title: The effect of additional etching and curing mechanism of composite resin on the dentin bond strength.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of additional acid etching and curing mechanism (light-curing or self-curing) of a composite resin on the dentin bond strength and compatibility of one-step self-etching adhesives.
  
  
  METHODS
  Sixteen human permanent molars were randomly divided into eight groups according to the adhesives used (All-Bond Universal: ABU, Clearfil S3 Bond: CS3), additional acid etching (additional acid etching performed: EO, no additional acid etching performed: EX), and composite resins (Filtek Z-250: Z250, Clearfil FII New Bond: CFNB). Group 1: ABU-EO-Z250, Group 2: ABU-EO-CFNB, Group 3: ABU-EX-Z250, Group 4: ABU-EX-CFNB, Group 5: CS3-EO-Z250, Group 6: CS3-EO-CFNB, Group 7: CS3-EX-Z250, Group 8: CS3-EX-CFNB. After bonding procedures, composite resins were built up on dentin surfaces. After 24-hour water storage, the teeth were sectioned to make 10 specimens for each group. The microtensile bond strength test was performed using a microtensile testing machine. The failure mode of the fractured specimens was examined by means of an optical microscope at ×20 magnification. The data was analyzed using a one-way ANOVA and Scheffe's post-hoc test (α=.05).
  
  
  RESULTS
  Additional etching groups showed significantly higher values than the no additional etching group when using All-Bond Universal. The light-cured composite resin groups showed significantly higher values than the self-cured composite resin groups in the Clearfil S3 Bond.
  
  
  CONCLUSIONS
  The additional acid etching is beneficial for the dentin bond strength when using low acidic one-step self-etch adhesives, and low acidic one-step self-etch adhesives are compatible with self-cured composite resin. The acidity of the one-step self-etch adhesives is an influencing factor in terms of the dentin bonding strength and incompatibility with a self-cured composite resin.
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Pusan National University, Dental Research Institute, Yangsan, Republic of Korea.
authors.forename: In-Su
authors.initials: IS
authors.lastname: Lee
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Pusan National University, Dental Research Institute, Yangsan, Republic of Korea.
authors.forename: Sung-Ae
authors.initials: SA
authors.lastname: Son
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Pusan National University, Dental Research Institute, Yangsan, Republic of Korea.
authors.forename: Bock
authors.initials: B
authors.lastname: Hur
authors.affiliation: Department of Dental Materials, School of Dentistry, Pusan National University, Yangsan, Republic of Korea.
authors.forename: Yong-Hoon
authors.initials: YH
authors.lastname: Kwon
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, Pusan National University, Dental Research Institute, Yangsan, Republic of Korea.
authors.forename: Jeong-Kil
authors.initials: JK
authors.lastname: Park
keywords: Acidity; Adhesive; Bond strength; Compatibility; Self-etch