Toothbrush wear in relation to toothbrushing effectiveness

Objective: To investigate to what extent the degree of toothbrush wear of 3-month-old manual toothbrushes influence plaque scores. Material and methods: During a recently published study with a follow-up of 1 year, all participants performed a similar basic home-based oral hygiene regimen. Hence, they were instructed to brush for 2 minutes twice daily according to the Bass method technique and using a standard dentifrice containing sodium fluoride. Toothbrushes were turned in every 3-month, and the degree of wear was scored. The mean plaque score data were additionally analysed and correlated with wear scores of the toothbrushes. Results: For analysis, for each of 172 individual participants, a set of three identical, 3-month-old used toothbrushes were available. Toothbrush wear varied widely between participants. However, per patient, the 3-month wear status of the three evaluated toothbrushes was strongly correlated (rho = 0.8, P < 0.0001). Participants who returned toothbrushes with extreme wear had significantly higher plaque scores than those who returned toothbrushes with no visible or light wear (P = 0.01). Conclusion: Toothbrush wear per individual patient is fairly consistent. Toothbrushes with extreme wear were less effective than those with no or light wear. Therefore, bristle splaying appears to be a more appropriate measure of brush replacement time then the commonly used toothbrush age. Splaying of the outer tufts beyond the base of the toothbrush is a condition that indicates it is time to change the brush.