Dental Research Journal
Volume:21 Issue: 1, Jan 2024

This review aims to perform a complete evaluation of the impact of photobiomodulation (PMB) on postoperative endodontic pain.

The PRISMA checklist was used to perform this systematic review. The electronic databases were searched, including Google Scholar, PubMed, and Embase. Sixty‑three papers were obtained through a main electronic search and a hand search. Nine trials met the criteria after screening the titles, abstracts, and/or full texts.

Seven out of nine studies showed that PMB has a significant impact on relieving postoperative endodontic pain, with no statistically significant difference in the severity of pain between the laser and control groups in the two remaining studies. In addition, eight studies showed no adverse effects, indicating that we can remove the adverse effects of drugs such as nonsteroidal anti‑inflammatory drugs. However, one study showed evidence of the consequences of PMB application on teeth with symptomatic irreversible pulpitis. Therefore, it can be concluded that PMB should not be used in teeth with pain because of irreversible pulpitis.

Although there is some understanding from a cellular viewpoint of the effects of PMB, there is still some uncertainty about whether these cell‑level modifications impact reducing the postendodontic pain.

The objective is to compare the impact of clear aligner treatment (CAT) versus conventional fixed appliance treatment (FAT) on oral health‑related quality of life (OHRQoL) among adults at five‑time points: pretreatment (T0), 1 week (T1), 1 month after (T2), and 6 months after (T3) treatment initiation, and in the long‑term follow‑up (T4).

Search terms were based on Medical Subject Headings (MeSH) and non‑MeSH. Potentially eligible studies compared OHRQoL in clear aligner (CA) and fixed appliance (FA) patients. In February 2023, Scopus, Web of Science, Cochrane, and PubMed were searched for published studies. Nine out of 94 shortlisted papers were eligible for a systematic review. Of these nine papers, five studies were considered for a meta‑analysis.

At T0, CA and FA patients had similar oral health impact profile (OHIP)‑14 questionnaire scores with a standard mean difference (SMD) of 0.105 (confidence interval [CI]: −1.029–1.48). The SMD of the OHRQoL related to T1, T2, and T3 was −3.119 (CI: −0.145, 0.355), −1.527 (CI: −5.597, −0.64), and − 2.331 (CI: −1.906, −1.148). T4 showed no difference between groups (SMD = 0.007, CI: CI: −4.286, −0.376). Regarding the OHIP‑14 domains, functional limitations remained consistent in both groups across all time intervals. Psychological discomfort exhibited a notable difference only at T2. Throughout the treatment, CAT showed significantly lower levels of physical, psychological, and social disability, as well as handicap, though these differences did not persist beyond T4. Notably, physical pain was the sole domain that remained elevated in the FAT group up to T4.

During the 1st day of the orthodontic treatment, both the CA and FA groups had comparable OHRQoL statuses. However, as time passed, the CA group notably improved their OHRQoL compared to the FA group. Interestingly, after a year or the completion of treatment, both groups eventually reached similar OHRQoL levels. Nevertheless, it is worth noting that FA patients continued to experience more physical pain even a year later.

Implant‑supported prostheses could serve as a reliable restorative option for partial edentulism. Various restorative materials have been utilized in fabricating these prostheses, impacting both esthetics and peri‑implant health. The present systematic review aimed to assess the survival rate and mechanical complications of zirconia ceramic compared to metal‑ceramic implant‑supported multiunit fixed dental prostheses (FDPs). We conducted searches in online databases such as MEDLINE (PubMed), Scopus, and Cochrane up until December 2022. A risk‑of‑bias assessment was done for all the included studies. Data extraction was performed based on the following parameters: author, year, study design, number of implants, abutment material, age range, observation period, incidence of mechanical complications, and survival rate. This systematic review included six studies (four randomized controlled trials and two retrospective studies). The meta‑analysis significantly favored metal‑ceramic restorations regarding mechanical complications with a risk ratio (RR) value of 1.64 and P = 0.001. Meta‑analysis showed no difference in metal‑ceramic FDPs in prostheses survival rate (P = 0.63; RR: 1.27, 95% confidence interval: 0.52–3.37; heterogeneity: P = 0.65; I2: 0%). While metal‑ceramic multiunit implant‑supported prostheses exhibited fewer mechanical complications compared to zirconia‑ceramic prostheses, there was no significant difference in terms of prosthesis survival rate between the two. Hence, both treatments appear to be viable options for long‑term implant‑supported prostheses.

