Interactions of self-etch adhesives with resin composites.
OBJECTIVE
Aim of this in vitro study was to investigate the correlation of shear bond strength and marginal cavity adaptation, together with polymerization shrinkage and contraction stress, using the combination of four self-etch adhesives and three resin composites.


METHODS
Interactions were studied between one two-step and three one-step adhesives, and the hybrid-type resin composites, Beautifil (BEU, Shofu) and Venus (VEN, Heraeus), and an experimental nano-hybrid resin composite NEUN (NEU, Heraeus). For all 12 combinations shear bond strengths (SBS) were determined on human dentin. Marginal adaptation (MGW) was assessed in cylindrical butt-joint dentin cavities. Further, polymerization contraction and contraction stress of the resin restoratives were measured.


RESULTS
Significant determinants of SBSs on dentin were time of testing (10min or 24h) and adhesives (p<0.001). Marginal adaptation was best for NEU, followed by VEN and BEU. Only the resin composite used was a highly significant determinant of cavity adaptation. Polymerization shrinkage after 5min was 2.58, 2.74, and 1.53% for BEU, VEN, and NEU, respectively. Polymerization contraction stresses were largest for BEU, less for VEN, and smallest for NEU (p<0.05).


CONCLUSIONS
No correlation was found between bond strength and marginal cavity adaptation. In contrast, reduced shrinkage and low polymerization contraction stress of resin composites were identified as important determinants of marginal cavity adaptation.
Kurokawa
Rie
R
Department of Oral Biological Science, Division of Orthodontics, Niigata University, Japan.
Finger
Werner J
WJ
Hoffmann
Marcus
M
Endo
Tatsuo
T
Kanehira
Masafumi
M
Komatsu
Masashi
M
Manabe
Atsufumi
A
D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000145:classification; D018772:Dental Marginal Adaptation; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties
C470433:Beautifil composite resin; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C503681:FL-BOND S-1; D008689:Methacrylates; D011108:Polymers; D019279:Resin Cements; C488393:Venus (composite resin); C470432:fluorobond self-etching primer; C477386:iBond; D017438:Bisphenol A-Glycidyl Methacrylate