The effect of toothbrush abrasion force on dentine hypersensitivity in-vitro

Abstract

ObjectivesThis study investigated the effect of tooth brushing force on changes in dentine tubule patency in an erosion-toothbrush abrasion model. Methods60 dentine samples prepared with an artificial smear layer and divided randomly into control (no toothbrush), 100g, 200g or 400g toothbrush groups. They were immersed in 3:1 artificial saliva/NaF 1450ppm and either brushed (p35 soft tooth brush; 120 strokes) or not brushed. Then samples were subjected to agitated acid challenge (0.3% citric acid pH2.6 for 2min). Finally, samples were re-brushed. Calibrated software calculated patent dentine tubules that cause DH in confocal microscopy images taken of samples at each stage. ResultsAt baseline, mean patent tubules in all samples were 188 (SD54) with no significant inter-group differences. Following first brushing, mean patent tubules decreased using 100g to 150 (SD32) (p<0.01) and increased using 400g to 215 (SD45) (p=0.02). Following acid challenge, patent tubules increased to 218 (SD40) in all samples (p<0.01) with no significant inter-group differences. Following further brushing, mean patent tubules decreased using 100g to 175 (SD72) (p<0.01), but increased with 400g to 232 (SD52). ConclusionsAt higher brushing forces (400g), more tubules were exposed. At lower brushing forces (100g), tubule patency decreased even post-acidic challenge. Clinical significanceIt is often recommended to our patients with DH to brush using lighter brushing forces but our understanding of this force on dentine tubule patency is unknown. The management of DH requires lighter brushing forces to reduce the numbers of patent dentine tubules.