Microtensile bond strength of a total-etching versus self-etching adhesive to caries-affected and intact dentin in primary teeth.
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.
Nakornchai
Siriruk
S
Department of Pediatric Dentistry, Faculty of Dentistry, Mahidol University, Bangkok, Thailand. dtsnk@mahidol.ac.th
Harnirattisai
Choltacha
C
Surarit
Rudee
R
Thiradilok
Sukhum
S
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
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