Aim: The integration of large language models (LLMs) such as ChatGPT and Gemini into healthcare education presents novel opportunities for knowledge dissemination and assessment. Despite their growing prominence, empirical evidence regarding their reliability and domain-specific accuracy in dental specialty examinations remains limited. This study aimed to evaluate and compare the performance of four AI-driven LLMs—ChatGPT-3.5, ChatGPT-4o, Gemini 2.0 Flash, and Gemini 2.0 Advanced— by employing official past questions from the Turkish Dental Specialty Examination (DUS) in Pediatric Dentistry and Restorative Dentistry. Methodology: A total of 178 multiple-choice questions (90 in Restorative Dentistry and 88 in Pediatric Dentistry) were obtained from DUS examinations conducted between 2012 and 2017. All items were presented in Turkish to each model via standardized prompts in isolated sessions to prevent cross-interaction and memory bias. Response accuracy was determined by evaluating the correctness of the chosen answers. Comparative analyses between models, domains, and annual trends were conducted using non-parametric statistical tests, including the Mann–Whitney U and Friedman tests. Results: ChatGPT-4o achieved the highest overall accuracy across both Pediatric (90.88%) and Restorative Dentistry (93.02%), whereas ChatGPT-3.5 exhibited the lowest performance in Pediatric Dentistry (70.71%). Statistically significant inter-model differences were observed in Pediatric Dentistry (p = 0.002), but not in Restorative Dentistry (p = 0.254). Temporal analyses highlighted the consistent performance of ChatGPT-4o, while Gemini 2.0 Flash displayed marked fluctuations in accuracy across certain years and subdomains. Conclusion: Among the evaluated LLMs, ChatGPT-4o demonstrated superior and stable performance in addressing dental specialty exam questions, particularly in content requiring contextual comprehension. These findings underscore the potential of advanced AI tools to enhance dental education and examination readiness. Nonetheless, appropriate model selection should be tailored to the complexity of the task, domain specificity, and pedagogical objectives.

Repairing composite resins is a less invasive alternative to complete restoration replacement. To achieve a successful bond between the existing and newly applied composite materials, various surface preparation methods, such as sandblasting and acid etching, have been explored. The aim of the study was to evaluate the effect of different surface treatments on the repair bond strength of a universal nanohybrid composite resin restorative material before and after thermal aging, by utilizing a micro-shear bond strength (µSBS) test. For the micro-shear bond strength test, a total of 120 cylindrical (3mmX2mm) nanohybrid resin based composite specimens were prepared. The prepared specimens were divided into three groups (n = 40/per group) based on surface treatment methods: a non-aged group, 10,000 thermal cycle aging and 50,000 thermal cycle aging. The aged and non-aged specimens were further divided into four groups according to adhesive application modes and surface pretreatment methods: 1.universal adhesive/self-etch mode, 2.aluminum oxide sandblasting + universal adhesive/self-etch mode, 3.universal adhesive/etch-and-rinse mode, 4.aluminum oxide sandblasting + universal adhesive/etch-and-rinse mode. Subsequently, 0.8mmX2mm disc shape light cure resin based composite specimens were applied with a direct placement technique on the treated surfaces of all samples for repair. µSBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. Kruskal-Wallis and Mann-Whitney tests were performed for statistical analysis. The µSBS values of the non-aged group were higher than those of the 10,000 and 50,000 thermal cycle groups, with no significant differences within the non-aged subgroup (p > 0.05). In the aged groups, significant differences were observed between adhesive application modes and surface treatments. Specifically, the etch-and-rinse mode showed higher bond strengths than the self-etch mode after 50,000 thermal cycles (p < 0.05). Sandblasting combined with universal adhesive (self-etch mode) improved bond strength, especially in the 10,000 thermal cycle group (p < 0.05). Aging reduced the bond strength of composite resin repairs, with the etch-and-rinse mode outperforming the self-etch mode in aged specimens. Sandblasting alone did not enhance bond strength. These findings highlight the importance of considering aging and adhesive strategies to optimize repair outcomes, with further research needed on long-term durability.

