Polycaprolactone Impregnated 3D Printed Nanohydroxyapatite for Sinus Augmentation: A Randomized Controlled Trial.

Objective: To compare the effect of polycaprolactone impregnated 3D printed nano-hydroxyapatite (3DPHA-PCL) with bovine bone substitute material (BB) in lateral maxillary sinus floor elevation (MSFE).

Materials and methods: Lateral MSFE with two bone substitute materials was randomly performed in two centers: group BB (n = 11 sinuses) or group 3DPHA-PCL (n = 11 sinuses). Lateral MSFE with two bone substitute materials was performed on 21 participants across two centers, resulting in a total of 22 sinuses analyzed. The sinuses were randomly allocated into two groups: group BB (11 sinuses) and group 3DPHA-PCL (11 sinuses). Cone beam computed tomography (CBCT) was taken before (T0) and immediately after MSFE (T1), at 6 months (implant placement; T2), and 1 year (T3). Dimensional stability of the augmentation was analyzed using serial CBCT scans. At the time of implant placement, bone core biopsy was performed, followed by microcomputed tomographic (micro-CT) and histomorphometric analyses.

Results: Based on the superimposed CBCT images between T1 and T2, the augmented height and volume decreased in both groups without a statistically significant difference between the groups (-0.48 ± 1.01 mm, -53.9 ± 117.8 mm³ in group BB vs. -0.39 ± 0.44 mm, -40.8 ± 101.2 mm³ in group 3DPHA-PCL, p > 0.05). The percentage of newly formed bone was statistically significantly lower in group 3DPHA-PCL (15.7 ± 7.5% histomorphometrically, 16.7 ± 7.5% in micro-CT) than group BB (25.6 ± 7.2%, 26.3 ± 4.1%) (p < 0.05 in both methods). Two implants failed in the 3DPHA-PCL group, while no failures in the BB group.

Conclusions: Dimensional stability of the augmented bone was comparable between the groups. However, group 3DPHA-PCL demonstrated inferior new bone formation and implant survival compared to group BB. Long-term follow-up is warranted to monitor the behavior of 3DPHA-PCL.