Dimensional changes and ultimate tensile strengths of wet decalcified dentin applied with one-bottle adhesives.
OBJECTIVE
The objectives of this study were to test the null hypothesis that no dimensional changes in wet decalcified dentin matrices will occur during the application of one-bottle adhesives, and to evaluate the ultimate tensile strengths (UTS) of resin-infiltrated dentin matrices using the microtensile test.


METHODS
Dentin disks 0.2 mm thick were prepared from mid-coronal dentin of human unerupted third molars. They were completely decalcified in 0.5 M EDTA (pH 7.4) for 5 days at 25 degrees C and then placed in the bottom of an aluminum well to permit use of the LVDT portion of a thermal mechanical analyzer. Changes in matrix height in response to the application of Single Bond, One-Step or Prime & Bond NT were measured along with the UTS of resin-infiltrated specimens that were compared using a one-way ANOVA and Fisher's PLSD test.


RESULTS
All one-bottle adhesives produced a gradual, progressive shrinkage of the decalcified matrix of 26-33%. The shrinkage produced by Single Bond was significantly greater (p<0.05) than that produced by the other adhesives. The UTS of One-Step was significantly higher (<0.05) than that of Prime & Bond NT (42.0+/-13.6 vs 29.7+/-1.9 MPa, respectively), with Single Bond producing intermediate UTS (34.3+/-7.4 MPa).


CONCLUSIONS
If the durability of resin-dentin bonds depends upon the size of interfibrillar spaces for both diffusion channels and resin uptake, then adhesive formulations should be designed to minimize matrix shrinkage during resin infiltration.
Nakajima
M
M
Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 5-45 Yushima 1-chome, Bunkyo-ku, 113-8549, Tokyo, Japan. nakajima.ope@tmd.ac.jp
Okuda
M
M
Pereira
P N R
PN
Tagami
J
J
Pashley
D H
DH
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000494:pharmacology; D003648:Decalcification Technique; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects*; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000494:pharmacology*; D024022:Fibrillar Collagens / Q000737:chemistry; D006801:Humans; D006860:Hydrogen Bonding; D008422:Materials Testing; D008689:Methacrylates / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D011109:Polymethacrylic Acids / Q000494:pharmacology; D016062:Porosity; D013718:Tensile Strength; D014867:Water
C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; D017220:Dentin-Bonding Agents; D024022:Fibrillar Collagens; D008689:Methacrylates; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate