Peel testing of bond between PDMS prosthetic elastomers and cpTi: A Weibull analysis approach

The purpose of this study was to investigate the bond strength of four silicone (PDMS) prosthetic elastomers, i.e. VST-50, A-588, TechSil 25 and Silbione used in the construction of facial prostheses to cpTi and acrylic resin as control through a primer and bonding enhancer application. A peel bond test at 90° was conducted according to ISO 813: 97 and the results were analyzed and interpreted using ANOVA and Weibull regression analysis. The bond failure mode was also examined under microscope. The results showed differences in mean bond strengths among PDMS with higher values showed by TechSil 25 and A-588. Also the failure mode showed differences between materials and substrates. Survival graphs showed that the failure pattern was different when different substrate or different bonding technique was used. Weibull analysis revealed that parameter β (Weibull modulus) had a value greater than 1 in all groups, indicating an increasing failure rate as expected and that only TechSil 25 had a high probability of surviving a stress of 0.30 N/mm in peel when bonded to a cpTi substrate.