Comparative professional plaque removal study using 8 branded toothbrushes

Considerable interest has been shown in the plaque removal properties of modern toothbrush designs. The primary aim of the study was to compare the plaque removal properties of 8 relatively recent designs of manual toothbrush using a professional tooth brusher and within a commonly used time frame. A secondary aim was established to utilise the data to observationally appraise plaque accumulation together with the patterns of removal as a consequence of using the timed professional tooth brusher.

The method was an 8-period, single-examiner, randomized, blind cross-over study involving 24 healthy volunteers, balanced for residual effects. Subjects accumulated plaque over a 4 day no oral hygiene period. On day 4, the accumulated plaque was scored by plaque index at the mesial, mid and distal sites of each of the buccal and lingual surfaces of the assessed teeth. Subjects were then removed from the assessment area where they received a professional brushing timed to last 48 s. Brushing was completed according to pre-study training without toothpaste and was followed by a re-scoring of the remaining plaque. A washout period of 3 days was then allowed prior to the next period during which normal oral hygiene was resumed.

Similar quantities of plaque accumulated in each arch, although the difference between the buccal and lingual surfaces was of the order of 30%. The professional toothbrusher removed approximately 40% of the accumulated plaque in the 48 s allocated. The buccal surfaces were most effectively cleaned (approximately 45%) compared with the lingual (approximately 25%), with the plaque removal in the mesial and mid sections approaching 40% and 60% respectively. The difference in performance between the test brushes corresponded to 5% of the residual plaque values with none being significantly more efficient overall. Pair wise site comparisons did produce differences of the order of 10% (p=0.004) at the mesio-buccal, and 8% (p=0.030) at the mid-buccal sites respectively in favour of 2 brushes compared to one other brush.

These data derived from a standardized brushing method support the contention of many researchers that there is no one superior design of manual toothbrush. The minor and few site differences in favour of some brushes are unlikely to be of clinical significance to gingival health. This leaves uncontested the conclusion that the user is by far the most significant variable. Perhaps methods such as used in the present study could be more gainly employed to set a minimum standard of toothbrush efficacy.