title: Micro-shear bond strength and surface micromorphology of a feldspathic ceramic treated with different cleaning methods after hydrofluoric acid etching.
abstract: The aim of this study was to evaluate the effect of feldspathic ceramic surface cleaning on micro-shear bond strength and ceramic surface morphology.
  
  
  
  Forty discs of feldspathic ceramic were prepared and etched with 10% hydrofluoric acid for 2 minutes. The discs were randomly distributed into five groups (n=8): C: no treatment, S: water spray + air drying for 1 minute, US: immersion in ultrasonic bath for 5 minutes, F: etching with 37% phosphoric acid for 1 minute, followed by 1-minute rinse, F+US: etching with 37% phosphoric acid for 1 minute, 1-minute rinse and ultrasonic bath for 5 minutes. Composite cylinders were bonded to the discs following application of silane and hydrophobic adhesive for micro-shear bond strength testing in a universal testing machine at 0.5 mm/min crosshead speed until failure. Stereomicroscopy was used to classify failure type. Surface micromorphology of each treatment type was evaluated by scanning electron microscopy at 500 and 2,500 times magnification.
  
  
  
  One-way ANOVA test showed no significant difference between treatments (p=0.3197) and the most common failure types were cohesive resin cohesion followed by adhesive failure. Micro-shear bond strength of the feldspathic ceramic substrate to the adhesive system was not influenced by the different surface cleaning techniques. Absence of or less residue was observed after etching with hydrofluoric acid for the groups US and F+US.
  
  
  
  Combining ceramic cleaning techniques with hydrofluoric acid etching did not affect ceramic bond strength, whereas, when cleaning was associated with ultrasound, less residue was observed.
authors.affiliation: Imperatriz School of Dentistry, Imperatriz, MA, Brazil.
authors.forename: Henrique Caballero
authors.initials: HC
authors.lastname: Steinhauser
authors.affiliation: School of Dentistry, Sao Leopoldo Mandic Dental Research Institute, Campinas, SP, Brazil.
authors.forename: Cecilia Pedroso
authors.initials: CP
authors.lastname: Turssi
authors.affiliation: School of Dentistry, Sao Leopoldo Mandic Dental Research Institute, Campinas, SP, Brazil.
authors.forename: Fabiana Mantovani Gomes
authors.initials: FM
authors.lastname: Franca
authors.affiliation: School of Dentistry, Sao Leopoldo Mandic Dental Research Institute, Campinas, SP, Brazil.
authors.forename: Flavia Lucisano Botelho do
authors.initials: FL
authors.lastname: Amaral
authors.affiliation: School of Dentistry, Sao Leopoldo Mandic Dental Research Institute, Campinas, SP, Brazil.
authors.forename: Roberta Tarkany
authors.initials: RT
authors.lastname: Basting
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000538:Aluminum Silicates / Q000737:chemistry*; D000704:Analysis of Variance; D002516:Ceramics / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D019232:Dental Restoration Failure; D006858:Hydrofluoric Acid / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D017680:Potassium Compounds / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength / Q000187:drug effects; D013499:Surface Properties / Q000187:drug effects; D013997:Time Factors
chemical_list: D000538:Aluminum Silicates; D003188:Composite Resins; D017680:Potassium Compounds; D019279:Resin Cements; C016447:feldspar; D006858:Hydrofluoric Acid