Secondary caries adjacent to restorative materials

To evaluate the laboratory potential secondary caries reduction of restorative dental materials.

20 maxillary molars received Class V cavities on both buccal and lingual surfaces with enamel and root surface margins adjacent to the restorations. The teeth were randomly assigned into four groups with five teeth per group. The treatment groups were: (1) Filtek Bulk Fil (negative control); (2) Equia Forte glass-ionomer (positive control); (3) Beautifil giomer (fluoride releasing); and (4) Activa Restorative (fluoride releasing). All teeth were restored following the manufacturers' instructions. All teeth received 10,000 thermal cycles followed by immersion in a demineralizing solution to produce artificial caries-like lesions. Polarized light microscope evaluation was performed on longitudinal sections (30 enamel lesions per the ten Cate method, and 30 root surface lesions per group). Lesion depth and wall lesions for both enamel and root surface adjacent to the restorations were evaluated using ANOVA and Duncan's Multiple Range test (P< 0.05).

On enamel surfaces, a significantly increased difference was seen with Filtek Bulk Fil compared with the other restorative materials for primary surface lesion depths and wall lesion frequency (P< 0.05: ANOVA and Duncan's Multiple Range Test). Significant difference was found with Activa Restorative (significantly less) compared with Equia Forte glass ionomer and Beautifil Giomer for primary surface lesion depths and wall lesion frequency (P< 0.05: ANOVA and Duncan's Multiple Range Test). On root surfaces, a significantly increased difference was recorded with Filtek Bulk Fil compared with the other restorative materials for primary surface lesion depths and wall lesion frequency (P< 0.05: ANOVA and Duncan's Multiple Range Test). A significant difference was found with Activa Restorative (significantly less) compared with Equia Forte glass ionomer and Beautifil giomer for primary surface lesion depths and wall lesion frequency (P< 0.05: ANOVA and Duncan's Multiple Range Test).

Both lesion depth and frequency of wall lesions in the enamel and root surfaces adjacent to the restorations in all treatment groups were significantly (P< 0.05) reduced compared with the control group for a enamel and root cavosurface wall lesions, which may imply effect of fluoride release from fluoride-containing restorative materials vs non-fluoride containing ones. Activa Restorative, compared to Equia Forte glass ionomer and Beautifil giomer, showed statistically significantly less enamel and root surface wall lesions.