title: The effect of poly(methyl methacrylate) surface treatments on the adhesion of silicone-based resilient denture liners.
abstract: BACKGROUND
  Different surface treatment protocols of poly(methyl methacrylate) have been proposed to improve the adhesion of silicone-based resilient denture liners to poly(methyl methacrylate) surfaces.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the effect of different poly(methyl methacrylate) surface treatments on the adhesion of silicone-based resilient denture liners.
  
  
  METHODS
  Poly(methyl methacrylate) specimens were prepared and divided into 4 treatment groups: no treatment (control), methyl methacrylate for 180 seconds, acetone for 30 seconds, and ethyl acetate for 60 seconds. Poly(methyl methacrylate) disks (30.0 × 5.0 mm; n = 10) were evaluated regarding surface roughness and surface free energy. To evaluate tensile bond strength, the resilient material was applied between 2 treated poly(methyl methacrylate) bars (60.0 × 5.0 × 5.0 mm; n = 20 for each group) to form a 2-mm-thick layer. Data were analyzed by 1-way ANOVA and the Tukey honestly significant difference tests (α = .05). A Pearson correlation test verified the influence of surface properties on tensile bond strength. Failure type was assessed, and the poly(methyl methacrylate) surface treatment modifications were visualized with scanning electron microscopy.
  
  
  RESULTS
  The surface roughness was increased (P < .05) by methyl methacrylate treatment. For the acetone and ethyl acetate groups, the surface free energy decreased (P < .05). The tensile bond strength was higher for the methyl methacrylate and ethyl acetate groups (P < .05). No correlation was found regarding surface properties and tensile bond strength. Specimens treated with acetone and methyl methacrylate presented a cleaner surface, whereas the ethyl acetate treatment produced a porous topography.
  
  
  CONCLUSIONS
  The methyl methacrylate and ethyl acetate surface treatment protocols improved the adhesion of a silicone-based resilient denture liner to poly(methyl methacrylate).
authors.affiliation: Graduate student, Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Yuri Wanderley
authors.initials: YW
authors.lastname: Cavalcanti
authors.affiliation: Graduate student, Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Martinna Mendonça
authors.initials: MM
authors.lastname: Bertolini
authors.affiliation: Professor, Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Altair Antoninha Del Bel
authors.initials: AA
authors.lastname: Cury
authors.affiliation: Professor, Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil. Electronic address: wanderjose@fop.unicamp.br.
authors.forename: Wander José
authors.initials: WJ
authors.lastname: da Silva
mesh_terms: D000085:Acetates / Q000737:chemistry; D000096:Acetone / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D003822:Denture Liners; D006801:Humans; D008422:Materials Testing; D020366:Methylmethacrylate / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D016062:Porosity; D012826:Silicone Elastomers / Q000737:chemistry; D012828:Silicones / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013500:Surface Tension; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D000085:Acetates; D000180:Acrylic Resins; D003764:Dental Materials; D012826:Silicone Elastomers; D012828:Silicones; D012997:Solvents; C483158:Ufi gel; C539102:vipi wave; D000096:Acetone; D020366:Methylmethacrylate; C007650:ethyl acetate; D019904:Polymethyl Methacrylate