Knowledge about the anatomic variations of the root canal system and their prevalence is necessary for clinicians to ideally clean the root canal system. The anatomic complexity of the root canal system is one of the reasons for its inadequate debridement, resulting in residual microorganisms and root canal treatment failure. The present study aimed to evaluate the prevalence of middle mesial root canals in mandibular molars in an Iranian population.

The samples in the present descriptive/cross‑sectional study consisted of mandibular first and second molars (n = 100, with 50 first and 50 s molars). A convenient sampling method was used to collect samples. The teeth were mounted in gypsum and scanned using a micro‑computed tomography unit. The images were reconstructed with software, and the relevant checklist was completed by the observers. The data were analyzed with SPSS v26 using the Chi‑squared test at a significance level of P < 0.05.

The prevalence of the middle mesial root canal in the present study was 36% for mandibular first molars and 22% for mandibular second molars, with an overall prevalence of 29%. The prevalence of the middle mesial root canal was not significantly different between the first and second mandibular molars (P = 0.12). The mean distance between the mesiobuccal and mesiolingual root canal orifices in the teeth with a middle mesial root canal was significantly higher than in those without the middle mesial root canal (P < 0.001). In addition, there was no significant difference in the prevalence of the middle mesial root canal between the teeth with and without the second distal root canal (P = 0.89).

The prevalence of the middle mesial root canal in the studied population was 29%, which is significant clinically. In addition, the mean distance between the mesiobuccal and mesiolingual root canal orifices in teeth with a middle mesial root canal was higher than that in teeth without this root canal.

Fixed orthodontic appliances enhance dental plaque accumulation. Glass ionomer (GI) is among the most popular orthodontic cement. It possesses antibacterial properties; however, its antibacterial activity may not be sufficient for caries prevention. Although evidence shows that the addition of 8wt% nano‑hydroxyapatite (nHA) may enhance the antibacterial properties of GI, no clinical study has been conducted in this respect. Thus, this study aimed to assess the subgingival accumulation of Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus) around orthodontic bands cemented with conventional GI and GI reinforced with 8wt% nHA.

This split‑mouth clinical trial was conducted on 20 patients requiring a lingual arch. The patients were randomly assigned to two groups. In group 1, the right molar band was cemented with pure Fuji I (GC), and the left was cemented with Fuji I containing 8wt% nHA. In group 2, the right molar band was cemented with Fuji I containing 8wt% nHA, and the left was cemented with Fuji I. After 3 months, subgingival sampling was performed by sterile paper points. S. mutans and L. acidophilus were cultured on MSB and MRS agar, and colonies were counted by a colony counter. Data were analyzed by independent samples t‑test using SPSS 25 at a 0.05 level of significance.

The mean counts of S. mutans, aerobic and anaerobic lactobacilli, and total bacterial around orthodontic bands cemented with Fuji I containing 8wt% nHA were significantly lower than those around orthodontic bands cemented with pure Fuji I (P < 0.05).

The addition of 8wt% nHA to GI cement can enhance its antibacterial properties for the cementation of orthodontic bands, decrease the accumulation of cariogenic bacteria, and probably decrease the incidence of caries in orthodontic patients.

Diagnosis of oral cancer in the early stages is the most effective tool to improve survival and reduce complications caused by the disease. The aim of this study was investigating the dental patients’ knowledge of oral cancer in Isfahan.

This descriptive cross‑sectional study was performed on 334 patients referred to dental centers in Isfahan, Shahinshahr, Najafabad, Khomeini Shahr, Harand, and Zarrinshahr cities. Data were collected by a researcher‑made 25‑item questionnaire. Data analysis was carried out by SPSS (version 26) software using the independent t‑test, one‑way analysis of variance, and Pearson correlation coefficient (P < 0.05).

The patients’ mean score of knowledge was 49.3 ± 21.4 in Isfahan city and 53.1 ± 18.4 in the other cities of Isfahan province. There was no significant difference between knowledge of oral cancer and gender, marital status, and residence, but there was a significant difference between employment status and knowledge (P = 0.03). The mean score of knowledge was significantly higher in patients who had a history of oral cancer in relatives than in other patients (P = 0.03). Virtual networks (Telegram, WhatsApp, and Instagram), journals, and books were the most common sources for patients about oral cancers.

Dental patients’ knowledge of oral cancer in Isfahan province and its cities was moderate, so it is necessary to increase their level of knowledge through more education.

Polyetheretherketone (PEEK) has favorable properties that make it able to be used as a denture base material, but it is also susceptible to the adhesion of microorganisms. In this study, we applied Octafluoropentyl (meth) acrylate (OFPA) coating on the PEEK polymer surface by using plasma spray and investigated the functional groups present on the surface, changes in the surface energy and Candida albicans adhesion.

