Journal of Dental School

Objective(s): This study aimed to assess the knowledge and attitudes of dentists regarding the etiology and management of non-carious cervical lesions (NCCLs) and to identify gaps in their understanding. Methods: A cross-sectional study was conducted involving 119 general dentists in Ilam, Iran. A validated questionnaire, consisting of 39 questions concerning the etiology and management of NCCLs, was distributed. Data were analyzed using descriptive and inferential statistical methods by Chi-square and T-test at p<0.05. Results: There was significant difference in knowledge and attitude based on age and experience. Dentists over 40 and those with over 10 years of experience displayed greater knowledge and attitude regarding the etiology and management of NCCLs (P < 0.01). However, no significant differences were observed between the two genders.

Conclusion: Findings highlight a critical need for continuing education among dentists, particularly for younger practitioners. Enhancing knowledge and attitudes towards NCCLs can improve clinical practices and patient outcomes. Targeted educational programs are recommended to address the identified gaps in understanding and management strategies for NCCLs.

Objective(s): Noise-induced hearing loss (NIHL) is a critical occupational hazard, particularly among dentists exposed to high-frequency sounds from dental equipment. This study aimed to assess hearing thresholds in dentists using Pure Tone Audiometry (PTA) and High-Frequency Audiometry (HFA). Methods: A cross-sectional study was conducted with 63 dentists in Yazd, Iran, who underwent audiometric testing across frequencies ranging from 250 Hz to 16,000 Hz. Dentists over 50 years old and those with a history of hearing problems or ototoxic drug use were excluded. Statistical evaluation included independent t-tests, ANOVA, Pearson’s correlation coefficient, and Chi-square tests at a significance level of 0.05. Results: hearing loss was most prevalent at 4,000 Hz in the normal frequency range, affecting 35% of participants in the right ear and 33% in the left ear. High-frequency hearing loss was significantly higher, with 86% of dentists exhibiting hearing loss at 16,000 Hz in the right ear and 79% in the left ear. The study also found a significant correlation between hearing thresholds, age, and work experience, emphasizing the increased risk of NIHL with prolonged exposure to dental equipment noise. Gender differences were noted, with men showing higher rates of hearing loss at 4,000 Hz. Conclusion: These findings underscore the necessity for regular auditory screening and the implementation of protective measures in dental practice to prevent long-term hearing damage. The study highlights the utility of HFA for early detection of NIHL, especially in high-risk professions like dentistry.

Objective(s): This research aimed to evaluate the immunohistochemical (IHC) expression of Galectin-3 (Gal-3), COX-2, and CD3 in oral lichen planus (OLP), lichenoid dysplasia (LD), and lichen planus with dysplasia (LPD). Analyzing these three markers can provide insight into the molecular role of inflammation in the differentiation and behavior of lichen planus and lichenoid lesions, as well as their potential for malignant transformation. Methods: This descriptive, cross-sectional study examined the paraffin blocks of OLP, LD, and LPD obtained from the archives of the Pathology Departments at Shahid Beheshti Dental School and Razi Hospital. A total of 17 OLP, 21 LPD, and 20 LD specimens were stained for Gal-3, COX-2, and CD3 markers using the En-Vision technique, and evaluated by two oral and maxillofacial pathologists. The expression of markers was compared and analyzed using the Chi-Square, Kruskal-Wallis, Mann-Whitney, and Fisher’s exact tests, as well as Spearman’s correlation coefficient at p<0.05. Results: High CD3 expression was observed in the connective tissue of all three groups with no significant difference (P=0.889). COX-2 expression was similarly low in both the connective tissue and epithelium of all three groups (P=0.778 and P=0.979, respectively). Gal-3 expression was moderately consistent in the connective tissue of all three groups (P=0.278), and weak in the epithelium (P=0.515). Conclusion: The findings suggested that CD3, COX-2, and Gal-3 play a similar role in inflammation in OLP, LPD, and LD, and are not associated with dysplastic changes.

Objective(s): To simplify the bonding steps of orthodontic brackets, GC Ortho Connect adhesive with a primer solution in its composition has been presented. As a result, the primer application phase after etching has been eliminated. This study examined the shear bond strength (SBS) and adhesive remnant index (ARI) of ceramic brackets to the ceramic surfaces using two bonding systems, GC Ortho Connect and Brace Paste American Composite, in the presence or absence of silane. Methods: In this laboratory study, 40 IPS e.max ceramic blocks were assigned to four groups, and Protect ceramic brackets were bonded to them using GC Ortho Connect or Brace Paste American Composite adhesive in the presence or absence of silane (Primer Ceramic X Rely). Under a stereo microscope, the ARI was ascertained, and a universal testing machine assessed the SBS amounts. One-way ANOVA, Post hoc Tukey tests, and chi-squared test were used for statistical analysis, at a significance level of 0.05. Results: The SBS of ceramic brackets to porcelain using GC Ortho Connect without silane and Brace Paste American Composite with silane differed significantly (p=0.008), although other pair comparisons did not show significant differences. There was no discernible difference between the groups in terms of type of failure (p=0.84). Conclusion: It is acceptable to use Brace Paste American Composite adhesive with or without silane, or GC Ortho Connect adhesive with silane, to achieve the bond of ceramic brackets to porcelain surfaces. However, the bond strength between ceramic brackets and porcelain surfaces was inadequate when using GC Ortho Connect without silane.

