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 standar-dized 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 as-signed in the three groups (n=20): Group 1- single bond + tetric ceram (hybrid composite) as control group. Group 2- single bond + tetric flow (flowable composite) light cured simultaneously + tetric ceram. Group 3- single bond + tetric flow light cured separately + tetric ceram. After sto-rage 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 dif-ferences between the three tested groups was observed. Group 3 (Flowable and adhesive cured sepa-rately) revealed the less microleakage. Conclusions: The marginal seal of Cl V cavities could im-proved 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 inter-face especially at the cervical margins.