Influence of endodontic access cavity design on mechanical properties of a first mandibular premolar tooth: a finite element analysis study.

OBJECTIVES: This study aimed to investigate the influence of access cavity designs on the mechanical properties of a single-rooted mandibular first premolar tooth under various static loads using a finite element analysis. MATERIALS AND METHODS: 3-dimensional FEA designs were modeled according to the access cavity designs: an intact tooth (control), traditional access cavity (TEC-I), traditional access cavity with Class-II mesio-occlusal cavity design (TEC-II), conservative access cavity (CEC), ninja access cavity (NEC), caries-driven access cavity (Cd-EC), buccal access cavity (BEC) and bucco-occlusal access cavity (BOEC). After the simulated access cavity preparations, root canal treatment was simulated and three different static loads which mimicked oblique and vertical mastication forces were applied to the models. The stress distribution and maximum Von Misses stress values were recorded. The maximum stress values were obtained on both enamel and dentin under multi-point vertical loads. RESULTS: The maximum stress values were obtained on both enamel and dentin under multi-point vertical loads. Under all load types, the minimum stress distribution was observed in the control group, followed by CEC, NEC and BEC designs. The highest stress concentration was detected in Cd-EC and TEC-II designs. Under single-point vertical loading, the stress was mostly concentrated in the lingual PCD area, while under multi-point vertical loading, the entire root surface was stress-loaded except for the lingual apical third of the root. CONCLUSION: Preserving tooth tissue by simulating CEC, NEC and BEC access cavities increased the load capacity of a single-rooted mandibular first premolar following simulated endodontic treatment.

Artificial intelligence in endodontics: Data preparation, clinical applications, ethical considerations, limitations, and future directions.

Artificial intelligence (AI) is emerging as a transformative technology in healthcare, including endodontics. A gap in knowledge exists in understanding AI's applications and limitations among endodontic experts. This comprehensive review aims to (A) elaborate on technical and ethical aspects of using data to implement AI models in endodontics; (B) elaborate on evaluation metrics; (C) review the current applications of AI in endodontics; and (D) review the limitations and barriers to real-world implementation of AI in the field of endodontics and its future potentials/directions. The article shows that AI techniques have been applied in endodontics for critical tasks such as detection of radiolucent lesions, analysis of root canal morphology, prediction of treatment outcome and post-operative pain and more. Deep learning models like convolutional neural networks demonstrate high accuracy in these applications. However, challenges remain regarding model interpretability, generalizability, and adoption into clinical practice. When thoughtfully implemented, AI has great potential to aid with diagnostics, treatment planning, clinical interventions, and education in the field of endodontics. However, concerted efforts are still needed to address limitations and to facilitate integration into clinical workflows.

Artificial intelligence in endodontics: Fundamental principles, workflow, and tasks.

The integration of artificial intelligence (AI) in healthcare has seen significant advancements, particularly in areas requiring image interpretation. Endodontics, a specialty within dentistry, stands to benefit immensely from AI applications, especially in interpreting radiographic images. However, there is a knowledge gap among endodontists regarding the fundamentals of machine learning and deep learning, hindering the full utilization of AI in this field. This narrative review aims to: (A) elaborate on the basic principles of machine learning and deep learning and present the basics of neural network architectures; (B) explain the workflow for developing AI solutions, from data collection through clinical integration; (C) discuss specific AI tasks and applications relevant to endodontic diagnosis and treatment. The article shows that AI offers diverse practical applications in endodontics. Computer vision methods help analyse images while natural language processing extracts insights from text. With robust validation, these techniques can enhance diagnosis, treatment planning, education, and patient care. In conclusion, AI holds significant potential to benefit endodontic research, practice, and education. Successful integration requires an evolving partnership between clinicians, computer scientists, and industry.

Propolis Use in Dentistry: A Narrative Review of Its Preventive and Therapeutic Applications.

