Effect of two different techniques of temporary cement removal on bond strength of lithium disilicate ceramic to dentin

This in-vitro study aimed to evaluate the effect of two techniques to remove temporary cement residues from the dentin surface on the bond strength of ceramic to human dentin. Materials and Methods: Twenty sound human molars were sectioned with diamond saw, temporary blocks made of self -cure acrylic resin affixed to their flat dentin surfaces using non-eugenol temporary cement. After specimens were stored for 14 days in distilled water, they were randomly divided into 2 groups according to method of removing temporary cement residues. In the first group “H”, hand excavator was used while using ultrasonic scaler in the second group “U”, (n=10) for each. Then E-max press ceramic blocks were fabricated, luted to dentin by SuperCem resin cement (Self-Etch/Self-Adhesive Resin Cement, DENTKIST, Korea) following manufacturer instructions. The bonded specimens were stored in distilled water for 3 months, thermocycled for 3000 cycles. Beams of 1mm×1mm were sectioned from tested specimens for micro-tensile bond strength test (μ-TBS). Normality test and independent sample t-test were used to statistically analyze the data at significant level (P=0.05). Results: Mean μ-TBS between E- max ceramic and dentin in H group was (10.48±6.383 MPa), and in U group was (14.06±7.8 MPa). No statistically significant difference was obtained between both groups. Conclusion: Application of different techniques to remove temporary cement residues would not affect the bond strength between ceramic and dentin.