Rahaf A. Almohareb

Background and Objectives. The aim of this study is to explore the current state of endodontic practical training in Saudi dental schools and its relevance to contemporary endodontic practice. Materials and Methods. An online questionnaire was developed and emailed to all dental schools in Saudi Arabia. This questionnaire was answered by the endodontic undergraduate program director. The data collected were analysed using descriptive statistics. Results. The response rate was 96.15%, which means twenty-five out of twenty-six dental schools participated in the study. The majority of the academic supervisors was endodontists (92%). The use of magnification and ultrasonic tips was not required by 84% and 76% of the dental schools, respectively. The main endodontic treatment techniques were the step-back technique and gates glidden for cleaning and shaping (76%) and cold lateral compaction for obturation (92%). Conclusions. The dental students were supervised by endodontic specialists and trained to use traditional endodontic methods. Encouraging dental educators to train students to use modern technology and equipment would probably improve their graduate clinical skills and performance.

This study is aimed at evaluating the use of microcomputed tomography (micro-CT) analysis and the dentinal microcrack formation following retreatment of bioceramic sealer employing adjunct laser-activated irrigation and ultrasonic-activated irrigation. Thirty sound human single-canal teeth ( n = 30 ) obturated using the single-cone technique with bioceramic sealer were retreated using nickel-titanium (NiTi) rotary files. The sample was randomly divided into three equal groups: group 1, the control group, was not subjected to further treatment; group 2 underwent ultrasonic activation of irrigants; group 3 underwent active irrigation with a diode laser (980 nm wavelength). Using micro-CT, the teeth were scanned before and after retreatment protocols. Two calibrated experienced observers viewed the cross-sectional images and calculated the number of dentinal defects. The presence of any crack or craze line on the external root surface or internal canal wall was counted. Data were analyzed using Friedman’s two-way analysis of variance and Fisher’s exact test. Statistical significance was set at p < 0.05 . A significant increase occurred in the number of cracks post retreatment protocols, specifically in the coronal and middle canal thirds, compared to pre- and postinstrumentation ( p = 0.0001 ). However, ultrasonic- or laser-activated irrigation did not result in a significant increase in the number of cracks ( p = 0.345 ). NiTi rotary root canal retreatment was associated with a significant increase in dentinal microcracks. However, employing ultrasonic- or laser-activated irrigation as adjunct retreatment techniques did not reveal a significant increase in dentinal microcracks within the roots.

In this study, we evaluate the surface roughness (SR) of three thermally treated nickel-titanium rotary instruments (i.e., TruNatomy [TN], ProTaper Gold [PTG], and EdgeTaper Platinum [ETP]) after impact testing with multiple autoclave sterilization cycles using scanning electron microscopy (SEM). Overall, 60 thermally treated files were sourced (i.e., 20 TN, 20 ETP, and 20 PTG files), and each group was divided into four equal subgroups of five files (n = 5). An unsterilized group was assigned as the pre-autoclaving group (Cycle 0), and the other three groups underwent various autoclave sterilization cycles (Cycles 1, 5, and 10). The roughness average (Ra), root mean square (Rq), and average maximum peak-to-valley height (Rz) values were evaluated using SEM and ImageJ software. The Shapiro–Wilk test, one-way analysis of variance, and post-hoc Tukey test were used to analyze the data. The statistical significance level was set at p < 0.05 . Before autoclaving, all instruments showed debris and SR but with no statistically significant differences existing between the groups. SR values decreased after one autoclaving cycle for all instruments. After five autoclave cycles, the Rz value of ETP was statistically higher compared with PTG and TN. After 10 autoclave cycles, the Ra and Rq values of TN were statistically higher compared with ETP and PTG. These results suggest that multiple autoclaving sterilization cycles influence the SR of TN, PTG, and ETP, with ETP showing higher levels of surface irregularities than PTG and TN.