The influence of water temperature during toothbrushing on root dentine: an in vitro study.

BACKGROUND/AIMS The use of cold water during toothbrushing can cause dentine sensitivity and, to avoid this painful stimulus, some patients used to rinse their mouths with warm water when brushing. Thus, the objective of this study was to determine the effect of water temperature on the dental root surface during toothbrushing. MATERIALS AND METHODS Fragments of bovine dental roots were submitted to 15,000 strokes in a toothbrushing machine using a slurry of toothpaste/water, medium brushes, and a 200-g load. They were randomly divided into two groups: toothbrushing with cold water or with hot water. Tooth wear was measured by loss of weight and by tissue height. STATISTICAL ANALYSIS The weight and height data obtained in 17 and 10 replicas respectively are presented as mean +/- standard error of mean. The data were compared using the Kolgomorov-Smirnof (Lilliefors) test followed by one-way ANOVA. The level of significance was 5% (P < 0.05). RESULTS There were no significant differences between the two experimental groups. The mean percentages of weight losses were 5.61 +/- 1.66 for cold water and 6.25 +/- 1.98 for hot water. The mean dentine height losses were 51.02 +/- 15.92 microm for cold water and 63.54 +/- 17.75 microm for hot water. CONCLUSION The use of warm water during toothbrushing promoted root dentine wear similar to that produced by the use of cold water. The results suggest that warm or cold water may be used during toothbrushing without any additional damage to the patients' dental hard tissues.