title: Assessment of Enamel Bond Strength of Hypoplastic Primary Teeth.
abstract: OBJECTIVE
  The purpose of this study was to compare the enamel bond strength of hypoplastic and healthy primary teeth.
  
  
  METHODS
  Twenty-five hypoplastic teeth (experimental group) and 25 healthy primary teeth (control group) were selected and conditioned with 35 percent orthophosphoric acid before a two-layer adhesive system (Single Bond) was applied. Composite resin (Filtek Z350) was inserted in a single application, two-mm high and one-mm in diameter, and then light-cured for 20 seconds. After being stored in distilled water for 24 hours, the specimens were submitted to a shear bond strength test. Fractures were analyzed under a stereomicroscope.
  
  
  RESULTS
  No significant differences in bond strength were observed between the experimental group (70.27±20.40 MPa) and control group (67.84±23.37 MPa; P>0.05). However, adhesive fractures were more frequently observed in healthy teeth (72 percent) while hypoplastic teeth presented mixed fractures (60 percent) and enamel cohesive fractures (36 percent).
  
  
  CONCLUSIONS
  The shear bond strength of the enamel of hypoplastic primary teeth was similar to that of healthy teeth. However, distinct characteristics were observed in the dental samples following fracture.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Cruzeiro do Sul University, São Paulo, São Paulo, Brazil.
authors.forename: Lisa
authors.initials: L
authors.lastname: Scheidt
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Mato Grosso do Sul Federal University, Campo Grande, Mato Grosso do Sul, Brazil.
authors.forename: Mariane Emi
authors.initials: ME
authors.lastname: Sanabe
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul UFRGS, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Fabrãcio Mezzomo
authors.initials: FM
authors.lastname: Collares
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul UFRGS, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Vicente Castelo Branco
authors.initials: VC
authors.lastname: Leitune
authors.affiliation: Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University UNESP, São Josã dos Campos, São Paulo, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bresciani
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Cruzeiro do Sul University, São Paulo, São Paulo, Brazil. mibdiniz@hotmail.com.
authors.forename: Michele Baffi
authors.initials: MB
authors.lastname: Diniz
mesh_terms: D000134:Acid Etching, Dental; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000737:chemistry* / Q000648:ultrastructure; D003744:Dental Enamel Hypoplasia / Q000473:pathology*; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D010756:Phosphoric Acids; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013499:Surface Properties; D014094:Tooth, Deciduous
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D019279:Resin Cements; C533204:filtek Z350; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; C030242:phosphoric acid