Method: 40 human posterior teeth were prepared with class I restorations and randomly divided into 4 groups (n=10): Group 1 was restored with a conventional composite resin with the incremental, diagonal technique and was used as a control. Group 2 was restored with Tetric EvoCeram Bulk Fill (Ivoclar, Vivadent). Group 3 was restored with Tetric EvoCeram Bulk Fill which was placed with a vibrating placement and modeling instrument (Compothixo, Kerr). Group 4 was restored with SonicFill (Kerr). Self-etch bonding systems were used and enamel was additionally etched. Teeth were polished, stored in physiological saline, thermocycled for 1500 cycles in 5°C/36°C/55°C/36°C (dwell time 15 secs), sealed with varnish except 1mm area around the restoration and immersed in 5% aqueous solution of methylene blue for 24h. Two longitudinal mesio-distal cuts were made in a microtome at 1 mm and at 2 mm away from the restoration margin and were studied under a stereomicroscope at 400X magnification. Microleakage was classified according to the degree of dye penetration observed. Mean scores were calculated for each specimen. Scores were analysed with SPSS 20.0 using Kruskal Wallis and Mann Whitney test for multiple comparisons. Statistical significance was set at p<0.05.
Results: Ascending microleakage mean scores were as follows: 2<3<1<4. No significant statistical difference was exhibited between Groups 1 and 4, 2 and 3 (p>0.05).
Conclusion: Performance of bulk fill composites and comparison to conventional restoratives seems to be product-dependent. Additional sonication during placement does not have an important effect on microleakage of the composite. Formation of gaps between pulpal wall and bulk fill composite depends on the material’s viscosity.