title: Tensile bond strength between auto-polymerized acrylic resin and acrylic denture teeth treated with MF-MA solution.
abstract: OBJECTIVE
  This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin.
  
  
  METHODS
  Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (α=.05).
  
  
  RESULTS
  The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P<.05) when compared within the same brand. Among the surface treatment groups of each brand, there were no significantly different tensile bond strengths between the MF-MA groups and the MMA 180 second group (P>.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05).
  
  
  CONCLUSIONS
  15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Ticha
authors.identifier: 0000-0002-0651-8965
authors.initials: T
authors.lastname: Thongrakard
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.; Developing Research Unit in Polymeric Dental Materials in Prosthodontics, Bangkok, Thailand.
authors.forename: Chairat
authors.identifier: 0000-0001-6410-3605
authors.initials: C
authors.lastname: Wiwatwarrapan
keywords: Auto-polymerized acrylic; Denture base; Denture teeth; Methyl acetate; Methyl formate; Tensile bond strength