In Vivo Test for Bonding Strength

¹ Department of Dental Materials, Marquette University School of Dentistry, Milwaukee, Wisconsin, and Research Department, L. D. Caulk Co., Milford, Delaware

A method has been developed for testing in vivo bonding of dental cements to dentin. Preliminary tests indicate that the grinding method and the conditioning of the dentin surface influence the strength of the bond, both for zinc phosphate cement and for resin cement. When cement was applied to dentin surfaces prepared according to accepted clinical procedures (12,000 rpm; diamond instrument at light pressure; water cooling), the bond strength was very low. Some improvement was observed when certain cavity-priming agents were applied to the dentin surface prior to cementation. None of the cementing substances used in this study resulted in early bonding strength values close to the known tensile strength values for dentin. No systematic relationship was established between the values obtained under in vivo and under in vitro conditions.