title: Effects of ceramic surface treatments on the bond strength of an adhesive luting agent to CAD-CAM ceramic.
abstract: OBJECTIVE
  The objective of this study was to evaluate the effect of different surface treatments on the micro-tensile bond strength (microTBS) of an adhesive luting agent to CAD-CAM ceramic. The hypothesis tested was that neither of the surface treatments would produce higher bond strength of the adhesive luting agent to CAD-CAM ceramic.
  
  
  METHODS
  Ceramic specimens of two different sizes (6 mm x 8 mm x 3 mm; 13 mm x 8 mm x 4 mm) were fabricated from ProCAD ceramic blocs (Ivoclar-Vivadent) with a low-speed diamond saw. The ceramic blocks were divided into seven groups and submitted to the following surface treatments: group 1: no treatment; group 2: etching with 37% H(3)PO(4); group 3: etching with 37% H(3)PO(4)+silane; group 4: etching with 37% H(3)PO(4)+silane+adhesive resin; group 5: etching with 4.9% HF acid; group 6: etching with 4.9% HF acid+silane; group 7: etching with HF acid+silane+adhesive resin. After surface treatment, two differently sized porcelain disks were bonded together with a composite luting agent (Variolink II, Ivoclar-Vivadent). The specimens were stored for 24h in distilled water at 37 degrees C prior to microTBS testing. One-way analysis of variance was used to test the influence of surface treatment and Scheffe multiple comparisons test determined pair-wise statistical differences (p<0.05) in microTBS between the experimental groups.
  
  
  RESULTS
  The mean microTBSs (standard deviation) are: group 1: 12.8 (+/-4.6)MPa; group 2: 19.1 (+/-5.0)MPa; group 3: 27.4 (+/-11.1)MPa; group 4: 34.0 (+/-8.9)MPa; group 5: 37.6 (+/-8.4) MPa; group 6: 34.6 (+/-12.8)MPa; group 7: 34.5 (+/-5.1)MPa. Statistical significant differences were found between group 1 and groups 3-7, and between group 2 and groups 4-7. All specimens of groups 1-4 exhibited adhesive failures, while a combination of adhesive and mixed (adhesive and cohesive) failures was observed in the specimens of groups 5-7.
  
  
  CONCLUSIONS
  The results show that surface treatment is important to bond to ceramic and suggests that etching is needed preferably with hydrofluoric acid than with phosphoric acid.
authors.affiliation: Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium. marleen.peumans@med.kuleuven.ac.be
authors.forename: M
authors.initials: M
authors.lastname: Peumans
authors.forename: K
authors.initials: K
authors.lastname: Hikita
authors.forename: J
authors.initials: J
authors.lastname: De Munck
authors.forename: K
authors.initials: K
authors.lastname: Van Landuyt
authors.forename: A
authors.initials: A
authors.lastname: Poitevin
authors.forename: P
authors.initials: P
authors.lastname: Lambrechts
authors.forename: B
authors.initials: B
authors.lastname: Van Meerbeek
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000538:Aluminum Silicates; D000704:Analysis of Variance; D001840:Dental Bonding; D003776:Dental Porcelain / Q000737:chemistry; D003799:Dental Stress Analysis; D006858:Hydrofluoric Acid; D008422:Materials Testing; D010756:Phosphoric Acids; D019279:Resin Cements; D012821:Silanes; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D000538:Aluminum Silicates; D010756:Phosphoric Acids; C454801:ProCAD Ceramic; D019279:Resin Cements; D012821:Silanes; D003776:Dental Porcelain; C078519:leucite; C030242:phosphoric acid; D006858:Hydrofluoric Acid