Statistics
tooth
SECONDARY, PLAQUE
The sample size calculation was based on similar studies, on the variable “average plaque score in each quadrant”, using a standard deviation of 0.4 [Shapiro-Wilks test and normal quantile plot was used to analyze normality of continuous variables. Primary outcome variable satisfied the normality assumption. Mean plaque score in the two quadrants was compared by using a two-sided independent sample t-test. As for the secondary outcomes, Wilcoxon signed-rank test was used to compare the mean difference between test and control, since the normality assumption was not satisfied. For both mentioned tests, significance level was set to 5%.The inter- and intra-examiner agreement was evaluated by the use of Cohens Kappa statistics (k), using the tooth as the statistical unit.For statistical analyses, the statistical Package for STATA (Stata version 17.0; college Station, TX, USA) was used.