title: Fabrication of calcite blocks from gypsum blocks by compositional transformation based on dissolution-precipitation reactions in sodium carbonate solution.
abstract: Calcium carbonate (CaCO3) has been used as a bone substitute, and is a precursor for carbonate apatite, which is also a promising bone substitute. However, limited studies have been reported on the fabrication of artificial calcite blocks. In the present study, cylindrical calcite blocks (ϕ6×3mm) were fabricated by compositional transformation based on dissolution-precipitation reactions using different calcium sulfate blocks as a precursor. In the dissolution-precipitation reactions, both CaSO4·2H2O and CaSO4transformed into calcite, a polymorph of CaCO3, while maintaining their macroscopic structure when immersed in 1mol/L Na2CO3solution at 80°C for 1week. The diametral tensile strengths of the calcite blocks formed using CaSO4·2H2O and CaSO4were 1.0±0.3 and 2.3±0.7MPa, respectively. The fabrication of calcite blocks using CaSO4·2H2O and CaSO4proposed in this investigation may be a useful method to produce calcite blocks because of the self-setting ability and high temperature stability of gypsum precursors.
authors.affiliation: Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: ishikawa@dent.kyushu-u.ac.jp.
authors.forename: Kunio
authors.initials: K
authors.lastname: Ishikawa
authors.affiliation: Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Giichiro
authors.initials: G
authors.lastname: Kawachi
authors.affiliation: Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kanji
authors.initials: K
authors.lastname: Tsuru
authors.affiliation: Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Ayami
authors.initials: A
authors.lastname: Yoshimoto
mesh_terms: D018786:Bone Substitutes; D002119:Calcium Carbonate / Q000737:chemistry*; D002133:Calcium Sulfate / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D012995:Solubility; D012996:Solutions / Q000737:chemistry; D013696:Temperature; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D018786:Bone Substitutes; D002254:Carbonates; D012996:Solutions; C005686:sodium carbonate; D002119:Calcium Carbonate; D002133:Calcium Sulfate
keywords: Calcite; Calcium carbonate; Calcium sulfate; Gypsum; Sodium carbonate