Effects of Artificial Aging of Direct Resin Nano-Hybrid Composite on Mean Bond Strength Values for Veneer Ceramic Samples.

BACKGROUND This study investigates the effect of artificial aging of direct resin nanohybrid composites on mean bond strength values for veneer ceramic samples. MATERIAL AND METHODS Ninety direct nanohybrid composite resin (Tetric N-Ceram) cylindrical discs were divided into 5 groups (n=18 each) based on aging cycles (thermocycling), as follows: TC=no aging (control), T1=850, T3=2500, T6=5000, and T12=10000 cycles, representing 1, 3, 6, and 12 months of clinical usage, respectively. Lithium disilicate glass ceramic (IPS e.max Press) cylindrical discs were cemented to resin discs using resin cement (Variolink N) after surface treatments (ceramic etching, silaning, composite abrasion). Differences in means between subgroups were calculated using one-way ANOVA, followed by the Tukey honestly significant differences post hoc test. Differences were considered statistically significant with a P value ≤0.05. RESULTS The highest SBS between ceramic and aged composite was observed at 1 month (m=20.35) but did not differ significantly from the control group (m=20.97). For all other subgroups (3, 6, 12 months) SBS was significantly less than that of the control (P≤0.05). At 1 and 3 months, cohesive failures were more common, whereas adhesive failures were more common in 6- and 12-month-old composites. CONCLUSIONS SBS of aged composites was less than that of non-aged composites, with SBS decreasing proportionally as the resin aged. When cementing a ceramic restoration over existing composite restorations, those older than 1 month should be removed and replaced with new ones.

The Role of Applied Behavior Analysis to Improve Knowledge on Oral Hygiene Practices among Cooperative Autistic Children: A Cross-Sectional Study from Jazan, Saudi Arabia.

OBJECTIVE: To assess the effectiveness of Applied Behavior Analysis (ABA) to improve knowledge regarding oral hygiene practices among cooperative autistic children. MATERIALS AND METHODS: A cross-sectional study was conducted among 15 children between the age group of 6-12 years and their parents who were randomly chosen from a special care autistic school in Jazan, Saudi Arabia. A mobile application was custom designed and programmed with videos on oral hygiene. A close-ended questionnaire comprising 14 questions for the cooperative autistic children and 21 questions for their parents was designed to assess their knowledge in relation to oral health and hygiene. After four weeks, a questionnaire-based knowledge assessment was conducted. The mean knowledge score was then calculated for children and their parents and compared using paired sample t-test. RESULTS: Poor knowledge regarding oral hygiene practices was revealed among the study participants. The estimated mean score among the children was 4.73 before the intervention, which significantly increased to 9.0. The estimated mean score for the parents was 9.3 before intervention and 14.6 after four weeks' period (P < 0.0001). CONCLUSION: The application of ABA using avatars and delivered through videos can significantly improve knowledge regarding oral health hygiene among cooperative autistic children.