power and 2 minutes of exposure time. Dye dilutions were 50, 100, 150 and 200 μg/mL. The viability of bacteria after and before laser treatment was calculated using single plate-serial dilution spotting methods. The activity of SC was detected by using human plasma for 4 hours incubation of crude-substrate interaction.

The results revealed a significant decrease in enzyme activity and colony-forming units (CFU) after irradiating bacterial suspension with 150 g/mL MB, as well as a decline in CFU. However, irradiation with a laser alone showed a significant increase in SC activity and CFU for the same exposure time.

Besides reducing the production of SC activity, PDT significantly inhibited the viability of S. aureus. The application of MB photosensitizer at a concentration of 150 g/mL in combination with a laser wavelength of 650 nm resulted in a complete decrease in the SC activity value as well as the viability of bacteria

Focal epithelial hyperplasia (FEH), also known as Heck’s disease, is a human papilloma virus-induced proliferation of epithelial cells, which causes asymptomatic lesions in the oral mucosa. Heck’s disease is more prevalent among children or in a family. Despite the self-limitation of lesions, they may progress or cause esthetical and functional discomforts. Hence, early diagnosis is necessary.

A middle-aged man with peripheral multiple soft, elevated, sessile, smooth, lobulated surface and nodular lesions in his right buccal mucosa was referred. The dimensions of the lesions varied from 5 to 25 mm. Through clinical and histopathological examinations, Heck’s disease was diagnosed. The diode laser (wavelengths of 980 nm), 1-W power using continuous waves) was applied serially (in 2 sessions with a 1-week interval) for surgically removing the lesions. The patient was followed up for 6 months with no lesion recurrence, and gradual healing was observed.

The laser is an effective treatment with no scar remaining after the procedure and brings satisfaction to patients.

Postoperative management of patients undergoing tonsillectomy is challenging. Photobiomodulation therapy (PBMT) has emerged as a new tool providing therapeutic benefits. However, the contribution of PBMT to the postoperative outcomes of tonsillectomy is still undefined. This systematic review and meta-analysis evaluated the published literature addressing the effects of PBMT on post-tonsillectomy.

Searches in Scopus, PubMed/MEDLINE, Embase, Web of Science, Cochrane Library, and grey literature were carried out for the identification of randomized controlled trials reported up to August/2021. The risk of bias with the Cochrane Collaboration tool and meta-analysis was performed. Outcomes were assessed with the Kaplan-Meier method and the log-rank test.

A total of 1183 articles were retrieved, of which only two were included for qualitative and quantitative analysis. The wavelengths were 685 nm and 980 nm with energy density set at 4 J/cm². The mandibular angle and the surgical wound were the sites of laser irradiation. Individuals who had not undergone PBMT after tonsillectomy were more likely to report pain and odynophagia in the first 24 hours after surgery than individuals who had undergone PBMT after tonsillectomy (P<0.001). Children who received PBMT after tonsillectomy were equally affected by pain and odynophagia in the first seven days after surgery compared to children who had not undergone PBMT after tonsillectomy (P>0.05). However, both studies found a significant association of PBMT with reduced analgesic consumption.

Although PBMT seems promising for the management of individuals undergoing tonsillectomy, a limited number of studies are available in the literature.

Gingival hyperpigmentation is an esthetic concern for some individuals. This study compared the effectiveness of CO2 and diode lasers for gingival depigmentation.

This randomized, split-mouth, clinical trial consisted of 12 patients with the chief complaint of hyperpigmented gingival areas. The upper right and left anterior segments and the mandibular anterior segment were randomly allocated to one of the treatment groups. The segments in group 1 underwent gingival depigmentation with a diode laser (810 nm) at 6 W and pulsed mode, whereas group 2 was ablated with a diode laser at 3 W and continuous mode. The removal of gingival pigments in group 3 was contemplated with a CO2 laser (10600 nm, 3 W, continuous mode). The operation chair time, bleeding during the procedure and post-operative pain were recorded. The gingival color and esthetic appearance were measured before the operation and at 1 week and 6 months later.

There was no significant difference in the bleeding scores, pain level, and color alteration values between the groups (P > 0.05). The operation chair time was significantly shorter when the diode laser was applied at pulsed mode (P < 0.05). The segments treated with the diode laser (pulsed or continuous mode) showed a higher esthetic appearance at the 6-month follow-up compared to those ablated with the CO2 laser (P < 0.05).

Higher esthetic appearance is expected when using the diode laser for gingival depigmentation compared to the CO2 laser. The application of the diode laser at pulsed mode could be recommended for gingival depigmentation, as it produced pleasing esthetic outcomes at reduced chair time.

In this study, the cytotoxic and anti-cancer effects of Irinotecan as a conventional chemotherapeutic agent compared to 17-(allyl amino)-17-demethoxygeldanamycin (17-AAG) as possible radiosensitizers in the HCT-116 cell line were investigated.

HCT-116 cells were treated with various concentrations of irinotecan and 17-AAG and also irradiated with a 2-Gy of X-ray radiation. Then, the cell viability was examined by a water-soluble tetrazolium-1 assay after 24 hours. For single therapies and double and triple combination cases, IC50, 0.5 × IC50 and 0.25 × IC50 concentrations of each drug were selected respectively for a terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay and other tests. In treated and untreated cells, the caspase 3 and Bcl-2 gene expression ratios were evaluated by the real-time PCR method. Likewise, caspase 3 activity was detected with a colorimetric assay.

In all combined treatments, including 17-AAG- radiation, irinotecan - radiation, irinotecan -17-AAG, and irinotecan-17-AAG-radiation, decreased cellular viability and increased TUNEL positive cells were presented versus the control group (P < 0.05). There were increased TUNEL positive cells in the triple combination, in concentrations of 0.25 × IC50 of each drug, in comparison with single and double agent treatments. Moreover, in triple combination, the caspase 3 mRNA level and caspase 3 activity increased versus related single treatments. Likewise, in the irinotecan-17-AAG-radiation combined treatment and the 17-AAG-radiation double treatment, the Bcl-2 gene expression level decreased in comparison with single therapies.

It can be indicated that the combination of chemo-radiotherapy versus single treatments has significant anti-cancer effects.

Long bone segmental deficiencies are challenging complications to treat. Hereby, the effects of the scaffold derived from the human demineralized bone matrix (hDBMS) plus human adipose stem cells (hADSs) plus photobiomodulation (PBM) (in vitro and or in vivo) on the catabolic step of femoral bone repair in rats with critical size femoral defects (CDFDs) were evaluated with stereology and high stress load (HSL) assessment methods.

hADSs were exposed to PBM in vitro; then, the mixed influences of hDBMS + hADS + PBM on CSFDs were evaluated. CSFDs were made on both femurs; then hDBMSs were engrafted into both CSFDs of all rats. There were 6 groups (G)s: G1 was the control; in G2 (hADS), hADSs only were engrafted into hDBMS of CSFD; in G3 (PBM) only PBM therapy for CSFD was provided; in G4 (hADS + PBM in vivo), seeded hADSs on hDBMS of CSFDs were radiated with a laser in vivo; in G5 (hADSs + PBM under in vitro condition), hADSs in a culture system were radiated with a laser, then transferred on hDBMS of CSFDs; and in G6 (hADS + PBM in conditions of in vivo and in vitro), laser-exposed hADSs were transplanted on hDBMS of CSFDs, and then CSFDs were exposed to a laser in vivo.

Groups 4, 5, and 6 meaningfully improved HSLs of CSFD in comparison with groups 3, 1, and 2 (all, P = 0.001). HSL of G5 was significantly more than G4 and G6 (both, P = 0.000). Gs 6 and 4 significantly increased new bone volumes of CSFD compared to Gs 2 (all, P = 0.000) and 1 (P = 0.001 & P = 0.003 respectively). HSL of G 1 was significantly lower than G5 (P = 0.026).

HSLs of CSFD in rats that received treatments of hDBMS plus hADS plus PBM were significantly higher than treatments with hADS and PBM alone and control groups.

This study aimed to develop the algorithm for choosing both effective and safe mode of dual-wavelengths copper vapor laser (CVL) photodestruction of dilated dermal vessels in PWS for different skin phototypes. This study is expected to assess the safe parameters for CVL treatment.

We used the multilayered skin model with different melanin content for simulation. The calculation of the vascular component’s selective heating with CVL radiation at the green and yellow wavelengths for different skin phototypes was performed with Matlab mathematical programming system and its application Femlab for solving partial differential equations using the Finite element method.

We determined the location depth and size of blood vessels that could be selectively heated to the coagulation temperature for different skin phototypes.

CVL can selectively heat 15-300 mcm vessel diameters that correspond to the PWS vessel diameter range. CVL fluence values need to be reduced almost twice for the IV skin phototype than the II skin phototype. The maximum depth of the vessels’ location also decreased for dark skin phototypes.

The present study aimed to test the efficiency of photoinduced photoacoustic streaming using 2940 nm Er: YAG laser and 980 nm diode laser agitation on smear layer removal, sealer penetration and push-out bond strength.

Sixty single canaled human permanent teeth were collected for this study. Specimens were grouped into three experimental groups (20 teeth in each group), depending on the activation protocol used for final irrigation: Group I (needle agitation), group II (980nm diode laser agitation) and group III (photon induced photoacoustic streaming (PIPS) using 2940 nm Er: YAG laser. The quantity of irrigant was standardized in all groups to 4 ml. The irrigant was activated for 40 seconds in different groups under continuous flow. Two teeth from each group were used to check the smear layer removal, and then the remaining teeth in each group were randomly divided into three equal experimental subgroups according to methods of evaluation used: subgroup A: Sealing ability evaluated by dye penetration method; subgroup B: SEM for sealer penetration; and subgroup C: Push-out bond strength assessed by the universal test machine.

As regards smear layer removal, results showed that the PIPS group had opened dentinal tubules, followed by the diode laser group, while the least cleaning effect was found in the Side-vented needle group. As for Sealing ability and dye penetration, a statistically significant difference was found between all of the three groups, with the Er:YAG laser (PIPS) having the best sealing ability and sealer penetration. Push-out bond strength results showed no statistically significant difference between diode and Er:YAG groups, with a significant difference between each of them and the Side-vented needle group.

Using the diode or Er:YAG laser (PIPS) for irrigant activation led to better irrigant penetration and smear layer removal which subsequently led to obvious sealer penetration, better sealing, and strength properties of endodontic treated teeth.

Crossbite is a common malocclusion with a 7-23% prevalence rate. Treatment is based on the expansion of the mid-palatal suture (MPS) with Rapid Palatal Expansion(RPE) followed by a retention period to reach new bone maturation, enough to maintain the results stable. This systematic review was conducted to evaluate the effectiveness of low-level laser therapy (LLLT) in increasing bone formation in MPS.

This article was written by the PRISMA checklist. Electronically, 3 databases, namely PubMed, Scopus, and Embase, were searched with the keywords selected based on PICO. Time (2010-2021) and language restrictions were performed.

528 articles, out of which 374 studies were screened, were found, and 9 full-text articles were subsequently included considering these inclusion criteria: randomized clinical trial (RCT) that examines the efficacy of LLLT in rapid palatal expansion (RPE), age under 15 years, non-surgical RPE with a tooth-supported appliance, and low-intensity laser application. Finally, 4 articles were appraised by Cochrane version 5.2.0 with 7 domains. 3 of 4 articles showed LLLT has a significant impact on bone formation. One of them showed no significant difference in pain perception and bone density between the laser and non-laser groups.

