The effect of re-bonding using surface sealant or adhesive system on microleakage of class V resin composite restorations

Abstract

Background: Microleakage is still one of the defects of resin composites that can lead to treatment

failure; and re-bonding technique is one of the effective ways to reduce it. This study evaluated

the effect of re-bonding with a surface sealant or a dentin adhesive on microleakage in class V

microhybrid, nanohybrid, and packable composite restorations.

Materials and Methods: In this in vitro study, class V cavities with occlusal margins in enamel and

cervical margins in dentin/cementum were prepared on the buccal and lingual surfaces of 54 extracted

premolars. The prepared teeth were randomly assigned to three groups (3 group’s × 18 teeth each),

with each group being restored with microhybrid (Point 4); nanohybrid (Herculite XRV Ultra), and

packable (Packable Premise) resin composite. Following finishing and polishing procedures, each group

was randomly subdivided in to three subgroups (n = 12). The margins of two groups were both etched

and re-bonded with surface sealant (Optiguard) or dentin adhesive (Opti Bond Solo Plus) and control

group received no treatment. Specimens were thermocycled 1500 cycles, immersed in a methylene

blue, sectioned, evaluated for microleakage using a stereomicroscope at a x 20 and scored on a scale

of 0-3. Data were analyzed with Kruskal — Wallis, Mann — Whitney, and Wilcoxon tests (á = 0.05).

Results: There were no significant differences among the three resin composites tested, and also

no significant differences among subgroups with the same surface treatment. Only the microhybrid

and packable composite restorations sealed with Optiguard had significantly lower microleakage

compared to the control subgroups at the occlusal margin. There were no significant differences

between occlusal and cervical margins regarding the microleakage scores when compared to the

control subgroups of microhybrid and packable composite restorations.

Conclusion: The re-bonding technique could be considered as an advisable procedure in order

to minimize microleakage and its effect might be material-dependent.

Key Words: Microleakage, re-bonding technique, resin composite, surface sealant