Unveiling the fatigue life of NiTi endodontic files: An integrated computational-experimental study.

Nickel-titanium (NiTi) rotary files used in root canal treatments experience fatigue and shear damage due to the complex curved geometries and operating conditions encountered within the root canal. This can lead to premature file fracture, causing severe complications. A comprehensive understanding of how different factors contribute to file damage is crucial for improving their functional life. This study investigates the combined effects of root canal curvature radius, file canal curvature, and rotational speed on the fatigue life and failure modes of NiTi endodontic files through an integrated computational and experimental approach. Advanced finite element simulations precisely replicating the dynamic motion of files inside curved canal geometries were conducted. Critical stress/strain values were extracted and incorporated into empirical fatigue models to predict the functional life of endodontic files. Extensive experiments with files rotated inside artificial curved canals at various canal curvatures and speeds provided validation. Increasing the canal curvature beyond 60∘ and shorter curvature radii below 5 mm dramatically reduced the functional life of the endodontic file, especially at rotational speeds over 360 rpm. The Coffin-Manson fatigue model based on strain amplitude showed the closest agreement with experiments. Shear stresses dominated damage at low canal curvatures, while the combined shear-fatigue loading effects were prominent at higher canal curvatures. This conclusive study elucidates how operational parameters like canal curvature radii, canal curvature, and rotational speed synergistically influence the fatigue damage processes in NiTi files. The findings offer valuable guidelines to optimize these factors, significantly extending the functional life of endodontic files and reducing the risk of intra-operative failures. The validated computational approach provides a powerful tool for virtual testing and estimation of the functional life of the new file designs before manufacturing.

Exploring Plant-Based Compounds as Alternatives for Targeting Enterococcus faecalis in Endodontic Therapy: A Molecular Docking Approach.

Endodontic infections pose significant challenges in dental practice due to their persistence and potential complications. Among the causative agents, Enterococcus faecalis stands out for its ability to form biofilms and develop resistance to conventional antibiotics, leading to treatment failures and recurrent infections. The urgent need for alternative treatments arises from the growing concern over antibiotic resistance and the limitations of current therapeutic options in combating E. faecalis-associated endodontic infections. Plant-based natural compounds offer a promising avenue for exploration, given their diverse bioactive properties and potential as sources of novel antimicrobial agents. In this study, molecular docking and dynamics simulations are employed to explore the interactions between SrtA, a key enzyme in E. faecalis, and plant-based natural compounds. Analysis of phytocompounds through molecular docking unveiled several candidates with binding energies surpassing that of the control drug, ampicillin, with pinocembrin emerging as the lead compound due to its strong interactions with key residues of SrtA. Comparative analysis with ampicillin underscored varying degrees of structural similarity among the study compounds. Molecular dynamics simulations provided deeper insights into the dynamic behavior and stability of protein-ligand complexes, with pinocembrin demonstrating minimal conformational changes and effective stabilization of the N-terminal region. Free energy landscape analysis supported pinocembrin's stabilizing effects, further corroborated by hydrogen bond analysis. Additionally, physicochemical properties analysis highlighted the drug-likeness of pinocembrin and glabridin. Overall, this study elucidates the potential anti-bacterial properties of selected phytocompounds against E. faecalis infections, with pinocembrin emerging as a promising lead compound for further drug development efforts, offering new avenues for combating bacterial infections and advancing therapeutic interventions in endodontic practice.

GIRFT and Measuring Outcomes in MCNs: endodontics in 646 teeth treated in Tier 2 (Primary Care) and Tier 3 (Secondary Care) settings in England.

AIM: This paper aims to assess the complexity, quality and outcome of endodontic treatment provided in Managed Clinical Networks (MCNs) in England to understand if we are "getting it right first time" (GIRFT). METHODS: In a convenient sample of endodontic treatments provided between May 2011 and April 2017, the complexity of teeth treated, the quality of treatment procedure, the radiographic appearance of root fillings, as well as clinical and radiographic healing were retrospectively assessed using records taken as part of treatment. Trained, calibrated examiners independently scored radiographs using previously published scoring systems. RESULTS: 646 teeth were followed up for 24.7 months (standard deviation [SD] 17.08). The average age of those patients treated was 46.7 years (SD 15.38) with 48.3% being male. Of teeth treated, 70.4% were of complexity level 3. 88.2% of teeth were asymptomatic, and 80% demonstrated complete radiographic healing. Procedural errors inhibited achieving correct working length and taper, with more voids within root canal fillings. When patency filing was reported as being carried out, complete radiographic healing was more likely. CONCLUSIONS: It is possible to collate outcome data in the NHS system, especially if there is provision for ongoing follow up and time allocated for collection of data. Endodontic treatment provided within primary and secondary care settings are of high quality, with outcomes being better with single operators carrying out high volumes of endodontic treatment.

