MDPB-Containing Restorations Inhibits Secondary Root Caries: An In Vitro Study

Objectives: To evaluate the inhibitory effects of restorative materials with MDPB in secondary root caries-like lesions formation in vitro.

Methods: Caries-free dental roots were embedded in acrylic resin with exception of an exposed surface and randomly assigned to five groups (n=15). Class V cavities were prepared on the exposed surface and restored with adhesive system and composite containing or not the antibacterial monomer MDPB. Acid resistant varnish was used to coat samples, leaving the restoration and a 1mm adjacent root surface exposed. The specimens were thermo cycled (1,500 cycles, 5°C and 55°C), placed in 24-wells cell culture plates and Gamma irradiated. Artificial root caries were induced using a microbiological model (Streptococcus mutans) during 15 days. Slices (±80 µm) were obtained from tooth samples and the lesions were then micro-photographed through polarized light microscopy. The depths of the lesions adjacent to restoration material were measured using image software (Photoshop CS) and the data were transformed in percentage related to the negative control. The data were compared by ANOVA and Tukey's test (p≤0.05).

Results: The depth of lesions adjacent to cavities filled with resin modified glass ionomer, considered as positive control, were significantly shallower than those adjacent to commercially available resin restorations (negative control, p<0.05). The cavities restored with antibacterial resin (containing 2.83% MDPB), in despite of the adhesive system used, were similar to those of positive control. Conclusions: MDPB is capable of impairing the advance of secondary caries-like lesions around dental roots restorations when incorporated to the resin composite.

This study was supported by FAPESP Grant 05/56158-5