Research Paper On X-Ray Diffraction

New commercial tricalcium silicate based cements were elaborated to improve handling properties and setting time. The goals of the present work were: (i) to determine the composition of the new injectable and/or fast setting calcium... more

New commercial tricalcium silicate based cements were elaborated to improve handling properties and setting time. The goals of the present work were: (i) to determine the composition of the new injectable and/or fast setting calcium silicate based cements, and (ii) to investigate the impact of the differences in composition on their setting kinetics. The materials considered were Angelus MTA™, Biodentine™, MM-MTA™, MTA-Caps™, and ProRoot MTA™ as control. Elemental composition of materials was studied by Inductively Coupled Plasma-Atomic Emission Spectroscopy and X-ray Energy Dispersive analysis, whereas phases in presence were analyzed by Micro-Raman spectroscopy and X-ray Diffraction analysis and cement surface by Scanning Electron Microscope. Setting kinetics was evaluated using rheometry. Elemental analysis revealed, for all cements, the presence of three major components: calcium, silicon and oxygen. Chlorine was detected in MM-MTA, MTA-Caps and Biodentine. Different radio-opacifiers were identified: bismuth oxide in ProRoot MTA, Angelus MTA and MM-MTA, zirconium oxide in Biodentine and calcium tungstate (CaWO4) in MTA-Caps. All cements were composed of di- and tri-calcium silicate, except Biodentine for which only the latter was detected. Major differences in setting kinetics were observed: a modulus of 8×10(8)Pa is reached after 12min for Biodentine, 150min for MM-MTA, 230min for Angelus MTA and 320min for ProRoot MTA. The maximum modulus reached by MTA-Caps was 7×10(8)Pa after 150min. Even if these cements possess some common compounds, major differences in their composition were observed between them, which directly influence their setting kinetics.

1. Blundell TL, Johnson LN. Protein crystallography. London: Academic Press, 1976.

2. Carter CW, Sweet RM, eds. Macromolecular crystallography, part A. Methods Enzymol 1997;276.

3. Carter CW, Sweet RM, eds. Macromolecular Crystallography, part B. Methods Enzymol 1997;277.

4. Luft JR, Arakali SV, Kirisits J, et al. A macromolecular crystallization procedure employing diffusion cells of varying depths as reservoirs to taylor the time course of equilibration in hanging drop and sitting drop vapour diffusion and microdialysis experiments. Journal of Applied Crystallography 1994;27:443–53.

5. Wilson LJ, Bray TL, Suddath FL. Crystallization of proteins by dynamic control of evaporation. Journal of Crystal Growth 1991;110:142–7.

6. Gernert KN, Smith R, Carter D. A simple apparatus for controlling nucleation and size in protein crystal growth. Anal Biochem 1988;168:141–7. [PubMed]

7. Carter CW, Carter CW. Protein crystallization using incomplete factorial experiments. J Biol Chem 1979;254:12219–23. [PubMed]

8. Carter CW, Baldwin ET, Frick L. Statistical design of experiments for protein crystal growth and the use of a precrystallisation assay. Journal of Crystal Growth 1988;90:60–73.

9. Jancarik J, Kim S-H. Sparse-matrix sampling—a screening method for crystallisation of proteins. Journal of Applied Crystallography 1991;24:409–11.

10. Hampel A, Labanauskas M, Connors PG, et al. Single crystals of transfer RNA from formylmethionine and phenylalanine transfer RNAs. Science 1968;162:1384–7. [PubMed]

11. Thomas DH, Rob A, Rice DW. A novel dialysis procedure for the crystallisation of proteins. Protein Eng 1989;2:489–91. [PubMed]

12. Song L, Gouaux JE. Membrane protein crystallisation: application of sparse matrices to the α-hemolysin heptamer. Methods Enzymol 1997;276:60–74.

13. Rossmann MG, Arnold E, Erickson JW, et al. Structure of a human common cold virus and functional relationship to other picornaviruses. Nature 1985;317:145–53. [PubMed]

14. Smyth M, Tate J, Hoey E, et al. Implications for viral uncoating from the structure of bovine enterovirus. Nat Struct Biol 1995;2:224–31. [PubMed]

15. Fitzgerald PMD, Madsen NB. Improvement of limit of diffraction and useful X-ray lifetime of crystals of glycogen debranching enzyme. Journal of Crystal Growth 1986;76:600–6.