Advancements in guided surgical endodontics: A scoping review of case report and case series and research implications.

This scoping review examined current case series and reports on guided surgical endodontic applications in order to provide a critical platform for future research. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews guidelines were followed. A search on PubMed and Scopus yielded 611 articles, with 17 case reports and 1 series meeting inclusion criteria. Overall, guided surgery addressed anatomical complexities, with 15 articles employing static protocols and 3 dynamic. Results showed minimal iatrogenic errors and reduced chair time, with no postoperative issues reported. Within the cases described, guided endodontic surgery exhibited satisfactory results in management of anatomical complex cases. Cost-effectiveness, the need for adequate follow-up, procedure's reproducibility and accuracy, and objective measurement of the reduction in operative times and iatrogenic errors are some of the limitations in the current reports that need to be considered for planning of future experimental and cohort studies.

Outcomes-Based Treatment Planning in Endodontics: Applying the Latest Evidence.

A comprehensive understanding of the factors that influence treatment outcomes is crucial in endodontic diagnosis and treatment planning. Having knowledge that takes into account dental and patient-related conditions when choosing procedures can help clinicians maximize the prognosis of natural teeth and reduce postoperative complications. That being said, the landscape of outcome studies in endodontics is continually evolving, presenting a challenge for many clinicians trying to stay current with the latest literature. This article reviews factors that influence the outcomes of the following endodontic therapies: primary root canal treatment, nonsurgical retreatment, and surgical retreatment. An emphasis is placed on the importance of considering preoperative and treatment-related factors as prognostic indicators before developing a treatment plan, with the ultimate goal of enhancing tooth durability and ensuring patient satisfaction.

Comparative analysis of diagnostic accuracy in endodontic assessments: dental students vs. artificial intelligence.

OBJECTIVES: This study evaluates the comparative diagnostic accuracy of dental students and artificial intelligence (AI), specifically a modified ChatGPT 4, in endodontic assessments related to pulpal and apical conditions. The findings are intended to offer insights into the potential role of AI in augmenting dental education. METHODS: Involving 109 dental students divided into junior (54) and senior (55) groups, the study compared their diagnostic accuracy against ChatGPT's across seven clinical scenarios. Juniors had the American Association of Endodontists (AEE) terminology assistance, while seniors relied on prior knowledge. Accuracy was measured against a gold standard by experienced endodontists, using statistical analysis including Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. RESULTS: ChatGPT achieved significantly higher accuracy (99.0 %) compared to seniors (79.7 %) and juniors (77.0 %). Median accuracy was 100.0 % for ChatGPT, 85.7 % for seniors, and 82.1 % for juniors. Statistical tests indicated significant differences between ChatGPT and both student groups (p<0.001), with no notable difference between the student cohorts. CONCLUSIONS: The study reveals AI's capability to outperform dental students in diagnostic accuracy regarding endodontic assessments. This underscores AIs potential as a reference tool that students could utilize to enhance their understanding and diagnostic skills. Nevertheless, the potential for overreliance on AI, which may affect the development of critical analytical and decision-making abilities, necessitates a balanced integration of AI with human expertise and clinical judgement in dental education. Future research is essential to navigate the ethical and legal frameworks for incorporating AI tools such as ChatGPT into dental education and clinical practices effectively.

Access to Care Considerations for the Endodontic Treatment of Immature Permanent Teeth: A National Survey of Pediatric Dentists and Endodontists.

