Effect of strontium on physicochemical properties and biocompatibility of calcium silicate bone grafts

• Main Authors: Ti-Hua, 關迪華
• Other Authors: 燕敏
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/89044506529585729492

碩士 === 中山醫學大學 === 口腔材料科學研究所 === 97 === Calcium silicate cements (CSC) have been regarded as a potential biomaterial for bone graft substitutes. Strontium (Sr) is a trace element in human body and been used for treatment of osteoporosis. Sr is found to induce osteoblast activity by stimulating bone formation and to reduce bone resorption by restraining osteoclasts. The aim of this study was to evaluate the physicochemical properties of Sr-containing CSC. The calcium silicate with equimolar ratio of Ca to Si was used as the control. Various amounts of Sr with a molar ratio of 1%, 5% and 10% for Sr/(Sr + Ca) were added to sol-gel precursors. The major techniques used for characterizing the various specimens included X-ray diffraction (XRD), scanning electron microscopy (SEM), diametral tensile strength and setting time. As a result, the particle size of calcium silicate ceramics powder ranged from 1 μm to 5 μm. The XRD patterns shows that major diffraction peaks of the four powders were at 2θ between 32 and 34o attributed to β-dicalcium silicate (β-Ca2SiO4) phase. Although the Ca was replaced in part by Sr through ionic exchange, the incorporation of Sr to calcium silicate ceramics may lead to a broadening peak. This can be explained by the fact that the radius of Sr ions (1.13Å) is larger than that of Ca ions (1.00Å), namely, the microstrain effect. After mixing with water, XRD patterns of all cements revealed an obvious diffraction peak around 2θ = 29.3o, corresponding to the calcium silicate hydrate gel, and incompletely reacted inorganic component phases of β-Ca2SiO4. 10% Sr significantly shortened setting time from 22 min for the CSC control to 17 min. The addition of Sr did not affect the strength ranged from 2.0 to 2.4 MPa as these specimens were not significantly different (p > 0.05) from control groups (2.5 MPa). Our findings indicated that Sr-CSC may be a candidate for bone repair.