PYRUVIC-ACID AS AN ETCHING AGENT IN CLINICAL DENTISTRY

This study evaluates the use of pyruvic acid as an alternative etching agent to phosphoric acid (H//3PO//4). Solutions containing 5, 10, 15, 20, 25, and 30 m/m% pyruvic acid and 50% m/m H//3PO//4 were prepared. The tensile bond strengths of a composite epoxy resin to enamel surfaces etched with the respective etching agents were determined. The rates of etching of enamel surfaces by each of the etching solutions were evaluated. Unground and polished enamel surfaces were etched with the respective etching solutions and the surfaces examined by scanning electron microscopy. The tensile bond strengths with 10-30% pyruvic acid exceeded those obtained on enamel surfaces etched with 50% H//3PO//4. The rates of etching of all the pyruvic acid solutions were significantly less than that of H//3PO//4.