Change of Plaque Removal Ability by Worn Toothbrush

Objectives: An investigation was conducted to examine the wear of 3-month-old toothbrushes and assess the effect of progressive toothbrush wear on plaque control and test the hypothesis that a new toothbrush is more effective in removing plaque from tooth surfaces than a 3-month-old one. Methods: A cohort study was performed in 52 periodontally healthy dental students. The questionnaire about their dental behaviors was fulfilled and the whole teeth were scaled. All subjects were asked to brush their teeth with the toothbrushes and toothpaste provided for the duration of the experiment. After 1 week (baseline) plaque levels were scored using the patient hygiene performance index. Plaque scores were examined after 2 months and 3 months. The amount of wear of the 3-month-old brushes was determined by measurement of brushing surface areas. Results: Forty six subjects completed the study. Plaque scores for whole sites at 2 and 3 months were not statistically different from baseline values (p=0.061, 0.065), but plaque scores for proximal sites at 3 months were significantly increased (p=0.017). Although the wear was increased by 21%, the correlation between the brushing surface areas and plaque scores at 3 months was weak (r=0.211). There were no correlations between the toothbrush wear and toothbrushing behaviors (replacement range of toothbrush, frequency, duration and methods of daily toothbrushing). However there was statistically significant correlation between plaque levels at 3 months and the duration (r=-0.343, p=0.02). Conclusion: Although the capacity to remove plaque at whole sites was not related to toothbrush wear, there was significant increase in plaque levels at proximal area.