Microleakage of a Self-adhesive Composite of Class V Cavities: Effect of Surface Treatment and Thermocycling

Aim: This study aimed to assess the microleakage of a self-adhesive composite compared to conventional composites in class V cavities.

Materials and methods: In this in vitro experimental study, standard class V cavities were prepared in the buccal surface of 204 extracted teeth and randomly divided into six groups for restoration with (A) Vertiseflow (Kerr) self-adhesive composite, (B) acid etching (Kerr) + Vertiseflow, (C) acid etching + Optibond FL (Kerr) + Vertiseflow, (D) Er,Cr:YSGG laser + Vertiseflow, (E) acid etching + Optibond FL + Premise Flowable (Kerr), and (F) acid etching + Optibond FL + Z250 (3M). The teeth in each group were then randomly divided into two subgroups of with and without thermocycling (10,000 cycles between 5°C and 55°C). The microleakage was then determined at the enamel and dentin margins under a stereomicroscope using the dye penetration method. Data were analyzed using the Kruskal-Wallis test (α = 0.05).

Results: No significant difference was noted in occlusal margin microleakage of no thermocycling groups, but acid etching + Vertiseflow showed the highest microleakage. At the gingival margin, the difference between acid etching + bonding agent + Z250 and laser + Vertiseflow was significant (p = 0.004). In thermocycling groups, the difference in the microleakage at the occlusal margin of Vertiseflow with that of acid etching + bonding agent + Premise (p = 0.002), acid etching + bonding agent + Vertiseflow (p = 0.009), and acid etching + bonding agent + Z250 (p = 0.037) groups was significant. The difference in the microleakage at the dentin margin was also significant among the groups (p < 0.05). The highest and the lowest microleakages were noted in laser + Vertiseflow and acid etching + bonding agent + Vertiseflow groups, respectively.

Conclusion: Surface preparation with etching and adhesive application results in lower microleakage in class V cavities. But laser irradiation and the use of self-adhesive composite increase the microleakage.

Clinical significance: It seems that self-adhesive composites cannot provide acceptable marginal integrity without any surface treatment.