Effects of Galla chinensis on inhibition of demineralization of regular bovine enamel or enamel disposed of organic matrix

Objective

This in vitro study was undertaken to assess the effects of Galla chinensis extract on inhibition of enamel caries-like demineralization and to elucidate the role of the organic matrix of enamel in this process.

Design

Either regular or enamel disposed of its organic matrix both of bovine origin were exposed to a demineralizing solution for 3 days (pH 4.5). Specimes were additionally treated with either 4 g/L of G. chinensis extraction (GCE) or double distilled water (DDW) four times daily for 5 min each time. Regular enamel exposed accordingly to sodium fluoride (1 g/L) during the demineralizing period served as positive control. After exposure mineral loss and lesion depth of all samples were analysed by transversal microradiography. One-way ANOVA and Student-Newman-Keuls test were used to compare the differences amongst groups. A factorial ANOVA was chosen to test the interaction between GCE and enamel organic matrix.

Results

Mineral loss and lesion depth of specimens in the positive control group were significantly lower compared to all other groups. Regular enamel treated with GCE showed significantly lower values compared to regular enamel treated with DDW or to enamel disposed of its organic matrix (p < 0.05). These three groups revealed similar values (p > 0.05). Significant interaction between GCE and enamel organic matrix with respect to both outcomes could be observed (p < 0.05).

Conclusions

G. chinensis inhibits enamel caries-like demineralization in vitro. However, its potential seems to be weaker compared to sodium fluoride. The organic matrix of enamel was shown to play a substantial role in the observed mechanism.