Comparative Evaluation of Effect of Polymerizable and non-Polymerizable Desensitizing Agents on Crown-Retentive-Strength of Zinc-Phosphate, Glass-Ionomer and Compomer Cements

Abstract - The Purpose of this study was to evaluate the effect of polymerizable and non-polymerizable dentine desensitizers on retention of complete cast crowns cemented with three different types of cements. Freshly extracted human molars (n=90) were prepared for standardized crown preparation (6-degree taper, 4-mm height). The axial surface area of each preparation was determined and specimens were distributed equally among groups (n=10). Dentine desensitizers, cementing agents, glass ionomer cement and compomer cement. Teeth were prepared and individual castings were made using high noble porcelain-metal alloy. Castings were cemented, thermo-cycled and removed along the path of insertion using a universal testing machine. Tooth surface as well as inner surface of the casting was examined and nature of cement failure was determined. Compomer cement exhibited the highest retentive strength and all dentine treatments resulted in significantly different retentive values. Zinc phosphate was the least retentive. Crown retentive values of Compomer cement were improved with Prime & Bond NT and Gluma Desensitizer. Retentive values of zinc phosphate cement with Prime & Bond NT were decreased and not affected with Gluma Desensitizer. Retentive values of Glass ionomer cement were not affected by any of the desensitizers used in the study.

KEY WORDS: desensitizer agents, crown retention