| Summary: | 博士 === 高雄醫學大學 === 牙醫學研究所 === 102 === Calcium phosphate cement (CPC) is widely used as a filling material in dental and orthopedic applications because of its superior biocompatibility and osteoconductivity. CPC presents several advantages because its paste can be easily shaped during operation and injected into cavities using a syringe without requiring an open portal through the tissues. The viscosity of the cement can be adjusted depending on its applications in orthopedic, craniofacial, and periodontal operations.
However, CPC is characterized by low strength, easy dispersion when in contact with body fluids and the application of CPCs is limited by poor bioresorption attributed to the stable product, apatite.
These study aim to compare the mechanical properties in vitro and biological performance in vivo of a newly developed CPC (New CPC) which has multiphasic product phase is evaluated and conventional CPC (c-CPC).
The pH values and dispersive properties of CPC during the early setting reactions were investigated as well as the compressive strength of New CPC after different immersion time. The composition and morphology of several bone cement samples during setting were analyzed using X-ray diffraction and transmission electron microscopy coupled with an energy dispersive spectroscopy system.
Cell adhesion, morphology, viability, and alkaline phosphatase (ALP) activity in the two CPCs were examined using progenitor bone cell D1 cultured in vitro. After CPC implantation in vivo, the residual implant ratio and new bone formation rate were analyzed by micro-CT analysis, and the image was obtained.
The compressive strength of New CPCs was greater than 30 MPa after different immersion time in vitro. The reaction of the CPCs produced steady final biphasic products of DCPs with apatite. Composite bone cements derived from tetracalcium phosphate mixed with surface-modified DCPA exhibited excellent mechanical properties, injectability, and interlocking forces between particles and featured nondispersive behavior when immersed in physiological solution. D1 cells cultured on the surfaces of New CPC exhibited higher cell viability, ALP activity, and ALP quantity than c-CPC. Histological evaluation indicated that New CPC showed better adhesion with bone tissues, less residual implant, and higher new bone formation rate than did c-CPC.
New CPC not only has great mechanical properties but also improve bioresorption.
In addition, New CPC can adjust the product phase to control the biological to improve the bone regeneration rate and bioresorption rate of implant in connection with different bone defect area.The newly developed New CPC exhibits potential therapeutic applications for bone reconstruction.
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