Microtensile Bond Strength of Four Adhesives to Dentin of Primary Teeth

Objectives: The purpose of this study was to determine microtensile bond strength of four adhesives to dentin of primary teeth. Methods: Flat dentin of seventy-six primary incisors were prepared with wet 600 grit silicon carbide paper. Two conventional adhesives (Scotchbond MultiPurpose Plus, Single Bond), and two self etching adhesives (Clearfil SE Bond and Prompt-L-Pop) were randomly applied according to manufacturer’s instructions and followed by a block of composite resin ( Z 250) application. The teeth were kept in tab water for 24 h at 37 °C, sectioned to obtain one or two bar-shape specimens, which were then shaped to an hour – glass form producing 1.0 ± 0.2 mm² bond surfaces. All specimens were stressed in tension until fractured at a cross-head speed of 1 mm/min. Fractured specimens were further observed by SEM. The bond strength values were analyzed using one-way ANOVA and LSD test with level of significance 0.05. Results: There were no statistically significant differences of the mean microtensile bond strength to dentin of primary teeth when using Scotchbond MultiPurpose Plus ( 25.28 ± 9.10 MPa ), Single Bond ( 23.79 ± 8.79 MPa ) and Clearfil SE Bond ( 23.48 ± 9.10 MPa). Prompt-L-Pop had a significantly different mean bond strength (11.76 ± 3.54 MPa ) from the others. The fracture modes were mostly mixed failure. Conclusion: Scotchbond MultiPurpose Plus, Single Bond and Clearfil SE Bond provided similar bond strengths to dentin of primary teeth while Prompt-L-Pop exhibited lower bond strength.