In this experimental study, the samples were placed in a control group without surface preparation and three experimental groups that were subjected to plasma spray for 10, 30, and 60 s and then impregnated with degassed Octa fluoropentyl (meth) acrylate (Sigma‑Aldrich, USA) monomer. Fourier transform infrared spectroscopy (FTIR) was used to identify the functional groups and new chemical bonds between PEEK and OFPA, and Sessile Drop Method was used to evaluate the surface’s wettability. The surface morphology was checked using a LEXT OLS4000 (Olympus®‑Japan) microscope, and the inhibition of C. albicans adhesion was also checked by counting the colonies in terms of colony forming unit/mL (CFU/mL). Kurskal–Wallis analysis was conducted to assess Candida adhesion, while wettability was evaluated using analysis of variance and post hoc analyses. The level of statistical significance was set at P < 0.05.

FTIR analysis confirmed that a chemical between OFPA and PEEK was established. The samples showed a significant increase in the contact angle after 30 s of plasma application (CA = 88.2 ± 7.3). The contact angle decreased again by increasing the surface modification to 60 s (CA = 64.33 ± 5.5). Examining the surface morphology of the samples shows an increase in surface roughness with increasing plasma time up to 60 s. The number of adherent colonies was the lowest in 30 s group, but it was not statistically significant (P = 0.658).

No statistically significant difference in C. albicans CFU/mL count was found between groups. The contact angle of the 30 s group was significantly higher than the control group.

The aim of this study was to compare the accuracy of apex locator, digital periapical radiography, and cone‑beam computed tomography (CBCT) for determining the root canal working length (WL) in teeth with external root resorption (ERR).

In this in vitro study, the sample consisted of 54 extracted permanent single‑rooted human teeth. ERRs were performed at the 3 mm apical root using 65% of nitric acid for 24 h. After determining the actual WL by K‑file #10 (gold standard) with the visualization method, the teeth were mounted in alginate and the WL of each tooth was determined using the electronic apex locator (EAL) equipped with a K‑file #15. The teeth were mounted with wax in the teeth sockets of a dry human mandible, and the images were obtained by digital phosphor plate receptors and CBCT scans. The mean registered WL of each method was statistically compared with the gold standard WL using one‑way ANOVA with P < 0.001.

The mean ± standard deviation (SD) of actual WL was 16.00 ± 2.24. The mean ± SD of WLs determined by CBCT, EAL, and digital radiography were 15.38 ± 2.19, 15.52 ± 2.32, and 16.83 ± 2.20, respectively. This study showed that the mean measured WL with ERR in all methods was significantly different from the actual WL (P < 0.001).

This study showed that there was a significant difference between the actual mean WL and the EAL, digital periapical radiography, and CBCT mean WL. Thus, the combination of EAL and CBCT could be a reliable method for determining WL in the presence of ERR.

Lip incompetence is an important issue in orthodontics. No study has evaluated the effects of the combination of headgear + lip exercises on lip incompetence. Therefore, this study was conducted.

This was a longitudinal randomized clinical trial on 29 subjects (16 controls and 13 experimental subjects). Both groups were treated with standardized activator high‑pull headgear (and followed up monthly) for 6–8 months. In the experimental group, patients were also instructed to practice certain lip exercises 3 sessions a day, 5 times per session. Pre‑/ post‑treatment interlabial gap, upper lip length and vermilion height, lower lip length and vermilion height, nasolabial angle, and profile convexity angle were measured clinically and photographically, immediately before treatment and after it. Data were analyzed using paired/unpaired t‑tests (α = 0.025) and partial correlation coefficient controlling for the intervention type (α = 0.05).

Lip exercise plus activator headgear significantly changed/improved all parameters (P ≤ 0.006) over the 6–8‑month course of treatment. Activator headgear alone changed/improved only 4 parameters: interlabial gap, upper and lower lip lengths, the lower lip vermilion height, and profile convexity (P ≤ 0.008). Compared to the control (activator headgear alone), in the experimental group, the changes observed in the interlabial gap closure (P = 0.011), upper lip lengthening (P = 0.002), and upper lip vermilion lengthening (P = 0.017) were significantly greater. Convexity angle corrections were more successful in cooperative patients (R = 0.469, P = 0.012). Cases with smaller pretreatment nasolabial angles may experience more changes in this angle after treatment (R = 0.581, P = 0.001).

The addition of lip exercises to activator high‑pull headgear can boost activator headgear’s efficacy in treating lip incompetence.