Sample size and statistical analysis
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Sample size was calculated using G*Power 3.1 (University Düsseldorf). Since the study is an explorative study, the total sample size was calculated with an effect size of 0.4, an α error of 0.1 and a power of 0.9. for a comparison of the cfu before and after rinsing (5 groups). A total sample size of 85 was calculated to give an actual power of 0.9.For comparison of the bacterial load before and after rinsing with Ocentidol® md, Granudacyn® or the placebo (Ringer solution), statistical evaluation was carried out using GraphPad Prism 4.00 using a one-way ANOVA with Dunn’s multiple comparison test. For comparison of effects between the different rinses at similar time points, one-way ANOVA with Tukey’s multiple comparison test was used.