While many studies have assessed the effect of LLLT on bone formation in animal models, high-quality clinical trials are missing in this regard. The available clinical trials suggest a positive effect of LLLT on sutural bone formation after RPE.

The presence of gaps at the bonding interface of resin composite restorations is known to have an impact on restoration longevity. This study aimed to evaluate the effect of erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er, Cr:YSGG) laser irradiation on gap formation at the tooth–resin interface and to compare the reliability of micro-computed tomography (μCT) and scanning electron microscopy (SEM) scans for gap formation assessment.

Thirty standardized non-retentive class V cavities were prepared on sound human premolars using either an Er,Cr:YSGG laser or a round carbide bur (n = 15 for each). A universal adhesive and A nano-filled resin composite were applied in accordance with the manufacturer’s recommendations. After water storage for 24 hours at 37°C, the teeth were subjected to thermocycling. Gap formation assessments were performed by μCT (Skyscan 1173 μCT, Brucker, Belgium) and SEM (JEOL JSM-6610LV, Japan), and SPSS version 24.0 (IBM Inc., Chicago, USA) was used to analyze the data at Pvalue < 0.05. Descriptive statistics were used to describe the gap formation percentages. To compare the impact of both preparation and assessment methods, a non-parametric Mann–Whitney U test was used.

In enamel, similar gap formation values were detected for the two preparation methods (bur and laser). However, the laser-prepared group showed higher gap formation values in dentin. Additionally, higher gap formation values were reported for both preparation methods when μCT was used for assessment.

Cavity preparation using a Waterlase laser led to higher gap formation percentages at the dentin–resin interface. In addition, SEM assessment is more reliable for assessing the tooth–resin interface.

As adipose tissue-derived stem cells (ADSCs) can divide rapidly and be prepared noninvasively, they have extensively been used in regenerative medicine. On the other hand, a new method of therapy, known as photobiomodulation (PHT), has been used to treat many diseases, such as inflammatory conditions, wound healing and pain. Besides, exposure to chemical substances such as bisphenol A (BPA), at low levels, can lead to autophagy. This study investigated the effects of BPA and PHT on the expression of autophagy-related genes, including LC3, NRF2, and P62, in rat ADSCs as a model.

ADSCs isolation and purification were confirmed by immunocytochemistry (ICC). The cells were then treated with different concentrations of BPA and also subjected to PHT. Reverse transcription polymerase chain reaction (RT-PCR) was used for the evaluation of LC3, NRF2 and P62 gene expressions. Oil red O staining was used for adipogenic vacuole formation.

ICC showed that the isolated cells were CD 49-positive but CD 31 and CD 34-negative. The viability test indicated that the number of live cells after 24 hours in the BPA groups at concentrations of 0, 1, 50, 100 and 200 μM was 100%, 93%, 81%, 72%, and 43% respectively. The difference in cell viability between groups 50, 100 and 200 μM was significant as compared with the control groups (P<0.05). Moreover, in the group with 1 μM concentration of BPA, the expressions of LC3, NRF2 and P62 genes were upregulated. However, in the treatment group at the concentration of 200 μM of BPA, the LC3 gene was expressed, but NRF2 and P62 genes were downregulated.

BPA and PHT induce autophagy and adiposeness in ADSCs in a dose-dependent manner.

Dark circles and wrinkles under the eyes are common cosmetic problems, caused by various conditions, especially aging and overproduction of melanin in the epidermis or dermis of the skin. In addition to the application of topical lightening agents, different types of lasers, especially the Q-Switched ND:YAG laser, has been used for the treatment of cutaneous hyperpigmentation. Because of a high prevalence of idiopathic eye dark circles (EDCs) or periorbital melanosis and a poor response to available therapies, we decided to evaluate the efficacy and safety of the Fractional QS 1064 nm ND:YAG Laser through a before-after trial.

18-65-year-old patients with skin Fitzpatrick phototype of I-V and without any usage of a topical or systemic therapeutic regimen (2-4 weeks before the trial) were enrolled in the study. Each patient was treated with 6 sessions of the Fractional QS 1064 nm ND:YAG Laser at 2-week intervals and assessed for response and possible side effects or recurrences through 4 outcome measures, including Visoface-based color and erythema, melanin index and lightness (Before the fourth and sixth sessions of the therapy; also 1 week and 3 months after finishing the trial).

The changes in Visoface-based color and erythema, the melanin pigment amount by the Mexameter (melanin index) and the degree of lightness by the Colorimeter of patients after 6 months of intervention were statistically significant (P<0.001).

The fractional QS 1,064 nm ND: YAG Laser is an effective and safe therapy in EDCs since objective outcomes like the reduction of the melanin index and improving lightness and subjective ones like the reduction of darkness and erythema were confirmed.

Thrombocytopenia is usually seen after allogeneic hematopoietic stem cell transplantation (HSCT) and may favor the development of oral bleeding, infections, and ulcerations.

A patient with chronic myelomonocytic leukemia had been submitted to allogeneic HSCT. Within a few days, she developed severe thrombocytopenia and an extensive ulcerative area comprising both lips, which bled spontaneously, as well as smaller ulcers on the tongue mucosa. The lesions were managed using a combination of phototherapies (photobiomodulation and antimicrobial photodynamic therapies), totalizing 4 laser sessions. After 4 days, there was an important reduction in the severity of the lesions, with spontaneous disappearance of the crusts and reepithelization.

The proposed combination of phototherapies would be a suitable therapeutic modality for the management of oral lesions related to platelet disorders induced by oncologic treatments.

Repair of old composite restorations is a conservative approach. This study sought to compare the effects of two adhesive systems on the bond strength of repaired composites prepared by three different surface treatments: erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation, air-abrasion, and bur preparation.

Eight microhybrid (Polofil Supra, VOCO, Germany) composite resin blocks were fabricated. The blocks were aged and assigned to four groups as stated by the surface treatment: (I) air-abrasion (50 μ aluminum oxide particles), (II) diamond bur (fine grit), (III) Er:YAG laser (3 W output power, 300 mJ energy) and (IV) control. After surface treatment, the blocks were acid-etched and salinized. Each group was divided two subgroups, and the Clearfil SE Bond or All-Bond Universal was applied on their surface. Composite resin was bonded to the aged composites. The blocks were cut into eight samples, and the microtensile bond strength (MTBS) was measured.

The maximum MTBS was noted in the air-abrasion (25.1 + 6 MPa) group, followed by the Er:YAG laser (21.2 + 4.7 MPa). The mean MTBS in laser and air-abrasion groups was significantly higher than that in other groups (P < 0.05). The mean MTBS was not significantly different between the laser and air-abrasion groups (P > 0.05). Composite resin conditioning by All-Bond Universal in laser and air-abrasion groups yielded significantly higher MTBS than the Clearfil SE Bond (P < 0.05).

All surface treatments created acceptable bond strength. The surface treatment of the aged composite by the Er:YAG laser or air-abrasion along with the application of silane and All-Bond Universal provide high bond strength.

Photodynamic therapy (PDT) is now a widely used treatment modality in many fields of dentistry, including endodontics. The most common application of PDT in endodontics is to disinfect root canals. The purpose of this study was to present the experience of using PDT in root canal disinfection of three patients.

Three patients were referred to the Endodontics Department of Shahid Beheshti University of Medical Sciences and were treated using 0.1 mg/mL Toluidine Blue (FotoSan® agent; CMS Dental, Denmark) irradiated with a light-emitting diode (LED) lamp (FotoSan®; CMS Dental, Denmark) with a mean wavelength of 630 nm and a mean power density of 3 W/cm2 over two 30-second periods.

PDT using LED lighting can be used in conjunction with conventional root canal treatment (RCT) to achieve great results.

The prevalence of using different esthetic methods increases the possibility of close contact between them with potential adverse interactions. This study aimed to compare the surface changes (microhardness and roughness) in two types of feldspathic porcelain after laser bleaching and post-bleach polishing.

12 standardized rectangular specimens were prepared for each porcelain group (conventionally layered and CAD-CAM milled). Vickers microhardness and roughness were evaluated before and after the bleaching procedure and after polishing. Data were statistically analyzed using repeated measures ANOVA and t test (P<0.05).

The surface roughness of both groups increased significantly after laser bleaching (P<0.001 for conventional and P=0.004 for CAD-CAM porcelains). The polishing process reduced the roughness of both groups; the reduction was significant in conventional specimens (P=0.020). The surface hardness values did not change significantly in the groups after the bleaching and post-bleach polishing stages (P=0.142). Generally, the average surface roughness of CAD-CAM specimens was significantly lower (P<0.001), and the surface microhardness of the CAD-CAM group was significantly higher than conventional porcelains (P=0.011).

Laser bleaching significantly increased the surface roughness of feldspathic porcelains; however, it did not affect the surface microhardness significantly. Unlike CAD-CAM specimens, polishing significantly improved the surface smoothness of conventional porcelains.

The application of low-level laser therapy (LLLT) and some medications have been shown to accelerate bone formation in the rapid palatal expansion (RPE). A combination of these two therapeutic modalities may reduce the time required for the retention period. This study sought to assess the effects of simvastatin and LLLT, alone and combined, on sutural bone formation in rats.

Sixty male Wistar rats averagely weighing 150 g were divided into five groups (n=12) of control (group 1), 5 mg simvastatin (group 2), 10 mg simvastatin (group 3), LLLT (group 4), and LLLT plus 10 mg simvastatin (group 5). The expansion appliance was placed in the parietal bone in all groups. One week after placing the appliance, the spring was fixed with Duralay acrylic resin to serve as a retainer during the rest of the experiment. The rats were sacrificed after 30 (for biomechanical and computed tomography [CT] assessments) or 60 days (for biomechanical, CT, and immunohistochemical [IHC] assessments).

Groups 3 and 4 showed a significant improvement in osteogenesis (confirmed by CT findings, histological analysis, and biomechanical test) compared to the control group. Group 5 was significantly superior to all other groups in terms of all parameters (P<0.001). Group 2 and the control group were not significantly different (P>0.05).

Although LLLT, simvastatin treatment, and the combination of both significantly improved sutural bone formation in rats compared to the control group, the combined treatment showed significantly superior clinical results compared to other interventions.

The lip repositioning surgical technique arose with the objective of correcting and harmonizing the act of smiling. Since the conventional technique was published, some modifications of the technique have been proposed in order to counteract postoperative recurrence and to achieve the best esthetic appearance of the smile. The objective of this paper was to describe the laser-assisted lip repositioning technique (laser-assisted LRS) with a 940nm diode laser and 2780nm Er, Cr: YSGG, as a modification to the conventional lip repositioning technique, for the treatment of a gummy smile.

The proposed technique consists in achieving the descent of the upper lip by removing the intraoral mucosal band through the laser peeling of the oral mucosa, preserving the connective tissue intact for healing by secondary intention. The technique was implemented in two patients with a diagnosis of a gummy smile caused by a short and hyperactive upper lip; the healing process was satisfactory, and there was no bleeding or postoperative edema. Postoperative controls were performed at 3 and 10 months, and no recurrence was found.

the 940nm Diode laser or 2780nm Er, Cr: YSGG laser-assisted lip repositioning the technique described here is less invasive than that performed with a conventional scalpel, offers aesthetic results, lower risk of infection, and recurrence of the gummy smile in the long term.

