Scanning electron microscopic evaluation of resin-dentin interface after Er:YAG laser preparation.
OBJECTIVE
The aim of this study was to observe the morphological characteristics of dentin-resin interfaces when a composite resin was bonded to Er:YAG laser irradiated dentin.


METHODS
Human dentin surfaces were divided into three equal areas. One third was prepared using a carbide bur and etched with phosphoric acid, the second third was conditioned using an Er:YAG laser, the third one was irradiated and etched. A hybrid composite resin was bonded on dentin surfaces using a single-component adhesive system. Longitudinal sections were exposed to 5 N HCl then to 1% NaOCl. The thickness of the hybrid layer and the dimensions of the resin tags were measured using scanning electron microscopy (SEM) pictures and an image analysis software.


RESULTS
When acid etching was performed, a hybrid layer as well as the characteristic funnel-shaped resin tags were observed. When Er:YAG laser was used alone, no hybrid layer could be detected. The resin tags appeared thinner and exhibited a cylindrical shape.


CONCLUSIONS
The acid pre-treatment of the irradiated surface allowed both the seal of the dentinal surface and the increase of the diameter of the resin tags.
Laboratory of Surfaces and Interfaces in Odontology, University of Nice--Sophia Antipolis, Nice, France. mfbertra@unice.fr
Marie-France
MF
Bertrand
Daniel
D
Hessleyer
Michèle
M
Muller-Bolla
Samir
S
Nammour
Jean-Paul
JP
Rocca
D003188:Composite Resins / Q000528:radiation effects*; D003804:Dentin / Q000528:radiation effects* / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning
D003188:Composite Resins; D017220:Dentin-Bonding Agents