Evaluation of the composite materials mixed with calcium phosphate cement and β-tricalcium phosphate granules

Calcium phosphate cement (CPC) demonstrates excellent shape retention; however, the material exhibits a prolonged resorption period. Despite its inferior mechanical strength and poor shape retention, beta-tricalcium phosphate (β-TCP) offers excellent osteoconductivity. We previously reported that incorporating β-TCP into CPC enhances mechanical strength and shape retention. However, the prolonged setting time poses a challenge for clinical application. We aimed to improve the clinical usefulness of the CPC/β-TCP composite material.

Samples with different mixing ratios of β-TCP (SUPERPORE) to quick-setting type of CPC (BIOPEX^®-R Quick Type) (C0, C10, C30, and C50 with mixing ratios of β-TCP of 0, 10, 30, and 50 wt%, respectively) were prepared. We evaluated the material properties. New bone formation was evaluated by histological and histopathological analysis after 4 and 8 weeks of implantation into the calvarial bone of Wistar rats.

This material was set in approximately 4 min. As the β-TCP content increased, the compressive strength decreased significantly. The average compressive strength C30 was 1.5 MPa. Penetration tests confirmed good permeability for C30 and C50. In the histological study, better new bone formation was observed in the C30 and C50 at 4 and 8 weeks.

These results suggested that the composite material made in this study had a shorter setting time and improved penetration than that in the previous study and confirmed its biocompatibility and osteoconductivity. Its compressive strength was low; therefore, it is necessary to examine whether the material can withstand the vertical and horizontal augmentation of the jawbone.