Fluoridated light-activated bonding resin adhesion to enamel and dentin: primary vs. permanent.

Purpose: This study compared fluoridated bonding resin adhesion to primary enamel (Group 1), primary dentin (Group 2), permanent enamel (Group 3), and permanent dentin (Group 4). Methods: The buccal surfaces of 24 primary molars and 24 premolars were used. The bonding system and resin composite used in this study were Imperva Fluorobond  and Lite-Fil II A  (Shofu Inc., Kyoto, Japan). Effects of tooth surface conditioning by FB primer were observed using SEM (N=2/group). Shear bond strengths (SBS) were tested, and the test surfaces of enamel, dentin, and resin specimens were observed using SEM (N=10/group). Data was statistically analyzed using one-way ANOVA with subsequent post hoc Duncan’s new multiple range test at P<0.05. Results: Effects of tooth surface conditioning by FB primer were appropriate to dentin but low to enamel. Means and standard deviations of the SBS for each group were: Group 1 (16.34 , 5.53 MPa), Group 2 (15.06, 7.02 MPa), Group 3 (14.39, 6.52 MPa) and Group 4 (15.45, 5.35 MPa). There was no significant difference of SBS among Groups 1, 2, 3, and 4. Conclusion: Imperva Fluorobond  system gave the same level of bond strength to primary enamel, primary dentin, permanent enamel, and permanent dentin. (Pediatr Dent 22:101-106, 2000) It has been reported by many in vivo and in vitro studies that fluoride-releasing restorative materials may prevent the development of secondary caries in the restored tooth and the initiation of primary caries in adjacent tooth tissue. Glass ionomer cements have been used as materials for a fluoride source. Resin composites have been effective as restorative materials and the release of fluoride from several fluoride containing composites have been evaluated. Several reports have compared the bond strength between primary dentin and permanent dentin using different bonding systems. The results have varied with findings indicating no significant difference of bond strength between primary dentin and permanent dentin, significantly lower bond strengths to primary dentin, and higher bond strengths to primary dentin. Bond strength to primary dentin and permanent dentin might vary according to the morphological, physiological, and chemical differences between primary and permanent dentin. From the clinical perspective, bond strengths to primary enamel and dentin should be equivalent to permanent enamel and dentin. Recently, Imperva Fluorobond (Shofu Inc., Kyoto, Japan) a fluoride-releasing bonding resin for composite restoration that contains pre-reacted glass ionomer fillers, was developed. Release of fluoride from this material, cavity adaptation to bovine permanent teeth using this material, and bond strengths to bovine permanent enamel and dentin or to human permanent enamel and dentin using this material have been reported. However, no information on bonding to primary teeth using this material has been reported. The purpose of this study was to compare the bond strengths to enamel and dentin for human primary and permanent teeth using the Imperva Fluorobond system.