Clinical Study :The Effect of Antibacterial Nanoparticles, Incorporated in Provisional Resin Based Cement, on S.Mutans in the Margins of Provisional Restorations

Provisional cement withholding antibacterial properties may be useful in preventing caries in the margins of provisional restorations. Covalently attached antibacterial polymers are a possible solution.

The provisional restoration is important in determine the success of the therapy. The provisional restoration protects the pulp and the dentin, and is used for diagnostic purposes. Sometimes provisional restoration can stay in the oral cavity for a long period. Through this time, the abutments must get the best biological and mechanical defense. The cement should have good mechanical properties, low solubility and good adhesion. The finishing line is a place prone to caries development due to the existence of a potential gap between the provisional restoration and the tooth.

This in vivo study will evaluate the antibacterial effect of alkylated polyethylenimine nanoparticles (IPN) incorporated to temporary cement, against S.mutans. We will compare 2 temporary cement, one with, and the other without the nano particles, using the direct technique for making provisional restoration with polymethyl methacrylate.

Baldissara et.al tested 4 kinds of temporary cements in 30 acryl resin crowns, prepared on extracted teeth. They authors found that in all 4 kinds of cements there was always a micro leakage, to some degree, in the margins of the restoration. These gap and micro leakage in restorations, contribute to restoration's failure.

Composites releasing Fluoride do not have antibacterial effect after light curing. This fact can explain why plaque tends to accumulate on composites. Polymethl metacrylate resin, the material used in direct provisional crown preparation, has a low antibacterial activity.