Contraction stress in dentin adhesives bonded to dentin.
Adhesives cured under constrained conditions develop contraction stresses. We hypothesized that, with dentin as a bonding substrate, the stress would reach a maximum, followed by a continuous decline. Stress development was determined with a tensilometer for two total-etch systems and two systems with self-etching primers. The adhesives were placed in a thin layer between a glass plate and a flat dentin surface pretreated with phosphoric acid or self-etching primer. After an initial maximum shortly after light-curing, the stress decreased dramatically for the total-etch systems (70%) and, to a lesser extent, for the adhesives with self-etching primers (30%). The greater stress decrease for the total-etch systems was ascribed to water and/or solvents released into the adhesives from the fully opened dentinal tubules by the pulling/sucking action of the contraction stress. This happened less with the adhesives with self-etching primers, where the tubules remained mainly closed.
Hashimoto
M
M
Division of Pediatric Dentistry, Hokkaido University, Graduate School of Dental Medicine, Kita 13, Nishi 7, Kitaku, Sapporo 060-8586, Hokkaido, Japan. masanori-h@mue.biglobe.ne.jp
de Gee
A J
AJ
Kaga
M
M
Feilzer
A J
AJ
D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003188:Composite Resins; D045662:Dental Etching / Q000379:methods*; D003799:Dental Stress Analysis; D003804:Dentin; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000528:radiation effects*; D044367:Phase Transition; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D016369:Smear Layer; D013193:Stainless Steel; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical
D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; D013193:Stainless Steel