Dental Research Journal
Volume:19 Issue: 11, Nov 2022

One of the most challenging esthetic concerns in dentistry is conservative replacement of the missing anterior teeth. Although implants are considered to be a better treatment option for rehabilitation of such patients, resin‑bonded bridges (RBBs) can conservatively restore the missing teeth and have thus gained popularity over the years. It consists of an artificial tooth with a wing‑like extension that is cemented to the adjacent teeth. There are various types of RBBs among which Maryland bridge is the simplest and the popular most due to its micromechanical retention enabled by acid etching of both tooth and metal retainer. It can be fabricated by various techniques and materials. In this case reports, we have discussed about two unique designs of Maryland bridge fabricated by two different materials (Porcelain‑fused metal and Graphene) and utilizing two different techniques (conventional and digital).

It may not be possible to treat large maxillofacial defects by surgical reconstruction alone. Prosthetic rehabilitation is invariably required to restore esthetics and function. Achieving adequate retention, stability, and support in these maxillofacial prostheses is a challenging task. This clinical report describes prosthetic rehabilitation of a midfacial defect following surgical resection of squamous cell carcinoma. The intraoral defect was restored with a maxillary obturator prosthesis with salivary reservoir, and the extraoral defect was restored with magnet‑retained facial prosthesis having an acrylic resin framework and an overlying silicone facial prosthesis.

The aim of this article is to compare the functional efficiency of tooth‑supported overdentures and implant‑supported overdentures in patients requiring oral rehabilitation. The comparative quantification of the improvement in functional efficiency is very difficult to assess because of the variations in the study designs like the age of the population studied, the male‑to‑female ratio, the outcome measures used, the clinical setting in which the implant therapy was provided, oral status of the subjects included and the type of implant therapy provided. In this systematic review, the articles included compared the functional efficiency by assessing the bite force, chewing efficiency, electromyographic (EMG) changes measured by EMG analysis, and patient satisfaction for subjects who have been rehabilitated with either a tooth‑supported overdenture or an implant‑supported overdenture. This will help the clinicians to better plan the treatment, keeping in mind the long‑term prognosis for that particular patient.

A significant improvement in the nasal symmetry after presurgical nasoalveolar molding (PNAM) is seen in complete unilateral cleft lip and palate (UCLP) infants. However, the follow‑up changes in the nasal symmetry before and after PNAM and surgical repair have not been well documented.

The purpose of this retrospective study is to assess the progressive changes in the nasal symmetry after PNAM and primary cheiloplasty to 1 year in complete UCLP infants. Out of 28 complete UCLP patients who were given PNAM treatment during the period between January 2014 to March 2019, 19 UCLP infants could be included for the study. Submental oblique photographs at the initial visit (T1), immediately after cheiloplasty (T2), and 1 year (T3) after cheiloplasty were selected, and quantity of nasal asymmetry at each period (T1–T2; T1–T3; and T2–T3) was analyzed by paired t‑test (P < 0.05).

The quantity of asymmetry revealed that there was a highly significant improvement(P < 0.001) in nasal asymmetry at T1–T2 and T1–T3. Nonsignificant relapse was observed at T2–T3; however, a significant relapse in nasal dome height was observed during this period.

The improvement in the nasal symmetry after cheiloplasty in PNAM‑treated patients is maintained till 1 year postsurgically though there is a nonsignificant relapse.

Dentin hypersensitivity is a prevalent problem, manifested as a short sharp pain. Researchers have used different lasers to treat this condition. The present study aimed to evaluate the effect of 980 and 810‑nm high‑level diode lasers on dentin hypersensitivity to determine proper laser parameters for clinical applications.

In this double‑blinded randomized clinical trial, seven patients with 60 teeth affected by dentin hypersensitivity were selected for the present double‑blind, randomized clinical trial. The patients’ teeth were randomly matched and assigned to three groups: Group 1:980‑nm diode laser; Group 2: 810‑nm diode laser; and Group 3: Control, which received only the guiding beam. The laser parameters were 1‑W power, continuous wave mode, a distance of 1 mm, no contact, a 45° irradiation angle, and a 30‑s exposure time using to‑and‑fro movements. The treatment consisted of two sessions with a 1‑week interval. Pain severity was determined with the visual analog scale (VAS) at all the study intervals using a dry ice spray. The data were analyzed with SPSS version 20 using one‑way ANOVA, repeated measures ANOVA, and least significant difference tests. Significance level was set at α = 0.05.