Propolis is a resinous substance produced naturally by bees, and it consists of the exudates of plants mixed with enzymes, wax, and pollen. Propolis continues to gain considerable scientific interest due to its potential health benefits. The modern-day use of propolis in pharmaceutical preparations, such as toothpastes, mouthwashes, chewable tablets, mucoadhesive gels, and sprays, is increasing. However, the effectiveness of using propolis-containing pharmaceuticals in dentistry is not clear. The present paper aims to review the literature on the dental applications of propolis in preventive dentistry, periodontics, oral medicine, and restorative dentistry and discuss its clinical effectiveness. A literature search was conducted using Scopus, PubMed, and Web of Science databases. In total, 104 studies were included, of which 46 were laboratory studies, 5 animal studies, and 53 human clinical studies. Overall, the laboratory studies revealed a range of antimicrobial effects of propolis on oral pathogens. Clinical investigations of propolis in biofilm and dental caries control as well as adjuvant periodontal therapies reported positive outcomes in terms of plaque control, pathogenic microbial count reduction, and periodontal tissue inflammation control. Additional investigations included the use of propolis for the management of recurrent aphthous stomatitis, oral mucositis, and cavity disinfection after caries removal as well as the development of a range of restorative dental materials. Based on the reported outcomes of the studies, the clinical usage of propolis has potential. However, the majority of the evidence is derived from studies with flaws in their methodological design, making their results and conclusions questionable. As a consequence, properly designed and well-reported clinical studies are required to affirm the effectiveness of propolis for dental applications. Additionally, the safety of propolis and the optimal concentrations and extraction methods for its clinical use warrant further investigation. Utilisation of standardised propolis extracts will help in quality control of propolis-based products and lead to the achievement of reproducible outcomes in research studies.

A laboratory study comparing the static navigation technique using a bur with a conventional freehand technique using ultrasonic tips for the removal of fibre posts.

AIM: There are currently no high-quality studies comparing the static navigation technique with conventional methods of fibre post removal. The aim of this ex vivo study was to compare the effectiveness of fibre post removal between a static navigation technique and a conventional freehand technique using ultrasonics by experienced and inexperienced operators. METHODOLOGY: Forty-eight extracted single-rooted human premolars were root-filled. A fibre post was cemented in all 48 teeth, which were then divided randomly into the following groups: static navigation group using burs; static navigation-ultrasonic group; and non-guided group using ultrasonic tips. The following parameters were evaluated for both experienced operators and inexperienced operators: reaching the gutta-percha root filling successfully, the time required to remove the entire post, the occurrence of lateral root perforations, and the amount of root dentine removed. The Kolmogorov-Smirnov test was used to examine the normality of the data; the anova test was used to compare the significant differences among groups; and Tukey tests were used for all two-by-two comparisons. The significance level was set at 0.05. RESULTS: In the static navigation group, the gutta-percha was reached significantly more frequently than in the non-guided group (p < .05). The static navigation approach required significantly less time than the non-guided approach to reach the gutta-percha (p < .05). The total removal of posts was significantly different between groups (p < .05), but there was no significant difference between experienced and inexperienced operators in the static navigation group (p > .05). More perforations were associated with the non-guided group than with the other two groups. The total mean loss of dentine in the non-guided group in all directions was 0.39 (±0.17) mm, with 0.25 (±0.09) mm for experienced, and 0.42 (±0.16) mm for inexperienced operators. CONCLUSION: When compared to a conventional ultrasonic technique for the removal of fibre posts, the static navigation method using burs resulted in less dentine removal, more rapid access to the gutta-percha root filling, less overall time to remove the posts, and fewer complications. When using static navigation, there was no difference in performance between experienced and inexperienced operators.

Validity and reliability of artificial intelligence chatbots as public sources of information on endodontics.

AIM: This study aimed to evaluate and compare the validity and reliability of responses provided by GPT-3.5, Google Bard, and Bing to frequently asked questions (FAQs) in the field of endodontics. METHODOLOGY: FAQs were formulated by expert endodontists (n = 10) and collected through GPT-3.5 queries (n = 10), with every question posed to each chatbot three times. Responses (N = 180) were independently evaluated by two board-certified endodontists using a modified Global Quality Score (GQS) on a 5-point Likert scale (5: strongly agree; 4: agree; 3: neutral; 2: disagree; 1: strongly disagree). Disagreements on scoring were resolved through evidence-based discussions. The validity of responses was analysed by categorizing scores into valid or invalid at two thresholds: The low threshold was set at score ≥4 for all three responses whilst the high threshold was set at score 5 for all three responses. Fisher's exact test was conducted to compare the validity of responses between chatbots. Cronbach's alpha was calculated to assess the reliability by assessing the consistency of repeated responses for each chatbot. RESULTS: All three chatbots provided answers to all questions. Using the low-threshold validity test (GPT-3.5: 95%; Google Bard: 85%; Bing: 75%), there was no significant difference between the platforms (p > .05). When using the high-threshold validity test, the chatbot scores were substantially lower (GPT-3.5: 60%; Google Bard: 15%; Bing: 15%). The validity of GPT-3.5 responses was significantly higher than Google Bard and Bing (p = .008). All three chatbots achieved an acceptable level of reliability (Cronbach's alpha >0.7). CONCLUSIONS: GPT-3.5 provided more credible information on topics related to endodontics compared to Google Bard and Bing.

