بررسي اثر روش هاي گوناگون پاك سازي سطح بر استحكام برشي باند پرسلن به عاج تازه مهر و موم شده

The Effect of Different Surface Cleaning Methods on Shear Bond Strength of Porcelain to Immediately Sealed Dentin

Statement of Problem: There is a probability of interaction between impression materials especially Polyether with the external surface of the adhesive layer of the immediately sealed dentin in the presence of oxygen inhibited layer. Purpose: The aim of the present study was to evaluate the effect of three different surface cleaning methods 011 the shear bond strength of porcelain to the immediately sealed dentin. Methods and Material: In this in-vitro study, the facial surfaces of 60 extracted premolars were immediately sealed, using single-bond adhesive. Then, the immediately sealed dentin surfaces were buried in the polyether impression material while setting. After the impression materials were removed, the samples were randomly divided into 4 groups. In group 1, porcelain samples were bonded to the teeth surfaces using resin cement without any surface cleaning. In groups 2, 3 and 4, surface cleaning using acid etche, air abrasion and pumice with rubber cup prophylaxis were applied respectively for each group before bonding the porcelain samples. Shear bond strength test was performed at the strain rate of 0.5 mm/min. The data were analyzed using One-way ANOVA and Tukey post- hoc tests. Results: There were significant differences between the shear bond strength of the control group and the three surface cleaning method groups (p <0.001). The mean of the shear bond strength in the acid etch group was greater than that of the two other experimental groups; however, there were no significant differences between the three surface cleaning methods (p = 0.5). Conclusion: Surface cleaning of immediately sealed dentin using acid etche, air abrasion and prophylaxis, after impression with polyether, significantly improves the strength of the bond. Key words: Immediate dentin sealing, Oxygen inhibited layer, Surface cleaning, Bond strength