Fabrication and Clinical Evaluation of a Novel 3D printed Hydroxyapatite/Polycaprolactone Composite (Novel 3DP HA/ PCL) for Maxillary Sinus Augmentation: A Preliminary Study

Abstract

Objective: To fabricate a 3DP hydroxyapatite/polycaprolactone composite graft material and assess its clinical efficacy in maxillary sinus augmentation through a preliminary assessment of bone density changes over a one-year period, compared to deproteinized bovine bone mineral graft. Methods: A 3DP hydroxyapatite/polycaprolactone (HA/PCL) composite was fabricated using 3D printing of calcium sulfate-based material, followed by phase transformation and PCL infiltration. The composite was characterized through SEM, XRD, micro-CT, and compression testing. In a clinical study, 3DP HA/PCL composite material was compared with deproteinized bovine bone graft in sinus augmentation procedures. Cone-beam computed tomography (CBCT) was used to measure bone density at baseline, 6 months, and 1-year post-operation. Results: SEM and micro-CT analyses revealed that the 3DP HA/PCL composite exhibited a highly porous, three-dimensional architecture with HA crystals combined with PCL. The microstructure was characterized by a mixture of spherical and irregular-shaped particles with 60.67% porosity. Compression testing demonstrated that the 3DP HA/PCL composite granules had a compressive load resistance of 7.55 ± 1.71 N. The calculated compressive strength of the granule was approximately 2.4 MPa. CBCT analysis of bone density changes revealed distinct patterns between the two groups. Significant differences in graft bone density were observed in the control group at all time points (P < 0.05) , while the 3DP HA/PCL group demonstrated no significant changes (P < 0.3831). However, between 6 months to 1 year, the 3DP HA/PCL group exhibited an increased bone density gain trend similar to the rate observed in the xenograft group. At 1 year, the increase in bone density from T1 to T3 was significant in both the control and test groups., These findings indicate that while 3DP HA/PCL grafts initially increase bone density more slowly than xenografts, they demonstrate a more pronounced gain in the later phase compared to the early phase. Conclusion: Based on the promising preliminary results from the sinus augmentation study, 3DP HA/PCL composite demonstrates potential as an alternative bone graft material to deproteinized bovine bone mineral.