In vitro caries inhibition by polyacid-modified composite resins (‘compomers’)

Objectives: The aim of this study was to compare the in-vitro caries inhibition of two polyacid-modified composite resins (PMCRs). Methods: Three standardized class V cavities were prepared in eight extracted human molar teeth. Two of these cavities in each tooth were restored with Compoglass and Dyract according to manufacturersʹ guidelines. A conventional glass-ionomer cement restoration (Chemfil II) was placed in the third cavity in each tooth as a control. The teeth were submerged in an acid gel (lactic acid, gelatin, thymol, pH 4.5) for 28 days and then resin embedded. Ground sections were examined at × 160 magnification for enamel surface lesion depth, dentine surface lesion depth, wall lesions and evidence of caries inhibition. Results: There was no significant difference between the depths of enamel or dentine surface lesions between the two compomer and conventional glass-ionomer materials. However, both PMCRs exhibited greater wall lesions than the conventional glass-ionomer material indicating less caries inhibition. Conclusions: These results suggest that PMCRs provide less caries inhibition than glass-ionomer cements.