title: Long-term microtensile bond strength of surface modified zirconia.
abstract: OBJECTIVE
  To compare long-term microtensile bond strength of zirconia, surface-modified via a novel treatment, to current surface conditioning methods for zirconia, when resin bonded to dental composite.
  
  
  METHODS
  Two ProCAD (porcelain) and 10 sintered ZirCAD (ZrO(2)) blocks (18 mm × 14 mm × 12 mm) were obtained from manufacturers. Twelve Herculite XRV composite blocks were fabricated (18 mm × 14 mm × 12 mm). Bonding surface of blocks was polished through 1200-grit SiC and air-abraded (50 μm alumina, 0.28MPa, 20s). Blocks were then separated into six groups: (1) porcelain (control), HF-etched/silane-treated, (2) ZrO(2), tribochemical-coated/silane-treated, (3) ZrO(2), primer-treated, (4) ZrO(2), modified via novel 3.2 nm silica layer/silane-treated, (5) ZrO(2), modified via novel 5.8nm silica layer/silane-treated, and (6) ZrO(2), modified via novel 30.4 nm silica layer/silane-treated. Blocks were bonded to composite using Clearfil Esthetic cement. Blocks were stored in distilled water (37°C, 24h), then cut into microtensile bars (n=8/gp), then bond strengths were measured using a universal testing machine at 0, 1, 3, and 6 months. All groups were statistically analyzed (ANOVA, Tukey's, p<0.05).
  
  
  RESULTS
  At 6 months (aging), all silica seed layer specimens displayed microtensile bond strength similar to CoJet specimens but less than that of silane-modified dental porcelain.
  
  
  CONCLUSIONS
  The deposition of a silica layer on zirconia resulted in similar or superior long-term resin bond strength when compared to traditional silanation and bonding techniques for zirconia but lower than that for silane-treated dental porcelain.
authors.affiliation: Bioscience Research Center, Nova Southeastern University, Fort Lauderdale, FL 33328-2018, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Smith
authors.forename: Carlos
authors.initials: C
authors.lastname: Villanueva
authors.forename: James K
authors.initials: JK
authors.lastname: Rothrock
authors.forename: Cristina E
authors.initials: CE
authors.lastname: Garcia-Godoy
authors.forename: Brian R
authors.initials: BR
authors.lastname: Stoner
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Piascik
authors.forename: Jeffrey Y
authors.initials: JY
authors.lastname: Thompson
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000537:Aluminum Oxide / Q000737:chemistry; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry; D003775:Dental Polishing / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D020156:Salicylic Acid / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D017554:Carbon Compounds, Inorganic; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; C076808:Monobond S; D010756:Phosphoric Acids; C454801:ProCAD Ceramic; D019279:Resin Cements; D012821:Silanes; D017655:Silicon Compounds; C530542:clearfil esthetic cement; D014867:Water; C065770:Herculite XR; D003776:Dental Porcelain; D012822:Silicon Dioxide; D015040:Zirconium; C030242:phosphoric acid; D000537:Aluminum Oxide; D020156:Salicylic Acid; C028541:zirconium oxide; C022088:silicon carbide