Impact of Contracted Endodontic Access Cavities on the Fracture Resistance of Endodontically Treated Teeth After Mechanical Aging by Simulated Chewing Forces.

INTRODUCTION: This in vitro study aimed to comparatively evaluate the fracture resistance of contracted endodontic cavities (CECs) versus traditional endodontic cavities (TECs) in mandibular molars after subjecting the samples to a chewing simulator. METHODS: A total of 24 freshly extracted human mandibular molars were included in the study. Teeth with intact crowns and mature root apices that were devoid of caries, attrition, restorations, and cracks were selected and randomly assigned to 3 groups (n = 8) as follows: Group 1: TECs, Group 2: CECs, and Group 3: intact teeth (control group). After endodontic treatment, the teeth were restored with EverX bulk-fill composite and layered occlusally with nanohybrid composite SolareX and subjected to a chewing simulator where 240,000 masticatory cycles were simulated, which translates to 1 year of clinical function. The teeth were then subjected to static loading in a universal testing machine and the maximum load to fracture and the pattern of failure (restorable/unrestorable) were recorded. Data were evaluated with analysis of variance and the Tukey post hoc test for multiple comparisons. RESULTS: The CEC group had higher fracture resistance when compared with the TEC group; however, the difference was not statistically significant. The fracture resistance of the samples in the control group was statistically higher than those in the experimental groups (P < .005). CONCLUSIONS: There was no difference observed in the fracture resistance of mandibular molars with TECs and CECs subjected to masticatory loading.

Comparative evaluation of the antimicrobial efficacy of nanoparticle-mediated photodynamic therapy versus photodynamic therapy and conventional disinfection in endodontics: A systematic review and meta-analysis.

Introduction: The aim of this systematic review was to assess the antimicrobial activity of nanoparticle-mediated photodynamic therapy (N-PDT) on Enterococcus faecalis biofilms in the presence of dentin substrate when compared to photodynamic therapy (PDT) and conventional disinfection protocols. Materials and Methods: This systematic review was registered in Open Science Framework (10.17605/OSF.IO/GBR3F). Six databases, namely PubMed, Embase, Web of Science, Scopus, Medline, and Google Scholar, were searched for English language articles until June 2022. Laboratory studies assessing the antimicrobial activity of N-PDT against E. faecalis biofilm in human or bovine teeth were included. The risk of bias (RoB) was evaluated using the Joanna Briggs Institute tool for quasi-experimental studies. Meta-analysis was performed using the random-effects maximum likelihood model. Results: The search revealed 2804 articles, out of which 9 studies were included in the final review. Seven articles had low RoB and two had moderate RoB. Chitosan and diode laser at 810 nm were the most commonly used nanoparticle and light source, respectively. The meta-analysis of bacterial reduction log and percentage reduction revealed that N-PDT had better antimicrobial efficacy than the control group. When the bacterial reduction log of N-PDT was compared with PDT, PDT performed better N-PDT, and for percentage reduction, there was no difference. Conclusion: The currently available evidence is low and inconclusive with regard to the superior efficacy of N-PDT. The type of nanoparticle, incubation time, light source, and exposure time were found to be covariates that influence the antimicrobial efficacy of N-PDT.

Dynamic Navigation in Guided Endodontics - A Systematic Review.

OBJECTIVE: The objective of this systematic review was to comprehensively assess the literature regarding the applications, accuracy, advantages and limitations of dynamic navigation in endodontics. METHODS: Case reports and laboratory studies in the English language, which used the Dynamic Navigation System (DNS) for endodontic application and assessed the accuracy of treatment, the time required for treatment and iatrogenic errors were included. PubMed, Scopus, Embase and Web of Science were searched for eligible articles (up to July 2021). Additional hand searching of four peer-reviewed endodontic journals and a grey literature search were also carried out. A risk of bias assessment was done using the Joanna Briggs Institute (JBI) critical appraisal checklists. Data were extracted based on endodontic application of DNS, tooth type, DNS brand, accuracy, iatrogenic errors, and time taken, followed by qualitative analysis. RESULTS: Fourteen articles (three case reports and eleven in-vitro studies) met the eligibility criteria and were included. The quality assessment revealed a low risk of bias, with mean scores of 83.34% for case reports and 84.09% for in-vitro studies. DNS was used for various clinical applications such as access cavity preparation, pulp canal obliteration, endodontic retreatment and microsurgery. The DNS brands used were Navident, X-guide, ImplaNav, and DENACAM. Due to the nature of the component studies, meta-analysis was not possible. CONCLUSION: Challenging clinical situations like pulp canal obliteration, conservative access preparation, endodontic retreatment and microsurgery can be managed efficiently with fewer iatrogenic errors in a shorter time using DNS. However, this systematic review's evidence is low since the included articles are either case reports or in-vitro studies. Clinical studies are needed to test DNS efficacy among operators, including those who are less proficient and compare the accuracy of currently available systems.