It has been demonstrated that laser technology can enhance topical drug absorption. This study aimed to determine the effects of Er, Cr: YSGG laser radiation before the application of topical corticosteroids in the healing of oral lichen planus.

In this double-blind split-mouth clinical trial, 32 lesions were chosen from eight patients affected by oral lichen planus (OLP). The oral lesions were randomly categorized into two groups. The first group had topical treatment with triamcinolone NN ointment and the second group had laser radiation (Er,Cr:YSGG) for eight weeks before starting the ointment. For each lesion, the irritating level based on the VAS score, the lesion level based on the Thongprasom scale score, and the healing time were measured, and the collected data were analyzed by the Friedman test and the Wilcoxon’s statistical test.

The mean healing time based on the verbal analog scale (VAS) score was not significantly different between the two treatment groups (P>0.05). The mean healing time based on Thongprasom scale scores did not show any significant difference between the two treatment groups (P>0.05).

The application of the Er,Cr:YSGG laser before treatment with triamcinolone NN ointment did not show any advantage for the average healing time compared to a medicine regimen with only triamcinolone NN ointment.

Magnetocardiography (MCG) based on optical atomic magnetometers has shown promise for detecting heart diseases accurately. Different methods were introduced to improve the sensitivity of detecting magnetic fields during cardiac activity.

In this paper, an optical pump-probe magnetometer operated on the ground-state Hanle effect based on the zero-field level crossing technique was developed and the laser output signal was optimized in an unshielded environment. Then, the optical magnetometer was utilized to record the simulated MCG trace of different stages of myocardial ischemia.

The probe output light intensity followed the variation of cardiac magnetic field (MCG trace) generated by the Helmholtz coil accurately.

Based on the results, the feasibility of our highly sensitive optical magnetometer in tracing showed no change in the P-QRS-T waveform associated with ischemic heart disease (IHD), where P indicates atrial depolarization, QRS is responsible for ventricular depolarization, and T represents ventricular repolarization.

Low-level laser radiation has a significant effect on cell proliferation. Various investigations into the effect of Er: YAG laser on the treated cell lines have been published. Determining core targeted proteins is an attractive subject. This research aimed at identifying the critical targeted protein by a low-level Er: YAG laser in primary osteoblast-like cells.

Data were extracted from the literature about proteomic assessment of 3.3 J/cm2 of low-level Er: YAG laser radiation on osteoblast-like cells of rat calvaria. The significant differentially expressed proteins plus 100 first neighbors were analyzed via network analysis and gene ontology enrichment.

Nine differentially expressed proteins among the 12 queried proteins were included in the main connected component. Analysis revealed that Cxcl1 was a key targeted protein in response to laser radiation. The presence of Cxcl1 in the significant cellular pathways indicated that cell growth and proliferation were affected.

It can be concluded that the immune system is affected by the laser to activate cellular defense against stress.

Low-level laser is a pain-free and non-invasive treatment modality. It is used in many acute and chronic painful conditions. This study aimed to determine the correlation between pain intensity, functional disability, and range of motion using low-level laser therapy (LLLT) in patients with discogenic lumbar radiculopathy.

This cross-sectional study was conducted as a part of a randomized controlled trial of LLLT to treat patients with discogenic lumbar radiculopathy in physical therapy departments of three different hospitals in Islamabad, Pakistan, from August 2021 to September 2021. The study was conducted according to STROBE guidelines. Fifty-Five patients from the experimental group of the trial were invited to participate in this study. The outcomes of the treatment were recorded on a semi-structured questionnaire on the first day and last day of their treatment from each patient’s pain intensity, functional disability, and Lumbar range of motion (L-ROM) (flexion and extension) by using the visual analogue scale (VAS) for pain intensity, Oswestry Disability Index (ODI) for functional disability, and dual inclinometer for L-ROM. The data were analyzed through SPSS version 26.0.

The results of the correlation coefficient/Pearson’s correlation of VAS, ODI, and dual inclinometer were varied. The strength of correlation between variables was weak to moderate (r = 0.033 to 0.425) with statistically insignificant correlation coefficient (P > 0.05, 95% CI) except for lumbar flexion (P < 0.05, 95% CI).

For acute low back pain (LBP) with discogenic lumbar radiculopathy, LLLT at a wavelength of 830-nm and a dose of 3 J/point in conjunction with conventional physical therapy had no significant correlation, but rather weak to moderate values with pain intensity, functional disability, and L-ROM.

The present study aimed to systematically explore available literature on the possible impact of photobiomodulation (PBM) therapy on the stability and success of orthodontic mini-implants.

A comprehensive electronic search was conducted in PubMed, ISI Web of Science, Scopus, Cochrane and Embase databases for human and animal studies published until July 2021. Two independent researchers reviewed the studies based on specific eligibility criteria.

15 studies were included in the systematic review after a comprehensive search. Ten studies were included in the meta-analysis. Four were human RCT studies that evaluated the stability with Preriotest. Three other human RCT studies and two animal studies had evaluated the Implant stability quotient (ISQ). Two human RCTs that had evaluated displacement of mini-implants were also analyzed. The analysis of Periotest stability results showed a positive effect of PBM on mini-implant stability at 30 and 60 days after implantation (P < 0.05). In human studies using the ISQ method, a slight improvement was seen in the PBM groups; however, this was not statistically significant (CI = -1.92-2.70, SMD = 0.39). In studies that examined the displacement of mini-implants, no statistically significant difference was observed between irradiated and non-irradiated groups (CI = -1.92-2.70, SMD = 0.03). According to the results of animal studies, which had used the ISQ method, the use of laser was statistically effective in increasing the stability of mini-implants (SMD = 1.43, CI = 1.00–1.85).

PBM therapy can be suggested as an adjunctive clinical method to improve the stability of mini-implant treatment. Further well-designed clinical studies can help establish evidence-based dosing and irradiation protocols.

Parkinson’s disease (PD) is a progressive and severe neurodegenerative disorder of the central nervous system (CNS). The most prominent features of this disease are cell reduction in the substantia nigra and accumulation of α-synuclein, especially in the brainstem, spinal cord, and cortical areas. In addition to drug-based treatment, other therapies such as surgery, cell therapy, and laser therapy can be considered. In this study, articles on cell therapy and laser therapy for PD have been collected to evaluate the improvement of motor function, cell differentiation, and dopaminergic cell proliferation.

Articles were collected from four electronic databases: PubMed, Scopus, Google Scholar, and Web of Science from 2010 to 2022. The keywords were “photobiomodulation”, “low-level light therapy”, “Low-level laser therapy”, “near-infrared light”, “Parkinson’s disease”, “Parkinsonism”, and “stem cell therapy”. About 100 related articles were included in the study.

The results of the studies showed that cell therapy and laser therapy are useful in the treatment of PD, and despite their limitations, they can be useful in improving PD.

Concomitant use of cell therapy and photobiomodulation therapy can improve the symptoms of PD

The purpose of the present study is to investigate the common causes of injuries, claims, and decisions related to laser therapy medical malpractice during a nine-year survey.

The legal documents in the Coroner’s Office of Forensic Medicine were investigated in a national database from 2012 to 2020 in Tehran, Iran. The frequency and nature of the cases, including the year of litigation, the location and certificate of the provider, the injury sustained, and the cause of legal action and judgment were collected.

Three hundred and eighty-three cases related to injury from laser therapy were registered in the coroner’s Office of Forensic Medicine during the study period. The incidence of litigation related to laser surgery showed an increasing trend, with a peak occurrence in 2020. Laser hair removal was the most common (51.2%) litigated procedure. General practice operators (48%) recorded the highest rate of laser-related medical complaints. Lack of skill was the most common reason for failure. Among 383 cases with public decisions, 62.4% of them were fault liability in paid judgment.

Medical claims related to laser application are increasing. However, as it is clear, the growth of laser technology and the increasing demand for lasers in medical science require more surveillance to avoid probable injuries and improve patient safety, especially surveillance of the physicians who work outside the scope of their specialty.

Intraoral repair has been suggested as a treatment option to repair the chipping or fracture of veneered zirconia; the success of the procedure is mainly determined by the bonding between zirconia and composite resin. The present study aimed to investigate and compare the shear bond strength (SBS) of two intraoral repair systems to zirconia ceramic treated with a laser or air-abrasion surface modification.

Ninety tube-shaped samples (diameter of 10 mm and height of 4 mm) were divided into three main groups: Group I (zirconia 100%, n = 30); Group II (veneer ceramic 100% n = 30); Group III (zirconia with a veneer ceramic n = 30). Each main group was subdivided into two subgroups (n = 15): Subgroup A: samples repaired with Ceramic Repair N; Subgroup B: samples repaired with the Cimara Repair System. The subgroup samples were further subdivided based on the treated surface (n = 5 samples): Control (no surface modification), Er,Cr:YSGG laser surface modification, and air-abrasion surface modification. The SBS was employed using a universal testing machine. The mode of failure was observed using a stereomicroscope.

Significant differences were observed in the mean SBS values between the different surface modifications (P ˂ 0.05). Tukey’s post hoc test showed that the air-abrasion surface modification of the veneer ceramic repaired with the Ceramic repair N system had the highest mean value (13.74 MPa) among the different groups, while no surface modification of zirconia repaired with the Cimara repair system had the lowest mean value (2.84 MPa). The control group (no surface modification) had the lowest mean value among all the treated groups.

The SBS is surface modification-dependent, and higher SBS is obtained by air-abrasion than Er, Cr:YSGG laser surface modifications with the selected parameters. The Ceramic repair N system had significantly higher SBS for all surface-treated substrates than the Cimara repair system.

Multiple sclerosis (MS) is one of the autoimmune and chronic diseases of the central nervous system; this disease occurs more frequently in young people and women and leads to neurological symptoms. Oxidative stress, inflammatory processes, and oligodendrocyte dysfunction have a pivotal role in the pathophysiology of this disease. Nowadays it is reported that photobiomodulation (PBM) as a non-invasive treatment has neuroprotective potential, but the exact mechanisms are not understood.

In this study, we reviewed the effects of PBM on MS. In this regard, we used the keywords “Photobiomodulation”, “Laser therapy”, and “Low-level laser therapy” on MS to find related studies on this subject in PubMed, Google scholar, Elsevier, Medline, and Scopus databases.

PBM has positive effects on MS by regulating the inflammatory process, controlling immune cell activity and mitochondrial functions, as well as inhibiting free radicals production which finally leads to a reduction in neurological defects and an improvement in the functional status of patients.

Overall, researchers have suggested the use of laser therapy in neurodegenerative diseases due to its numerous therapeutic effects.

This study aimed to investigate the effects of photobiomodulation (PBM) therapy associated with biphasic calcium phosphate on calvaria critical defects in rats.

Forty-eight (90 days old) adult male rats (Rattus norvegicus, Albinus variation, Wistar) received critical defects of 5 mm in diameter, which were made on their skull, and they were randomly assigned into the following groups: C-blood clot, B-biphasic calcium phosphate, L-photobiomodulation therapy, and B + L-biphasic calcium phosphate + photobiomodulation therapy. A low-level a gallium aluminum arsenide (GaAlAs) laser was applied in a single dose during surgery, in a wavelength of 660 nm and total energy density of 45 J/cm2. On 30th and 60thdays, the animals from each group were euthanized. Histological and histomorphometric analyses were performed.

