Methods: Three kind of commercially available self-adhesive cements, RelyX Unicem (3M ESPE), Clearfil SA Luting (Kuraray) and G-Luting (GC), were used. Super-Bond C&B (Sun Medical) was used as a control. Buccal surface of extracted human deciduous incisors and canines was ground by SiC abrasive paper(#600) , and applied the self-adhesive cements on tooth surface and light-cured without loading. After 24h storage in 37 degree distilled water, the shear bond strength to human deciduous enamel were measured according to ISO/TS 11405:2003. The mode of failure and enamel etching pattern were also determined by light microscope and SEM.
Results: The mean shear bond strength of Rely X Unicem, Clearfil SA Luting, G-Luting and Super-Bond C&B was 2.2(SD:1.5) MPa, 3.0(SD:2.0) MPa, 5.2(SD:3.8) MPa and 6.3(SD:2.1) MPa, respectively. Those of Rely X Unicem and Clearfil SA Luting showed significantly small value compared with that of Super-Bond C&B. However, there was no significant difference between those of G-Luting and Super-Bond C&B. Cohesive failure in cement layer was observed in G-Luting and Super-bond C&B. In contrast, the occurrence of cohesive failure in cement layer was observed in few samples of Rely X Unicem and Clearfil SA Luting. Treatment of deciduous enamel with phosphoric acid gel caused significant surface demineralization, whereas such changes were less apparent following treatment with unset G-luting cements.
Conclusion: The results suggest that G-Luting would be useful as a splint material for fixation of luxated deciduous teeth.