title: Comparison of bond stability between dual-cure resin cements and pretreated glass-infiltrated alumina ceramics.
abstract: OBJECTIVE
  To evaluate the bond stability of resin cements used for luting alumina-based all-ceramic dental restorations.
  
  
  BACKGROUND
  Although different pretreatments may be applied on alumina to improve bond strengths, any previous study investigated the bond stability of resin-based cements luted to laser-irradiated alumina.
  
  
  METHODS
  64 sintered, glass-infiltrated alumina blocks were sandblasted and randomly assigned to the following subgroups: 1. no additional treatment (NT); 2. Rocatec (Roc); 3. Nd:YAG laser (L); and 4. Nd:YAG laser plus Rocatec (LRoc). Composite samples were bonded to conditioned ceramics using two different resin based cements: a self-etching adhesive cement-Panavia F (PF) and a self-adhesive resin cement-RelyX Unicem (RXU). After 24 h, bonded specimens were cut into microtensile sticks (1 ± 0.1 mm(2)). One-half of the beams were loaded in tension until failure. The remaining one-half was immersed in 10%-NaOCl aqueous solution (NaOCl(aq)) for 12 h before testing. ANOVA and Student-Newman-Keuls tests were run (P < 0.05). Failure mode was recorded. Ceramic topography was SEM-analyzed.
  
  
  RESULTS
  After 24 h, L-sticks achieved the highest MTBS despite the cement type, whereas NT-samples recorded the lowest values. After NaOCl(aq) immersion bond strengths decreased except for RXU luted to NT-alumina. PF luted to L- and LRoc-samples, and RXU luted to L-sticks attained the highest bond strength.
  
  
  CONCLUSIONS
  Nd:YAG laser irradiation improved bond strength between alumina ceramics and resin cements (PF or RXU). Chemical challenging impaired adhesion, mainly through resin matrixes and silane coupling degradation. Laser-treated specimens remained with the highest bond strength.
authors.affiliation: Department of Prosthodontics, School of Dentistry, Complutense University of Madrid (UCM), Spain.
authors.forename: Raquel C
authors.initials: RC
authors.lastname: Oyagüe
authors.forename: Raquel
authors.initials: R
authors.lastname: Osorio
authors.forename: Bruno Lopes
authors.initials: BL
authors.lastname: da Silveira
authors.forename: Manuel
authors.initials: M
authors.lastname: Toledano
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000704:Analysis of Variance; D002516:Ceramics / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D007834:Lasers; D019279:Resin Cements / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D003738:Dental Cements; D017220:Dentin-Bonding Agents; C438843:Panavia-Fluoro; C483701:Rely X Unicem; D019279:Resin Cements; C076811:Rocatec; C023506:Glass ceramics; D000537:Aluminum Oxide