This study evaluated the effect of resin cements and post-space irrigation solutions on the push-out bond strength of diabetic and non-diabetic dentin. A total of 160 human central teeth (80 diabetic, 80 non-diabetic) were prepared using X5 files and obturated with AH Plus sealer and X5 gutta-percha. Post spaces were prepared, and teeth were divided into eight groups based on resin cements (Variolink N, Panavia SA Universal) and irrigation protocols (saline, saline + 2% CHX). A 1 mm slice from each tooth’s middle third was tested for push-out bond strength. Statistical analysis was performed using three-way ANOVA and Tukey HSD tests. In non-diabetic dentin, saline + CHX with Variolink N achieved the highest bond strength. In diabetic dentin, saline with Panavia SA Universal resulted in the lowest bond strength (p < 0.05). The dentin type, resin cement, and irrigation solution significantly impacted fiber post bond strength, and CHX irrigation improved it.

Background: Toothpastes are widely used oral care products and may contain trace and heavy metals originating from raw materials or manufacturing processes. Continuous monitoring of both toxic and essential metal content is therefore important to ensure consumer safety, particularly for products intended for children. Materials and methods: Fifteen commercially available toothpaste products marketed in Türkiye were purchased and classified as children’s, adult, or herbal formulations. Samples were digested using microwave-assisted nitric acid digestion and analyzed for aluminum (Al), chromium (Cr), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) using inductively coupled plasma mass spectrometry (ICP-MS). Metal concentrations were compared according to target group, formulation type, and country of manufacture using non-parametric statistical tests. Results: Mercury and arsenic were below the detection limits in all samples. Cadmium and lead were detected at concentrations within internationally recommended safety limits, while nickel, chromium, copper, zinc, aluminum, and iron were reported at varying concentrations without direct comparison to specific regulatory threshold values due to the lack of established limits for these metals in toothpaste products. No statistically significant differences were observed between children’s and adult toothpastes or between herbal and conventional formulations ( p > 0.05). However, toothpastes manufactured in Türkiye exhibited significantly higher chromium concentrations compared to imported products ( p = 0.028). Conclusion: The evaluated toothpaste products contained low levels of potentially toxic metals, with concentrations remaining within accepted safety limits. The findings suggest general compliance with international regulations; however, periodic surveillance remains important, particularly for products intended for children.

Background: Remaining dentin thickness (RDT) beneath restorations is an important factor for pulpal health; yet, its quantitative relationship with periapical lesion presence remains inadequately characterized. This study aimed to evaluate RDT using cone beam computed tomography (CBCT) and investigate its association with periapical lesion presence. Methods: This retrospective cross-sectional study analyzed CBCT images from 500 restored posterior teeth (211 patients). Remaining dentin thickness was measured as the shortest distance between the pulp chamber and deepest restoration point. Periapical status was recorded as present/ absent. Inter-observer agreement was assessed using intraclass correlation coefficient for continuous RDT measurements and weighted Cohen’s kappa for categorized RDT. Generalized estimating equations (GEE) with binomial distribution and logit link were used to evaluate associations accounting for multiple teeth being analyzed per patient (211 patients, 500 teeth). Results: Periapical lesion prevalence varied across RDT categories: 67.8% for <0.5 mm, 25.9% for 0.5-0.99 mm, 8.8% for 1-1.99 mm, and 0% for ≥2 mm. Multivariable GEE analysis demonstrated that each unit increase in RDT category was significantly associated with lower odds of periapical lesion presence (odds ratio [OR] = 0.21; 95% CI: 0.15-0.30; P < .001). Presence of caries was associated with increased lesion odds (OR = 5.70; 95% CI: 3.18-10.23; P < .001), while restorative material showed no significant association (P = .068). Conclusion: In this retrospective cross-sectional sample, RDT was significantly associated with periapical lesion presence. An RDT of ≥2 mm was associated with the absence of periapical lesions in the present sample; however, this observation does not establish a definitive clinical threshold. Minimally invasive approaches prioritizing dentin preservation are consistent with these findings.