In 30 days, almost all specimens (C, L, B and B + L) showed bone neoformation areas in regions near the borders of the surgical defect. In 60 days, in many specimens (C, L, B, B + L), it was possible to see a narrow neoformed bone structure along almost the whole extension of the surgical defect, though it was thinner than the original calvary bone. Data were recorded as mean ± standard deviation, and after normality was tested, a suitable statistical test was applied (α = 5%). On day 60, there was a statistically significant difference when comparing the proportion of neoformation area between group L (0.52% ± 0.13) and group B + L (0.20% ± 0.08). Group L showed a difference compared with all the groups when we compared the remaining distance between the edges of neoformed bone (C × L, P = 0.0431; B × L, P = 0.0386; L × B + L, P = 0.0352), demonstrating a great defect closure.

Our findings suggest that although biphasic calcium phosphate exerts some osteogenic activity during bone repair, PBM therapy is not able to modulate this process.

Autoimmune thyroiditis (AIT) is an autoimmune disorder that is characterized by thyroid gland dysfunction. Low-level laser therapy (LLLT), as a safe and non-invasive intervention, has gained much attention in many clinical applications including pain relief, regenerative medicine, and autoimmune.

In this review, we discuss the effect of LLLT on cellular responses and its application in the treatment of AIT. Such keywords as “low-level laser therapy”, “photobiomodulation” and “autoimmune thyroiditis” were used to find studies related to laser therapy in AIT in Google Scholar, PubMed and Medline databases.

LLLT reduced thyroid gland inflammation and inhibited immune cell trafficking. LLLT modulated inflammatory responses and improved thyroid gland regeneration.

Investigations indicated that besides current treatment strategies, LLLT could be a promising therapeutic approach for the treatment of AIT

 Understanding molecular mechanism of chronic low-dose ionizing radiation (LDIR) effects on human body is subject of many researches. Several aspects of cell function such as cell proliferation, apoptosis, inflammation, and tumorigenesis are affected by LDIR. Detection of the main biological process that is targeted by LIDR via network analysis is the main aim of this study.  

 GSE66720 including gene expression profiles of human umbilical vein endothelial cells (HUVECs) included irradiated and control cells is downloaded from gene expression omnibus (GEO). The significant differentially Expressed genes (DEGs) are determined and analyzed via protein-protein interaction (PPI) network analysis to find the central individuals. The main cell function which was related to the central nodes was introduced.

Among 64 queried DEGs 48 genes were recognized by STRING database. Five hub nodes including; C-X-C motif chemokine ligand 8 (CXCL8), intercellular adhesion molecule 1 (ICAM1), Melanoma growth-stimulatory activity/growth-regulated protein α (CXCL1), vascular cell adhesion molecule 1 (VCAM-1), and nerve growth factor (NGF) were introduced as hub nodes.

 Findings indicates that inflammation is the main initial target of LDIR in cellular level which is associated with alteration in the other essential functions of the irradiated cells.

Many systemic and ocular diseases cause macular edema (ME). Macular edema is seen in two primary forms; the first is diffuse thickening of the macula, and the other is a macula with a distinct petaloid (cloverleaf) appearance called cystoid macular edema. Macular edema has a known role in the reduction of visual equity, and many options have been proposed for the reversal of this condition.

Articles on the effects of macular laser grid photocoagulation on diabetic macular edema (DME) or cystoid macular edema published between 2000 and 2022 were collected from PubMed, Google Scholar, and Web of Science. The following keywords were used for the search: “macular laser photocoagulation”, “macular edema”, “cystoid macular edema”, “intravitreal pharmacotherapies”, and “antivascular endothelial growth factor”. Two hundred nineteen articles were found in google scholar and 165 articles in PubMed, and a total of 58 articles were included in the study after applying the exclusion criteria.

We investigated the effects of various lasers photocoagulation such as Focal and/or grid macular laser, subthreshold micropulse laser (SMPL), as well as intravitreal pharmacotherapies with triamcinolone acetonide, and fluocinolone, and extended released intraocular implants such as Ozurdex, Retisert, Iluvien, and anti-vascular endothelial growth factors such as bevacizumab (Avastin), Eyela, and Lucentis. Corticosteroids were more effective than lasers, although some researchers have found that lasers and combined lasers and corticosteroids are more effective. In addition, some studies have shown that the frequency and concentrations of intravitreal pharmacotherapies are effective in increasing visual outcomes.

The results of the studies showed that the combined intravitreal corticosteroids are much more effective in improving visual acuity (VA) than a single corticosteroid, and the low concentration of the drug is safer. Still, corticosteroids have side effects such as increased intraocular pressure and glaucoma. Therefore, combining the medication with a laser is much more reasonable than each alone. Also, the subthreshold photocoagulation laser (670 nm) is better at reducing the central macular thickness (CMT) and improving VA than the micro pulse yellow laser and pan-retinal photocoagulation (PRP).

After caries, periodontal tissue inflammation (periodontitis) is the most common oral health problem. Photoacoustic imaging (PAI) is a new technique that uses simple components such as a diode laser and a condenser microphone. This study aimed to evaluate the performance of a simple PAI system in periodontal disease imaging by using an animal model.

Normal periodontal and periodontitis tissues were obtained from Sprague–Dawley rats categorized as the control group, treatment group 1 (7 days of periodontitis induction), treatment group 2 (11 days of periodontitis induction), and treatment group 3 (14 days of periodontitis induction). The PAI system was controlled by LabVIEW and Arduino IDE software from a personal computer.

Results revealed that the optimal frequency of laser modulation for periodontal tissue imaging was 19 kHz with a duty cycle of 50%. The photoacoustic (PA) intensity of periodontal tissues was −68.71 dB for treatment group 3, −70.34 dB for treatment group 2, −71.69 dB for treatment group 1, and −73.07 dB for the control group. PA image analysis showed that the PA intensity from periodontal disease groups was higher than the control group.

This study indicates the feasibility of using a simple PAI system to differentiate normal periodontal tissues from periodontitis tissues.

Weakened wound healing is a popular, severe complication of patients with diabetes which poses a risk for foot infection and amputation. Researchers have searched for new treatments for treating diabetic foot ulcers (DFUs) in recent years. In this case report, for the first time, we applied photobiomodulation therapy (PBMT) and Altrazeal powder together to treat a severe case of DFU in a 47-year-old woman who was suffering from type 1 diabetes. Along with the progress of combination therapy, we observed that the ulcer area was significantly reduced, and the wound healed within 16 weeks. Furthermore, dermatitis and purulent secretion were treated, and the pain was reduced. This reported case study indicated the beneficial effect of the combination of PBMT and Altrazeal powder for the healing of a severe DFU in a patient with type one diabetes. The combined application of PBMT plus Altrazeal powder demonstrated an additive effect. Further clinical trials in the clinical setting are suggested to validate the results further. Besides, more studies in preclinical models are suggested to find the mechanism of the action of combination therapy.

Introduction:

 Conventional fractionation (CF) and hypofractionation (HF) are two radiotherapy methods against cancer, which are applied in medicine. Understanding the efficacy and molecular mechanism of the two methods implies more investigations. In the present study, proteomic findings about the mentioned methods relative to the controls were analyzed via network analysis.

The significant differentially expressed proteins (DEPs) of prostate cancer (PCa) cell line DU145 in response to CF and HF radiation therapy versus controls were extracted from the literature. The protein-protein interaction (PPI) networks were constructed via the STRING database via Cytoscape software. The networks were analyzed by “NetworkAnalyzer” to determine hub DEPs.

126 and 63 significant DEPs were identified for treated DU145 with CF and HF radiation respectively. The PPI networks were constructed by the queried DEPs plus 100 first neighbors. ALB, CD44, THBS1, EPCAM, F2, KRT19, and MCAM were highlighted as common hubs. VTM, OCLN, HSPB1, FLNA, AHSG, and SERPINC1 appeared as the discriminator hub between the studied cells.

70% of the hubs were common between CF and HF conditions, and they induced radio-resistance activity in the survived cells. Six central proteins which discriminate the function of the two groups of the irradiated cells were introduced. On the basis of these findings, it seems that DU145-CF cells, relative to the DU145-UF cells, are more radio-resistant.

In this study, we aimed to compare visual field defects in two different laser methods, namely conventional pan-retinal photocoagulation (PRP) and pattern scanning PRP, in patients with either proliferative diabetic or very severe non-proliferative diabetic retinopathy.

This study was a randomized, single-blind, prospective clinical trial. Twenty patients with either proliferative or very severe non-proliferative diabetic retinopathy were enrolled in this study. Notably, only those patients with the same severity scores in both eyes were included. One eye underwent the conventional PRP laser and another eye underwent the pattern scanning PRP laser simultaneously. Swedish interactive threshold algorithms (SITA) standard perimetry was performed at baseline and one month after the treatment, and visual field defects were evaluated.

The pattern standard deviation (PSD) significantly increased in both the pattern and conventional PRP laser groups after one month. The change of the PSD at baseline and after the treatment was not significant between the groups. The mean deviation (MD) level significantly decreased in the conventional group after one month. The change in the MD level at baseline and after the treatment was not significant between the pattern and conventional groups. The change in the mean best corrected visual acuity (BCVA) between the groups was not significant.

Changes in visual acuity and visual fields of the patients between the pattern and conventional PRP laser methods showed no significant difference; however, the pattern PRP method caused a smaller reduction in overall sensitivity in the patient’s visual field.

Gingival hyperpigmentation is caused by an increase in the amount of melanin production or the number of melanocytes in the epithelium, which can impair smile esthetics. The current study aimed to report the experience of using a diode laser for gingival depigmentation of three different patients.

Three adult patients are presented with hyperpigmentation in labial gingivae of both jaws. The depigmentation was done using a diode laser at a wavelength of 808 nm, fiber diameter of 300 μm, and power of 1 W and in continuous mode. All three patients showed proper resolution of hyperpigmented areas in short- and long-term follow-up sessions. However, degrees of recurrence were noticeable in two cases.

The 808-nm diode laser can be utilized safely and efficiently in gingival depigmentation, resulting in an acceptable cosmetic outcome

Radiodermatitis (RD) is the most common side-effect of radiation therapy, yet its prevention and treatment through photobiomodulation therapy (PBMT) have demonstrated promising results. This study aimed to synthesize the evidence concerning the use of PBMT in managing RD among breast cancer patients undergoing radiation therapy.

This is a systematic review with no time restrictions, based on the methodology proposed by the Joanna Briggs Institute (JBI), including such databases as PubMed, Cochrane, Web of Science, Scopus, and CINAHL. The studies were selected based on the following inclusion criteria: female participants over 18 years of age and females having breast cancer and undergoing radiation therapy using a three-dimensional technique or an intensity-modulated radiation therapy (IMRT) technique. Two reviewers assessed the methodological quality using the JBI Critical Appraisal Checklist,and the report was described based on PRISMA guidelines.

Red and infrared wavelengths were used. Device power ranged from 1.1 W to 0.08 W for continuous modes and 25 W for pulsed mode, resulting in a 3 and 4 J/cm2 fluence, applied throughout radiation therapy, leading to a reduced severity in cutaneous reactions.

