Comparison of Retentive Strength of Glass Ionomer Cement, Resin-modified Glass Ionomer Cement, and Adhesive Resin Cement with Nickel–Chromium Cast Crown: An In Vitro Study

Abstract

Aim: This study was undertaken to compare and evaluate retentive strength of glass ionomer cement (GIC), resin-modified glass ionomer cement (RMGIC), and adhesive resin cement with nickel-chromium (Ni-Cr) cast crowns. Materials and methods: Thirty orthodontically extracted caries-free premolars were prepared using a surveyor and jig assembly to achieve standardized tooth preparation. All the 30 teeth after tooth preparation and fabrication of metal copings were divided into the following three groups: group I is the control group in which conventional GIC was used as the cementing agent. Twenty teeth were prepared, of which 10 were for group II (RMGIC) and 10 specimens for group III 3M ESPE (adhesive resin luting cement). Metal crowns were cemented using conventional GIC, RMGIC, and adhesive resin cement, and all specimens were stored at 37°C for 1 week. Before testing for retention, crown pull test was done using universal testing machine and a tensile load at crosshead speed of 0.5 mm/minute was applied. The maximal force to remove the crown was recorded in kgF and was converted to MPa. Results: Group I had a mean retentive strength of 2.276 MPa. Group II had a mean retentive strength of 5.516 MPa. Group III had a mean retentive strength of 6.446 MPa. The results were subjected to statistical analysis, and the mean retentive strength and standard deviation of each group were calculated. Tukey's multiple comparison test and analysis of variance yielded significant results. Interpretation and conclusion: Within the limitations of the study, the following conclusions can be drawn: The retentive strength of selfadhesive resin cements was better than RMGIC and conventional GIC.