Objective: The aim of this study was to evaluate the influence of autoclave sterilization on the resistance to cyclic fatigue of two nickel-titanium (NiTi) endodontic files of identical design and taper, but with different NiTi alloy treatments: the newly introduced heat-treated Race Evo and the electropolished Race files. Materials and methods: Fifteen Race (25/0.06) files and fifteen Race Evo (25/0.06) files (n = 30 in total) were randomly assigned to five sub-groups each consisting of three files of the same NiTi alloy treatment. One group served as a control with files unautoclaved. The four remaining groups were sterilized in a steam sterilizer for 1, 3, 5, and 10 autoclave cycles, respectively. Files then underwent cyclic fatigue testing in a simulated metal canal block. A scanning electron microscope was used to inspect the surface of the fractured instruments. Statistical analysis was conducted using independent t-test and multi-factorial analysis of variance with significance set at a p value of ≤0.05. Results: Both Race Evo and Race files showed no significant difference between the different autoclaving cycles in terms of the number of cycles to fracture (p = 0.232 and p = 0.359). Despite rotating at a higher speed, the number of cycles to fracture of heat-treated Race Evo files was significantly higher than that of Race files (p ≤ 0.0001). Conclusion: Autoclave sterilization has no significant effect on the resistance to cyclic fatigue of heat-treated Race Evo or electropolished Race files. However, Race Evo files showed superior resistance to cyclic fatigue irrespective of autoclaving cycles.

Objectives. This study aimed to compare the effectiveness of super floss and water flosser in plaque removal for patients undergoing orthodontic treatment. Methods. A single-blind, randomized, controlled, parallel clinical trial with a split-mouth protocol was conducted on young adult orthodontic patients who were recruited from Riyadh Specialized Dental Center in Riyadh, Saudi Arabia. The type of floss used was randomly assigned to each side of the oral cavity; Super-Floss® (Oral-B) was used on one side, while the Waterpik® water flosser was used on the other. Patients’ plaque level was assessed using Rustogi et al. modified navy plaque index (RMNPI) at baseline and immediately after cleaning. Results. A total of 62 subjects were screened; however, only 34 subjects were enrolled in the study with an equal number of males and females. Overall, the plaque score was significantly reduced from 0.56 ± 0.35 to 0.13 ± 0.26 in the super floss group and from 0.61 ± 0.35 to 0.13 ± 0.28 in the water flosser group. There was no significant difference between the mean difference of super floss and water flosser ( p = 0.951 ). On the other hand, there was no significant difference between both groups in terms of the preintervention plaque score ( p = 0.379 ). The water flosser had a greater effect size on plaque removal compared to super floss on distal interproximal surface of the molar tooth with a mean difference of (−0.21, 95% CI: 00.37 to −0.04, p = 0.033 ). Conclusions. The use of super floss or water flosser as interproximal aids for plaque removal in patients undergoing orthodontic treatment are both effective. Trial registration. ISRCTN, ISRCTN83875016. Registered 12 September 2021-retrospectively registered, https://www.isrctn.com/ISRCTN83875016.

The aim was to identify the influence of conventional polymeric resin based cement (RC), hybrid polymer modified glass ionomer (RMGIC) and Zinc phosphate cement (ZPC) on the pull out strength of the customized zirconia post in premolars. Access cavity and root canals were performed in sixty premolar teeth with the standardized crown down technique (ProTaper Universal, Dentsply). Post space impressions were scanned, and the pre-sintered Zenostar Zr Translucent blanks (Weiland Dental, Pforzheim) were milled with the Opera-system to form the post. All prepared specimens were divided equally in three groups based on the cement type employed for luting as follows: group A: ZPC; group B (GC Fuji PLUS Capsule): RMGIC; group C (and RC (3M RelyX ARC). Ten specimens in each group were thermocycled (TC) at 5 and 55 °C in distilled water baths (40,000 cycles). Pull out bond strength was assessed using a universal testing machine at 0.5 mm/min. The means and standard deviations were compared using ANOVA and Tukey Kramer multiple comparisons tests. A significant difference among the cement groups as well as between TC and non-thermocycled (NTC) groups (p < 0.05) was observed. The highest tensile stress was demonstrated among group C (Resin, 69.89 ± 4.81 (NTC), 64.06 ± 4.36 (TC)) with the least in group A, (zinc phosphate, 43.66 ± 5.02 (NTC), 37.70 ± 5.10 (TC)) for both groups. Group A presented with 100% adhesive bond failures, followed by 80% in group C and 70% in group B, respectively. A similar outcome was observed in the TC group for the cement; however, unlike the NTC group, the TC group showed more cohesive failures compared to the NTC mixed failure. Dual cure polymer based cement demonstrated higher bond strength and efficient adhesive bonding of the customized Zr post with root dentine compared to zinc phosphate (non-polymeric) and RMGIC (hybrid polymer). Thermocycling compromised Zr post adhesive bonding to root dentin.