Performance of progressive and constant tapered instruments rotary systems at canal preparation / Desempenho de sistemas endodônticos rotatórios constante e progressivo no preparo do canal radicular

ABSTRACT Objective: The aim of this study was to compare the performance of two nickel-titanium rotary systems regarding the preparation time, final shape of canal, incidence of aberration, transportation, and fracture of instrument. Methods: A total of 40 simulated canals in resin blocks with 30o curves and a length of 17 mm were divided randomly into two groups: preparation with ProTaper and BioRaCe systems up to F5 and BR5 respectively. Pre- and post-operative canal images were taken and superimposed in order to identify aberrations, transportation, and to take measurements of the canal width. In addition, the preparation time and instrument fractures were recorded. The data were analyzed using Student's t test. Results: There is no difference (p>.05) comparing the systems regarding preparation time, canal aberration, and instrument fracture rates. The progressive tapered instruments of ProTaper prepared significantly larger canal widths in the apical third (p<.05). Conclusion: Overall, both systems provided safe canal preparation, associated with few canal aberrations and instrument fractures.

RESUMO Objetivo: Comparar o desempenho de dois sistemas rotatórios em relação ao tempo de preparo, formato final e alterações do canal, desvio e fratura de instrumento. Métodos: Um total de 40 canais simulados em blocos de resina com curvatura de 30o e comprimento de 17 mm foram divididos randomicamente nos sistemas ProTaper e BioRaCe preparados até F5 e BR5 respectivamente. Imagens pré e após o preparo dos canais foram obtidas e superpostas para identificação de alterações de forma, desvios e largura. O tempo de preparo e fratura de instrumentos também foram avaliados. Os dados foram analisados por teste t de Student. Resultados: O tempo de preparo, alterações de forma e taxa de fratura de instrumentos não teve diferença entre os dois sistemas avaliados (p>0,05). Os instrumentos progressivos do ProTaper resultou em canais significativamente mais largos no terço apical (p<0,05). Conclusão: Os dois sistemas rotatórios avaliados resultaram em preparo endodôntico seguro, com poucas alterações e fratura de instrumento.

Unusual Deviation of the Main Foramen from the Root Apex

Abstract The relationship of the main foramen to the anatomic root apex has been the subject of several studies. Although they are anatomically close, they rarely coincide, and their distance can vary according to age or tooth type, ranging from 0.2 to 3.0 mm. The aim of this short communication was to evaluate the distance between the main foramen of independent middle mesial canals (MMCs) and the anatomical mesial root apex of mandibular first molars using the micro-computed tomography. Twenty-five mandibular first molars with MMCs were scanned (resolution of 9.9 µm), and the distance from its main foramen to the anatomical apex was evaluated. Overall, the distance ranged from 0.2 to 2.4 mm; however, in 3 specimens the distance was greater than 3 mm. This report demonstrates that the exit of the main foramen of the MMC varies considerably and could approach a substantial distance from the anatomical apex greater than previously reported in the literature.

Resumo A relação do forame principal com o ápice anatômico da raiz tem sido objeto de vários estudos. Embora estejam anatomicamente próximos, eles raramente coincidem, e a sua distância pode variar de acordo com a idade ou o tipo de dente, oscilando entre 0,2 e 3,0 mm. O objetivo deste artigo é relatar que a saída foraminal do canal mediano (MMC), presente na raiz mesial de molares inferiores, pode apresentar variações significativas, atingindo distâncias acima de 3 mm do ápice anatômico. Vinte e cinco primeiros molares inferiores com MMC foram escaneados (resolução de 9,9 mm) e a distância do forame principal ao ápice anatômico avaliada. Em geral, a distância mostrou variações consideráveis; no entanto, em 3 espécimes esta distância ficou acima de 3 mm. Este estudo teve como objetivo relatar que a saída do forame principal de canais medianos de primeiros molares inferiores pode apresentar variações consideráveis, podendo atingir distâncias maiores do que as relatadas previamente na literatura.