Assessment of the effect of spacer material on gap and void formation in an endodontic temporary restoration using micro-computed tomography.

This study aimed to evaluate the effect of two spacer materials (cotton pellet and polytetrafluoroethylene [PTFE]) on gap and void formation in the Cavit restoration used for endodontic temporization. Thirty-four extracted human single-rooted premolars were matched and allocated into two groups (n = 17/group) according to the access cavity spacer (cotton pellet or PTFE). Standardized endodontic access cavities were prepared in all the teeth. Subsequently, the teeth were scanned by micro-computed tomography (micro-CT) to determine the volume of the access cavities. The teeth were then temporized by placing either cotton pellet or PTFE as spacer materials on the canal orifices, followed by the Cavit restoration. Following the temporization procedure, the teeth were subjected to a second micro-CT scan to determine the percentage volume of gaps and voids along the margins and within the Cavit restoration, respectively. Statistical analysis was performed using the Shapiro-Wilk and Wilcoxon signed-rank tests with a 5% significance level. The PTFE spacer was associated with significantly less gap formation between the Cavit restoration and the access cavity walls (P < 0.05) compared with the cotton pellet. No difference existed in void formation between the groups (P > 0.05). These findings indicate that the spacer material placed under the Cavit restoration can influence the quality of overlying restoration. PTFE was associated with less gap formation and, therefore, performed better than the cotton pellet as a spacer material beneath the Cavit restoration during endodontic treatment.

Undergraduate Endodontic Training and Its Relation to Contemporary Practice: Multicenter Cross-Sectional Study in Saudi Arabia.

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.

Cyclic fatigue resistance of EdgeTaper Platinum, Protaper Gold, and TruNatomy Prime rotary files before and after autoclave sterilization.

Background: This in vitro investigation aimed to determine the influence of multiple autoclave cycles on the cyclic fatigue resistance of three heat-treated nickel-titanium (NiTi) files: EdgeTaper Platinum (ETP), ProTaper Gold (PTG), and TruNatomy Prime (TN). Materials: Sixty NiTi files, twenty of each NiTi file type: ETP 25/.06, PTG 25/.08, and TN 26/.04 were randomly divided into four equal subgroups (n = 5). The files for the control group were left un-autoclaved. Different autoclave sterilization cycles (one, five, and ten) were used for the other three groups. The files were then placed in a metal canal block and rotated according to the manufacturer's instructions until fracture. The length of the broken segment and the time taken for fracture were measured. The fractured surfaces were subsequently subjected to SEM imaging. The Kruskal-Wallis test was used to analyze the data, followed by Dunn-Bonferroni pairwise comparisons. Statistical significance was set at p < 0.05. Results: ETP showed significantly greater resistance to cyclic fatigue than TN in all autoclave groups and PTG after five autoclave cycles (p = 0.014). Fatigue resistance was not affected by the number of autoclaving cycles, except for ETP. After the first and tenth autoclaving cycles, they required significantly more rotations to failure than the non-sterilized files (p = 0.039 and p = 0.021, respectively). The fractured segments of the ETP files in these two groups were also longer than those in the control group (p = 0.010). Conclusion: The cyclic fatigue resistance of ETP was greater than that of TN in all tested conditions. Repeated autoclave cycles of sterilization improved the cyclic fatigue resistance of the ETP files only and did not affect the cyclic fatigue resistance of TN and PTG. However, the ETP files separated at a longer distance from the tip with increased autoclaving cycles.

Assessment of dens invaginatus and its characteristics in maxillary anterior teeth using cone-beam computed tomography.

This cone-beam computed tomographic (CBCT) study aimed to evaluate the prevalence of dens invaginatus (DI) and its characteristics in maxillary anterior teeth in a Saudi population. A total of 505 CBCT scans were evaluated, including a total of 2790 maxillary anterior teeth. The patients' demographic data, including age and sex, were recorded. The presence of DI and the related characteristics including bilateral occurrence; DI type according to Oehlers classification; and presence of periapical radiolucency, open apex, and/or nearby impacted teeth were analyzed. The associations between DI and the other factors were analyzed using the chi-square and fisher exact tests. DI was detected in 7.3% of the patients and 1.6% of the teeth examined. Most of the DI-affected teeth were maxillary lateral incisors (76.1%), followed by mesiodens (19.6%) and maxillary central incisors (4.3%), while no DI was observed in the maxillary canines. Bilateral DI was found in 24.3% of the affected patients. Oehlers type I DI was the most frequent (80%). Periapical radiolucencies, open apices, and nearby impacted teeth were observed in 10.9%, 4.3%, and 30% of the invaginated teeth, respectively. DI was significantly associated with tooth type (P < 0.0001) but not with sex (P > 0.05). Although most of the DI cases are limited to the crown, CBCT imaging is essential for DI evaluation and management.

Ex vivo microbial leakage analysis of polytetrafluoroethylene tape and cotton pellet as endodontic access cavity spacers.

BACKGROUND: The endodontic spacers are placed between the endodontic appointments or after completion of the endodontic therapy, and until the placement of a definitive restoration. AIMS: The aim of this study was to evaluate the sealing ability of polytetrafluoroethylene (PTFE) access spacer against microbial leakage and to compare it with that of a cotton pellet. MATERIALS AND METHODS: Fifty-two extracted human single-rooted premolars were divided into two experimental groups (n = 20) according to the endodontic spacer; cotton pellet or PTFE tape, and two control groups (n = 6). Following standardized access cavity, cleaning, and shaping procedures, the access cavities received a standardized thickness of the spacer material followed by a Cavit restoration in all the teeth except for the positive controls, which were left empty. Negative controls had the root surfaces completely sealed with nail polish. A dual-chamber microbial leakage model was used with Enterococcus faecalis as the test strain. At days 7 and 30, samples of the lower chambers' solution were obtained and subjected to the quantitative real-time polymerase chain reaction (qPCR) analysis to quantify bacterial levels. Furthermore, broth turbidity in the lower chambers was recorded weekly. The Mann-Whitney U test and Wilcoxon test were used to compare E. faecalis counts between and within groups, respectively. RESULTS: At days 7 and 14, the experimental groups leaked similarly as determined by broth turbidity. However, at days 21 and 30, a significantly higher number of cotton pellet samples exhibited microbial leakage. Analysis by qPCR revealed higher levels of E. faecalis counts in cotton pellet samples compared with PTFE samples. This difference was statistically significant at day 7, but not at day 30. CONCLUSIONS: PTFE spacer showed improved sealing ability compared with the commonly used cotton pellet and may serve as an alternative endodontic access cavity spacer.