Micro-CT evaluation of internal adaptation in composite restorations using incremental and sonic-activated techniques

Internal adaptation of composite restorations remains a challenge, particularly in posterior cavities, as voids and gaps can compromise clinical longevity. Therefore, it is of interest to compare the internal adaptation of composite restorations placed using conventional incremental, oblique incremental and sonic-activated bulk-fill techniques using high-resolution micro-computed tomography. Sixty standardized Class II cavities were restored (n=20 per group) and evaluated for internal gap volume, void volume and total defect percentage. The sonic- activated bulk-fill technique demonstrated significantly lower internal gap and void volumes compared to both incremental techniques (p<0.001). Sonic-activation provides superior internal adaptation, suggesting improved clinical performance over conventional layering methods.