TY - JOUR
T1 - Formation of hydroxyapatite in new calcium phosphate cements
AU - Takagi, S.
AU - Chow, L. C.
AU - Ishikawa, K.
N1 - Funding Information:
This study was supported, in part, by USPHS Grant DE05030 and DE11789 to the American Dental Association Health Foundation from the National Institutes of Health—National Institute of Dental Research and is part of the dental research program conducted by the National Institute of Standards and Technology in cooperation with the American Dental Association Health Foundation.
PY - 1998/9
Y1 - 1998/9
N2 - Tetracalcium phosphate (TTCP) has been shown previously to be an essential component of self-setting calcium phosphate cements that form hydroxyapatite (HA) as the only end-product. We report herein on a new self-setting calcium phosphate cement that does not contain TTCP. These cements consist of dicalcium phosphate anhydrous (DCPA), dicalcium phosphate dihydrate (DCPD), α-tricalcium phosphate, or amorphous calcium phosphate and, as an additional source of calcium, calcium hydroxide or calcium carbonate. These cements require the use of a phosphate (0.2 mol l-1 or higher) solution or a high pH solution as the cement liquid. The cements harden in relatively short time (5-30 min) and form HA as the dominant end-product in 24 h. The diametral tensile strengths of the 24-h samples are in the range of 0.2 to 7.5 MPa. Results from X-ray diffraction studies suggest that the cement setting is caused by rapid HA formation induced by the high phosphate concentration of the cement liquid. Because DCPA and DCPD are highly soluble at pH values above 12.7, which is the pK3 of phosphoric acid, high phosphate concentration in the slurry solution was also attainable by using a highly alkaline solution as the cement liquid. The physicochemical properties of these cements are comparable to those of TTCP-containing cements, and the new cements may be expected to have in vivo characteristics similar to those of TTCP-containing cements as well.
AB - Tetracalcium phosphate (TTCP) has been shown previously to be an essential component of self-setting calcium phosphate cements that form hydroxyapatite (HA) as the only end-product. We report herein on a new self-setting calcium phosphate cement that does not contain TTCP. These cements consist of dicalcium phosphate anhydrous (DCPA), dicalcium phosphate dihydrate (DCPD), α-tricalcium phosphate, or amorphous calcium phosphate and, as an additional source of calcium, calcium hydroxide or calcium carbonate. These cements require the use of a phosphate (0.2 mol l-1 or higher) solution or a high pH solution as the cement liquid. The cements harden in relatively short time (5-30 min) and form HA as the dominant end-product in 24 h. The diametral tensile strengths of the 24-h samples are in the range of 0.2 to 7.5 MPa. Results from X-ray diffraction studies suggest that the cement setting is caused by rapid HA formation induced by the high phosphate concentration of the cement liquid. Because DCPA and DCPD are highly soluble at pH values above 12.7, which is the pK3 of phosphoric acid, high phosphate concentration in the slurry solution was also attainable by using a highly alkaline solution as the cement liquid. The physicochemical properties of these cements are comparable to those of TTCP-containing cements, and the new cements may be expected to have in vivo characteristics similar to those of TTCP-containing cements as well.
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U2 - 10.1016/S0142-9612(97)00119-1
DO - 10.1016/S0142-9612(97)00119-1
M3 - Article
C2 - 9830985
AN - SCOPUS:0032170766
SN - 0142-9612
VL - 19
SP - 1593
EP - 1599
JO - Biomaterials
JF - Biomaterials
IS - 17
ER -