Effect of a Desensitizer on the Luting Agents/Dentin Bond Strength

Objective: Different processes for desensitization of dentin are used after preparation of teeth for indirect restorations. Controversial results have been presented in the literature regarding dentin pre-treatment before crown cementation. This study evaluates the effect of a dentin desensitizer on the microtensile bond strength (MTS) of dental luting cements.  Methods: Occlusal surfaces of non-carious extracted molar teeth were ground flat to expose dentin. Teeth were divided according to dentin surface treatment consisting of two groups: control, and desensitizer agent (GLUMA, Heraeus Kulzer).  Teeth were divided in three subgroups according to the luting agents used: Ketac-Cem, RelyX Unicem, RelyX ARC (3M ESPE). A composite build-up (Z-100; 3M ESPE) was luted to the teeth using the respective luting agents. Samples were stored for 24hrs, and then sectioned into beams. Specimens (n=20) were tested using a universal test machine at crosshead speed of 1mm/min. MTS was calculated. Statistical analysis was performed using a One-way ANOVA followed by Tukey’s test (95% significance level) Result: All Ketac-Cem specimens de-bonded prematurely. MTS were as follow: RelyX Unicem 7.5MPa, RelyX Unicem+Gluma 10.5MPa, RelyX ARC 11.5 MPA, RelyX ARC+Gluma 17.3MPa. The RelyX ARC with Gluma group showed statistically significantly higher average bond strength than the other three groups. Conclusion: Application of Gluma did not adversely affect the luting agent/dentin bond strength regardless of the system used. The hypothesis that dentin surface treatment does not have an effect on the bond strength of luting cements used for indirect restorations was rejected, since an increase in MTS was observed for one of the treated groups.