Shear bond strength of composite resin bonded to preformed metal crowns for primary molars using a universal adhesive and two different surface treatments: an in vitro study.

AIM

This was to determine the shear bond strength of composite resin bonded to preformed metal crowns with a new adhesive. Buccal surfaces of the crowns were roughened by two different methods to increase retention.

METHOD

Typodont mandibular second primary molars (38) were divided into two groups (19 per group). Preformed metal crowns were cemented to the teeth with glass-ionomer cement. To enhance retention, buccal surfaces of the crowns in group I were roughened with cross-cut carbide burs (SS White #56); crowns in group II were sandblasted (aluminium oxide, 50 µm). Scotchbond Universal Adhesive (3 M-ESPE) was used to bond composite resin to the crowns. A universal testing machine tested the maximum shearing force withstood by the veneered composite surfaces.

RESULTS

Sandblasted crowns demonstrated significantly higher resistance (p = 0.001) to shearing force (324.4 N) than did the crowns that were roughened with a bur (234.2 N).

CONCLUSION

Chairside veneering of composite resin to pretreated crowns could be a feasible, aesthetically pleasing, and an economical option in paediatric dentistry.