title: XP BOND in self-curing mode used for luting porcelain restorations. Part A: Microtensile test.
abstract: OBJECTIVE
  To assess the bond strength to dentin of an experimental adhesive and the proprietary resin cement used in different curing modes to lute ceramic disks of different thicknesses.
  
  
  METHODS
  Empress II disks (Ivoclar-Vivadent) were luted to dentin using XP BOND (Dentsply [XP]) in combination with the proprietary self-curing activator (SCA) and cement Calibra (Dentsply [C]). Curing of the adhesive was induced either by mixing with the activator (activator, groups 3 to 6) or by light irradiation for 20 s (group 2). The cement was either light cured for 40 s through the ceramic onlay (groups 1 to 5) or cured chemically (groups 6 and 7). Groups 2 and 4 were compared with group 1, in which Prime & Bond NT (Dentsply DeTrey) was tested as control. In groups 3 and 6, 2-mm-thick onlays were luted with XP+SCA, and the cement was light cured for 40 s or autocured for 5 min, respectively. These groups were compared with group 7, in which Syntac (Ivoclar Vivadent) was applied with C and, in order to reproduce the handling procedures of group 6 (although contrary to manufacturer's instructions), no light irradiation was provided for the adhesive or the cement. The influence of onlay thickness (2, 3, 4 mm) on the bond strength developed by XP+SCA/C was assessed by comparing groups 3, 4, 5. In these groups, C was light cured for 40 s through the onlay. Microtensile beams were obtained from the luted teeth.
  
  
  RESULTS
  Bond strengths not including pretest failures (in parentheses: value including pretest failures as 0 MPa) were 21.0 (17.5) MPa in group 1, 24.9 (21.2) MPa in group 2, 23.7 (21.3) MPa in group 3, 29.9 (26.7) MPa in group 4, 30.3 (24.6) MPa in group 5, 28.6 (24.6) MPa in group 6, and 17.1 (9.2) MPa in group 7. Statistically significant differences were found between groups 1 and 4, groups 3 and 5, and groups 6 and 7.
  
  
  CONCLUSIONS
  The bonding potential of XP BOND used with the activator or light cured in combination with Calibra in self- or dual-curing mode outperformed that of a control adhesive-cement system. The bond strength of XP+ SCA + Calibra was not negatively affected by the onlay thickness.
authors.affiliation: Department of Dental Materials and Prosthodontics, University of Siena, Siena, Italy.
authors.forename: Ornella
authors.initials: O
authors.lastname: Raffaelli
authors.forename: Maria Crysanti
authors.initials: MC
authors.lastname: Cagidiaco
authors.forename: Cecilia
authors.initials: C
authors.lastname: Goracci
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
mesh_terms: D001840:Dental Bonding; D003776:Dental Porcelain; D003804:Dentin; D006801:Humans; D007284:Inlays; D013718:Tensile Strength
chemical_list: D003776:Dental Porcelain