1954 B.S. Adamson University (Manila)
1957 M.S. New York University
1959 Brooklyn Polytechnic Institute
1967 Ph.D. New York University

• Role of carbonate, magnesium, fluoride, strontium, zinc, etc on the formation and stability of biological and synthetic apatite
• Effects of carbonate, citrate, pyrophosphate, fluoride, magnesium, zinc on the formation of biologically relevant calcium phosphates [amorphous calcium phosphate (ACP), dicalcium phosphate dihydrate (DCPD), tricalcium phosphate (b-TCP). [Relevance to calcium phosphate formation and transformation in biological systems - normal and pathological].
• Substitution of fluoride, carbonate, strontium, magnesium in synthetic apatites and effect on properties.
• Preparation and characterization of calcium phosphate-based biomaterials (from synthetic or natural systems) for bone substitution, augmentation or repair. These include: polymer/calcium phosphate composites; cements; ceramics; coatings.
• In situ characterization of plasma-sprayed coatings on orthopedic and dental implants and determination of dissolution properties.
• Deposition of calcium phosphate coating by electrochemical method - an alternative to plasma-spraying method.
• Surface modification of titanium and titanium alloy substrates.
• Calcium phosphates related to dental caries and dental calculus.
• Analytical tools include: x-ray diffraction, infrared spectroscopy (FTIR), scanning (SEM) and transmission (TEM) electron microscopy. Dissolution properties of synthetic and biological calcium phosphates and implant coatings are made in buffers at low and neutral pH.

Formation and Stability of Biological and Synthetic Calcium Phosphates - Effect of Fluoride, Magnesium, Carbonate, Strontium and Other Trace Elements

Our research program is oriented toward the elucidation of the effect of carbonate, magnesium, fluoride, strontium, zinc, and other trace elements on the formation and stability of calcium phosphates (substituted and unsubstituted apatite, amorphous calcium phosphates (ACP), dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP), tricalcium phosphate (TCP) relevant to dental caries, dental calculus and pathological calcifications; characterization of mineral phases of calcified tissues (normal and pathological); and preparation/characterization of calcium phosphate materials (including coatings on implants) used for bone repair, augmentation and substitution.
Our methodology includes X-ray diffraction, infrared (IR) spectroscopy, thermogravimetry (TGA), atomic absorption, inductive coupled plasma (ICP) scanning (SEM) and transmission electron microscopy (TEM), chemical analyses, studies using pHstat and ion selective electrodes, and syntheses.

Current Funding: (1) National Institute of Dental and Craniofacial Research of the National Institutes of Health (NIDCR/NIH). No P50 DE10593 (Director: Racquel Z. LeGeros, Co-Director: Henry Margolis of Forsyth Institute; NYUCD PI's: R. Craig, A. Spielman, S.Y. Barrow, J. Goldstein, G. Cruz; (2) Stryker-Howmedica-Osteonics, P.I.: John P. LeGeros, Co-P.I.: Racquel LeGeros; (3) Warner-Lambert, P.I.: Racquel LeGeros, Co-P.I.: John LeGeros; (4) Smith-Kline, P.I.: Racquel Z. LeGeros, Co-P.I.: John P. LeGeros; (5) Institut de Recherches Internationales Servier (IRIS), P.I.: Racquel Z. LeGeros.

Wieliczka, D.M., Spencer, P., LeGeros, R.Z. Surface Spectroscopy of Apatitic Materials: Limitations and Concerns. J. Dent. Res., 75 (1996): 1865-1870.

Okazaki, M., LeGeros, R.Z. Properties of heterogenous apatites containing magnesium, fluoride and carbonate. Adv. Den. Res., 10 (1996): 252-259.

LeGeros, R.Z., Sakae, T., Bautista, C., Retino, M., LeGeros, J.P. Magnesium and carbonate in enamel and synthetic apatites. Adv. Dent. Res., 10 (1996): 252-259.

LeGeros, R.Z., Margolis, H., Spielman, A., Bivona, P. Minority Oral Health Research Center: improving oral health and expanding opportunities. N.Y. State J., November 1996.

Weiss, P., Lapkowski, M., LeGeros, R.Z., Bouler, J.M., Jean, A., Daculsi, G. Fourier-transform infrared spectroscopy study of an organic-mineral composition of bone and dental substitute materials. J. Mat. Scie: Materials in Med., 8 (1997): 621-629.

Daculsi, G., Bouler, J.M., LeGeros, R.Z. Adaptive crystal formation in normal and pathological calcifications in synthetic calcium phosphate and related biomaterials. Int. Rev. Cytol., 172 (1997): 129-191.

Wu, L.N., Genge, B.R., Dunkelberger, D.G., LeGeros, R.Z., Concannon, B., Wuthier, R.E. Physicochemical characterization of the nucleational core of matrix vesicles. J. Biol. Chem., 272 (1997): 4404 - 4411.

Takagi, T., Ogasawara, T., Tagami, J., Akao, M., Kuboki, Y., Nagai, N., LeGeros, R.Z. pH and carbonate levels in developing enamel. Conn. Tiss. Res., 38 (1998): 181 - 187.

LeGeros, R.Z., Kim, Y.E., Kijkowska, R., Zurita, V., Bleiwas, C., Edwards, B., Huang, P.Y., Dimaano, F., LeGeros, J.P. HA/ACP ratios in calcium phosphate coatings on dental and orthopedic implants; Effects on properties. In: Bioceramics II in LeGeros, R.Z., LeGeros, J.P. (Eds) World Scientific Publications, Singapore, pp. 181-184, 1998.

Vallet-Regi, M., Romero, A.M., Ragel, C.V., LeGeros, R.Z. XRD, SEM, EDS and FTIR studies of in vitro growth of an apatite-like layer on sol-gel glasses. J. Biomed. Mater. Res., 44 (1998): 416-421.

LeGeros, R.Z., Bleiwas, C.B., Retino, M., Rohanizadeh, R., LeGeros, J.P. Zinc Effect on the in vitro formation of calcium phosphates; relevance to clinical inhibition of calculus formation. Am. J. Dent., 12: 1999.

Rohanizadeh, R., LeGeros, R.Z., Fan, D., Jean, A., Daculsi, G. Ultrastructural properties of laser-irradiated and heat-treated dentin. J. of Dental Res. 78 (1999): 1829 - 35.

Ryan, L.M., Cheung, H.S., LeGeros, R.Z., Kurup, I.V., Toth, J., Westfall, P.R., McCarthy, G.M. Cellular responses to whitlockite. Calc. Tiss. Int. 65 (1999): 374-7.

Craig, R.G., LeGeros, R.Z. Early events associated with periodontal connective tissue attachment formation on titanium and hydroxyapatite surfaces. J. Biomed. Mat. Res. 47 (1999): 585-94.

LeGeros, R.Z. Calcium Phosphaqtes in Demineralization/Remineralization Processes. J. Clin Dent 10 (1999): 65-73.