PBMT can reduce the severity of RD. New clinical trials are required to standardize protocols, given the scarcity of studies for the adopted site and methodological diversity.

Introduction:

 There is an interest in developing materials with bioactive potential that could block exposed dentinal tubules. This study compared the effects of eggshell and seashell nanoparticles individually or combined with ND:YAG laser on dentinal tubules occlusion and remineralization.

Fifty radicular dentin discs were prepared from freshly extracted human premolars. The smear layer created by cutting was removed using 37% phosphoric acid gel for 15 sec. The discs were divided into five groups according to the applied treatment(A) (n = 10 each): (A1) control, (A2); Nano eggshells, (A3); Nano seashells, (A4); Nano eggshells + Nd: YAG Laser, and (A5); Nano sea shell + Nd: YAG Laser. Each specimen was evaluated for tubular patency and mineral contents before and after each therapy using ESEM-EDXA energy dispersive spectroscopy for the assessment of tubule occlusion and remineralization.

ESEM results revealed a statistically significant decrease in the mean percent changes of the dentinal tubules number after the treatment of the experimental groups compared to the control. The greatest percent decrease was recorded in the seashell NPs + Nd: YAG laser, followed by the eggshell NPs + Nd: YAG laser, then Eggshell NPs only and then Seashell NPs only, while the lowest percentage decrease was recorded in the control group. EDXA revealed that the greatest percentage increase in Ca wt% was recorded in the Eggshell + Nd:YAG laser group, followed by Eggshell only, then Seashell only and then Seashell NPs + Nd: YAG laser, while the lowest percent increase was recorded in the control group. The post hoc test revealed no significant difference between the experimental groups.

Both eggshell and seashell nanoparticles are effective in the occlusion and remineralization of dentinal tubules. The combined treatments with Nd: YAG laser had no benefits when compared to the effect of treatments alone.

Photodynamic therapy (PDT) is a demonstrated therapeutic method for basal cellcarcinoma (BCC), which is the most common human cancer. Here, we present a case report about systemic PDT with chlorine e6 as a photosensitizer (PS) for BCC treatment. 

Case Report:

A 78-year-old man was diagnosed with a history of a 4-year nodular BCC in the nasal area. The patient was under control and treatment for hypertension and type 2 diabetes. Chlorine e6 was injected intravenously at a 0.08 mg/kg dosage in 500 cc normal saline within 20 minutes. Three hours after injection, laser irradiation was performed with a wavelength of 665 nm, a dosage of 150 J/cm2, and an irradiance value of 150 mW/cm2. His nodular BCC was completely cured without any side effects after one session of PDT with chlorine e6.

Systemic PDT with chlorine e6 as a PS may be safe and effective in removing BCC lesions due to the data obtained in a two-month follow-up.

Introduction: 

The aging process in the skin naturally happens over time, affected by several factors, of which ultraviolet irradiation is a major factor, and this leads to the appearance of wrinkles, pigmentations, and textural irregularities. Lasers for facial rejuvenation are very popular in Asian patients, but melanin rick skin types like Asians are more susceptible to pigmentary alterations. Most Indonesians have brown skin, and just a few have light skin. The purpose of this study was to know the efficacy and safety of the picosecond 755 nm laser in facial rejuvenation in Indonesian skin.

This is an analysis of 20 healthy patients with Fitzpatrick skin type III-V with facial photoaging from 36 to 55 years. Examinations were evaluated before therapy and 4 weeks after the second therapy. The front and side of both cheeks were photographed and analyzed by using VISIA. Clinical improvement was categorized as excellent-mild. The patients were also asked and examined about the presence of adverse events.

The patients were predominantly female with an average age of 44 years. Sixty percent of the patients had a good improvement and 40% of the patients had a moderate improvement. The VISIA analysis showed a significant improvement in wrinkles, pigments, and textures (P < 0.001). Only mild anticipated adverse events were observed, and there was no post-inflammatory hyperpigmentation or hypopigmentation.

the picosecond 755 nm laser is effective and safe for facial rejuvenation in the skin of Indonesian patients without significant adverse events.

Hirsutism, mainly due to polycystic ovary syndrome (PCOS), causes stress, anxiety, and depression in females. Laser-assisted hair removal (LAHR) is currently accepted as a good treatment option for hirsutism. The goal of the current study was to ascertain how LAHR affected the degree of hirsutism, quality of life, and depression in hirsute females.

A single-arm before/after clinical trial was designed and performed in the Razi hospital Laser Clinic over a 15-month period. All hirsute females visiting the Razi hospital laser clinic were enrolled and received three sessions of LAHR every 4-6 weeks if they were interested and signed an informed consent form. Before the commencement of LAHR and six to eight weeks after the last session, the Ferriman-Gallwey score (hirsutism severity), Beck score (depression index) and DLQI score (quality of life index) were calculated and stored.

There were 80 subjects in all. The mean ± SD of the Ferriman-Gallwey score was reduced from 7.05 ± 2.27 to 4.91 ± 2.41, P < 0.001. The mean ± SD of the Beck depression score was reduced from 13.3 ± 8.7 to 10.2 ± 8.4, P < 0.001, and the mean ± SD of the DLQI score decreased from 5.6 ± 5.2 to 3.5 ± 2.3, P < 0.001. No significant complications were reported.

LAHR can improve hirsutism-related depression and degradation of quality of life, as well as hirsutism physical signs.

There are documents about the biological effects of blue light radiation on different organisms. An understanding of the molecular mechanism of radiation effects on biological samples is an important event which has attracted researchers’ attention. Determining the critical dysregulated proteins of Lentinulaedodes following blue light radiation is the aim of this study.

22 differentially expressedproteins of L.edodes in response to 300 lux of blue light were extracted from the related literature. Experimental, text mining and co-expression connections between the queried proteins were assessed via the STRING database. The maps were compared and the critical proteins were identified.

Among the 21 queried proteins, six individuals including heat shock HSP70 protein, 20S proteasome subunit, 26S proteasome subunit P45, Aspartate aminotransferase, phosphopyruvate hydratase, and phosphoglucomutase were highlighted as the critical proteins in response to blue light radiation.

Thefinding indicates that protein homeostasis and glycogen synthesis are affected by blue light radiation. Due to the critical roles of proteins as enzymes and structural elements in life maintenance and involvement of glycogen synthesis in energy consumption, blue light radiation can be considered as a life promotional agent in future investigations.

Bone healing depends on inflammation control and tissue repair time. Low-level laser therapy (LLLT) has been investigated to accelerate this process. Methylene blue (MB), together with LLLT, has been investigated for its antioxidant and anti-inflammatory potential; however, the effects of photosensitizers (photodynamic therapy, PDT) are controversial. This study aimed to verify whether the combination of MB and LLLT changes the course of the consolidation of experimental bone defects.

SixteenWistar rats underwent femoral bone defects. In the control group (n = 4), LLLT simulations were performed without MB. The MB group (n = 4) received MB and simulation of LLLT. The LLLT group (n = 4) was exposed to LLLT. The PDT + LLLT group (n = 4) received MB and LLLT. At the end of 7 or 14 days, the animals were euthanized, and samples were collected.

PDT and LLLT induced osteogenic formation with cellularity (after seven days) and union of bony edges (14 days). On the seventh day, LLLT combined with PDT induced an increase (P < 0.05) of 484% in the area of bone neoformation compared to the control. On the fourteenth day, LLLT combined with PDT or alone increased (P < 0.05) the area of bone neoformation by 214% and 240% respectively, compared to the control group. The PDT/LLLT combination was associated with increased radiopacity (P < 0.038).

The combined use of MB with LLLT initiated during the transoperative phase may stimulate the bone repair process in rats.

Due to the increasing prevalence and high mortality rate of oral squamous cell carcinoma (OSCC) and problems with its routine treatments, more recent modalities like photodynamic therapy (PDT) have been developed. PDT effectively destroys tumor cells with minimum side effects. Research on in vitro effects of PDT may be helpful in determining the molecular mechanisms responsible for its effectiveness and can lead to the development of more efficient techniques. The aim of this study was to review the use of PDT in OSCC among in vitro studies.

A literature search for English articles on PDT in OSCC was performed in PubMed, Scopus, Google Scholar, and Web of Science. Data were extracted based on the inclusion/exclusion criteria, which were detailed using the PICO framework: all eligible in vitro studies evaluating the effects of PDT on the viability of OSCC compared to controls without PDT were included.

Forty-one out of 567 studies were selected. The tongue was the most common OSCC site, 5-aminolevulinic acid was the most used photosensitizer (PS), cell viability/toxicity and apoptosis were the most evaluated outcomes, and lasers with wavelengths of 600-700 nm were the most common light sources and wavelengths respectively.

PDT showed promising effects on reducing the viability of OSCC cells. Cell lines from various sources or even those originating from the same location sometimes responded differently to the same protocol. Considering the favorable results obtained from natural PSs and regarding their additional health-promoting properties, their use in future investigations with different cell lines and light specifications is recommended.

One of the essential factors in successful endodontic therapy is the effective cleaning and disinfection of the root canal. This study aimed to determine the effect of cold plasma on infected root canals with Enterococcus faecalis and compare its antibacterial effect with the conventional medicaments in vitro.

Sixty-tree single-root teeth were extracted. Canals were cleaned and shaped. Ten teeth were selected as the negative control randomly. The rest of the teeth were incubated at 37°C for 21 days to form E. faecalis biofilm. The specimens were divided into six groups; each group had 10 teeth. In group 1 (the positive control group of calcium hydroxide and triple antibiotic paste [TAP]), methylcellulose was placed in the root canal; in group 2, calcium hydroxide was placed in the root canal for 12 days; in group 3, 10 mg/mL of TAP was placed in the root canal for 12 days; in group 4, helium/oxygen plasma jet was used for 10 minutes. Group 5 was considered as a positive control of plasma, and group 6 was the negative control. After treatment, F4 Pro-Taper rotary file was used to collect root canal microbial biofilms. Bacterial suspensions were serially diluted, and the percentage of growth reduction for each group was obtained by dividing the logarithm of CFU/mL of each group by CFU/mL of the control of the same group.

The CFU/mL of TAP and plasma-treated samples was significantly lower than that of the control groups; however, there were no significant differences between the control group and the samples treated by calcium hydroxide. The most percentage of CFU reduction was in the TAP-treated group compared with plasma and calcium hydroxide-treated groups.

The application of cold plasma effectively inhibited the growth of E. faecalis and reduced bacterial biofilm. Also, in the present study, 10 mg/mL of TAP caused the complete elimination of E. faecalis. Calcium hydroxide had the most negligible effect on E. faecalis biofilm elimination.

Chronic tonsillitis has a global prevalence, ranging from 5% to 12%. Its clinical manifestations, like recurrent acute tonsillitis, tonsils hypertrophy, caseum and halitosis, can lead adult patients to be submitted to palatine tonsillectomy, surgery that has morbidity and the potential risk of complications, including severe bleeding. This article proposes a new therapy for chronic tonsillitis in adult patients using a fractional carbon dioxide (CO2) laser, which is a fast, minimally invasive procedure capable of removing the need for the traditional tonsillectomy in many patients. The present research aimed to verify the efficacy of tonsillotomy by fractional ablation using the CO2 laser by comparing the number of bacterial infections, tonsils hypertrophy, halitosis and caseum; it is also aimed at analyzing the benefits, risks and complications of the technique.

