Abstract
Objectives: This study tested the impact of Gluma Desensitizer on the tensile strength of zirconia crowns bonded to dentin. Methods: Human teeth were prepared and randomly divided into 5 groups (N=120, n=24 per groups). For each tooth a zirconia crown was manufactured. The zirconia crowns were cemented with: i) Panavia21 (control group), ii) RelyX Unicem, iii) RelyX Unicem combined with Gluma Desensitizer, iv) G-Cem, v) G-Cem combined with Gluma Desensitizer. The initial tensile strength was measured in half (n=12) of each group and the other half (n=12) was subjected to a chewing machine (1.2 Mio, 49N, 5°C/50°C). The cemented crowns were pulled in a Universal Testing Machine (1 mm/min, Zwick Z010) until failure occured and the tensile strength was calculated. Data were analyzed with one-way and two-way ANOVA followed by a post-hoc Scheffé test, t-test and Kaplan-Meier analysis with a Breslow-Gehan analysis test (alpha = 0.05). Results: After chewing simulation, the self-adhesive resin cements combined with Gluma Desensitizer showed significantly higher tensile strength (RelyX Unicem: 12.8 ±4.3 MPa, G-Cem: 13.4 ±6.2 MPa) than the control group Panavia21 (7.3 ±1.7 MPa). Within the groups, Panavia21 and RelyX Unicem resulted in significantly lower values when compared to the initial tensile strength; the values of all other test groups were stable. Conclusion: In this study self-adhesive resin cements combined with Gluma Desensitizer reached better long-term stability compared to control group after chewing simulation.
Hartmann, L