Ação de abrasivos no esmalte humano submetido à erosão: um estudo in situ/ex vivo

Abstract

This in situ/ex vivo study aimed to investigate the effects of two non-fluoridated dentifrices with calcium carbonate (CaCO3) and silica (SiO2) on human permanent enamel eroded by a carbonated soft drink. During two phases over 5 days, 12 volunteers (mean age 28) used a palatal appliance with 6 enamel blocks. In each period, the appliances were immersed in the soft drink for 5 min, 4 times a day. In two moments of the erosive challenge, 2 enamel blocks were not additional treatment, 2 blocks were brushed either with a CaCO3 or SiO2 dentifrices, immediately after the erosive treatment and 2 blocks 1 h later. Brushing was made for 30 s. Between phases a 2 day washout period was followed. An in vitro study was also conducted to investigate artificial and natural saliva influence on the erosion variation. The results were expressed in enamel roughness (Ra, ìm) and morphology analysis. The eroded and abrasioned enamel blocks showed superficial roughness changes significant higher than the eroded blocks (p<0.05). Blocks submitted to immediate abrasion or 1 h later did not show significant statistical difference. Both dentifrices had a similar abrasive effect on the eroded blocks. There was no significant difference in roughness between the enamel blocks from the experimental group (in vitro) and blocks from the in situ/ex vivo groups (CaCO3 and SiO2 control). Data showed that independently of the abrasive used, surface roughness is increased when erosion is associated to dental abrasion. It also did not have a 12 higher effect when comparing natural with artificial saliva in relation to dental