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 microm). 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.