Fig. 3. Comparison of residual toothpaste after using regular-sized and large-head toothbrushes. The used toothbrushes were cleaned by shaking them five times in 200 ml of distilled water and then air-dried at room temperature for 2 weeks. The amount of residual toothpaste was considered the difference between the weight of the dried used toothbrush and the weight of an identical unused toothbrush (n=15/each group). The results are expressed as the mean±standard deviation. p-value was determined using the Wilcoxon signed-rank test.