Effect of desensitizers on retention of castings cemented to anatomically prepared teeth

Abstract

Context : The extensive use of desensitizing agents to control incidences of post-cementation sensitivity can variably affect the forces required for debonding of the prosthesis. The available literature offers inconsistent results and is generally carried out using a flat occlusal preparation. Aims: Evaluation of effect of desensitizing agents-nonpolymerizable (Systemp) and polymerizable (Clearfil SE Bond)-on retention of complete veneer castings luted to anatomically prepared teeth with zinc phosphate and glass ionomer cement (ZPC and GIC). Materials and Methods: Seventy maxillary second premolars were prepared conforming to the anatomic form to receive complete veneer castings. Two sets of dies were prepared; one for obtaining castings and second to permit mathematical calculation of the surface area. The specimens were divided into four experimental groups of 15 samples each and two control groups of 5 samples each. Two desensitizers and two luting cements were used. After cementation, the samples were tested at crosshead speed of 0.5 mm/min on universal testing machine (UTM) using a customized self-aligning device. Minimum load required to debond the specimens was recorded. Force value for each specimen was divided by its surface area to obtain the tensile bond strength. Results: Significant reduction in tensile bond strength was noted for all the experimental groups, irrespective of luting cement used. Conclusion: Systemp-glass ionomer group exhibited highest bond strength followed by Systemp-zinc phosphate, Clearfil SE Bond-glass ionomer and Clearfil SE Bond-zinc phosphate group.