INTRODUCTION: This study aimed to investigate access to care and financial considerations associated with the endodontic treatment of immature permanent teeth. METHODS: Surveys were distributed to endodontists (n = 2,457) and pediatric dentists (n = 3,974) in the United States. Data were analyzed using X2 analysis and logistic regression. The level of significance was set to 0.05. RESULTS: The response rate was 13% (n = 840). Respondent specialist groups were similar by age and years since specialty residency completion, but significantly different with regard to primary practice setting (eg private practice, Federally Qualified Health Center, hospital), (P = .001). The majority (91%) of respondents reported participation with dental insurance. Pediatric dentists (69%) were significantly more likely than endodontists (17%) to participate with public-payer dental insurance (P < .001). The majority of respondents (82%) indicated that patients reported economic factors (time or money) as a barrier to accessing endodontic treatment. Pediatric dentists were significantly more likely to consider economic factors when planning for treatment (P < .001). Pediatric dentists were more likely than endodontists to have the opinion that endodontic procedures for treatment of necrotic immature permanent teeth should cost less than root canal therapy (apexification, P < .001; regenerative endodontic procedures, P = .002). Pediatric dentists (33%) reported encountering barriers when attempting to refer their patients to an endodontist. Inability to find an endodontist that participates with dental insurance was the most frequently cited barrier. CONCLUSIONS: Limited clinician participation with dental insurance and gaps in insurance coverage for endodontic procedures appear to contribute to access to care barriers for pediatric patients.

Microrobotics in endodontics: A perspective.

Microorganisms are the primary aetiological factor of apical periodontitis. The goal of endodontic treatment is to prevent and eliminate the infection by removing the microorganisms. However, microbial biofilms and the complex root canal anatomy impair the disinfection process. Effective and precise endodontic therapy could potentially be achieved using advanced multifunctional technologies that have the ability to access hard-to-reach surfaces and perform simultaneous biofilm killing, removal, and detection of microorganisms. Advances in microrobotics are providing novel therapeutic and diagnostic opportunities with high precision and efficacy to address current biofilm-related challenges in biomedicine. Concurrently, multifunctional magnetic microrobots have been developed to overcome the disinfection challenges of current approaches to disrupt, kill, and retrieve biofilms with the goal of enhancing the efficacy and precision of endodontic therapy. This article reviews the recent advances of microrobotics in healthcare and particularly advances to overcome disinfection challenges in endodontics, and provides perspectives for future research in the field.

[Need for dentists with post-graduate training in endodontology according to members of the Swiss Dental Association].

This questionary-based study was financed by the Swiss Society for Endodontology (SSE). At the time of this survey (2022) there were merely 20 board-certified endodontists in Switzerland, and 239 other members of the SSE, i.e. general practitioners with some form of post-graduate endodontic training or a keen interest in the field. The aim of this investigation was to evaluate the need for a higher number of trained endodontists as viewed by the general population of dentists in Switzerland. An electronic questionary in either German, French, or Italian was sent to all 4072 active members of the Swiss Dental Association (SSO). The questionnaire focused on the background of the surveyed dentists, their willingness to refer endodontic cases to a specialist or colleague with a focus on endodontics, their propensity to do so, and their perceived need for endodontists in their region. The response rate was 21%, and was similar between the different regions and cantons. Seventy-nine (9%) of the dentists participating in the survey were members of the SSE, while 16 (2%) were board-certified. Merely 7% of the participants received endodontic referrals themselves, while 81% referred cases in some instances. However, only 13% of participants referred endodontic cases always or regularly. The main reason for not referring was the belief by the surveyed dentists that they could perform the endodontic treatments themselves. Long distance to the next endodontic specialist or expert was the second most frequently given reason not to refer cases. A total of 58% of the participants believed that there were enough endodontists in Switzerland to cover the encountered clinical problems.

[A survey on the application of online and offline blended teaching in microendodontics].

Objective: To evaluate the effect of online and offline blended teaching in microendodontics, attempting to promote the widespread application of blended teaching mode in Operative Dentistry and Endodontics. Methods: A questionnaire survey was carried out among 865 trainees who attended the blended teaching in microendodontics combined the online theory curriculum and offline practice training from April 6 to 28 in 2022, organized by Department of Operative Dentistry and Endodontics, Hospital of Stomatotogy, Sun Yat-sen University. The content of questionnaire included trainees' basic information as well as their perspectives and expectations on the teaching mode. Data was analyzed by SPSS 24.0 and Chi-square test was used for enumeration data. Results: A total of 855 trainees participated in the valid survey with the effective recall rate of 98.8% (855/865), 50.3% (430/855) of which were young people in 18-30 years old. Their working period ranged from 0.5 to 40 years. Physicians and physician assistants occupied 40.9% (350/855) and 32.9% (281/855), respectively. And the intermediate and senior titles accounted for 26.2% (224/855). The proportion of trainees who had used and never used dental operative microscope (DOM) were 70.5% (603/855) and 29.5% (252/855), respectively. The blended teaching in microendodontics was universally approved by the trainees, which showed more superiority in the improvement of learning efficiency and interest, comprehension of knowledge as well as practical ability, etc., compared to the traditional offline teaching. For the current stomatology education, trainees were inclined to choose the blended teaching mode combining online theory curriculum and offline practice training, whereas 41.3% (353/855) and 39.6% (339/855) of trainees agreed that the teaching effectiveness was likely influenced by the condition and frequency of the offline training, respectively. Besides, significant differences were detected in the question about the factors affecting the blended teaching effectiveness of microendodontics between the trainees who had used and not used DOM (χ²=13.37, P=0.004). Conclusions: The application of online and offline blended teaching in microendodontics was affirmed to have some advantages, and it should be considered that the discrepancy in the level of expertise among trainees probably influenced the teaching effectiveness, which may promote the quality and effect of teaching, the spread and sharing of microendodontics, and provide experience and reference for the practice teaching of Operative Dentistry and Endodontics.

