title: Effect of citric acid on setting reaction and tissue response to β-TCP granular cement.
abstract: We recently reported that when an acidic calcium phosphate solution is mixed with β-tricalcium phosphate (β-TCP) granules, the resulting dicalcium phosphate dihydrate (DCPD) crystals form bridges between the β-TCP granules, creating a set interconnected porous structure in approximately 1 min. Although this self-setting β-TCP granular cement (β-TCPGC) is useful for clinical applications, the short setting time is a key drawback for handling. In this study, the setting time of β-TCPGC was adjusted with the addition of citric acid, which is a known inhibiter of DCPD crystal growth. As the concentration of citric acid in the acidic calcium phosphate solution increased, the amount of DCPD formation in the set β-TCPGC decreased, and the crystal morphology of DCPD became elongated. β-TCPGC prepared with various citric acid concentrations were used as grafting material in rat calvarial bone defects to evaluate bone regeneration in vivo. Four weeks after implantation, no inflammatory reaction and approximately 20% new bone formation were observed, regardless of the presence or absence of citric acid in the liquid phase of β-TCPGC. We concluded, therefore, that citric acid might be a useful retarder of β-TCPGC setting times.
authors.affiliation: Department of Biomaterials, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Section of Oral and Maxillofacial Surgery, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Fukuda
authors.forename: Kanji
authors.initials: K
authors.lastname: Tsuru
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Mori
authors.forename: Kunio
authors.initials: K
authors.lastname: Ishikawa
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000737:chemistry*; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry* / Q000494:pharmacology; D003460:Crystallization; D006863:Hydrogen-Ion Concentration; D008297:Male; D008422:Materials Testing; D016062:Porosity; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery; D055114:X-Ray Microtomography
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D019343:Citric Acid