Effect of Contamination with Impression Materials on Shear Bond Strength of Porcelain to Immediately Sealed Dentin

Objective: The aim of the present study was to evaluate the effect of two impression materials on the shear bond strength of porcelain to immediately sealed dentin. Materials and Methods: Smooth dentin surfaces of 45 extracted premolars were immediately sealed with Adper Single Bond adhesive agent. Forty-five porcelain specimens were also prepared. The teeth were divided into one control and two experimental groups. In control group, an adhesive layer to dentin was applied and feldspathic porcelain specimens were bonded to dentin with Relay X dual-curing cement. In one experimental group, the teeth were embedded in condensational silicon (Speedex) and in the other group in polyether (Impregum Soft) impression materials before bonding the porcelain specimens as in the control group. Shear bond strengths were measured using a universal testing machine. Fracture modes were evaluated under a stereomicroscope. Data was analyzed using oneway ANOVA, Tukey, and chi-square tests (α=0.05). Results: No significant differences existed between bond strength of the control and condensational silicon groups (P=0.31). Bond strength was significantly lower in polyether group in comparison with the control (P<0.0005) and condensational silicon groups (P=0.002). Conclusion: Contamination with polyether impression material adversely affects the shear bond strength of porcelain to immediately sealed dentin.