Calcium Phosphate Apatite Formation on Biological Bone Surfaces via Low-Intensity Pulsed Ultrasound (LIPUS) for Osseointegration

Background

Hydroxyapatite (HA) is widely utilized as a coating material for dental implants and artificial joints due to its excellent osteoconductivity. The author has previously demonstrated that low-intensity pulsed ultrasound (LIPUS) promotes osseointegration by facilitating the precipitation of bone-like calcium phosphate apatite on the surface of HA-coated materials through a physical crystallization mechanism. However, no previous studies have examined the effects of LIPUS irradiation on the biological bone that faced to the implant.

Purpose

This study aimed to investigate whether LIPUS stimulation could similarly promote the precipitation of bone-like calcium phosphate apatite on the surface of natural bone paired with an implant using this crystallographic mechanism.

Materials and Methods

Natural bone samples were immersed in simulated body fluid (SBF) and subjected to LIPUS irradiation. The resulting surface precipitates were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD).

Results

The results indicated that hydroxyapatite precipitation on the natural bone surface was significantly greater than that observed on synthetic biomaterials.

Conclusion

These findings suggest that LIPUS irradiation promotes vigorous calcium phosphate precipitation on both implant and natural bone surfaces. This physical mechanism potentially enhances the process of osseointegration, providing a promising approach for clinical implant applications.