Contributions of microstructure and chemical composition to the mechanical properties of dentin

  • H. Ryou
  • N. Amin
  • A. Ross
  • N. Eidelman
  • D. H. Wang
  • E. Romberg
  • D. Arola


The influence of microstructural variations and chemical composition to the mechanical properties and apparent flaw sensitivity of dentin were evaluated. Rectangular beams (N = 80) of the deep and superficial coronal dentin were prepared from virgin 3rd molars; twenty beams of each region were nominally flaw free and the remainder possessed a single “surface flaw” via a Vickers indentation. Mechanical properties were estimated in four-point flexure and examined using Weibull statistics. Fourier Transform Infrared Microspectroscopy in Reflectance Mode (FTIR-RM) was used to quantify the relative mineral to collagen ratios. Results showed that the average flexural strength, and strain and energy to fracture of the deep dentin beams were significantly lower (P < 0.005) than for the superficial dentin. While the deep dentin exhibited the highest mineral/collagen ratio and lowest damage tolerance, there was no significant effect of the surface flaws. Weibull analyses suggest that deep dentin possesses a larger distribution of intrinsic flaw sizes that contributes to the location dependence in strength.


Damage Dentin FTIR microspectroscopy Fracture Strength 



This research was supported in part by an award from the National Institutes of Health (NIDCR DE016904) and the National Science Foundation (BES 0238237). Aftin Ross, Heon Ryou and Nikhil Amin were undergraduate students during the course of the research and Ms Ross acknowledges support from the MARC U-STAR program.