In this clinical prospective study, 20 patients were subjected to one session of tonsillotomy by fractional ablation and were followed up for a year. The control group was formed by the same patients in the pre-procedure period (one year) without treatment. Statistical analysis: The Wilcoxon paired test, Friedman tests, and multiple non-parametric comparisons were utilized to analyze the data (significance level of 5%).

No complications occurred, and the procedure was fast (30 seconds), safe and tolerated well without general anesthesia. After 1 year, there was a total remission of recurrent acute tonsillitis in 95% of the patients, and after 6 months there was a statistically significant improvement in halitosis and caseum, and tonsils size reduction (P < 0.05). The level of satisfaction average was 10 after 3 months and 8 after one year.

Tonsillotomy by fractional ablation using the CO2 laser is a safe, efficient procedure for chronic tonsillitis in adults, and it can be incorporated into daily clinical practice.

Fear memories are influenced by psychological and environmental variables. We evaluated the effect of 2.45 GHz microwave radiation on rats’ fear learning and memory ability to determine the potential risks. The present study aimed to assess the impacts of corticosterone (CORT) levels on the consolidation and reconsolidation of fear conditioning memories.

The rats were evaluated in contextual fear conditioning using foot shocks in both short-term (7 days) exposure and long-term (30 days) exposure. Young male Wistar rats were continually exposed to radio frequency electromagnetic field radiation for 5-6 weeks (1 h/day) with a frequency, power density, and pulse width of 2.45 GHz, 6.0 mW/cm2, and 2 ms, respectively. Several animals housed in identical conditions without exposure to radiation were monitored.

Based on the results, a significant increase and decrease in body weight and percentage of the freezing time were observed after the short-term group respectively. However, in the long term, we observed no significant difference in body weight, and the freezing time decreased substantially.

As CORT levels were analyzed, long-term radiation might increase stress, which was associated with significant weight loss in rats.

Laser acupuncture (LA) is a medically approved treatment for chronic pain, especially fibromyalgia. It is widely known that all pain is related to autonomic modulation, which may influence heart rate variability (HRV). There are robust studies in the literature on the effect of LA with continuous frequency on musculoskeletal pain and autonomic modulation. However, little is known about the effect of pulsed frequency on fibromyalgia. Therefore, this study aimed to evaluate whether an individualized intervention protocol applying pulsed LA would provide benefits related to pain symptoms and cardiac autonomic modulation in patients with fibromyalgia.

In this pilot randomized clinical controlled trial, the sample consisted of women with fibromyalgia between the ages of 40 and 80, randomized into two groups: a control group (CG; n = 10) and an experimental group (EG; n = 10). EG received the intervention twice per week for 3 weeks. Statistical analysis was conducted by delta (difference between post-intervention and pre-intervention) and the Shapiro-Wilk test (normality). For comparison between the groups, the Mann-Whitney test was used.

The results showed a significant reduction in pain intensity as reported via the pain numerical scale (PNS; P = 0.00), generalized pain index (GPI; P = 0.00), and symptom severity scale (SSS; P = 0.00). There was no significant difference in any HRV variable (P > 0.05).

Pulsed LA, when applied in an individualized protocol, can reduce pain intensity, as reported on the PNS, GPI, and SSS. However, no therapeutic effect was observed for HRV.

Aesthetic applications of botulinum toxin type A (BoNT-A) may lead to some complications, including unwanted muscle paralysis. Moreover, BoNT-A effects may last several months, and there is no medical intervention so far to accelerate muscle function recovery.

Case Report:

A female patient with a movement disorder of the mimic muscles resulting from BoNT-A injections received daily sessions of photobiomodulation therapy (PBMT). A fast improvement in both facial asymmetry and muscle function was noted within a few weeks. After nine weeks, almost complete recovery was achieved.

According to the current case, PMBT seems to be an effective intervention to accelerate muscle function recovery following BoNT-A use.

Implant surface disinfection is the most difficult phases in treatment of peri-implantitis. This study sought to assess the efficacy of antimicrobial photodynamic therapy (aPDT) with phycocyanin and diode laser for the reduction of Porphyromonas gingivalis.

In this in vitro, experimental study, first the minimum inhibitory concentration (MIC) of phycocyanin, the sub-lethal exposure time of the diode laser, and the sub-lethal dose of aPDT were determined. The wells containing P. gingivalis suspension were randomly divided into three experimental groups for exposure to ½ MIC phycocyanin for 5 minutes, minimum lethal dose of diode laser (635 nm, 4 minutes), and aPDT with phycocyanin and diode laser. The positive control group was exposed to 0.2% chlorhexidine (CHX) for 5 minutes, and the negative control group received no treatment. The colony count was calculated in the five groups and compared using one-way ANOVA and t test.

aPDT with a diode laser (635 nm, 4 minutes) and 125 μg/mL phycocyanin caused a significantly greater reduction in P. gingivalis count (mean reduction of 44.24%) compared with other groups (P < 0.0001). Minimum and maximum colony counts were noted in 0.2% CHX and negative control groups respectively. The reduction in the colony count was significant in all experimental groups, compared with the control group (P < 0.0001).

aPDT with 635-nm diode laser and phycocyanin can significantly decrease P. gingivalis count in vitro. Considering the conservative nature of this modality, it may be used for the decontamination of peri-implant.

The effects of short-term and long-term exposures to 2.45 GHz radiofrequency electromagnetic radiation (RF-EMR) on anxiety-like behavior, corticosterone level, and gene expression were investigated. The goal of this study was to explore the effect of electromagnetic fields of 2.45 GHz on clinical signs such as body weight and anxiety-like behavior, including the elevated plus maze test and open-field test, and also on messenger RNA (mRNA) expression of Bax (Bcl2-associated x) and Bcl-2 (B-cell lymphoma 2) genes on the cognitive memory functions in an animal model of rats.

The animals were classified into eight groups, sham groups and exposed groups for short-term and long-term exposures to the same dose of RF-EMR for one hour daily. The Wi-Fi equipment in the sham control group was not turned on during the experiment. Both genes were further confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR). The semi-quantitative PCR method of electromagnetic fields in the 2.45 GHz range impacted the expression of Bax and Bcl-2 genes in the rat’s memory.

The present study exhibited that short-term radiation could decrease the percentage of entry into the open arm and the percentage of time spent, while there were no substantial impacts on the long-term radiation effect. Our data support the hypothesis that short-term exposure worked as a systemic stressor, raising plasma corticosterone and changing glucocorticoid receptor expression in the hippocampus.

Additional research on this specific frequency and amount of radiation is required to discover strategies for protecting the nervous system from the detrimental effects of RF-EMR radiation.

Er:YAG laser is a non-destructive tool for debonding of laminate veneers. This study investigated the effect of different laser powers on the pulp temperature and the time required to perform the debonding of lithium disilicate laminate veneers with different thicknesses.

The labial enamel of 48 maxillary central incisors was flattened and polished. The teeth were restored with flat lithium disilicate ceramic veneers (4.0 mm × 6.0 mm) with one of two different thicknesses (0.5 and 1.0 mm). Veneer debonding was performed with an Er:YAG laser with a wavelength of 2940 nm, pulse duration of 100 μm (VSP mode), 10 Hz, and one of the three laser power settings: 1.5 W (150 mJ), 3.0 W (300 mJ). and 5.4 W (540 mJ) (n = 8). Veneer detachment time and intra-pulp temperature change (ΔT) were measured. Statistical analysis was performed using the two-way ANOVA and Bonferroni’s post hoc test (α = 0.05). The correlation between debonding time and temperature change was calculated using Pearson’s correlation.

The longest time was recorded to remove the 1.0-mm veneer at 1.5 W (P < 0.05) and the shortest time was recorded when deboning the 0.5 mm veneer with 5.4 W (P < 0.05). ΔT decreased significantly with increasing laser power. A low correlation was found between time and ΔT (R² = 0.113).

Laser power and veneer thickness are important factors for veneer debonding; thinner veneers are removed faster. When debonding thick veneers, 5.4W laser power is more efficient and causes fewer changes to the pulp temperature.

Dental pulp capping is a technique that is highly applicable in dental restorations. In this technique, a material is directly placed over the exposed pulp tissue, which promotes pulp healing and generates reparative dentin. Herein, we aimed to investigate the combined effect of different pulp capping agents, including mineral trioxide aggregate (MTA), Emdogain (EMD), calcium-enriched mixture (CEM), and low-level laser therapy (LLLT), on enhancing viability and proliferation of stem cells from apical papilla (SCAPs).

SCAPs were isolated from two immature third molar teeth through collagenase type I enzymatic activity. Isolated stem cells were then cultured with DMEM and α-MEM media enriched with 15% and 10% FBS respectively. After reaching 70%-80% confluency, the cells were seeded in a 96-well plate. Cell viability percent was assessed using the MTT assay after treatment with MTA, EMD, CEM and LLLT (λ = 630 nm, 5 mW, 4 J/cm2) alone and in combination for 24, 48 and 168 hours.

Combination of MTA, CEM, EMD and LLLT resulted in significantly increased SCAPs viability as compared with other treatment groups. Increased SCAPs proliferation and viability were also observed in groups treated with the combination of MTA and CEM with EMD. However, the SCAPs survival rate in all defined time spans was reduced after treatment with MTA and CEM alone.

LLLT can be a stimulator of SCAPs cell viability when applied in combination with dental capping agents such as MTA, EMD and CEM, providing a therapeutic option for stem cell-based dental regeneration.

This study assessed the effect of a high-intensity laser on Candida albicans colony count.

This in vitro, experimental study was conducted on standard-strain C. albicans (ATCC18 804). Seventy-two samples with two different concentrations of C. albicans (104 cells/mL and 106 cells/mL) were randomly assigned to three groups of control, laser and nystatin. Each group included 12 samples from each concentration. In the nystatin group, 10 cc of nystatin suspension was added to the samples and mixed for 30-60 seconds. In the laser group, the Ga-Al-Ar diode laser with a 940-nm wavelength and 2-W power was irradiated to the samples with 0.4 mm tip diameter in non-contact mode (1-mm distance) at a speed of 1 mm/s. The suspensions in the three groups were cultured on the Sabouraud dextrose agar culture medium and incubated at 37°C for 24 hours. The number of C. albicans colonies was then counted and reported. The three groups were compared by ANOVA and Tukey’s test (alpha = 0.05).

In both concentrations, the mean colony count in the nystatin group was significantly lower than that in the control (P < 0.05) and laser (P < 0.05) groups. The mean colony count in the laser group was significantly lower than that in the control group (P < 0.05).

The high-intensity laser with a 940-nm wavelength and 2-W power in non-contact mode can significantly decrease the C. albicans colony count in vitro, but its effect is lower than that of nystatin.

This study assessed the effect of low-level laser (LLL) irradiation on the viability of dental pulp stem cells (DPSCs).

