Effect of acidic and neutral buffer solutions on the stability of a visible light-cured periodontal dressing material.

Abstract

The aim of the present study was to assess the chemical changes induced on the surface of a visible light-cured periodontal dressing material after storage in acidic and neutral buffer solutions, and to monitor the changes in the pH and conductivity of the solutions. The product tested was Barricaid. Twelve disk shaped specimens (8 mm in diameter and 1,5 mm in thickness) were prepared by irradiating the specimens for 40 s with a visible light-cured unit emitting 560 mW/cm2 light intensity. The specimens were divided into two groups of six and were immersed in an acidic (pH: 4,4) and a neutral (pH: 6,8) buffer solution respectively for 7 d at 37±1Æ C. The specimen surfaces before and after exposure to the solutions were studied by micro-MIR FTIR. Moreover, the changes in the pH and conductivity of the solutions were monitored before and after immersion. The statistical analysis of the pH and conductivity measurements was performed by t-test (· =0,05). The results showed a reduction in the amide absorption intensity after immersion in the acid solution. An increase in the solution pH and conductivity was observed after immersion, but the difference was not statistically significant. The results of the present study imply that Barricaid is a quite stable product under acidic pH. Nevertheless, This stability minimizes its therapeutic potential, because has no capacity in increasing the pH of the incubating solution as the products set by an acidbase reaction.