Study of Mineral and Matrix Maturation in Dentin

Spectroscopic analysis was used to study the patterns of changes in the mineral and matrix properties of dentin during maturation of the tissue. Fourier Transform Infrared Imaging (FTIRI) analyses on undecalcified semi-thin sections from fetal bovine incisors and developing mouse molars were performed. In addition, fetal bovine microdissected mantle and circumpulpal dentin specimens of successive tissue age were analyzed by Fourier Transform Infrared (FTIR) analysis and by amino acid and matrix phosphate assays.

In the initial studies, the formation of mantle and circumpulpal dentin as two distinct dentin compartments in the developing fetal incisors was established through analysis of distribution of mineral:matrix and mineral crystallinity values. Changes in the mineral:matrix, mineral crystallinity, acidic phosphate substitution and carbonate substitution in the mineral of mantle and circumpulpal dentin during maturation were subsequently quantitatively analyzed from FTIRI results. In this study, separate patterns of changes in mineral properties were found for mantle and circumpulpal dentin, in terms of initial and final levels and rates of increase or decrease of mineral properties values. Spectroscopic analysis of different maturation stages microdissected mantle and circumpulpal dentin specimens showed a great decrease in the dentin relative water content, affecting the dentin matrix conformation.

Chemical analyses of similar microdissected specimens showed a significant increase in the organic phosphate of dentin matrix occurring during maturation. This increase was associated with continuing phosphorylation of existing phosphoproteins without further changes in the protein density. Finally, the study of dentin maturation using 6 day-old mouse molars by FTIRI was validated. Reproducibility in the pattern of changes in the mineral properties examined was found to be highly dependent on the sectioning orienation of molars. It is likely that higher resolution analytical methods and/or slightly older animal age would enhance the analytical outcome in such studies.

