Objective: To examine the retention strengths of self-adhesive luting cements between zirconia copings and dentin in vitro. The following groups were tested (N=12 per group):
Group 1: Maxcem Elite (Kerr)
Group 2: G-CEM Automix (GC America)
Group 3: Rely-X Unicem Clicker (3M ESPE)
Group 4: MonoCem Self-Adhesive Resin Cement (Shofu)
Methods: Forty-eight (48) extracted human molars were prepped for all-ceramic crowns. The copings were cemented according to manufacturer's directions for each of the four cement groups. Cemented teeth were stored in distilled water for 3 days at 37°C and thermocycled for 300 cycles between 5°C and 55°C with a dwell of 30 seconds. Each sample was subjected to a “pull-out test” using an Instron Universal Testing Machine model 4201 at a crosshead speed of 5.0 mm/min until failure.
Results: The data was compared using one-way analysis of variance (ANOVA). The p-value of 0.066 suggested that there was no statistically significant difference among the four groups. The mean retention strengths were Group 2=294.7N, Group 4=230.7N, Group 3 =204.3N, and Group 1=187.1N.
Conclusion: There was no statistically significant difference between the retention strengths in each group.
Research sponsored in part by GC America.