The changes in VAS were significant only in the first stage (P = 0.046). The mean VAS scores decreased over time in the 810‑nm and 980 laser groups. A comparison of VAS changes relative to the baseline revealed significant changes in VAS scores at all the time intervals with both lasers. The two 810 and 980‑nm laser groups did not exhibit any significant differences for 2 months postoperatively (P = 0.098).

The application of 810 and 980‑nm diode lasers at 1‑W power and an exposure time of 30 s was effective in decreasing pain in patients with dentin hypersensitivity, with no significant difference between these two lasers.

Silver and zinc oxide (ZnO) nanoparticles have recently become common to coat ligatures in order to take advantage of positive properties of nanoparticles, although there are concerns about their cytotoxicity. This study tended to compare subcutaneous inflammatory response induced by elastomeric orthodontic ligatures coated with silver and ZnO nanoparticles with a control group in rats.

In this in vitro and animal cross‑sectional descriptive‑analytical study, silver nanoparticles were synthesized by chemical reduction of silver nitrate solution in the presence of sodium borohydride and ZnO nanoparticles by the same method and by chemical reduction of zinc sulfate solution with sodium hydroxide and were coated on elastomeric ligatures. Subcutaneous inflammation degrees were assessed after 15 and 30 days and were compared in the groups by Kruskal–Wallis test and ordinal generalized estimation equation with exchangeable correlation matrix. All tests were performed with a significance level (P = 0.05).

There was a significant difference in terms of degrees of inflammation in the groups coated with ZnO nanoparticles (P = 0.003) and silver nanoparticles (P = 0.04) compared to the control group in 15‑ and 30‑day samples. Zinc nanoparticles caused 3.22 times more inflammation than silver nanoparticles (P = 0.053). The decrease in inflammation was significant over time in all groups (P = 0.001).

There was a significant more inflammation in the groups receiving ZnO and silver nanoparticles compared to the control group in 15‑ and 30‑day samples. Silver nanoparticles are probably safer than zinc nanoparticles for tissue and a better material to choose for antibacterial effects.

Oral lichen planus (OLP) is a chronic immune‑mediated mucocutaneous disorder, with an unknown etiology. Since, both pain and discomfort are observed in patients with the erosive type, many drugs have been studied to alleviate pain and clinical symptoms. The present study aimed to assess the effectiveness of systemic Echinacea on clinical indices of OLP.

In this randomized, double‑blind, placebo‑controlled trial, 70 patients with erosive OLP were randomly divided into two groups, and each was treated with Echinacea tablets or placebo, 3 times a day, for 35 days. In addition, betamethasone lotion (0.1%) or nystatin (100,000 units) mouthwash were used by patients. The pain severity (visual analog scale [VAS]), lesion size, and the number of lesions were assessed at baseline and on days 10, 25, and 35 after study initiation. Finally, the obtained data were analyzed by statistical software, and Mann–Whitney test, Wilcoxon test, KaplanMeier, Chi‑squared, and paired t‑test.

The VAS scores in the Echinacea group were significantly reduced at each visit compared to the placebo group (P < 0.001). We observed a significant difference between the two groups (P < 0.01).

We showed that Echinacea is an effective and complementary therapy for OLP. Furthermore, in short‑term usage, Echinacea is almost completely tolerable.

Head‑and‑neck radiotherapy can change oral Candida species and cause candidiasis resistance to common antifungals by making the changes to the oral cavity environment. Voriconazole is a synthetic azole with extensive antifungal activity. The current study aimed at comparing the antifungal activity of fluconazole and voriconazole on Candida species isolated from the oral cavity of patients undergoing head‑and‑neck radiotherapy.

