Comparação da ação de princípios ativos incorporados a um enxaguatório bucal na prevenção/controle da erosão dental

Abstract

The objective of this study was to compare, in vitro, using different methods of analysis, the effect on surface of an experimental mouthrinse modified with different active ingredients for the prevention / control of dental erosion caused by hydrochloric acid. An experimental mouthrinse without additives, a commercially available mouthwash for erosion Elmex Erosion ® (AmF/NaF/SnCl2) (ELM) and four mouthrinses added 4 different additives were tested for their ability to protect against erosion in a model of erosion-remineralization, where the response variables were the change of micro-and nanohardness and the quantities of released calcium and phosphate in solution, determined by optic emission spectrometry. The additives used were: casein (CAS 5 g/L), sodium hexametaphosphate (HMP 0.2 g/L), titanium tetrafluoride (TiF4 3.4 g/L) and stannous fluoride (SnF2 8.7 g/L). Bovine enamel specimens were embedded in acrylic resin and polished. They were ramdomily distributed in groups (n=8) and submitted to the following cycle: (1) immersion in 20 ml of 0,01M hydrochloric acid (HCl), pH = 2.4 10 s, (2) immersion in 20 ml of saliva artificial for 60 s, (3) immersion in 20 ml of test solution for 30 seconds and (4) immersion in 20 ml of artificial saliva for 60 s. This cycle was repeated three times during the same day and the solutions were stored for later evaluation. For microhardness, the specimens treated with ELM and SnF 2 showed the highest values of hardness, being significant different from TiF4 solution, which presented the lowest value. The ELM, SnF 2 , CAS and HMP were statistically similar to C. For nanohardness, the TiF4 had the lowest value of hardness, being significant different from C. The SnF 2 , ELM, CAS and HMP were statistically similar to C. In the calcium analysis after the last cycle, ELM and HMP resulted in less calcium loss, which was significantly different from C. After the first immersion, all groups tested, except casein, showed statistically lower calcium loss when compared to group C and there was no difference in statistical analysis of loss of phosphate in the second. In analysis of phosphate loss after the final cycle, ELM TiF4 showed the lowest losses being significant different from C. After the first and the second cycles, only ELM was statistically different from C. It can be concluded that the ELM, HMP and TiF 4 protect the enamel surface against ions loss but the hardness tests could not detect this protection.