title: Durability of resin cement bond to aluminium oxide and zirconia ceramics after air abrasion and laser treatment.
abstract: OBJECTIVE
  The erbium laser has been introduced for cutting enamel and dentin and may have an application in the surface modification of high-strength aluminum oxide and zirconia ceramics. The aim of this study was to evaluate the durability of the bond of conventional dual-cured resin cements to Procera Al(2)O(3) and zirconium oxide ceramics after surface treatment with air abrasion and erbium laser.
  
  
  METHODS
  One hundred twenty Al(2)O(3) and 120 zirconia specimens measuring 3 × 3 × 0.7 mm(3) were divided equally into three groups, and their surfaces treated as follows: either untreated (controls), air abraded with Al(2)O(3) particles, or erbium-laser-treated at a power setting of 200 mJ. The surface of each specimen was then primed and bonded with one of two dual-cured resin cements (either SCP-100 Ceramic Primer and NAC-100 or Monobond S and Variolink II) using a 1-mm thick Tygon tube mold with a 0.75-mm internal bore diameter. After 24 hours and 6 months of water storage at 37°C, a microshear bond strength test was performed at a crosshead speed of 1 mm/min. Surface morphology was examined using a confocal microscope, and failure modes were observed using an optical microscope. The data were analyzed using the Kaplan-Meier nonparametric survival analysis.
  
  
  RESULTS
  In the case of zirconia, air abrasion and Erbium:yttrium-aluminum-garnet (Er:YAG) laser treatment of the ceramic surface resulted in a significant reduction in the bond strengths of both resin cements after 6 months water storage; however, when the zirconia surface was left untreated, the SCP-100/NAC-100 group did not significantly reduce in bond strength. In the case of alumina, no treatment, air abrasion and Er:YAG laser treatment of the surface led to no significant reduction in the bond strengths of the three SCP-100/NAC-100 groups after 6 months water storage, whereas all three Monobond S/Variolink II groups showed a significant reduction.
  
  
  CONCLUSIONS
  Er:YAG laser treatment of the zirconia surface did not result in a durable resin cement/ceramic bond; however, a durable bond between a conventional dual-cured resin cement and Procera All Ceram and Procera All Zirkon was formed using a ceramic primer containing the phosphate monomer, MDP, without any additional surface treatment.
authors.affiliation: Department of Restorative Dentistry, King's College London Dental Institute at Guy's, King's and St. Thomas' Hospitals, King's College London, UK. richard.foxton@kcl.ac.uk
authors.forename: Richard M
authors.initials: RM
authors.lastname: Foxton
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Cavalcanti
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakajima
authors.forename: Peter
authors.initials: P
authors.lastname: Pilecki
authors.forename: Martyn
authors.initials: M
authors.lastname: Sherriff
authors.forename: Luciana
authors.initials: L
authors.lastname: Melo
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Watson
mesh_terms: D020906:Air Abrasion, Dental; D000537:Aluminum Oxide; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods*; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D004871:Erbium; D053208:Kaplan-Meier Estimate; D053844:Lasers, Solid-State; D008422:Materials Testing; D011897:Random Allocation; D019279:Resin Cements; D055116:Self-Curing of Dental Resins; D033081:Shear Strength; D013499:Surface Properties; D015040:Zirconium
chemical_list: D019279:Resin Cements; D003776:Dental Porcelain; D004871:Erbium; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide