Assessment of dental students' knowledge and performance of master gutta-percha cone selection and fitting during root canal treatment: a pilot study.

BACKGROUND: Misconceptions should be detected early in dental students' training to improve their clinical performance. Accordingly, this study aimed to assess undergraduate dental students' knowledge and performance of master gutta-percha (GP) cone selection and fitting during clinical endodontic courses at the College of Dentistry, King Saud University. METHODS: Ninety-nine undergraduate dental students completed an online survey about their knowledge of master GP cone selection. Forty-five of these students were observed by faculty members in clinical endodontic courses while they fitted master GP cones during root canal treatments. The observers recorded the details of each student's cone-fitting techniques. The data were analysed using t-tests, one-way analysis of variance, and chi-square tests (p < 0.05). Inter- and intra-observer reliability were tested using Fliess' Kappa. RESULTS SURVEY: All participants had good knowledge of over-extended cone management, while 80.8% knew how to properly manage a short cone. The proper flaring assessment method was selected by 86.9% of the female and 34.2% of the male students, and this difference was statistically significant (p = 0.0001). OBSERVATION: The students labelled the working length on the master GP cone with an indentation in 64.4% of the cases and by bending the cone 35.6% of the time. Of all students, 84.4% encountered an apical stop, and this rate correlated significantly with the length of the cone on the master apical cone radiograph (p = 0.001). Improper shaping of the canal was the most common cause of ill-fitting cones (83.3%), while 16.7% of the students chose the wrong cone size. The final obturation length was adequate in 80% of the cases; 57.8% of the students were helped by instructors. CONCLUSIONS: Most students had the basic knowledge required to solve problems related to the selection of master GP cones. However, in the clinical setting, more than half of the students required the assistance of an instructor to adjust their cone's fit. The presence of an apical stop had the most significant effect on the length of the fitted master GP cone on radiography. The most common cause of ill-fitting master cones was improper shaping of the canal.

Prevalence of middle mesial canal using cone beam computed tomography: A systematic review and meta-analysis.

Background: The presence of middle mesial canals in mandibular molars are not commonly encountered in daily practice. However, locating and debriding such anatomical variation during the endodontic therapy is essential to avoid endodontic failure. The aim of this systematic review was to identify the overall prevalence of middle mesial canals (MMC) in mandibular molars using cone-beam computed tomography (CBCT), to assess the influence of different gender on the prevalence of MMCs in mandibular molars and to describe the MMC configurations. Methods: The review protocol was registered in the PROSPERO database (CRD42021238523). The main electronic databases were searched until February 2022 for prevalence studies on root/canal anatomy in mandibular molars using CBCT imaging, in addition to hand-searched scientific articles in peer-reviewed journals and grey literature. The quality of the included studies was assessed using the Joanna Briggs Institute Critical Appraisal tool. Egger's and Begg's tests and Pearson's chi-square test were used for statistical analysis. Results: From 523 records, 488 studies were excluded after screening the title and abstract. 35 relevant studies were included for full-text assessment and 28 studies were included in the meta-analysis. The overall prevalence of MMC out of the 19,256 teeth was 5.09% (95% CI: 2.894 to 7.784). The prevalence of MMC was 9.79% (95% CI: 4.296 to 17.224) in males and 13.96% (95% CI: 0.541 to 40.737) in females with a statistically significant difference of 4.16% (95% CI: 2.29 to 6.01). The most MMC configuration found in this review to be confluent with the mesiobuccal canal. Conclusion: The results showed an overall 5.09% prevalence of MMC in mandibular molars, with a significantly high prevalence in female subjects. Additionally, this canal was found to be confluent with the mesiobuccal canal.