Changes in microtopography across polished resin-dentin interfaces.
OBJECTIVE
To investigate the resistance of the hybrid layer to polishing and argon-ion etching by measuring the microprofile along the resin-dentin interface.


METHODS
Mid-coronal human dentin disks were treated with one of three commercially available dentin bonding systems (All-Bond 2, Clearfil Liner Bond II, Scotchbond Multi-Purpose Plus), and bonded together so as to prepare three pairs of specimens. The bonded assemblies were sectioned perpendicular to the adhesive interface and embedded in epoxy resin. The polished interfaces were argon-ion etched through a grid square mesh placed on the interface. A profile of the hybrid layer in the ion-etched and non-etched areas was taken using a surface analyzing scanning electron microscope.


RESULTS
The normal mineralized dentin showed no reduction after argon-ion etching. The hybrid layer was reduced more than the adhesive resins during argon-ion etching. Reduction of the hybrid layer by argon-ion etching was greater with phosphoric acid-treated groups than with a self-etching-treated group (P < 0.05). The surface profiles of the non-etched, polished hybrid layer showed a slight concavity, with the deepest point in the middle of the hybrid layer. Argon-ion etching created non-uniform reduction of the hybrid layer, producing the deepest point close to the top of the hybrid layer in all systems.
Harada
N
N
Department of Operative Dentistry, Faculty of Dentistry, Tokyo Medical and Dental University, Japan. n.harada.odnt@dent.tmd.ac.jp
Inokoshi
S
S
Tagami
J
J
D000704:Analysis of Variance; D003775:Dental Polishing; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D019279:Resin Cements; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors
C112274:Clearfil Liner Bond 2; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C100742:All-Bond 2