title: Evaluation of the Effect of Different Surface Treatments on Luting CAD/CAM Composite Resin Overlay Workpieces.
abstract: OBJECTIVE
  To evaluate the effect of different surface treatments on luting CAD/CAM composite resin workpieces.
  
  
  METHODS
  One-hundred eight (108) composite CAD/CAM block sections (Lava Ultimate) 3 mm in thickness were polished up to 4000 grit and then randomly assigned to 6 experimental groups according to the applied surface treatment (no treatment, sodium bicarbonate [NaHCO3], glycine, alumina [Al2O3], CoJet, and SilJet). After standardized sandblasting procedures, 2 block sections from each group were randomly chosen for the qualitative SEM evaluation of the sandblasted surfaces. The remaining 96 CAD/CAM block sections were luted in pairs using a bonding agent (Single Bond) and a restorative composite resin (Filtek Ultimate). Specimens were aged for 2 weeks in 37°C water with 3000 thermal cycles (5°C/55°C), the microtensile test was performed (n = 30), and the values were statistically analyzed with ANOVA and Tukey's HSD post-hoc test (p = 0.05).
  
  
  RESULTS
  The qualitative SEM evaluation of the sandblasted surfaces showed that sodium bicarbonate and glycine had almost no conditioning effect on the CAD/CAM composite resin. In contrast, aluminum oxide, CoJet, and SilJet had a profound conditioning effect on the CAD/CAM composite resin. No treatment, sodium bicarbonate, and glycine specimens were debonded after thermal stressing (0 MPa), while aluminum oxide, CoJet, and SilJet showed high microtensile values (Al2O3: 104.45 ± 18.76 MPa; CoJet: 105.55 ± 11.88 MPa; SilJet: 105.02 ± 20.84 MPa), which were not statistically significantly different from each other.
  
  
  CONCLUSIONS
  Aluminum oxide-based sandblasting powders are the best choice for the surface treatment of CAD/ CAM workpieces.
authors.forename: Emmanuel M
authors.initials: EM
authors.lastname: Kassotakis
authors.forename: Minos
authors.initials: M
authors.lastname: Stavridakis
authors.forename: Tissiana
authors.initials: T
authors.lastname: Bortolotto
authors.forename: Stefano
authors.initials: S
authors.lastname: Ardu
authors.forename: Ivo
authors.initials: I
authors.lastname: Krejci
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002484:Cementation / Q000379:methods*; D003188:Composite Resins / Q000737:chemistry*; D017076:Computer-Aided Design; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000379:methods; D005998:Glycine / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry; D010316:Particle Size; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D017693:Sodium Bicarbonate / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D017693:Sodium Bicarbonate; D000537:Aluminum Oxide; D005998:Glycine