title: Effect of light aging on silicone-resin bond strength in maxillofacial prostheses.
abstract: OBJECTIVE
  The aim of this study was to investigate the effect of accelerated light aging on bond strength of a silicone elastomer to three types of denture resin.
  
  
  METHODS
  A total of 60 single lap joint specimens were fabricated with auto-, heat-, and photopolymerized (n = 20) resins. An addition-type silicone elastomer (Episil-E) was bonded to resins treated with the same primer (A330-G). Thirty specimens served as controls and were tested after 24 hours, and the remaining were aged under accelerated exposure to daylight for 546 hours (irradiance 765 W/m(2) ). Lap shear joint tests were performed to evaluate bond strength at 50 mm/min crosshead speed. Two-way ANOVA and Tukey's test were carried out to detect statistical significance (p < 0.05).
  
  
  RESULTS
  ANOVA showed that the main effect of light aging was the most important factor determining the shear bond strength. The mean bond strength values ranged from 0.096 to 0.136 MPa. The highest values were recorded for auto- (0.131 MPa) and photopolymerized (0.136 MPa) resins after aging.
  
  
  CONCLUSIONS
  Accelerated light aging for 546 hours affects the bond strength of an addition-type silicone elastomer to three different denture resins. The bond strength significantly increased after aging for photo- and autopolymerized resins. All the bonds failed adhesively.
authors.affiliation: Associate Professor and Chief of Maxillofacial Prosthetics Unit, Department of Prosthodontics, Dental School, University of Athens, Athens, Greece.
authors.forename: Gregory
authors.initials: G
authors.lastname: Polyzois
authors.forename: Antonis
authors.initials: A
authors.lastname: Pantopoulos
authors.forename: Triantafillos
authors.initials: T
authors.lastname: Papadopoulos
authors.forename: Muhanad
authors.initials: M
authors.lastname: Hatamleh
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry / Q000528:radiation effects*; D000269:Adhesives / Q000528:radiation effects*; D001840:Dental Bonding / Q000379:methods; D008027:Light; D008422:Materials Testing; D008447:Maxillofacial Prosthesis; D055595:Mechanical Phenomena / Q000528:radiation effects*; D055668:Photochemical Processes / Q000528:radiation effects*; D033081:Shear Strength / Q000528:radiation effects*; D012826:Silicone Elastomers / Q000737:chemistry / Q000528:radiation effects*; D013472:Sunlight
chemical_list: D000180:Acrylic Resins; D000269:Adhesives; D012826:Silicone Elastomers; C545984:episil
keywords: Bond strength; denture resins; light aging; silicone facial prosthesis