Scanlling eldctron microscopic study of the enalnel surface with various kinds of acid

Abstract

One hundred and thirty five human complete impacted third molars were used. In this experiment, some acids were used, which were (1N,0.5N,0.01N) acetic acid, (0.01N,0.001N) hydrochloric acid and (0.1N,0.01N,37%,50%) phosphoric acid. The etched ena-mel surface treated with these acids were observed by scanning electron microscope, and were measured the depth of etched surface by the stereoscope.

The results were as follows.

1) From the effects of the various acids, four patterns were observed on the etched enamel surface. Pattern I : Peeled off the layer of the surface of enamel. Pattern Ⅱ : The center of the enamel rod was depressed. Pattern Ⅲ : The border of enamel rod was depressed. Pattern Ⅳ : Mixed with pattern Ⅱ and pattern Ⅲ.

2) Regardless of the kinds of acid, the depth of dissolved enamel decrease with increasing lower pH and treated time.

3) On the quantity of ething of enamel surface, the effect of acetic acid (organic acid) were weakly. It seemed that organic acid has aspecific characteristics compared with inorganic acid.