Influence of adhesive system on quartz fiber post dislocation resistance in endodontically treated teeth

Aim: To evaluate the dislocation resistance of the quartz fiber post/cement/dentin interface after different adhesion strategies. Methods: Forty bovine lower central incisors were selected and prepared with K-files using the step-back technique, and irrigated with 3 mL of distilled water preceding the use of each instrument. Prepared teeth were stored at 37ºC and 100% humidity for 7 days. The roots were prepared and randomized into 4 groups. The quartz fiber post was cemented with an adhesion strategy according to the following groups: GBisCem- BISCEM; GOneStep±C&B- One Step ± C&B; GAllBond±C&B- AllBond3 ± C&B; GAllBondSE±C&B- AllBondSE ±C&B with a quartz fiber post. Cross-sectional root slices of 0.7 mm were produced and stored for 24 h at 37° C before being submitted to push-out bond strength. Results: The mean and standard deviation values of dislocation resistance were GBisCem: 1.12 (± 0.23) MPa, GOneStep±C&B: 0.81 (± 0.31) MPa, GAllBond±C&B: 0.98 (± 0.14) MPa, and GAllBondSE±C&B: 1.57 (± 0.04) MPa. GAllBondSE±C&B showed significantly higher values of dislocation resistance than the other groups. Conclusions: Based on this study design, it may be concluded that adhesion strategies showed different results of quartz post dislocation resistance. Simplified adhesive system with sodium benzene sulphinate incorporation provided superior dislocation resistance.

Evaluation of Educational Environment for Medical Students of a Tertiary Pediatric Hospital in Tehran, Using DREEM Questionnaire

Background: Tertiary pediatric hospitals usually provide excellent clinical services, but such centers have a lot to do for educational perfection. Objectives: This study was performed to address under-graduate educational deficits and find feasible solutions. Patients and Methods: This cross-sectional study was done in a target population of 77 sixth year undergraduate medical students (response rate = 78%) who spent their 3-month pediatric rotation in the Children’s Medical Center, the Pediatrics Center of Excellence in Tehran, Iran. The Dundee ready educational environment measure (DREEM) instrument was used for assessing educational environment of this subspecialized pediatric hospital. Results: Among 60 students who answered the questionnaires, 24 were male (40%). Participants’ age ranged from 23 to 24 years. The mean total score was 95.8 (48%). Comparison of scores based on students’ knowledge showed no significant difference. Problematic areas were learning, academic self-perception, and social self-perception. Conclusions: Having an accurate schedule to train general practitioner, using new teaching methods, and providing a non-stressful atmosphere were suggested solutions.