Materials and methods: 60 freshly extracted mandibular molars were selected and standard class II cavities were made on mesial surface of each tooth. Samples were then randomly divided into 3 groups i.e. Group I- Activa bioactive (n=20), Group II- Tetric-N Ceram (n=20) and Group III- Filtek Bulk fill (n=20) and restored with the respective composite material. After storage and thermocycling, the samples were subjected to dye extraction method for microleakage analysis using a spectrophotometer.

Results: Results demonstrated that the bioactive restorative material Activa Bioactive (Group I) and Tetric-N-Ceram bulk fill (Group II) showed least microleakage followed by Filtek bulk Fill composite (Group III).The difference between Group I and Group II was not statistically significant (p<0.05) whereas the Group I and Group III and Group II and Group III was statistically significant (p<0.05).

Conclusion: Based on the results of the study it can be concluded that Activa bioactive and Tetric - N-Ceram showed least microleakage.