Changes of Human Dentin by Brushing with Commercial Dentifrices for Sensitive Teeth in vitro

By using commercial dentifrices for sensitive teeth, automatic two-dimensionally rotated toothbrushing was performed on the tangential ground surfaces of human sound dentin in the cervical regions for 10 min in vitro. The dentin surfaces were observed with scanning electron and scanning laser microscopes. The brushing caused remarkable abrasion with the traces of toothbrush bristles on account of the abrasive agents, while most of the dentinal tubules were occluded with dentin sludge or covered with smear layers. Therefore, daily toothbrushing with such dentifrices will promote the formation of wedge-shaped defects in the cervical regions, even if the dentin hypersensitivity is decreased temporarily due to the occlusion of the exposed tubules.