Coke Influence on Enamel with and without Tootbrushing Abrasion

Objectives: The aim of this study was to “in situ” evaluate the influence of coke soft drink on bovine enamel, associated or not to toothbrushing, by using profilometry (profile analysis) and microhardness. Methods: Five volunteers participated wearing intra-oral palatal appliances containing 6 bovine enamel specimens which separated in 2 groups of 3 were submitted in a unique stage to: 1- coke(C); 2- coke+toothbrushing with no fluor paste (CT). Each treatment was performed in each 3 specimens in one side of the appliance (left/right). For the profile analysis, half of the surface of the specimens was previously protected with nail varnish to avoid the erosive drink action. The volunteers used the appliance for 5 days, immerging it in 250mL of the drink for 10 minutes, 4 times/day. After that, the specimens were brushed in only one side(CT) and the appliance restored into the mouth. The Hommel Tester T1000 Rugosimeter was used to trace the normal / treated profile and Shimadzu-HMV2000 to measure microhardness. Results: The mean wear values and microhardness alterations were: 2.77µm; 352 KHN for C and 3.80µm; 222 KHN for CT. The results were analyzed using Student test (p<0.05) and there was statistical significance between wear(p=0.01) and microhardness(p=0.00) groups. Conclusions: It was concluded that coke promoted bovine enamel superficial erosion more pronounced when associated to toohbrushing abrasion, however the toohbrushing promoted a higher hardness since it removed the altered superficial layer.