title: Pressable feldspathic inlays in premolars: effect of cementation strategy and mechanical cycling on the adhesive bond between dentin and restoration.
abstract: OBJECTIVE
  To evaluate the effect of the cementation strategy and mechanical cycling (MC) on the microtensile bond strength (MTBS) of feldspathic inlays cemented to premolars.
  
  
  METHODS
  Forty-eight human premolars were prepared and porcelain inlays were produced. Specimens were allocated into 3 groups, based on the cementation strategy: 1) conventional adhesive cementation (RelyX ARC, 3M ESPE): application of etch-and-rinse single bottle adhesive to dentin / ceramic surface treated with hydrofluoric acid (HF) and silane (S) / cementation with resin cement; 2) simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE); 3) modified simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE) with HF+S treatment. Half of the specimens from each group were submitted to MC (2x106 pulses, frequency = 4 Hz, load = 100 N). Each specimen was serially sliced for MTBS and the failures were classified. The stress distribution analysis using FEA was verified.
  
  
  RESULTS
  All of the bar-samples from G2 were lost during cutting of the specimens. Mechanical-cycling had no significant effect on bond strength, whereas cementation strategy significant affected MTBS results. The most common type of failure was cohesive of cement. FEA showed that stresses were concentrated mainly at the loading region going up to the root fixation.
  
  
  CONCLUSIONS
  Porcelain inlays cemented with conventional resin cement or self-adhesive resin cement should be associated with ceramic surface treatment. FEA showed the most critical zone for failure is located in the cement region close to the marginal crest.
authors.forename: Sabrina Alves
authors.initials: SA
authors.lastname: Feitosa
authors.forename: Pedro Henrique
authors.initials: PH
authors.lastname: Corazza
authors.forename: Paulo Francisco
authors.initials: PF
authors.lastname: Cesar
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Bottino
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Valandro
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D000538:Aluminum Silicates / Q000737:chemistry*; D001641:Bicuspid / Q000648:ultrastructure*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002484:Cementation / Q000379:methods*; D003188:Composite Resins / Q000737:chemistry; D017076:Computer-Aided Design; D001840:Dental Bonding / Q000379:methods*; D003737:Dental Cavity Preparation / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure*; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D007284:Inlays; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D000538:Aluminum Silicates; D003188:Composite Resins; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; D017680:Potassium Compounds; C462240:RelyX ARC; D019279:Resin Cements; D012821:Silanes; D003776:Dental Porcelain; C016447:feldspar; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C030242:phosphoric acid; D006858:Hydrofluoric Acid