title: Effect of reducing acid etching time on bond strength to noncarious and caries-affected primary and permanent dentin.
abstract: OBJECTIVE
  The purpose was to evaluate the effect of acid etching time on the bond strength of a simplified etch-and-rinse adhesive system to noncarious and caries-affected dentin of primary and permanent teeth.
  
  
  METHODS
  Twenty-four extracted primary and permanent teeth were divided into three groups, according to the acid etching time. Four teeth from each group were exposed to a microbiological caries-inducing protocol. After caries removal, noncarious and caries-affected dentin surfaces were etched with 37 percent phosphoric acid for five, 10, or 15 seconds prior to the application of Prime & Bond NT adhesive. Crowns were restored with resin composite and prepared for microtensile testing. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05).
  
  
  RESULTS
  Higher bond strengths were obtained for noncarious dentin vs. caries-affected dentin for both primary and permanent teeth. Reducing the acid etching time from 15 to five seconds did not affect the bond strength to caries-affected or noncarious dentin in primary teeth. For permanent teeth, lower bond strength values were observed when the noncarious dentin was etched for five seconds, while no difference was seen between 10 and 15 seconds.
  
  
  CONCLUSIONS
  For Prime & Bond NT, the etching of dentin for five seconds could be recommended for primary teeth, while 10 seconds would be the minimum time for permanent teeth.
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, at the Araraquara School of Dentistry, UNESP - Univ Estadual Paulista, Araraquara, São Paulo, São Paulo, Brazil.
authors.forename: Débora Lopes Salles
authors.initials: DL
authors.lastname: Scheffel
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, at the Araraquara School of Dentistry, UNESP - Univ Estadual Paulista, Araraquara, São Paulo, São Paulo, Brazil.
authors.forename: Hérica Adad
authors.initials: HA
authors.lastname: Ricci
authors.affiliation: Department of Physiology and Pathology, at the Araraquara School of Dentistry, UNESP - Univ Estadual Paulista, Araraquara, São Paulo, São Paulo, Brazil.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Souza Costa
authors.affiliation: Oral Biology, Department of Oral Biology, College of Dental Medicine, Georgia Health Sciences University, Augusta, Ga., USA.
authors.forename: David Henry
authors.initials: DH
authors.lastname: Pashley
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, at the Araraquara School of Dentistry, UNESP - Univ Estadual Paulista, Araraquara, São Paulo, São Paulo, Brazil. jhebling@foar.unesp.br.
authors.forename: Josimeri
authors.initials: J
authors.lastname: Hebling
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D001641:Bicuspid / Q000473:pathology / Q000648:ultrastructure; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000382:microbiology / Q000473:pathology*; D003764:Dental Materials / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000473:pathology / Q000648:ultrastructure; D010756:Phosphoric Acids / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D013295:Streptococcus mutans / Q000502:physiology; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014094:Tooth, Deciduous / Q000473:pathology / Q000648:ultrastructure*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; C533204:filtek Z350; C030242:phosphoric acid