[Influence of smear layer and adhesive resin on the retentive force of amalgam restoration in vitro study].
The purposes of this in vitro study were to determine whether removing of smear layer and using of self-cured adhesive can increase retentive strength of amalgam restoration and to understand the adhesive mechanism between amalgam and adhesive. Class I cavities without mechanical retention were prepared in the occlusal surfaces of 45 extracted molars which were randomly divided into 3 groups. Group 1: 10%EDTA(pH 7.4) was applied to cavity walls for 1 minute prior to amalgam condensation. Group 2: 10%EDTA was applied in the same manner as in group 1, then the walls were water-sprayed and dried. Miradapt adhesive was applied, and amalgam must be packed into cavity before the adhesive cures.


METHODS
no special treatment before amalgam condensation. The tensile strength of the restorations were measured. The adhesive interface of two samples from group 2 were evaluated by SEM and EDS. As a result, removing smear layer had little effect on retentive force of amalgam (P > 0.05), while removing smear layer and applying adhesive improved the retentive strength of amalgam fillings significantly (P < 0.05), and there were micromechanical interlock between amalgam and adhesive according to SEM and EDS observation.
Chen
X
X
College of Stomatology, West China University of Medical Sciences.
Duan
H
H
D000269:Adhesives; D003723:Dental Amalgam; D003738:Dental Cements; D003781:Denture Retention; D006801:Humans; D066298:In Vitro Techniques; D008963:Molar; D011897:Random Allocation; D016369:Smear Layer
D000269:Adhesives; D003738:Dental Cements; D003723:Dental Amalgam