Comparative evaluation of tensile bond strength of silicone‑based denture liners after thermocycling and surface treatment.

ABSTRACT

Purpose: To examine, evaluate, and compare the tensile bond strength of two silicone‑based liners; one autopolymerizing and one heat cured, when treated with different chemical etchants to improve their adhesion with denture base resin. Materials and Methods: Hundred and sixty test specimens of heat‑cured polymethyl methacrylate (PMMA) were fabricated; out of which 80 specimens were tested for tensile bond strength after bonding it to autopolymerizing resilient liner (Ufigel P) and rest 80 to heat‑cured resilient liner (Molloplast B). Each main group was further divided into four subgroups of 20 specimens each, one to act as a control and three were subjected to surface treatment with different chemical etchants namely dichloromethane, MMA monomer, and chloroform. The two silicone‑based denture liners were processed between 2 PMMA specimens (10 mm × 10 mm × 40 mm) in the space provided by a spacer of 3 mm, thermocycled (5–55°C) for 500 cycles, and then their tensile strength measurements were done in the universal testing machine. Results: One‑way ANOVA technique showed a highly significant difference in the mean tensile bond strength values for all the groups. The Student’s t‑test computed values of statistics for the compared groups were greater than the critical values both at 5% and at 1% levels. Conclusion: Surface treatment of denture base resin with chemical etchants prior to the application of silicone‑based liner (Ufigel P and Molloplast‑B) increased the tensile bond strength. The increase was the highest with specimens subjected to 180 s of MMA surface treatment and the lowest with control group specimens.