Loss of enamel due to etching with phosphoric or maleic acid.

In this study, the effect of enamel etching resulting in permanently lost enamel was investigated. Phosphoric acid and maleic acid were used as etchants. Also the etch duration was varied. The results of the study show that phosphoric acid removed significantly more enamel than maleic acid. The relationship found between the loss of enamel and the etch duration suggested that a diffusion controlled mechanism plays a role in the case of both acids. Morphological information obtained by scanning electron microscopy indicated that the surface structure resulting from etching with phosphoric acid and maleic acid is similar.