Objectives: In pediatric dentistry, it is common practice to place sealants over composite resin restorations, however, the methods by which this is done may vary. The aim of this research project was to measure and compare the bond strength between sealant and composite resin using several different methods. The techniques compared were direct placement of sealant material over composite resin with no pre-treatment, etching the surface prior to placing sealant, roughening the surface prior to placing sealant, and etching and placing a bonding agent prior to placing sealant. Methods: Cylindrical specimens (8x10mm) of composite resin (Heliomolar; Ivoclar Vivadent) were formed and the surface of one end of the cylinder was treated according to the following group designations (n=15/group): 1. Composite resin no treatment (control). 2. Composite resin treated with etch only (Total Etch, 37% phosphoric acid gel; Ivoclar). 3. Composite resin with etch & adhesive (Heliobond, Ivoclar). 4. Composite resin, roughened (600 grit SiC paper).
Cylindrical specimens (3x4mm) of sealant (Helioseal; Ivoclar) were bonded to the composite cylinders using molds, an incremental technique, and manufacturer’s instructions for light curing. The bonded specimens were thermocycled (5/55oC) for 2500 cycles. The bond strength was determined in a shear mode of action using a universal testing machine (Instron). Bond strength data was examined with one-way ANOVA. Results: The shear bond strengths for Groups 1-4 were: 21.7 ±6.1, 24.1 ±5.6, 21.9 ±6.2, and 16.4 ±6.1 MPa, respectively. Group 2 was significantly (P<.05) greater than Group 4, but no significant differences were observed between Groups 1, 2, and 3. Conclusions: Etching the surface of the composite resin prior to sealant application resulted in the greatest bond strengths, although it was not significantly different from etching and bonding or no surface treatment. Roughening the composite resin surface was detrimental to the bond strength compared to using an etch approach.