Brushing force of manual and sonic toothbrushes affects dental hard tissue abrasion.
OBJECTIVE
This study aimed to determine the brushing forces applied during in vivo toothbrushing with manual and sonic toothbrushes and to analyse the effect of these brushing forces on abrasion of sound and eroded enamel and dentin in vitro.


METHODS
Brushing forces of a manual and two sonic toothbrushes (low and high frequency mode) were measured in 27 adults before and after instruction of the respective brushing technique and statistically analysed by repeated measures analysis of variance (ANOVA). In the in vitro experiment, sound and eroded enamel and dentin specimens (each subgroup n = 12) were brushed in an automatic brushing machine with the respective brushing forces using a fluoridated toothpaste slurry. Abrasion was determined by profilometry and statistically analysed by one-way ANOVA.


RESULTS
Average brushing force of the manual toothbrush (1.6 ± 0.3 N) was significantly higher than for the sonic toothbrushes (0.9 ± 0.2 N), which were not significantly different from each other. Brushing force prior and after instruction of the brushing technique was not significantly different. The manual toothbrush caused highest abrasion of sound and eroded dentin, but lowest on sound enamel. No significant differences were detected on eroded enamel.


CONCLUSIONS
Brushing forces of manual and sonic toothbrushes are different and affect their abrasive capacity.


CONCLUSIONS
Patients with severe tooth wear and exposed and/or eroded dentin surfaces should use sonic toothbrushes to reduce abrasion, while patients without tooth wear or with erosive lesions confining only to enamel do not benefit from sonic toothbrushes with regard to abrasion.
Department of Preventive Dentistry, Periodontology and Cariology, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland. annette.wiegand@zzm.uzh.ch
Annette
A
Wiegand
John Patrik Matthias
JP
Burkhard
Florin
F
Eggmann
Thomas
T
Attin
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003743:Dental Enamel / Q000473:pathology; D003799:Dental Stress Analysis; D003804:Dentin; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D014072:Tooth Abrasion / Q000209:etiology* / Q000517:prevention & control; D014077:Tooth Erosion; D014099:Toothbrushing / Q000009:adverse effects* / Q000295:instrumentation*; D014465:Ultrasonics; D055815:Young Adult