2004 Volume 22 Issue 3 Pages 195-205
The purpose of this study was to observe the resin-dentin interface after various surface treatments, and examine the relationship between the bond strength and the structure of the resin-impregnated layer. The methods of the dentinal surface treatment were divided into three groups. Group 1: etched by K-etchant, Group 2: etched by K-etchant, followed with 5% sodium hypochlorite for 60sec, Group 3: treated by the Clearfil MegaBond Primer, before application of the bonding agent, Clearfil PhotoBond (PB) or Clearfil MegaBond (MB). Firstly, the tensile bond strengths to dentin were measured, and then FESEM observation on the resin-dentin interface was performed after the argon ion beam etching or additionally treated with phosphoric acid and hypochlorite to partially remove the tooth tissues. The tensile bond strengths of each group were about 5MPa (Group 1)<7-9MPa (Group 2)<12-18MPa (Group 3), respectively. In group 1, the bonding resin monomer could not reach to the bottom of the decalcified dentin layer, while in group 3, bonding resin penetrated the decalcified dentin layer sufficiently and combined strongly with the underneath dentin layer.