The present in vitro study was performed on samples isolated from patients undergoing head‑and‑neck radiotherapy, before and during radiotherapy. After the identification of the species, the antifungal effect of fluconazole and voriconazole was determined by the microdilution method, and the minimum inhibitory concentration (MIC), the minimum fungicidal concentration, and the antifungal susceptibility of the isolated strains were also measured. The data were analyzed by the Chi‑squared and then two‑sided Fisher’s exact tests. P < 0.05 was considered statistically significant.

The study findings showed no significant difference in the susceptibility of Candida albicans to voriconazole and fluconazole before and during radiotherapy. Before radiotherapy, both voriconazole and fluconazole had similar effects on Candida tropicalis, but after radiotherapy, voriconazole was less effective. However, both before and during radiotherapy, fluconazole had a greater antifungal effect than voriconazole on Candida glabrata strains. The MICs of voriconazole and fluconazole for both Candida parapsilosis and Candida krusei isolates were within the susceptible or dose‑dependent range.

The current study results showed that voriconazole was not more effective than fluconazole in the treatment of oral candidiasis in patients undergoing head‑and‑neck radiotherapy.

Denture bases undergo repeated flexing during mastication leading to fatigue failure, demanding a high fatigue strength property. Flexural (transverse) strength is required high to prevent catastrophic failure under load for success. Denture base resins are fabricated by three different types of manufacturing: Compression molding, injection molding and computer-aided design (CAD/ CAM) milling technique. The study was conducted to identify the denture with the highest flexural strength (Fs) from these methods.

In this in vitro study. Three groups of 15 PMMA acrylic denture base resins (total 45) were processed into rectangular plates of size 65mm × 10mm × 3mm. The three groups differed in the method of processing as compression molded, injection molded, and prepolymerized CAD/CAM milled resins. A 3‐point bend test was used to measure the Fs. One‐way analysis of variance (ANOVA) with the Post hoc Tukey method was used for statistical analysis. Data was statistically significant with Post hoc Tukey method significance at P < 0.05.

The mean Fs of CAD/CAM, injection molding, and compression molding manufacturing techniques are 97.46, 84.42, and 71.72 respectively and standard deviation obtained are 9.93, 10.42, and 11.58, respectively. Statistical analysis suggested the CAD/CAM technique as the best method for the fabrication of dentures because it had the maximum mean Fs and the lowest Fs standard deviation when compared with compression molding and injection molding.

Denture bases fabricated through CAD/CAM technique are more sustainable than the compression‐molded and injection‐molded denture bases.

Despite significant improvements in the physical and esthetic properties of modern composite resins, there are still concerns about their biocompatibility. The aim of the current study was to evaluate the toxicity of X‑tra fil, Grandio, and Admira Fusion composites on dental pulp stem cells (DPSCs) and human gingival fibroblast (HGF) cells.

In this in vitro experimental study, 48 composite disks were made using Grandio, Admira Fusion (2 mm high and 4 mm in diameter), and X‑tra fil (4 mm high and 4 mm in diameter) composites and cured for 40 s. The composite blocks were then crushed with a sterile mortar and dissolved in phosphate saline buffer solution. Tetrazolium salt (3-(4,5-dimethyl thiazol-2yl)-2,5 diphenyltetrazolium bromide (MTT_, neutral red (NR) assay, flow cytometry, and quantitative real‑time polymerase chain reaction (RT‑PCR) tests (n = 5) were used to evaluate the toxicity of the composites on two cell types (HGF, DPSCs). Data were analyzed using one‑way ANOVA test followed by Newman–Keuls test. Level of significance was set at P < 0.05.

According to the results of MTT test, only Grandio showed a significant cytotoxicity in DPSCs, but in HGF cells, Grandio and X‑tra fil both showed a significant cytotoxicity. In NR test, Grandio and X‑tra fil composites showed a significant cytotoxicity on both HGF and DPSC cells. RT‑PCR test results on both DPSC and HGF cells indicated that bax gene expression in the Grandio composite was significant. In this test, the nonexpression of the bcl2 gene in DPSCs was significant in Grandio (100 and 200 µg/ml) and in X‑tra fil (200 µg/ml). All of the tests performed in this study showed no significant toxicity of Admira fusion.

Admira Fusion is suitable for oral cells in terms of biocompatibility and can be used as a suitable restorative material for deep restorations near the pulp or adjacent to the gums.