In this in vitro experimental study, human DPSCs were purchased from the cell bank of Iranian Genetic Resources and cultured in flasks containing Dulbecco's modified Eagle's medium supplemented with 20% fetal bovine serum (FBS) at 37°C, 5% CO2, and 95% humidity. The cells were stored in semi-confluent form, and the culture medium was refreshed every two days. The cells in the control group were not laser-irradiated, but the cells in the experimental groups were irradiated with 660-nm and 808-nm diode lasers with 4.1 J/cm2 energy density. Cell viability was assessed at baseline and after 24, 48, and 72 hours using the methyl thiazolyl tetrazolium (MTT) assay. The effects of laser irradiation, laser wavelength, and time on the percentage of cell viability were analyzed by two-way ANOVA and Tukey's test.

The effects of laser irradiation and its wavelength (P = 0.04), time of assessment (P < 0.001), and the interaction effect of group and time (P = 0.02) on cell viability were significant. Cell viability in 660-nm and 808-nm laser groups at 48 and 72 hours was higher than that of the control group; however, only the difference in cell viability between the 660-nm laser group and the control group at 72 hours was statistically significant (P = 0.03).

Considering the optimal effect of diode laser irradiation (particularly 660 nm) on the viability of DPSCs, we conclude that it may be suitable for relevant clinical applications.

Lasers and optics have been used extensively in dental procedures in recent years, and realizing the optical properties of the tooth is also an essential in its successful applications. The aim of this study was to compare the absorption and transmission of applied wavelengths in the range of 190–1100 nm at different dentin thicknesses and the effect of changing the direction of radiation emission on the dentin tubules.

There were fifteen dentin specimens with thicknesses of 300, 600, and 1000 mm, five specimens for each thickness, prepared through a transverse section of the coronal dentin over the pulpal roof area of human molars. Considering the coronal-apical and apical-coronal directions, we measured the absorption and transmission of parallel light rays perpendicular to the dentin samples in different thicknesses and two directions with a Cecil CE 7400 UV/Vis spectrometer. Data analysis was performed using SPSS software version 19. P value < 0.05 was considered significant.

The absorption rate of the ultraviolet wavelength range was significantly higher than that of visible and infrared light irradiation from both directions at three thicknesses (P < 0.001). The radiation shift direction had no significant differences in the absorption and transmission of wavelengths of ultraviolet, visible, and infrared light in any of the three thicknesses (P > 0.05).

Accordingly, attenuation or transmission losses of light in the ultraviolet to infrared range clearly depend on the wavelength of light and the optical properties of dental dentin, and the thickness of the dentin used in this study has a little effect.

Rheumatoid arthritis (RA) is an inflammatory and autoimmune disorder that is characterized by joint inflammation, pain, physical disability, and morning stiffness. In the present study, the effect of low-level laser therapy (LLLT) on RA was reviewed.

“Low-level laser therapy”, “rheumatoid arthritis disease”, and “photobiomodulation” keywords were searched in Google Scholar, PubMed, and Medline.

A literature survey led to a discussion about the immunology of the RA, laser therapy, mechanism of LLLT action, and anti-inflammatory and immunomodulatory properties of LLLT.

It was concluded that LLLT could improve RA patients’ quality of life, reduce pain, and enhance physical movement.

Inhalation of laser-induced smoke is a potential health hazard to exposed physicians and laser operators. To date, little is known about the perception of health hazards related to laser-induced smoke exposure among physicians and the actual use of safety measures to mitigate these risks.

In May 2020, 514 members of the European Society for Lasers and Energy-Based Devices (ESLD) were invited by email to participate in an online survey. The survey comprised 16 questions including multiple-choice and open-ended questions.

Responses were received from 109 participants. The majority (90%) were aware of potential hazards and highlighted a desire for better protective measures (60%). A smoke evacuation system was frequently used with ablative lasers (66%) and fractional ablative lasers (61%), but less the case with non-ablative lasers (30%) and hair removal lasers (28%). The COVID-19 outbreak had no clear effect on the use of smoke evacuation systems. Prior to the COVID-19 outbreak, mainly surgical masks were used (40-57%), while high filtration masks (FFP1, FFP2 or FFP3) were used by only a small percentage (15-30%). Post COVID-19 outbreak, the use of high filtration masks increased significantly (54-66%), predominately due to an increase in the use of FFP2 masks. Reasons mentioned for inadequate protective measures were sparse knowledge, limited availability, discomfort, excessive noise, high room temperatures, and financial costs.

While there is considerable awareness of the hazards of laser-induced smoke among physicians and laser operators, a substantial number of them do not use appropriate protective measures. The implementation of regulations on safety measures is hampered by sparse knowledge, limited availability, discomfort, excessive noise, financial issues, and high room temperatures.

In everyday life, electrical devices are the primary sources of extremely low-frequency electromagnetic fields (ELF-EMF), and the human body may be a great conductor of these fields. We chose alpha band power, especially at 10 Hz frequency, due to its prior beneficial role in memory. The purpose was to clarify whether there is a relationship between ELF-EMF exposure and cognitive deficits in rats, clinical signs, behavioral analysis, and the impact of ELF-EMF during different times of exposure on neuroplasticity via the expression of BDNF.

Forty adult male rats were selected randomly. The rats were exposed to ELF-EMF (10 Hz, 4 mT) for 7 days and 30 days, one hour daily. The expression of BDNF proteins in the hippocampus was evaluated after sacrificing animals to assess learning and memory function. The body weight of rats in the long-term exposed group differed significantly (P < 0.05). The level of BDNF mRNA in the hippocampus was found by the RT-PCR method.

Our findings indicate that exposure to ELF-EMF affects spatial learning and memory and can improve memory, especially with long-term exposure. In addition, we discovered a significant difference in the long-term exposed group (P < 0.05), where radiation for 30 days resulted in a substantial rise in BDNF levels.

After prolonged exposure, male rats spent more time and traveled a greater percentage of their distance in the target quadrant, demonstrating that long-term exposure improves spatial memory and that 10 Hz might be safe. 

This study intended to evaluate the safety and possible therapeutic effect of transcranial infrared laser stimulation (TILS) based on photobiomodulation (PBM) among patients with traumatic brain injury (TBI).

Eleven participants who were diagnosed with TBI after full neurological examination and MRI evaluation by a board-certified neurologist completed five to eight 20-minute TILS sessions using the Cytonsys CytonPro-5000 apparatus (pilot laser control, focused wavelength of 1064 nm, maximum output power of 10W, maximum optical power density of 500 mW/cm2, effective area 4.5 cm2 in diameter). Per TILS session, participants underwent a laser dose of 250 mW/cm2 continuous laser wave to each hemisphere using predetermined patient-specific coordinates. Structural imaging was used to neuronavigate individual treatment targets in the frontal cortex (Brodmann area 10). The primary safety measure for this study was the occurrence of adverse events (AEs) or serious adverse events (SAEs). The primary efficacy outcome measure was the participant-rated global rating of change (GRC) post-intervention. Secondary outcome measures included a battery of neuropsychological testing and mood questionnaires done both pre- and post-intervention.

All patients enrolled in this study protocol were able to tolerate the study procedures without any AEs or SAEs. Nine out of eleven participants had clinically significant improvements in GRC score (≥ + 2). Neuropsychological testing and mood questionnaire outcomes also suggested a positive therapeutic effect.

This study provides preliminary evidence supporting the safety and potential efficacy of TILS as a non-invasive clinical intervention for individuals with TBI.

In root canal therapy, the cleaning and shaping of canals are routinely applied by clinicians in order to remove microorganisms. Eradicating bacteria from the root canal system plays a crucial role in long-term success; however, it is not always easy to disinfect root canals properly because of their complicated anatomy and bacterial load. Achieving an optimally disinfected root canal environment requires adjunctive antibacterial therapeutic methods. High-power laser utilization as an adjunctive strategy to conventional treatment is a relatively new approach that helps clinicians.

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Online databases, namely Web of Science, PubMed/MEDLINE, Scopus, and Cochrane Library, were searched electronically regarding lasers and endodontic treatments. Appropriate studies were included according to the inclusion/exclusion criteria.

Among 504 obtained studies by search, 48 were considered for a detailed analysis. Ten articles performed in vivo evaluation, while nine assessed the effect of lasers on artificial models, and 29 conducted ex vivo experiments on extracted teeth. When the diode laser, the most frequently used laser, was utilized as an adjunct therapy after NaOCl irrigation, it killed more bacteria than conventional irrigation with NaOCl. Laser-activated irrigation (LAI) with the Er, Cr: YSGG laser and NaOCl disinfects the root canal effectively. Also, photon-induced photoacoustic streaming (PIPS) with Er: YAG and NaOCl exhibited a high bactericidal effect and deep tubular penetration.

High-power laser utilization, considering proper case selection and method, can assist in root canal treatment of infected teeth.

Cleft lip and cleft palate are the most typical congenital craniofacial anomalies. Post-surgical scars in cleft lip patients can cause shallow upper labial sulcus and reduced upper lip length. The aim of the present study was to evaluate the impact of CO2 laser vestibuloplasty on the electromyographical (EMG) activity of patients’ superior orbicularis oris muscle, depth of labial sulcus, and upper lip length, and their satisfaction with the procedure and its results. The CO2 laser is an effective vestibuloplasty procedure, is safe and highly acceptable for patients, and has little effect on muscle contraction.

A total of 15 cleft lip and cleft palate patients participated in this study. Vestibuloplasty was performed using carbon dioxide laser therapy in one session in such a way that EMG activity in the upper lip muscle, depth of labial sulcus, and upper lip length were measured two times: before (T0) and twenty days after surgery (T1). Patients’ satisfaction surveys were also recorded using a patient questionnaire at T1.

The mean values for vestibular depth at T0 and T1 were 2.00 ± 1.71 and 4.52 ± 1.43, respectively. The mean values for upper lip length at T0 and T1 were 6.90 ± 2.32 and 8.00 ± 2.40, respectively, suggesting a significant change in vestibular depth and upper lip length. The vestibular depth and upper lip length significantly increased at T1. The EMG recording of the upper lip muscle experienced a moderate decrease after laser treatment, both at rest and at maximum lip protrusion. Moreover, patients’ satisfaction with the surgical procedure was 82% positive.

Using the CO2 laser increased the vestibular depth and upper lip length successfully and made small changes in the EMG activity of the superior orbicularis oris.

Circadian rhythms refer to daily cyclic events such as activity and rest in biology. A protein-based core related to the mechanism of circadian is identified. In the present study, the gene expression profiles of mouse skin in different conditions of light-dark times were investigated via protein-protein interaction (PPI) analysis to explore the main affected genes.

GSE174155 was derived from Gene Expression Omnibus (GEO) and was analyzed via GEO2R to find the significant differentially expressed genes (DEGs). The gene expression profiles of Cry-null (genotype: cryptochrome-1(-/-): crytochrome-2 (-/-)) mouse skin versus the wild-type samples in the various circadian times (CTs) were assessed. The queried DEGs plus 50 first neighbors were included in a PPI network via the STRING database by Cytoscape software. The networks were analyzed and the central nodes were evaluated.

Three groups of mice based on CTs were identified. 15, 15, and 14 central nodes were determined as central nodes for the analyze networks. There was not a common central node for the analyzed networks.

It was pointed out that the light/dark time ratio had a gross effect on the gene expression profile of the skin in the mice. Results imply more investigations to suggest a standard protocol related to CT, considering human lifestyle and exploring suitable protective methods for the jobs which are fixed in the abnormal CT sets. 

