Effects of Clinical Training and Case Difficulty on the Radiographic Quality of Root Canal Fillings Performed by Dental Students in Saudi Arabia

Introduction: The aim of this study was to evaluate the effects of training duration and case difficulty on the radiographic quality of root canal fillings performed by dental students in Saudi Arabia. Methods and Materials: A longitudinal cohort study was conducted at King Saud University. Root canal treatments performed by 55 dental students from 2012-2014 were included in the study. Each student treated at least five teeth during the first year of clinical endodontic training and another five teeth during the second year. Case difficulty was assessed based on tooth position in the dental arch and preoperative conditions. The radiographic quality of the root canal filling was evaluated by two endodontists blinded to treatment completion date. The evaluation criteria were adequate obturation, presence of mishaps and preparation taper. The data were statistically analysed using univariate and multivariate logistic regression analyses; and the level of significance was set at 0.05. Results: Inadequate obturation and mishaps were significantly less prevalent in teeth treated after 2 years of clinical training. The odds ratios for inadequate obturation and mishaps increased significantly as tooth position moved posteriorly. Inadequate obturation and more mishaps were significantly more prevalent in teeth with preoperative conditions. Preparation taper was not significantly affected by training duration or case difficulty. Conclusion: The quality of root canal fillings performed by Saudi students was adversely affected by case difficulty. The radiographic quality of root canal fillings improved significantly after 2 years of clinical training. Preparation taper outcome is likely dependent on the preparation technique and instrument taper.Keywords: Obturation Density; Obturation Length; Preparation Taper; Procedural Accident; Root Canal Treatmen

Dentinal Microcrack Formation after Root Canal Instrumentation by XP-Endo Shaper and ProTaper Universal: A Microcomputed Tomography Evaluation

Aim. To evaluate dentinal microcrack formation on root canals instrumented, continuously in the body temperature, with XP-endo shaper (XPES) and ProTaper Universal (PTU), by means of microcomputed tomographic (micro-CT) analysis. Methodology. Nineteen mesial roots with two separate canals (Vertucci Type IV) of extracted mandibular molars were used in this study. The root canals (N = 38) were divided into 2 groups. Group 1 (n = 19): all MB canals were instrumented with XPES. Group 2 (n = 19): all ML canals were instrumented with PTU. All roots were scanned with micro-CT before and after instrumentation. Two precalibrated examiners evaluated the cross-sectional images of each sample with DataViewer program. The dentinal microcracks (complete and incomplete) were counted in each third of the root for the preinstrumentation and the postinstrumentation images. Wilcoxin signed-rank and Mann–Whitney U tests were used for statistical analysis at a significance level of P<0.05. Results. The number of microcracks increased significantly (P<0.05) after instrumentation with XPES in the middle and cervical thirds. The number of microcracks increased significantly (P<0.05) after instrumentation with PTU in the cervical third only. There was no significant difference between the groups in the cervical and apical thirds. In the middle third, the XPES induced more incomplete microcracks than PTU (P<0.05). Conclusion. Within the limitations of this study, there was no significant difference in the dentinal microcrack formation between XPES and PTU in the apical and cervical thirds of the root. However, XPES instrumentation induced more incomplete microcracks than PTU in the middle third of human roots

Effectiveness of PBL methodology in a hybrid dentistry program to enhance students’ knowledge and confidence. (a pilot study)

Abstract Background Knowledge and self-confidence are two critical determinants of future success of dental students. The present pilot study was conducted with an objective to simultaneously assess both knowledge and confidence gained by dental undergraduate students in the Head and Neck Anatomy course by employing didactic lecture-based and problem-based learning methods. Methods A paper-based assessment tool comprising of 30 Multiple choice questions to assess knowledge, followed by a Likert’s scale to assess students’ confidence to answer the given knowledge question was designed. This tool was used in a cohort of first year dental students before the commencement of Head and Neck Anatomy course (Pre-course), immediately after the completion of Head and Neck Anatomy course (Post-course), and again in third year before the same cohort entered their clinical courses (Pre-clinics). The difference in students’ knowledge and confidence through both pedagogies was evaluated by Paired ‘t’ test. Pearson correlation analysis was done to determine the correlation between knowledge scores and self-reported confidence. Results A statistically significant increase (p < 0.05) was noted in the mean knowledge and confidence scores in the post-course evaluation, through both didactic lecture-based and problem-based learning methods. On the other hand, a significant decrease (p < 0.05) in the mean knowledge and confidence scores of didactic lecture-based items in comparison to problem-based items was noted in the pre-clinics evaluation.. The post-course evaluation results yielded a Pearson correlation coefficient of r = 0.514, p = 0.002 for lecture-based items and r = 0.495, p = 0.003 for problem-based items, denoting a positive moderate correlation between the knowledge and confidence scores for both lecture-based and problem-based methods. Conclusion A significant improvement in both knowledge and self-reported confidence demonstrated at the end of Head and Neck Anatomy course proves both didactic lectures and problem-based learning methods to be equally effective in a hybrid dentistry program in the short term. However, the non-significant reduction in the pre-clinics knowledge and confidence scores among the PBL lessons proves it to be a potent learning tool for long term retention of knowledge, and sustainability of confidence

Regenerative Healing of Chitosan Scaffold Impregnated with Simvastatin in Repairing Furcal Perforation

This study aimed to evaluate the healing of furcation when repaired with Chitosan (CS) scaffold impregnated or not with Simvastatin (SIM) compared with CollaCote (CL) in goat premolar teeth. Root canal treatment was performed in 52 mandibular premolars followed by furcal perforation induction. The perforation was repaired with CL, CS, or CS with SIM after leaving it untreated for 4 weeks. White mineral trioxide aggregate was carried into the furcal site followed by a 2–3 mm resin-modified glass ionomer. The perforation was left untreated, and the access cavity was left open without coronal filling in the control group. The animals were sacrificed after one and three months. Block sections of the premolars were prepared and examined histologically to evaluate the inflammation and type of healing. Hard tissue formation was found in CL, CS, and CS/SIM groups in both periods. At one month, no significant differences were detected among the experimental groups, whereas at three months, CS without SIM showed significantly better performance compared to CL and CS/SIM groups (p = 0.040). Therefore, repairing furcal perforation with CS scaffolds shows desirable biological responses and healing characteristics in favor of bone regeneration at three months