Abstract
The effect of fluoride on the hydrolysis of tetracalcium phosphate (TTCP; Ca4(PO4)2O) was investigated in 0.1 mol l−1KH2PO4 containing 0–83 mol l−1 KF. Characterization of the final apatite phase formed by the hydrolysis was made with X-ray diffraction and SEM. The initial pH was between 4.5 and 5.4, depending on the solutions, and the pH rapidly increased and was kept constant between 7.3 and 6.5. An increase in KF concentration tended to lower the pH in the final stage of hydrolysis. The calcium concentration was considerably lower than the phosphorus concentration throughout the reaction. The fluoride concentration decreased shortly after the start of hydrolysis. The hydrolysis of TTCP in 0.1 mol l−1 KH2PO4 proceeded to form hydroxyapatite via DCPD when the KF concentration was low. The hydrolysis product was a calcium-deficient non-stoichiometric hydroxyapatite with a Ca/P ratio of about 1.5. With an increase in the KF concentration in the 0.1 mol l−1 KH2PO4 solution, TTCP directly transformed into hydroxyapatite containing F- ions or fluorapatite and with improved crystallinity. The addition of fluoride in the solution initially accelerated the formation of apatite. However, the layer of newly formed apatite adhering to the TTCP particles retarded TTCP dissolution; as a result, hydrolysis was delayed. IR analysis showed that the apatite phase contained HPO2−4 ions in the structure. The formula for the hydrolysis product of TTCP in the presence of fluoride can be expressed as follows: Ca10−x(HPO4)x(PO4)10−x(OH)2−x−yFy. © 1998 Chapman & Hall.
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References
W. E. Brown and L. C. Chow, in “Cements Research Progress 1986”, edited by P. W. Brown (American Ceramic Society, Westerville, OH, 1987) pp. 351–79.
L. C. Chow, S. Takagi, P. D. Constantino and C. D. Friedman, Mater Res. Symp. Proc. 179 (1991) 3.
L. C. Chow, J. Ceram. Soc. Jpn 99 (1991) 954.
Y. Doi, S. Shibata, Y. Takezawa, N. Wakamatsu, N. Kamemizu, M. Iijima, Y. Moriwaki, K. Uno, F. Kubo and Y. Haeuchi, J. Jpn Soc. Dent. Mater. Dev. 7 (1988) 176.
Y. Fukase, E. D. Eanes, S. Takagi, L. C. Chow and W. E. Brown, J. Dent. Res. 69 (1990) 1852.
P. W. Brown and M. Fulmer, J. Am. Ceram. Soc. 74 (1991) 934.
P. W. Brown, N. Hocker and S. Hayle, ibid. 74 (1991) 1848.
M. Fulmer and P. W. Brown, J. Biomed. Mater. Res. 27 (1993) 1095.
P. W. Brown and M. Fulmer, ibid. 31 (1996) 395.
K. S. Tenhuisen and P. W. Brown, J. Mater. Sci. Mater. Med. 7 (1996) 309.
S. Matsuya, S. Takagi and L. C. Chow, J. Dent. Res. 70 (Special issue) (1991) 308.
H. Monma, M. Goto, H. Nakajima and H. Hashimoto, Gypsum Lime 202 (1986) 17.
L. Xie and E. A. Monroe, Mater. Res. Symp. Proc. 179 (1991) 25.
K. Ishikawa and E. D. Eanes, J. Dent. Res. 72 (1993) 474.
S. Matsuya, S. Takagi and L. C. Chow, J. Mater. Sci. 31 (1996) 3263.
H. Monma and S. Ueno, Gypsum Lime 172 (1981) 11.
M. S. Tung, L. C. Chow and W. E. Brown, J. Dent. Res. 64 (1985) 2.
M. S. Tung, B. Tomazic and W. E. Brown, Archs. Oral Biol. 37 (1992) 585.
M. Fulmer and P. W. Brown, J. Am. Ceram. Soc. 75 (1992) 3401.
E. J. Duff, J. Chem. Soc. (A) (1971) 33.
J. Lin, S. Raghavan and D. W. Ferstenau, Colloids Surface 3 (1981) 357.
R. Z. Legeros, in “Calcium Phosphates in Oral Biology and Medicine, Monographs in Oral Science”, Vol. 15, edited by H.M. Meyers, (Kargel, Basel, 1991) pp. 30.
R. Z. Legeros and S. Suga, Calcif. Tissue. Int. 32 (1980) 169.
B. Menzel and C. H. Amberg, J. Coll. Interface Sci. 38 (1972) 256.
R. A. Young and D. W. Holcomb, Calcif Tissue Int. 36 (1984) 60.
J. Arends, J. Christoffersen, M. R. Christoffersen, H. Eckert, B. O. Fowler, J. C. Heughebaert, G. H. Nancollas, J. P. Yesinowski and S. J. Zawacki, J. Crystal Growth 84 (1987) 515.
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Matsuya, S., Matsuya, Y., Takagi, S. et al. Effect of fluoride on apatite formation from Ca4(PO4)2O in 0.1 mol L−1 KH2PO4. Journal of Materials Science: Materials in Medicine 9, 325–331 (1998). https://doi.org/10.1023/A:1008850829768
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DOI: https://doi.org/10.1023/A:1008850829768