title: Microtensile bond strength of a total-etching versus self-etching adhesive to caries-affected and intact dentin in primary teeth.
abstract: BACKGROUND
  The objec tives of this study were to determine microtensile bond strengths of two dentin adhesives and to compare the micromorphological structure of the resin/dentin interface in caries-affected dentin with that of intact dentin.
  
  
  METHODS
  The authors randomly divided 40 proximal dentinal carious primary teeth and 40 noncarious anterior primary teeth into two groups (self-etching and total-etching). They used a caries-detecting dye as an indicator of the need to remove the outer carious dentin. The authors restored the teeth with a hybrid resin-based composite. After 24 hours' storage in 37 C water, specimens were sectioned and shaped to form a curved section with a cross-sectional area of 1 square millimeter, then tension was applied until they fractured. The authors prepared the resin/dentin interfaces for the two bonding systems and examined them in 10 occlusal carious and 10 noncarious teeth.
  
  
  METHODS
  The bond strengths for intact and caries-affected dentin within the same group were analyzed via a t test. The authors compared the remaining dentin thickness (RDT) and dentin hardness using analysis of variance and the least significant difference test at the .05 level of significance.
  
  
  RESULTS
  The self-etching adhesive demonstrated no statistical difference in bond strength between intact and caries-affected dentin. However, the total-etching adhesive demonstrated different bond strengths for intact and caries-affected dentin. Moreover, the RDT of specimens with intact and caries-affected dentin was not significantly different, whereas the dentin hardness of caries-affected dentin was significantly lower than that of intact dentin. The authors found a thicker hybrid layer in intact and caries-affected dentin of specimens in the total-etching group.
  
  
  CONCLUSIONS
  The adhesives exhibited significantly different bond strengths in intact dentin of primary teeth. However, they exhibited similar bond strengths in caries-affected dentin.
authors.affiliation: Department of Pediatric Dentistry, Faculty of Dentistry, Mahidol University, Bangkok, Thailand. dtsnk@mahidol.ac.th
authors.forename: Siriruk
authors.initials: S
authors.lastname: Nakornchai
authors.forename: Choltacha
authors.initials: C
authors.lastname: Harnirattisai
authors.forename: Rudee
authors.initials: R
authors.lastname: Surarit
authors.forename: Sukhum
authors.initials: S
authors.lastname: Thiradilok
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003731:Dental Caries / Q000473:pathology*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013718:Tensile Strength; D014094:Tooth, Deciduous / Q000648:ultrastructure*; D015040:Zirconium / Q000737:chemistry
chemical_list: C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C083568:Z100 composite resin; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D015040:Zirconium