The extended finite element method in endodontics: A scoping review and future directions for cyclic fatigue testing of nickel-titanium instruments.

OBJECTIVES: The present study reviews the current literature regarding the utilization of the extended finite element method (XFEM) in clinical and experimental endodontic studies and the suitability of XFEM in the assessment of cyclic fatigue in rotary endodontic nickel-titanium (NiTi) instruments. MATERIAL AND METHODS: An electronic literature search was conducted using the appropriate search terms, and the titles and abstracts were screened for relevance. The search yielded 13 hits after duplicates were removed, and four studies met the inclusion criteria for review. RESULTS: No studies to date have utilized XFEM to study cyclic fatigue or crack propagation in rotary endodontic NiTi instruments. Challenges such as modelling material inputs and fatigue criteria could explain the lack of utilization of XFEM in the analysis of mechanical behavior in NiTi instruments. CONCLUSIONS: The review showed that XFEM was seldom employed in endodontic literature. Recent work suggests potential promise in using XFEM for modelling NiTi structures.

Effect of different instrumentation techniques on students' performance and outcomes of nonsurgical root canal treatment.

OBJECTIVES: This study compared, retrospectively, the incidence of clinical errors and effects on treatment outcomes, when students were exposed to two different instrumentation techniques: a hybrid rotary technique (HYB), consisting of both hand instrumentation with hand stainless steel and Ni-Ti files plus the use of a rotary system (Vortex Blue, Dentsply Sirona), versus a full reciprocation instrumentation technique (WaveOne Gold [WOG], Dentsply Sirona). METHODS: A total of 368 endodontic cases (n = 184) in anterior and premolar teeth, completed by dental students at the University of Michigan School of Dentistry from 2013 to 2022, were used for the study. The groups were evaluated by two calibrated clinicians, observing the incidence of clinical errors: file separations, over-instrumentation, ledges and transportations. Treatment outcomes were also observed. Data were analyzed statistically by Fisher's exact test and Mann-Whitney U test (p < 0.05). RESULTS: No significant difference in file separations, ledges, and transportation was observed between the two groups. However, the WOG Group experienced significantly more over-instrumentation than HYB group, although this did not significantly affect tooth survival or periapical index (PAI). Cases with PAI scores of 5 were found to have significantly less tooth survival compared to the other PAI scores. CONCLUSIONS: It can be concluded that both techniques in our study are well suited to advancing the endodontic dental education of students and novice operators, anticipating relatively successful outcomes of tooth survival, as long as the cases selected are less severe in progression preoperatively.

Cementoblastoma Mimicking Pathology of Endodontic Origin: A Case Report.

Interdisciplinary care in the management of complex pathology is critical to ensure patients receive predictable, evidence-based treatment. The authors report the unique case of a healthy 38-year-old female patient who presented to a private endodontics practice with a radiopaque lesion associated with the root of tooth No. 20. The patient experienced mild and occasional palpation tenderness associated with the tooth. Extraoral examination and intraoral soft tissues presented without any abnormalities. Intraoral radiographs revealed a radiopacity overlying the apex of tooth No. 20. A cone-beam computed tomography scan of the region revealed a well-delineated bulbous radiopaque lesion attached to the lingual aspect of the apical third of the root of tooth No. 20. The lesion could not be distinguished from the root outline and presented with a radiolucent halo along its periphery. The differential diagnosis at the time consisted of cementoblastoma, condensing osteitis, hypercementosis, and periapical cemento-osseous dysplasia. The patient was referred to an oral and maxillofacial surgeon for evaluation and treatment. Tooth No. 20 was subsequently treated with an excisional biopsy and concurrent extraction of the tooth. Histologic examination of the lesion supported the diagnosis of cementoblastoma.