Comparative Study On The Adhesion To Primary Dentin

Objective: Resin composite in association with an adhesive system represents the gold standard in direct restorative dentistry both for permanent and for primary teeth. Simplification of the bonding procedures is especially desirable in pediatric dentistry, in order to provide restorations for young or non-complaint children. Therefore, because of its ease of use, self-etch technique may be preferable in the restoration of primary teeth. The latest trend has developed toward the self-adhesive resin cements, which may generate adhesions through mechanical and chemical interactions with tooth structure without requirement of a separate adhesive or etchant. The aim was to compare in-vitro the bond strength to human primary dentin of a self-adhesive light-curing resin composite, a self-etch adhesive and a glass-ionomer cement by means of µSBS test and SEM observations.

Method: Thirty primary human molars were sectioned to obtain a 2 mm-thick slab of mid-coronal dentin, randomly divided into three groups (n=10). Nine conical frustum-shaped build-ups were constructed on the occlusal surface of each dentin slab using a self-adhesive light-curing resin composite (Vertise Flow; Group 1), bonding agent (Optibond All-in-One; Group 2) combined with resin composite (Premise Flow) and a glass-ionomer cement (Ketac-Fil; Group 3). After thermo-cycling, specimens were subjected to µSBS test. All debonded specimens were observed at SEM. Data were statistically analyzed.

Result: The bond strength measured in Group 1 (9.8±4.3 MPa) was significantly lower than that one recorded in Group 2 (21.2±11.2 MPa) although it was significantly higher than the one recorded in Group 3 (4.9±2.4 MPa). Failures were mainly adhesive in all Groups.

Conclusion: The light-cured self-adhesive resin composite (Vertise Flow) was demonstrated to be a good compromise as regards bond strength, simplicity of use and operational times when applied to primary dentin. Therefore, this material may be useful in order to provide resin composite restorations for noncompliant children.