Abstract
The purpose of this study was to investigate the effects of the self-etching system on the resin ad hesion to the primary enamel and dentin, and compare the results with those to the primary enamel and dentin which were previously reported.
The labial surfaces of 48 extracted and frozen bovine mandibular primary incisors were used. The adhesive system and composite resin used in this study were Kuraray Co. Clearfil Liner Bond II (LB II) and Clearfil Photo Anterior. The adhesive systems used in the previous studies were Kuraray Co. Liner Bond (LB), K-etchant and Photo Bond (KP), Sunmedical Co. Super bond D Liner (SDL), Bisco Inc. All Bond 2 (AB 2) and 3 M Co. Scotchbond Multi Purpose (SMP). Thermal cycling tests thermocycled 10,000 times between water baths maintained at 4°C and 60°C were attempted. The tooth surface conditioning effects were observed in the SEM. The shear bond strength was tested and the test surfaces of the enamel, dentin and resin specimens were observed in the SEM.
1. The tooth surface conditioning effect of the LB Primer to the enamel was low and that to the dentin was mild.
2. In the comparison of the bond strengths of the non-thermal cycled groups and the thermal cycled groups of LB II, in the dentin, the bond strength of the thermal cycled group was significantly lower than that of the non-thermal cycled group (P<0.01).
3. In the comparison of the bond strengths to the enamel and to the dentin, in the thermal cycled groups, the bond strength to the dentin was significantly lower than that to the enamel (P< 0.01).
4. In the enamel, the bond strengths of LB II was significantly lower than those of all bond strengths which were previously reported except for the non-thermal cycled KP and LB groups.
5. In the dentin, the bond strengths of LB II was significantly lower than those of all bond strengths which were previously reported except for the non-thermal cycled LB and SMP groups.
6. No correlation was found between the enamel-resin or dentin-resin fracture mode and bond strength for the LB II system.
