Abstract
Background and Objectives: One of the disadvantages of dental composites is polymerization shrinkage and subsequent microleakage. Since the use of a thin layer of flowable composite under composite restorations is one of the methods in improving marginal seal and microleakage reduction, the aim of the present study was to evaluate the effect of flowable composite liner on the microleakage of gingival margin of class V cavities restored with a seventh-generation (all-in-one) adhesive resin.
Materials and Methods: In buccal surfaces of 30 sound human premolars (with closed apex and extracted for orthodontic reason) class V cavities were prepared and their gingival margins were located 1 mm below CEJ. The teeth were randomly divided into two groups. In group 1, the samples were restored without flowable composite liner while group 2 specimens were restored using flowable composite liner. In order to restore the teeth, in both groups all-in-one adhesive resin and Z100 composite (using incremental technique) were used. Following finishing and polishing, the samples were subjected to thermocycling. Then they were immersed in 2% basic Fushin solution for 24 hours. Following sectionings the microleakage of gingival margin of the samples was evaluated under stereomicroscope. Non-parametric Mann-Whitney U test was used to compare the gingival microleakage of two groups.
Results: There were statistically significant differences in microleakage scores between two groups (P<0.0005).
Conclusion: The use of flowable composite liner in composite class V cavities restored with an all-in-one adhesive resin significantly reduced the microleakage of gingival margin.