Randomized Controlled Clinical Trial After power analysis calculation, cervical lesions will be pretreated with 10% DMSO/H2O (Dimethyl Sulfoxide/Water, OT Primer, OT Dent). Control groups will be bonded with SBU+ (Scotch Bond universal plus, 3M ESPE). Cavities will be restored with nanohybrid composite restoration (Z350 XT, 3M ESPE) under rubber dam isolation. Follow-ups will be performed by double-blinded evaluators at baseline and after 6m, 12m, 18m and 24m using the FDI criteria. Photographic documentation will be performed for all restorations.~Sample size calculation In a previous study response within each subject per group was normally distributed. If the true difference in the experimental and control means is 20%, the investigators will need to study 31 subjects per group (62 subjects) to be able to reject the null hypothesis that the population means of the experimental and control groups are equal with probability (power) 0.8. The sample size was increased by 15% to compensate for dropouts to reach a total of 74 (37 per group). The Type I error probability associated with this test of this null hypothesis is 0.05. The sample size had been calculated using the Z test (difference between two independent proportions).~Statistical Analyses After confirming the normality, Shapiro-Wilk test, and the homoscedasticity of the data, Barlett test, ANOVA will be used. Differences between groups were calculated using Tukey's post hoc test (α=0.05). Statistical analysis will be performed with IBM SPSS Statistical Package for the Social Sciences statistical Version 25 for Windows.
This study is conducted to assess the clinical effectiveness of 10% Dimethyl Sulfoxide application prior to universal dental adhesive on the durability of composite restoration.