While a wound caused by a minor cutaneous incision routinely heals in a short time, wounds from major surgical operations might need numerous days to heal and may leave an obvious cicatrix. The use of blue light therapy (BLT) to destroy infectious microorganisms and disrupt biofilm formation could be an efficient method for healing ulcers. This systematic review focused on the effects of BLT in different preclinical in vivo studies and clinical models of skin wound healing. Furthermore, this study attempted to determine what main light parameters should be tested in preclinical and clinical studies.

The online databases PubMed.gov, Google Scholar, Scopus, Web of Science, and Cochrane were searched using the keywords “blue light” and “wound healing” according to PRISMA guidelines. No publication time limit was enforced.

A total of 858 articles were identified, and 17 articles in three distinct categories were included for review. They comprised two articles on humans, fourteen articles on healthy animals, and one article on diabetic animals.

Some studies have shown that the application of BLT on preclinical and clinical models of wound healing in vivo is able to significantly accelerate the healing process. Few studies, however, have explored the bactericidal effect of BLT on skin injury repair in burn patients. Further preclinical investigations designed to provide a better understanding of the bactericidal effect of BLT using standardized protocols, different BLT wavelengths, and different stages of the wound healing process of infected wounds and ulcers in healthy and diabetic animals should be carried out before clinical trials can be considered. BLT could eventually be a good option for treating infected chronic wounds, including those in diabetic patients.

Cold physical plasma is a growing tool in medicine which is applied for the treatment of different cancers. In the present study, the gene profiles of human melanocytes exposed to indirect cold physical plasma versus control individuals are analyzed via protein-protein interaction (PPI) network analysis.

The gene expression profiles were derived from Gene Expression Omnibus (GEO), and the significant differentially expressed genes (DEGs) were decoded via “Expression Atlas”. PPI network analysis was applied to find the targeted central genes by indirect cold physical plasma.

The main connected component of the constructed network including 74 queried DEGs and 50 added first neighbors was analyzed. Considering degree value, betweenness centrality, closeness centrality, and stress, IGF1 and HMOX1 were introduced as the central nodes.

The finding of this study indicates that the down-regulation of IGF1 and the up-regulation of HMOX are the prominent events in response to indirect cold physical plasma treatment at the cellular level. Detection of related biological terms via gene ontology is suggested.

Biomechanical qualities of the skin tissue change following numerous pathological and natural (ageing) conditions. The best skin treatments are those resulting in a positive outcome with the fewest adverse effects. In this study, high-frequency ultrasonography (US), which provides a quantifiable scale, was utilized to evaluate the impact of a 2-W laser on characteristics of nasolabial fold (NLF) including depth and area, epidermis and dermis thicknesses, and Young’s modulus (YM).

Nine female subjects (54.09 ± 0.09 years old) with Fitzpatrick skin types III-IV and five young control participants (26 ± 1.28 years old) for providing the control data were included in this study. Laser therapy was applied twice weekly for seven consecutive sessions. A class IV laser with 810-nm and 980-nm wavelengths, 2-W power, and 25-Hz frequency was applied twice a week for seven consecutive sessions. The energy administered had a density of 8 J/cm2. An evaluation using high-frequency ultrasound (40 MHz) was accomplished before and 48 hours after the final treatment session. The Face-Q questionnaire was used to assess the patient’s perspective on this procedure.

For each US parameter, the intraclass correlation coefficient was high (ICC > 0.9). After the laser treatment, NLF depth, area, epidermis, dermis, YM, and Face-Q significantly improved compared to baseline (P < 0.05).

For the assessment of skin tissue, high-frequency US is a reliable technique. The 2-W laser is a safe, effective, and non-invasive procedure for enhancing skin features.

Many studies have recognized the importance of new methods in wound healing. This study aims to investigate the healing effects of allograft extra embryonic mesenchymal stem cells (MSCs) with and without low-level diode laser irradiation when grafted into full-thickness skin defects in diabetic animal models.

In this experimental study, in order to make the rats diabetic, we used an intra-peritoneal injection of streptozotocin. Human amniotic membrane derived mesenchymal stem cells (hAMSCs) were irradiated with a low-level diode laser. Two full-thickness excisions were made on the backs of the rats. Next, the rats were divided into the following groups: group 1: low-level laser (LLL) irradiated hAMSCs and group 2: hAMSCs alone transplanted into skin wound. Histopathologic, ultrasound and elasticity evaluations were performed 7, 14 and 21 days after grafting.

In the evaluated rats, epithelial formation was on day 7 and increased until day 14. On days 7, 14 and 21, the percentage of epithelial formation in the irradiated cell group was significantly higher than that in the cell group, so that, on day 21, the epithelium in this group completely covered the wound surface while in the control group the wound surface was still not completely covered. In terms of angiogenesis, on day 7, the irradiated cells were significantly lower than the cells. Also, the formation of collagen in the cellular hydrogel group could confirm the effectiveness of amniotic MSCs in collagen production and thus accelerate the wound healing process. In comparison with hAMSCs alone, irradiated hAMSCs increased the thickness and elasticity of the skin.

Low-power laser along with MSCs can be effective in improving chronic wound condition in the animal model.

The most common type of neck pain is chronic nonspecific pain. There are conflicting opinions about the beneficial effects of a low-level laser in reducing chronic nonspecific neck pain. The aim of this study was to evaluate the efficacy of low-level laser therapy (LLLT) for the treatment of non-specific chronic neck pain.

This study was conducted as a prospective randomized clinical trial. Forty-four patients were randomly divided into two groups: (1) Intervention group (n = 22): LLLT in the red spectra range with a wavelength of 980 (nm) and a power of 16 (J/cm2) was irradiated in the affected areas of the neck, the muscles along the spine, and the upper trapezius; (2) sham group (n = 22): A low-level laser was irradiated with a passive probe (non-laser red light) in the affected areas of the neck, the muscles along the spine, and the upper trapezius. The treatment protocol consisted of 12 sessions (15 minutes, three times a week, for four weeks). These patients were evaluated for pain using the visual analog scale (VAS) (0-10). The patients were followed up for four weeks.

This study showed a statistically significant reduction in chronic nonspecific neck pain in the LLLT group (P < 0.05).

It is concluded that LLLT was effective in reducing chronic nonspecific neck pain. LLLT is a non-invasive, safe and effective method that can improve chronic nonspecific neck pain in patients in the short term.

About 50% of infertility problems are related to male factors and reduced sperm motility. The important factor that affects the structure and function of sperm is reactive oxygen species (ROS), and over-concentration of ROS reduces the quality and motility of sperm. Photobiomodulation therapy (PBMT) using red to near-infrared (NIR) light is useful in oxidative stress restoration. It plays a therapeutic role in disorders such as asthenospermia, oligospermia cases, and cryopreserved sperm. It also enhances the metabolic capacity of sperm and increases the low-level and non-harmful intracellular content of Ca2 + , nitric oxide (NO), and ROS in the stressed cells. Likewise, it modulates survival intracellular pathways and maintains the motility, viability, DNA, and acrosome integrity of sperm. This article reviews the state-of-the-art preclinical and clinical evidence regarding the efficacy of semen PBMT.

Due to widespread penetration of UV radiation in human life, the biological effect of UV radiation is studied through many investigations in the field of medicine. There are many assessments about UV radiation which are concerned with protein-protein interaction (PPI) network analysis. In the present study, a network analysis associated with the complementary evaluation of UV radiation on human primary melanocytes is presented.

The gene expression profiles of the irradiated human primary melanocytes and the control cells were extracted from Gene Expression Omnibus (GEO) and were evaluated via PPI network analysis and action map assessment.

69 significant differentially expressed genes (DEGs) were included in the main component of the PPI network. Brain-derived neurotrophic factor (BDNF), SNAI1, and SOCS1 were highlighted as the top dysregulated and hub genes. Results indicate that BDNF and SNAI1 participate in the regulatory unit including the total hubs and top dysregulated genes.

Considerable down-regulation of BDNF and up-regulation of SNAI1 as the two critical targeted genes by UV radiation are accompanied by gross alteration in cell functions.

The present study was performed to evaluate the influence of a 1064 nm fiber laser on shear bond strength (SBS) at the interface of titanium and resin cement.

Forty titanium discs of 6 mm × 3 mm (diameter and thickness respectively) were categorized into four groups (n = 10): control group without any surface treatment and three groups treated with a fiber laser with 81 ns pulse duration, 30 kHz frequency, 10 000 mm/s scanning speed, 0.05 mm spot size, and different average power values (3, 5 and 7 W) depending on the tested group. Titanium disc characterization was performed by the scanning electron microscope (SEM) and surface roughness tester. Phase analysis was achieved using an X-ray diffractometer (XRD). Following these tests, resin cement application to titanium discs was performed. SBS values were determined by the universal testing machine. After debonding, the surface of titanium discs was examined by the stereomicroscope for the determination of failure modes. Data analysis was performed using analysis of variance (ANOVA) and Tukey HSD tests (α = 0.05).

A higher surface roughness value was observed in the 7 W group followed by the 5 W and 3 W groups, and the lowest surface roughness was in the control group. Additionally, the lowest SBS value was obtained from the control group and the highest SBS value was obtained from the 7 W group followed by the 5 W and 3 W groups.

SBS between titanium abutment and resin cement can be significantly enhanced by using a fiber laser as a surface treatment considering tested laser parameters; additionally, a positive association between surface roughness and SBS was noted in the experimental groups.

There are various types of treatment targeting healing traumatic or accidental skin scars. Transplantation of skin grafts and surgical alternatives, including autologous transplantation of melanocyte-keratinocyte suspension, have also been suggested previously. This study is representing a case of previous skin graft transplantation, complaining of scar formation and discoloration on the transplanted segment.

The patient was a 37-year-old lady. This patient underwent melanocyte-keratinocyte suspension transplantation and narrow-band ultraviolet B (NUVB) therapy and could reach 40% re-pigmentation enhancement. This method could be introduced as an efficient and safe method of approaching facial scarring.

This method could be introduced as an efficient and safe method of approaching facial scarring.

Although tattoos are ancient and very popular among young people, it is also a reason for regret, and many people today have a desire to remove them. Among the possibilities for this, laser removal is the most successful procedure with the highest degree of pigment removal and the lowest risk of complications.

This study was recorded on three patients with tattoos, and only the black pigments were removed. None of the patients involved had a history of skin allergies, skin cancer, and/or keloid formation. Case 1 had a professional tattoo removed in the right calf region in two sessions. Case 2 had an amateur tattoo that was removed on the scalp in three sessions. Finally, Case 3 had two professional tattoos, which were removed from the face in a total of eleven sessions. The following equipment was used: Spectra XT Q-Switched Nd:YAG 1064 nm with a pulse width of 5 ns; Pico Ultra 300 Nd:YAG 1064 nm with a pulse width of 300 ps; and SoftLight Q-Switched Nd:YAG 1064 nm with a pulse width of 17 ns.

In general, satisfactory results were obtained, but hypopigmentation was present in Cases 1 and 3. This was probably due to sun exposure at the laser removal site, the short interval between the sessions, and/or higher radiant exposure combined with a smaller spot size, respectively.

To achieve a successful tattoo removal in the higher phototypes and reduce unwanted effects, the professionals must know the best parameters to be used, as well as the adequate foundation on the individual characteristics of each patient and the tattoos. Furthermore, patient compliance with the pre/post session care and a suitable interval between the laser sessions are essential to avoid undesirable complications.