In vitro studies on the microleakage of new kind of bonding agents

Objective To study the sealing ability of novel bonding agents. Methods TypeⅠcavities were prepared on occlusal surface of 30 freshly extracted molars. Teeth were randomly divided into 3 groups. Cavities were restored with 3M Z250, bonding by the following 3 type of adhesive system: one-component self-etch system, two-component self-etch system and total-etch system respectively. After thermal cycling, all teeth were immersed in methylene blue solution and then sectioned longitudinally. The cavity walls were examined by stereomicroscope to investigate the microleakage of the resin. Results There were significant differences in the results of the three groups (P 0.05). The one-component self-etch system showed the lowest incident of microleakage while the two-component self-etch system showed the highest incident of microleakage. Conclusion The new generation of one-component self-etch adhesive demonstrates a better effect of adhesion and marginal integrity.