Demineralization Inhibition of Glass Ionomer Base In Class V Preparations

Objectives: Extracted human teeth were restored in three ways to determine best possible placement of a glass ionomer cement base, Vitrebond Plus, in a Class V preparation to inhibit the formation of secondary caries. Methods: Thirty extracted teeth were collected, placed in three groups of ten and Class V preparations were placed on facial surface of each tooth. Preparations were standardized with the following dimensions: pulpal extension of 1.5mm, mesiodistal width of 8mm and occlusogingival dimension of 6mm. Group I contained preparations with glass ionomer placed on the pulpal floor. Group II contained preparations with glass ionomer covering all exposed dentin. Group III was the control group with Single Bond adhesive placed over all prepared dentin. All three groups were then restored with a non-fluoride releasing resin composite, according to manufacturer's instructions and an acid protective varnish applied to the teeth excluding a window with the experimental restoration. Teeth were thermo-cycled then placed in a demineralization solution after which teeth were sectioned and viewed with a polarized light microscope. The gingival dentin cavosurface margin demineralization was measured with an imaging software program. Results: The mean areas (µm²) of the artificial lesions (±S.D.) in the dentin 100 µm from the gingival cavosurface margins were: Group I: 53.3±10.8; Group II: 64.9±13.8; Group III: 85.4±19.2. ANOVA indicated significant variation among the groups (p<0.001). A Dunn's multiple comparison test indicated both Group I and Group II to have significantly less demineralization than the control (Group III), however, there was no significant difference between Groups I and II (p<0.05). Conclusions: The data from this study indicates there is significantly less dentin demineralization next to the gingival dentin cavosurface margin if a resin-modified glass ionomer cement base has been placed prior to a resin-based composite restoration. Supported by CO*STAR, NIDCR DE 14318.