title: [Effect of surface pretreatment with chemical etchants on bond strength between a silicone-based resilient liner and denture base resin].
abstract: OBJECTIVE
  To evaluate the effect of denture base resin surface pretreatment with chemical etchants on microleakage and bond strength between silicone-based resilient liner and denture base resin. The initial bending strength of denture base resin after surface pretreatment was also examined.
  
  
  METHODS
  Thirty-six polymethyl methacrylate (PMMA) denture base resin blocks (30 mm × 30 mm × 2 mm) were prepared and divided into three groups: group acetone, group methyl methy acrylate (MMA) and group control. Subsequently, a 2 mm silicone-based resilient liner was applied between every two blocks. After 5000 cycles in the thermal cycler (5 and 55°C), they were immersed in the (131) I solution for 24 hours and γ-ray counts were measured. Another 36 PMMA resin blocks (30 mm × 10 mm × 7.5 mm) were prepared. The blocks were divided into three groups and treated as mentioned above. A 3 mm silicone-based resilient liner was applied between every two blocks. After 5000 thermal cycles, tensile bond strength of the sample was measured in a universal testing machine. Another 18 PMMA resin blocks (65 mm × 10 mm × 3.3 mm) were prepared. They were divided into 3 groups and treated in the same way. After an adhesive was applied, the bending strength was measured with three-piont bending test.
  
  
  RESULTS
  Two experimental groups showed lower microleakage (520.0 ± 562.2 and 493.5 ± 447.9) and higher tensile bond strength [(1.5 ± 0.4) and (1.4 ± 0.5) MPa] than the group control [microleakage: (1369.5 ± 590.2); tensile bond strength: (0.9 ± 0.2) MPa, P < 0.05]. There was no statistically significant difference between group acetone and MMA in microleakage and tensile bond strength (P > 0.05). There was no statistically significant difference in bending strength among the three groups (P > 0.05).
  
  
  CONCLUSIONS
  Treating the denture base resin surface with acetone and MMA decreased the microleakage, increased the tensile bond strength between the two materials and did not make the initial bending strength of denture base resin decline.
authors.affiliation: Institute of Stomatology, Nanjing Medical University & Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Huai-qin
authors.initials: HQ
authors.lastname: Zhang
authors.forename: Jun-chi
authors.initials: JC
authors.lastname: Ma
authors.forename: Si-yuan
authors.initials: SY
authors.lastname: Jin
mesh_terms: D001840:Dental Bonding; D003738:Dental Cements; D003764:Dental Materials; D003819:Denture Bases; D003822:Denture Liners; D004129:Dimethylpolysiloxanes; D006801:Humans; D008422:Materials Testing; D019904:Polymethyl Methacrylate; D012826:Silicone Elastomers; D012828:Silicones; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003738:Dental Cements; D003764:Dental Materials; D004129:Dimethylpolysiloxanes; D012826:Silicone Elastomers; D012828:Silicones; D019904:Polymethyl Methacrylate