Adhesion of silicone elastomer to different dental alloys - laboratory investigations

The establishment of a strong, permanent, gap-free connection between a soft lining and the denture base material represents a significant laboratory and clinical requirement. Objectives: Present study aimed at determination and evaluation of procedures for connection of silicone elastomer material with dental alloys using tribochemical system. Methods: Rocatec bonding system (ESPE) was used to bond Molloplast-B (DETAX) silicone elastomer to metal alloys: Remanium GM380 and Rematitan (DENTAURUM). The mechanical strength of the bonds was examined using an Instron 5565B GB instrument (tensile and shearing tests). For every test three sets of 30 samples each were examined. Samples were tested after being stored in water for one day (group 1) and after 3 and 6 months (group 2 and 3). Data were assessed statistically using the ANOVA method. Results: The tribochemical system gave higher mean values of the tensile stress for chromium-cobalt alloy (1.88±0.27MPa - group 1; 2.26±0.15MPa - group 3) in comparison with titanium alloy (1.73±0.25 MPa and 2.03±0.28 MPa, respectively). There were not significant differences between group 1 and 3 of chromium-cobalt alloy samples. At both testing times, the Rocatec system exhibited high reproducibility and high mean tensile strength. The shear test demonstrated lower mean values for Remanium (1.41±0.21 MPa - group 1; 1.34±0.14 MPa - group 2; 1.26±0.12 MPa - group 3) and for Rematitan (1.23±0.19 MPa, 1.03±0.30 MPa, 1.15±0.16 MPa, respectively). No significant differences were noted between 1 and 3 groups in both types of dental alloys. The properties of the samples obtained using the Rocatec system significantly improved after storage for 6 months in distilled water at 37°C. The best results were obtained for Molloplast-B where bonded with chromium-cobalt alloy. Conclusion: Presented technology (Rocatec system) allows to achieve sufficient bond of elastic material to the metal framework and does not require any retainers.