title: The Effect of Surface Treatments on the Bond Strength Between CAD/CAM Blocks and Composite Resin.
abstract: OBJECTIVE
  The aim of this study was to evaluate the microtensile bond strength of three computer-aided design/computer-aided manufacturing (CAD/CAM) blocks repaired with composite resin using three surface treatment techniques.
  
  
  METHODS
  Three different CAD/CAM blocks were used in this study: (1) Lithium disilicate, (2) feldspar ceramic, and (3) resin nano ceramic. All groups were further divided into four subgroups according to surface treatment: control, roughened with bur (B); roughened with bur and 5% Hydrofluoric acid (HF); roughened with bur and sandblasting (HF); and roughened with bur and CoJet (C). After surface treatments on each group, a silane and bonding agent were applied, and ceramics were repaired with a nano-hybrid composite. Then, the repaired ceramics were cut with a low-speed diamond saw for microtensile bond testing. Microtensile bond tests for 40 specimens per subgroup were carried out with a universal testing machine. The data were analyzed with ANOVA, Tukey's, and LSD at the 95% significance level.
  
  
  RESULTS
  Mean bond strengths (MPa) of subgroups B, HF, S, and C were: 0, 29.8, 0, 23.3 for lithium disilicate ceramic; 26.4, 22.3, 22.4, 22 for feldspar ceramic; 54.8, 25.3, 42.1, 25.7 for resin nano ceramic. For subgroups B and S of lithium disilicate ceramics, bonding failed during specimen preparation. No significant differences were observed among all CoJet groups. In subgroups B and S, resin nano ceramics showed the highest bond strength. In feldspar groups, subgroup B showed higher bond strength than the other subgroups.
  
  
  CONCLUSIONS
  This study demonstrates that lithium disilicate porcelain blocks required etching for repairing with composite material. Surface treatments did not increase the bond strength in feldspar ceramic groups and reduced the bond strength in resin nano ceramic groups.
authors.affiliation: Department of Restorative Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Duzyol
authors.affiliation: Department of Restorative Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Omer
authors.initials: O
authors.lastname: Sagsoz
authors.affiliation: Department of Restorative Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Nurdan
authors.initials: N
authors.lastname: Polat Sagsoz
authors.affiliation: Department of Restorative Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Nilgun
authors.initials: N
authors.lastname: Akgul
authors.affiliation: Department of Restorative Dentistry, Ataturk University, Erzurum, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yildiz
mesh_terms: D000134:Acid Etching, Dental; D002516:Ceramics; D003188:Composite Resins; D001840:Dental Bonding; D003776:Dental Porcelain; D008422:Materials Testing; D019279:Resin Cements; D012821:Silanes; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D019279:Resin Cements; D012821:Silanes; D003776:Dental Porcelain
keywords: CAD/CAM restorations; acid etching; intraoral porcelain repair; microtensile bond strength; resin composite; sandblasting; surface treatment