Objective(s): Due to the high prevalence of dental caries among children, and considering the effectiveness of fluoride in caries prevention, coupled with the significant role of mothers in children's oral health, enhancing maternal knowledge about fluoride therapy can improve children's oral health. This study aimed to compare the impact of education using two methods, brochures and mobile applications, on knowledge and attitude of mothers, concerning topical fluoride application for their children. Methods: This longitudinal interventional study involved 140 mothers attending the Pediatric Dentistry Department, divided into two groups. A questionnaire regarding children's topical fluoride application was administered to them. After receiving the completed questionnaires, brochures were provided to the mothers in the first group, while a mobile application was provided to the second group. Immediately following the educational intervention, the same questionnaire was re-administered. Three months later, both groups were recalled to complete the questionnaire to assess information retention. Finally, the data were analyzed using Pearson's correlation, chi-square, analysis of variance, independent samples t-test, and Bonferroni post-hoc test (p < 0.05). Results: Mothers' knowledge and attitude significantly increased in both groups immediately after the intervention (p < 0.001). There was no significant difference in attitudes between the two groups immediately after the intervention (P = 0.17), but three months after the intervention, attitudes were higher in the mobile application group compared to the brochure group (P = 0.01). Knowledge was higher in the brochure group immediately after the intervention (p < 0.001), but three months after the intervention, it was higher in the mobile application group (p < 0.001). Conclusion: Maternal knowledge and attitudes toward topical fluoride application significantly improved following the brochure study and the mobile application use. In the long term, the mobile application demonstrated superior efficacy in enhancing knowledge and attitudes.

Objective(s): This research aimed to design and implement an artificial intelligence (AI) model for dental age estimation in panoramic radiographs using the Demirjian method. Accurate dental age estimation is crucial in forensic and clinical dentistry. Traditional methods for this purpose are typically time-consuming and require expertise, which increases the likelihood of human error. This study explored the potential of AI, particularly Vision Transformers (ViTs), to overcome these limitations. Methods: A number of 422 panoramic radiographs were analyzed, yielding 2,836 individual tooth images. The developmental stages of left mandibular teeth were determined according to the Demirjian method. Initially, 15% of the data was randomly separated for the test set. Subsequently, five-fold cross-validation was employed to partition the remaining data into training and validation sets. Three Convolutional Neural Network (CNN) models (ConvNeXt-Tiny, EfficientNet-V2-S, RegNet-Y-16GF) and three ViT models (ViT-B-16, Swin-V2-T, MaxVit-T) were trained using transfer learning. Model performance was evaluated using accuracy, precision, recall, and F1-score. The best-performing model, based on F1-score, was deployed in a web-based application. Mean Absolute Error (MAE) was used to assess the accuracy of AI-based age estimation compared to chronological age. Results: The Swin-V2-T model achieved the highest performance across all metrics (F1-score of 87%, Accuracy of 87.09%, Precision of 87.17%, and Recall of 87.09%). Analysis of AI-based age estimation accuracy revealed an MAE of 0.953 years. Conclusion: This study highlighted the applicability of AI, particularly ViT-based models, in automated dental age estimation using the Demirjian method. The developed AI model has the potential to streamline dental age assessments in both clinical and forensic settings, minimizing human error and enhancing efficiency.

Objective(s): Application of fibroblast growth factor 2 (FGF2) as an adjunctive treatment in periodontal regeneration is a treatment modality. Several recent case reports describe the application of FGF-2 in different periodontal defects with detailed information and long-term follow-ups. The aim of this review was to assess the effect of FGF-2 on periodontal regeneration and patient quality of life in cases with long-term follow-up. Methods: An electronic search was performed in PubMed Central, Scopus, and web of science databases from 1990 until December 2023. The search included all case reports in which FGF2 was used for periodontal defect treatment with long-term follow-up. Case series which described detailed data of their cases were also evaluated. Ten articles including 12 patients, 23 teeth, and 25 defects were included in the study.  Results: Most of the treated defects were infrabony defects (84%), followed by furcation defects (12%). Probing depth (PD) reduction and clinical attachment loss (CAL) gain were seen in all defects and evidence of bone fill was documented. All cases had a follow-up duration of at least 12 months, with the greatest follow-up time of 9 years. Conclusion: Adjunctive treatment of periodontal defects using FGF-2 is an effective and stable treatment modality that provides patients’ satisfaction. However, more studies in this field are recommended.

Objectives: Lipoma, the most frequently observed benign mesenchymal neoplasm, is infrequently encountered within the oral cavity. Typically manifesting in middle-aged individuals irrespective of sexual predilection, it presents as an asymptomatic, slowly progressive lesion. Within the oral cavity, the buccal mucosa and mucobuccal fold represent the most common anatomical locations for lipoma development. Case: A 36-year-old male patient's medical history included a shotgun injury 15 years prior, which resulted in the avulsion of multiple mandibular teeth. Subsequently, tongue tissue was grafted to the affected area. A pedunculated lesion later developed within the grafted tissue and was surgically removed.  Histopathological examination of the excised lesion revealed an intraoral lipoma. The patient's medical history was otherwise unremarkable, with no reported systemic illnesses or medication use. A separate, analogous case involved tongue tissue grafting to a cleft palate defect, which also exhibited similar characteristics. Conclusion: The significance of this case lied in the rare occurrence of a lipoma on an edentulous mandibular ridge previously augmented with a tongue tissue graft. The etiology of lipoma may be linked to both the surgical trauma and the inherent properties of the grafted tissue. Critically, this report highlighted the potential for donor tissue characteristics to persist within the recipient site following grafting, contrasting with the typical physiological traits of the recipient site itself. This observation warranted careful consideration in comparable clinical scenarios.