title: Surface treatment with methyl formate-methyl acetate increased the shear bond strength between reline resins and denture base resin.
abstract: BACKGROUND
  Chemical surface treatment increases the shear bond strength (SBS) between hard reline resins (HRRs) and denture base resin.
  
  
  OBJECTIVE
  To evaluate the effect of methyl formate-methyl acetate (MF-MA), when used as a surface treatment agent, on the SBS between denture base resin and different HRRs.
  
  
  METHODS
  One hundred and twenty specimens of heat-polymerised acrylic resin denture base (Meliodent(®) ) were divided into 12 groups. These groups comprised denture base relined with three self-polymerised HRRs [Unifast trad(®) (UT), Tokuyama(®) RebaseII Fast (TR), Ufi gel hard(®) (UG)], and treated with their respective Bonding Agent (BA) or by MF:MA solutions at ratios of 35:65, 25:75, and 15:85 for 15 s. The SBS was measured using a Universal Testing Machine. The data were analysed using two-way anova and post hoc Tukey's analysis at p < 0.05.
  
  
  RESULTS
  The highest SBS was in the UT treated with MF:MA at a ratio of 25:75 group, followed by UT treated with MF:MA at ratios of 15:85, 35:65, UT treated with BA, and all UG treated with MF:MA groups. The SBS of the UT treated with MF:MA at a ratio of 25:75 group was significantly higher than those of the groups treated with BA. The SBS of the UG treated with MF:MA groups was significantly higher than control. The TR groups treated with BA or MF:MA groups showed no significant difference in SBS.
  
  
  CONCLUSIONS
  Surface treatment with MF-MA significantly enhanced the SBS of denture base resin and UT and UG compared to that of the groups treated with BA.
authors.affiliation: Faculty of Dentistry, Department of Prosthodontics, Chulalongkorn University, Bangkok, Thailand.
authors.forename: Rachanee
authors.initials: R
authors.lastname: Osathananda
authors.affiliation: Faculty of Dentistry, Department of Prosthodontics, Chulalongkorn University, Bangkok, Thailand.|Developing Research Unit in Dental Polymeric Materials in Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok Thailand.
authors.forename: Chairat
authors.initials: C
authors.lastname: Wiwatwarrapan
mesh_terms: D000085:Acetates; D000180:Acrylic Resins; D001840:Dental Bonding / Q000379:methods*; D003819:Denture Bases; D003823:Denture Rebasing / Q000379:methods; D005563:Formic Acid Esters; D006801:Humans; D008422:Materials Testing; D033081:Shear Strength
chemical_list: D000085:Acetates; D000180:Acrylic Resins; D005563:Formic Acid Esters; C025468:methyl formate; C046923:methyl acetate
keywords: denture base; hard reline resin; shear bond strength; surface treatment.