title: Can heat treatment procedures of pre-hydrolyzed silane replace hydrofluoric acid in the adhesion of resin cement to feldspathic ceramic?
abstract: OBJECTIVE
  To evaluate the influence of heat treatment (HT) procedures of a pre-hydrolyzed silane on bond strength of resin cement to a feldspathic ceramic.
  
  
  METHODS
  Ceramic and composite blocks (N = 30) were divided into six groups (n = 5) and subjected to the following conditioning procedures: G1: 9.6% hydrofluoric acid (HF) for 20 s + silane (RelyX Ceramic Primer, 3M ESPE) + resin cement (Panavia F2.0, Kuraray) (control); G2: HF (20 s) + silane + heat treatment in furnace (HTF) (100°C, 2 min) + resin cement; G3: silane + HTF + resin cement; G4- HF (20 s) + silane + heat treatment with hot air (HTA) (50 ± 5°C for 1 min) + resin cement; G5: silane + HTA + resin cement; G6: silane + resin cement. The microtensile bond strength (MTBS) test was performed using a universal testing machine (1 mm/min). After debonding, the substrate and adherent surfaces were analyzed using a stereomicroscope and SEM to categorize the failure types. The data were statistically evaluated using one-way ANOVA and Tukey's test (5%).
  
  
  RESULTS
  The control group (G1) showed no pre-test failures and presented significantly higher mean MTBS (16.01 ± 1.12 MPa) than did other groups (2.63 ± 1.05 to 12.55 ± 1.52 MPa) (p = 0.0001). In the groups where HF was not used, HTF (G3: 12.55 ± 1.52 MPa) showed significantly higher MTBS than did HTA (G5: 2.63 ± 1.05 MPa) (p < 0.05). All failure types were mixed, ie, adhesive between the resin cement and ceramic accompanied by cohesive failure in the cement.
  
  
  CONCLUSIONS
  Heat treatment procedures for the pre-hydrolyzed silane either in a furnace or with the application of hot air cannot replace the use of HF gel for the adhesion of resin cement to feldspathic ceramic. Yet when mean bond strengths and incidence of pre-test failures are considered, furnace heat treatment delivered the second best results after the control group, being considerably better than hot air application.
authors.forename: Caroline
authors.initials: C
authors.lastname: Cotes
authors.forename: Rodrigo Furtado
authors.initials: RF
authors.lastname: de Carvalho
authors.forename: Estevão Tomomitsu
authors.initials: ET
authors.lastname: Kimpara
authors.forename: Fabíola Pessoa
authors.initials: FP
authors.lastname: Leite
authors.forename: Mutlu
authors.initials: M
authors.lastname: Ozcan
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000268:Adhesiveness; D000538:Aluminum Silicates / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods*; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006358:Hot Temperature; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry*; D006868:Hydrolysis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D017680:Potassium Compounds / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000538:Aluminum Silicates; D003188:Composite Resins; C438843:Panavia-Fluoro; D017680:Potassium Compounds; D019279:Resin Cements; D012821:Silanes; D003776:Dental Porcelain; C016447:feldspar; D006858:Hydrofluoric Acid