Plaque removal by worn toothbrush.

Background/aims: Assessment of the influence of toothbrush wear on plaque (PI) and gingival (GI) indexes.
Method: 20 university students were recruited. PI and GI were recorded at the starting point (T0). Each subject received a toothbrush and toothpaste. 5 measurements of toothbrush were recorded to establish the initial size. The subjects were instructed to brush 3 x a day and to refrain from using other plaque removal aids. After 1 month (T1), the subjects were randomly divided into 2 groups: group no. 1 substituted the toothbrush at each monthly visit; group no. 2 brushed only with the toothbrush provided at T0. Recalls were scheduled after 1 (T1), 2 (T2) and 3 months (T3). PI, GI and an index of wear (WI) were calculated using 5 measurements of the toothbrush head and were recorded at recalls.
Results: From T0 to T3, a significant increase of PI was found within both groups. Non-significant differences, but very close to the significant level (p= 0.063), in group no. 1 and significant differences in group no. 2 of GI were found. No significant differences of PI and GI were found between groups. Increase of the WI was registered from T0 to T3 (p<0.001).
Conclusion: Each individual is capable of maintaining low PI, even if using a toothbrush that shows evidence of wear.