Marginal seal of class V restorations using thermoviscous and sonic-fill bulk fill composites

Abstract Aim To investigate the cervical and occlusal marginal seal of class V restorations using thermoviscous, sonic-fill bulk-fill and conventional SDR flowable bulk-fill composites. Materials and methods Standardized class V cavities were prepared in 45 extracted sound human molars that were randomly divided into three equal groups (n = 15) according to the restorative material used. This was divided as follow: group I (Surefil SDR flowable bulk-fill composite), group II (VisCalor bulk-fill composite), and group III (Sonic-fill 2 composite). Each restoration was applied according to the manufacturer’s instructions. All the specimens were subjected to 500 thermocyclings then were immersed in 2% methylene blue dye and sectioned to detect extend of the dye penetration using stereomicroscope. The data were collected, tabulated, and statistically analyzed using SPSS, version 26. Results There was no significant difference between the three tested groups in both occlusal and cervical marginal adaptation. However, a statistically significant difference was observed between group I which recorded a higher mean score of microleakage versus group II with P value = 0.059 at the occlusal walls. Concerning the comparison between occlusal and cervical dye penetration, it was found that there was no significant difference in both group I and group III. While in group II the occlusal margins had a lower mean score values of microleakage than the cervical walls with statistically significant difference ( P = 0.053). Conclusion All the tested materials presented nearly comparable occlusal and cervical marginal adaptation results. However, VisCalor bulk-fill composite enhanced the cervical marginal adaptation compared the occlusal margins.