title: Comparative evaluation of tensile bond strength of silicone-based denture liners after thermocycling and surface treatment.
abstract: OBJECTIVE
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Prosthodontics, Maulana Azad Institute of Dental Sciences, New Delhi, India.
authors.forename: Harsimran
authors.initials: H
authors.lastname: Kaur
authors.forename: Kusum
authors.initials: K
authors.lastname: Datta
mesh_terms: D003822:Denture Liners; D019904:Polymethyl Methacrylate / Q000737:chemistry; D012828:Silicones / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D012828:Silicones; D019904:Polymethyl Methacrylate