Effects of Flowable Composite Resin and curing method on Microleakage

Aims: The purpose of this invitro study was to evaluate the effects of a flowable composite associated with an adhesive, either light cured separately or co-cured on the microleakage of class V composite restorations. Material and methods: Sixty extracted human premolars were prepared with standardized box shaped class V cavities of 3.0mm (Mesial distal), 2.mm (occlusal gingival) and 2.0mm depth with margins located on enamel and dentin on the buccal surfaces. The cavities were randomly assigned in the three groups (n=20): Group 1single bond + tetric ceram (hybrid composite) as control group. Group 2single bond + tetric flow (flowable composite) light cured simultaneously + tetric ceram. Group 3single bond + tetric flow light cured separately + tetric ceram. After storage period of one week in water, All specimens were thermo-cycled for 300 times with 15 seconds dwell time, and immersed in 2% methylene blue, sectioned and evaluated for microleakage using 0-3 scale. Data were subjected to Fisher Freeman Halton test at p<0.05. Results: Statistical significant differences between the three tested groups was observed. Group 3 (Flowable and adhesive cured separately) revealed the less microleakage. Conclusions: The marginal seal of Cl V cavities could improved by the use of flowable resin with rigid composite resin, but even with supposedly better flow and adaptation characteristic of this material it could not completely sealed the tooth/ restoration interface especially at the cervical margins.