Purpose: The aim of this clinical trial was to compare a self-adhesive flowable resin composite, a highly filled flowable resin composite used in combination with a universal adhesive applied in self-etch mode, and a conventional flowable resin composite used in combination with a universal adhesive applied using two different application modes in occlusal cavities.
Materials and Methods: Twenty-eight patients received 114 occlusal restorations. Cavities were divided into four groups: CS: a self-adhering flowable (Constic, DMG); GF: a highly filled flowable (G-ænial Universal Flo, GC) in combination with a universal adhesive applied in self-etch mode (G-Premio Bond, GC); TF-SE: a conventional flowable (Tetric N-Flow, Ivoclar Vivadent) in combination with a universal adhesive (Tetric N-Bond Universal, Ivoclar Vivadent) applied in self-etch mode; TF-ER: a conventional flowable (Tetric N-Flow, Ivoclar Vivadent) in combination with a universal adhesive (Tetric N-Bond Universal, Ivoclar Vivadent) applied in etch&rinse mode. Restorations were scored using modified USPHS criteria. Descriptive statistics were performed using chi-squared tests.
Results: At 24-month evaluations, none of the restorations were lost. The CS group showed significantly higher bravo scores for marginal adaptation than did the other experimental groups (p = 0.024). Significant changes were seen for CS and GF regarding marginal adaptation compared to baseline.
Conclusion: Although the self-adhering flowable resin composite exhibited inferior marginal adaptation compared to the highly filled flowable and conventional flowable resin composites, the restored teeth demonstrated a clinically acceptable performance after 24 months.