Year	Entry
1983	Bonar LC, Roufosse AH, Sabine WK, Grynpas MD, Glimcher MJ. X-ray diffraction studies of the crystallinity of bone mineral in newly synthesized and density fractionated bone. Calcif Tiss Int. December 1983;35(2):202-209.
1991	Rey C, Renugopalakrishman V, Collins B, Glimcher MJ. Fourier transform infrared spectroscopic study of the carbonate ions in bone mineral during aging. Calcif Tiss Int. October 1991;49(4):251-258.
1977	Nomura S, Hiltner A, Lando JB, Baer E. Interaction of water with native collagen. Biopolymers. 1977;16:231-246.
1999	Nanci A. Content and distribution of noncollagenous matrix proteins in bone and cementum: relationship to speed of formation and collagen packing density. J Struct Biol. June 30, 1999;126(3):256-269.
1996	Gadaleta SJ, Camacho NP, Mendelsohn R, Boskey AL. Fourier transform infrared microscopy of calcified turkey leg tendon. Calcif Tiss Int. January 1996;58(1):17-23.
1977	White SW, Hulmes DJS, Miller A, Timmins PA. Collagen-mineral axial relationship in calcified turkey leg tendon by X-ray and neutron diffraction. Nature. March 31, 1977;266(5601):421-425.
1992	Fratzl P, Groschner M, Vogl G, Plenk H Jr, Eschberger J, Fratzl-Zelman N, Koller K, Klaushofer K. Mineral crystals in calcified tissues: a comparative study by SAXS. J Bone Miner Res. March 1992;7(3):329-334.
1993	Fratzl P, Fratzl-Zelman N, Klaushofer K. Collagen packing and mineralization: an x-ray scattering investigation of turkey leg tendon. Biophys J. January 1993;54(1):260-266.
2002	Aparicio S, Doty SB, Camacho NP, Paschalis EP, Spevak L, Mendelsohn R, Boskey AL. Optimal methods for processing mineralized tissues for Fourier transform infrared microspectroscopy. Calcif Tiss Int. May 2002;70(5):422-429.
2001	Ou‐Yang H, Paschalis EP, Mayo WE, Boskey AL, Mendelsohn R. Infrared microscopic imaging of bone: spatial distribution of CO₃²⁻. J Bone Miner Res. May 2001;16(5):893-900.
1989	Rey C, Collins B, Goehl T, Dickson IR, Glimcher MJ. The carbonate environment in bone mineral: a resolution-enhanced fourier transform infrared spectroscopy study. Calcif Tiss Int. September 1989;45(3):157-164.
1998	Boskey AL, Gadaleta S, Gundberg C, Doty SB, Ducy P, Karsenty G. Fourier transform infrared microspectroscopic analysis of bones of osteocalcin-deficient mice provides insight into the function of osteocalcin. Bone. September 1998;23(3):187-196.
1999	Boskey AL, Wright TM, Blank RD. Collagen and bone strength. J Bone Miner Res. March 1999;14(3):330-335.
2001	Boskey AL. Bone mineralization. In: Cowin SC, ed. Bone Mechanics Handbook. 2nd ed. Boca Raton, FL: CRC Press; 2001:chap 5.
2003	Boskey A. Bone mineral crystal size. Osteoporos Int. September 2003;14(suppl 5):S16-S20.
2002	Boskey AL, Spevak L, Paschalis E, Doty SB, McKee MD. Osteopontin deficiency increases mineral content and mineral crystallinity in mouse bone. Calcif Tiss Int. August 2002;71(2):145-154.
1996	Paschalis EP, DiCarlo E, Betts F, Sherman P, Mendelsohn R, Boskey AL. FTIR microspectroscopic analysis of human osteonal bone. Calcif Tiss Int. December 1996;59(6):480-487.
1997	Paschalis EP, Betts F, DiCarlo E, Mendelsohn R, Boskey AL. FTIR microspectroscopic analysis of normal human cortical and trabecular bone. Calcif Tiss Int. December 1997;61(6):480-486.
1996	Landis WJ, Hodgens KJ, Arena J, Song MJ, McEwen BF. Structural relations between collagen and mineral in bone as determined by high voltage electron microscopic tomography. Microsc Res Tech. 1996;33(2):192-202.
2003	Paschalis E, Recker R, Dicarlo E, Doty S, Atti E, Boskey A. Distribution of collagen cross-links in normal human trabecular bone. J Bone Miner Res. November 2003;18(11):1942-1946.
2002	Tarnowski CP, Ignelzi MA Jr, Morris MD. Mineralization of developing mouse calvaria as revealed by Raman microspectroscopy. J Bone Miner Res. June 2002;17(6):1118-1126.
1991	Pleshko N, Boskey A, Mendelsohn R. Novel infrared spectroscopic method for the determination of crystallinity of hydroxyapatite minerals. Biophys J. October 1991;60(4):786-793.
1996	Gadaleta SJ, Paschalis EP, Betts F, Mendelsohn R, Boskey AL. Fourier transform infrared spectroscopy of the solution-mediated conversion of amorphous calcium phosphate to hydroxyapatite: new correlations between X-ray diffraction and infrared data. Calcif Tiss Int. January 1996;58(1):9-16.
1997	Paschalis EP, Betts F, DiCarlo E, Mendelsohn R, Boskey AL. FTIR microspectroscopic analysis of human iliac crest biopsies from untreated osteoporotic bone. Calcif Tiss Int. December 1997;61(6):487-492.

Year

Entry

1983

Bonar LC, Roufosse AH, Sabine WK, Grynpas MD, Glimcher MJ. X-ray diffraction studies of the crystallinity of bone mineral in newly synthesized and density fractionated bone. Calcif Tiss Int. December 1983;35(2):202-209.

1991

Rey C, Renugopalakrishman V, Collins B, Glimcher MJ. Fourier transform infrared spectroscopic study of the carbonate ions in bone mineral during aging. Calcif Tiss Int. October 1991;49(4):251-258.

1977

Nomura S, Hiltner A, Lando JB, Baer E. Interaction of water with native collagen. Biopolymers. 1977;16:231-246.

1999

Nanci A. Content and distribution of noncollagenous matrix proteins in bone and cementum: relationship to speed of formation and collagen packing density. J Struct Biol. June 30, 1999;126(3):256-269.

1996

Gadaleta SJ, Camacho NP, Mendelsohn R, Boskey AL. Fourier transform infrared microscopy of calcified turkey leg tendon. Calcif Tiss Int. January 1996;58(1):17-23.