Shear Bond Strength of Self-adhesive Cements After Thermocycling

Objectives: Objective: to evaluate shear bond strength of self-adhesive cements to superficial dentin after thermocycling
Methods: Methods: 60 recently extracted caries and restoration free, human molars, were section with a slow speed saw (Buehler) under water to expose superficial dentin. Pre-made composite cilinders (2mm diameter) were cemented over dentin with a pressure of 200gr using self adhesive cements SoloCem (Coltene), Panavia SA Luting Plus (Kuraray) and Multilink (Vivadent) following manufacturer’s instructions, 20 teeth per cement. Multilink was used with its dentin bonding adhesives recommended by manufacturer. Excess cement was removed before light curing specimens for 20 seconds in two different areas. Specimens were then divided into two groups (n=10), one group was stored in water at 37° C for 30 days, and the other was thermocycled form 5° to 55° with 30 seconds dwell time, for 5000 cycles. Specimens were tested in shear at 0.1 cm/min until break on a universal testing machine (Tinius Olsen H10K-S). Bond strength was calculated in MPa, data were analyzed with two-way ANOVA calculated at 0.05 significance level. Means were compared using Tukey HSD interval also calculated at 0.05 significance level.
Results: Results: Means (Std Dev) are shown in table. Thermocycling increased SBS of Panavia SA and Multilink, but had no effect on Solocem. Due to a high variation, there was no statistical difference among cements, but the storage factor did make a difference. After thermocycling both Panavia SA and Multilink had statistical higher shear bond strength.
Conclusions: Conclusion: Thermocycling increased shear bond strength of some self-adhesive cements