Jun-Ichi Sasaki1, Wakako Kiba1, Gabriela L Abe1, Chihiro Katata2, Masanori Hashimoto3, Haruaki Kitagawa4, Satoshi Imazato5. 1. Department of Biomaterials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan. 2. Department of Biomaterials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan; Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan. 3. Institute of Dental Research, Osaka Dental University, 8-1 Kuzuhahanazonocho, Hirakata, Osaka 573-1121, Japan. 4. Department of Biomaterials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan. Electronic address: h-kita@dent.osaka-u.ac.jp. 5. Department of Biomaterials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan; Department of Advanced Functional Materials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan.
Abstract
OBJECTIVES: Bioactive glass (BG) is widely used as a bioactive material for various clinical applications, and effective and efficient elemental release and an increase in mechanical strength are expected with further development. The purpose of this study is to clarify the physicochemical and biological characteristics of Sr-doped BG-incorporated glass ionomer cements. METHODS: Sr-doped BGs (45SiO2-6P2O5-24.5Na2O-(24.5-x)CaO-xSrO) (wt%), where × = 0, 6, 12, were prepared, and the particle size, crystallinity, and elemental release profiles were evaluated. The Sr-doped BGs were then incorporated into a glass ionomer cement at a weight ratio of 1:4, and the physicochemical properties (compressive strength, bending strength, hardness, and elemental release profile) were investigated. Cell attachment, cell proliferation, and osteoblastic differentiation were used to evaluate the biological characteristics. RESULTS: The Sr-doped BGs were amorphous phases with a homogeneous particle size and exhibited sustained release of Ca, Si, and Sr. The BG-incorporated cements were able to release these elements while retaining the same mechanical properties as those of the pure glass ionomer cement. In addition, no cytotoxicity of osteoblasts or differences in the cell attachment or proliferation were observed for the BG-incorporated cements. In contrast, the Sr-doped BG-incorporated cements promoted the alkaline phosphatase activities of the osteoblasts without the need for any media supplements for osteoblastic differentiation. SIGNIFICANCE: Sr-releasable inorganic cements with high mechanical properties were successfully fabricated by incorporating Sr-doped BGs in glass ionomer cement. These bioactive materials are promising candidates for bone grafting materials, bone cements, and pulp capping materials.
OBJECTIVES: Bioactive glass (BG) is widely used as a bioactive material for various clinical applications, and effective and efficient elemental release and an increase in mechanical strength are expected with further development. The purpose of this study is to clarify the physicochemical and biological characteristics of Sr-doped BG-incorporated glass ionomer cements. METHODS:Sr-doped BGs (45SiO2-6P2O5-24.5Na2O-(24.5-x)CaO-xSrO) (wt%), where × = 0, 6, 12, were prepared, and the particle size, crystallinity, and elemental release profiles were evaluated. The Sr-doped BGs were then incorporated into a glass ionomer cement at a weight ratio of 1:4, and the physicochemical properties (compressive strength, bending strength, hardness, and elemental release profile) were investigated. Cell attachment, cell proliferation, and osteoblastic differentiation were used to evaluate the biological characteristics. RESULTS: The Sr-doped BGs were amorphous phases with a homogeneous particle size and exhibited sustained release of Ca, Si, and Sr. The BG-incorporated cements were able to release these elements while retaining the same mechanical properties as those of the pure glass ionomer cement. In addition, no cytotoxicity of osteoblasts or differences in the cell attachment or proliferation were observed for the BG-incorporated cements. In contrast, the Sr-doped BG-incorporated cements promoted the alkaline phosphatase activities of the osteoblasts without the need for any media supplements for osteoblastic differentiation. SIGNIFICANCE: Sr-releasable inorganic cements with high mechanical properties were successfully fabricated by incorporating Sr-doped BGs in glass ionomer cement. These bioactive materials are promising candidates for bone grafting materials, bone cements, and pulp capping materials.