16. Smyth M, Fry E, Hoey E, et al. Preliminary crystallographic analysis of bovine enterovirus. J Mol Biol 1993;231:930–2. [PubMed]

17. Helliwell JR. Macromolecular crystallography with synchrotron radiation. Cambridge: Cambridge University Press, 1992.

18. Ealick S, Walter R. Synchrotron beamlines for macromolecular crystallography. Curr Opin Struct Biol 1993;3:725–36.

19. Hope H. Crystallography of biological macromolecules at ultra-low temperature. Annual Review of Biophysics and Biophysical Chemistry 1990;19:107–26. [PubMed]

20. Miyahara J, Takahashi K, Amemiya Y, et al. A new type of X-ray area detector utilising LASER stimulated luminescence. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1986;A246:572–8.

21. Moy J-P. A 200 mm input field, 5–80 keV detector based on an X-ray image intensifier and CCD camera. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Methods 1994;A348:641–4.

22. Gruner SM. X-ray detectors for macromolecular crystallography. Curr Opin Struct Biol 1994;4:765–9.

23. Dauter Z. Data collection strategy. Methods Enzymol 1997;276:326–44.

24. Leslie A. Data collection and processing. In: Sawyer L, Isaac N, Bailey S, eds. Proceedings of the CCP4 study weekend. Warrington, UK: SERC Daresbury Laboratory, 1993:44–51.

25. Kabsch W. Automatic indexing of rotation diffraction patterns. Journal of Applied Crystallography 1988;21:67–71.

26. Otwinowski Z, Minor W. Processing of X-ray diffraction data collected in the oscillation mode. Methods Enzymol 1997;276:307–26.

27. Collaborative Computing Project Number 4. The CCP4 suite: programs for protein crystallography. Acta Crystallogr D 1994;D50:760–3. [PubMed]

28. Otwinowski Z. Isomorphous replacement and anomalous scattering. In: Wolf W, Evans PR, Leslie AGW, eds. Proceedings of the CCP4 study weekend. Warrington, UK: SERC Daresbury Laboratory, 1991:80–6.

29. Dickerson RE, Kendrew JC, Strandberg BE. The phase problem and isomorphous replacement methods in protein structures. In: Pepinsky R, Robertson JM, Speakman JC, eds. Computing methods and the phase problem in X-ray crystal analysis. Oxford: Pergamon Press, 1961:236–51.

30. Hengming K. Overview of isomorphous replacement phasing. Methods Enzymol 1997;276:448–61.

31. Terwilliger TC, Eisenberg D. Isomorphous replacement—effects of errors on the phase probability-distribution. Acta Crystallogr A 1987;A43:6–13.

32. Rossmann MG, ed. The molecular replacement method. New York: Gordon and Breach, 1972.

33. Rossmann MG, Blow DM. The detection of sub-units within the crystallographic asymmetric unit. Acta Crystallogr 1962;15:24–31

34. Rossmann MG. The molecular replacement method. Acta Crystallogr A 1990;A46:73–82. [PubMed]

35. Taylor CA, Morley KA. An improved method for determining the relative positions of molecules. Acta Crystallogr 1959;12:101–5.

36. Fujinaga M, Read RJ. Experiences with a new translation-function program. Journal of Applied Crystallography 1987;20:517–21.

37. Brunger AT. X-plor manual. New Haven: Yale University Press, 1992.

38. Navaza J, Saludjian P. AMoRe: an automated molecular replacement program package. Methods Enzymol 1997;276:581–94.

39. Ten Eyck LF. Crystallographic fast fourier transforms. Acta Crystallogr A 1973;A29:183–91.

40. Jones TA, Zou J-Y, Cowan SW, et al. Improved methods of building protein models in electron density maps and the location of errors in these models. Acta Crystallogr A 1991;A47:110–19. [PubMed]

41. Arnold E, Rossmann MG. Effect of errors, redundancy and solvent content in the molecular replacement procedure for the structure determination of biological macromolecules. Proc Natl Acad Sci USA 1986;83:5489–93. [PMC free article][PubMed]

42. Molinaro M, Grossman G. UCB enhanced RASMOL version 2.6. MultiCHEM Facility, University of California, Berkeley. ©; 1995, 1996 UC Regents/ModularCHEM Consortium.

43. Brunger AT, Kuriyan J, Karplus M. Crystallographic R-factor refinement by molecular dynamics. Science 1988;235:472–5. [PubMed]

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