INFLUENCE OF THE PRESENCE OF CALCIUM IN BLEACHING AGENTS AND THEIR RELATION TO THE MICROHARDNESS OF HUMAN ENAMEL

Abstract

Objective: This study examined the microhardness of tooth enamel exposed to the bleaching agent hydrogen peroxide 35%, with or without calcium in its composition in order to ascertain whether the addition of this substance influences the change in microhardness. Material and methods: The samples were composed of ten intact human third molars, of which three fragments were obtained, so that each fragment from the same tooth was part of a different group. Group B consisted of ten samples, bleached with hydrogen peroxide 35% containing calcium. Group M consisted of ten samples, bleached with hydrogen peroxide at 35% without calcium, and group C (control) consisted of ten samples immersed in artificial saliva. The microhardness was evaluated before the treatment and after three sessions with an interval of seven days between them. Results: In Group B there was an increase of 5.47% in microhardness, considered significant, assigned to the presence of calcium in the bleaching agent. There was a reduction of 2.59% and 0.64% in groups M and C respectively, both considered nonsignificant. Conclusion: It was concluded that the presence of calcium in the whitening gel increases the microhardness of the bleached enamel, providing a remineralization of this substrate.