  1. 1.
    Marshall DB, Evans AG, Khuri Yakub BT, Tien JW, Kino GS. Nature of machining damage in brittle materials. Proc Roy Soc Lond Ser A Math Phys Sci. 1983;385(1789):461–75.CrossRefGoogle Scholar
  2. 2.
    Xu HHK, Padture NP, Jahanmir S. Effect of microstructure on material-removal mechanisms and damage tolerance in abrasive machining of silicon carbide. J Am Cer Soc. 1995;78(9):2443–8.CrossRefGoogle Scholar
  3. 3.
    Quinn GD, Ives LK, Jahanmir S. On the nature of machining cracks in ground ceramics. Part I: SRBSN strengths and fractographic analysis. Mach Sci Technol. 2005;9(2):169–210.CrossRefGoogle Scholar
  4. 4.
    Quinn GD, Ives LK, Jahanmir S. On the nature of machining cracks in ground ceramics: part II, comparison to other silicon nitrides and damage maps. Mach Sci Technol. 2005;9(2):211–37.CrossRefGoogle Scholar
  5. 5.
    Sehy C, Drummond JL. Micro-cracking of tooth structure. Am J Dent. 2004;17(5):378–80.Google Scholar
  6. 6.
    Yan J, Taskonak B, Mecholsky JJ. Fractography and fracture toughness of human dentin. J Mech Behav Biomed Mater. 2009;2(5):478–84.CrossRefGoogle Scholar
  7. 7.
    Staninec M, Meshkin N, Manesh SK, Ritchie RO, Fried D. Weakening of dentin from cracks resulting from laser irradiation. Dent Mater. 2009;25(4):520–5.CrossRefGoogle Scholar
  8. 8.
    Nalla RK, Imbeni V, Kinney JH, Staninec M, Marshall SJ, Ritchie RO. In vitro fatigue behavior of human dentin with implications for life prediction. J Biomed Mater Res. 2003;66(1):10–20.CrossRefGoogle Scholar
  9. 9.
    Arola D, Reprogel R. Tubule orientation and the fatigue strength of human dentin. Biomaterials. 2006;27(9):2131–40.CrossRefGoogle Scholar
  10. 10.
    Arola D, Reprogel R. Effects of aging on the mechanical behavior of human dentin. Biomaterials. 2005;26(18):4051–61.CrossRefGoogle Scholar
  11. 11.
    Arola D, Huang MP, Sultan MB. The failure of amalgam restorations due to cyclic fatigue crack growth. J Mat Sci Mater Med. 1999;10(6):319–27.CrossRefGoogle Scholar
  12. 12.
    Bajaj D, Sundaram N, Arola D. An examination of fatigue striations in human dentin: in vitro and in vivo. J Biomed Mater Res Appl Biomat. 2008;85(1):149–59.CrossRefGoogle Scholar
  13. 13.
    Staninec M, Marshall GW, Hilton JF, Pashley DH, Gansky SA, Marshall SJ, Kinney JH. Ultimate tensile strength of dentin: evidence for a damage mechanics approach to dentin failure. J Biomed Mater Res. 2002;63(3):342–5.CrossRefGoogle Scholar
  14. 14.
    Kinney JH, Marshall SJ, Marshall GW. The mechanical properties of human dentin: a critical review and re-evaluation of the dental literature. Crit Rev Oral Biol Med. 2003;14(1):13–29.CrossRefGoogle Scholar
  15. 15.
    ISO Standard 18756 (2003) Fine ceramics (advanced ceramics, advanced. technical ceramics)-determination of fracture. Toughness of monolithic ceramics at room temperature by the surface crack in flexure (SCF) method.Google Scholar
  16. 16.
    Scherrer SS, Kelly JR, Quinn GD, Xu K. Fracture toughness (KIc) of a dental porcelain determined by fractographic analysis. Dent Mater. 1999;15(5):342–8.CrossRefGoogle Scholar
  17. 17.
    Peterson RE. Stress concentration factors. New York: Wiley; 1974.Google Scholar
  18. 18.
    Weibull W. A statistical distribution function of wide applicability. J Appl Mech. 1951;18:293–7.Google Scholar
  19. 19.
    Davies IJ. Best estimate of Weibull modulus obtained using linear least squares analysis: an improved empirical correction factor. J Mat Sci. 2004;39(4):1441–4.CrossRefGoogle Scholar
  20. 20.
    Tesch W, Eidelman N, Roschger P, Goldenberg F, Klaushofer K, Fratzl P. Graded microstructure and mechanical properties of human crown dentin. Calcif Tissue Int. 2001;69(3):147–57.CrossRefGoogle Scholar
  21. 21.
    Eidelman N, Simon CG. Characterization of combinatorial polymer blend composition gradients by FTIR Microspectroscopy. J Res Natl Inst Stand Technol. 2004;109(2):219–31.Google Scholar
  22. 22.
    Chalmers JM, Everall NJ, Ellison S. Specular reflectance: a convenient tool for polymer characterisation by FTIR-microscopy? Micron. 1996;27(5):315–28.CrossRefGoogle Scholar
  23. 23.
    Pashley D, Okabe A, Parham P. The relationship between dentin microhardness and tubule density. Endod Dent Traumatol. 1985;1(5):176–9.CrossRefGoogle Scholar
  24. 24.
    Kinney JH, Balooch M, Marshall SJ, Marshall GW Jr, Weihs TP. Atomic force microscope measurements of the hardness and elasticity of peritubular and intertubular human dentin. J Biomech Eng. 1996;118(1):133–5.CrossRefGoogle Scholar
  25. 25.
    Fuentes V, Toledano M, Osorio R, Carvalho RM. Microhardness of superficial and deep sound human dentin. J Biomed Mater Res A. 2003;66(4):850–3.CrossRefGoogle Scholar
  26. 26.
    Carvalho RM, Fernandes CA, Villanueva R, Wang L, Pashley DH. Tensile strength of human dentin as a function of tubule orientation and density. J Adhes Dent. 2001;3(4):309–14.Google Scholar
  27. 27.
    Inoue S, Pereira PN, Kawamoto C, Nakajima M, Koshiro K, Tagami J, Carvalho RM, Pashley DH, Sano H. Effect of depth and tubule direction on ultimate tensile strength of human coronal dentin. Dent Mater J. 2003;22(1):39–47.Google Scholar
  28. 28.
    Giannini M, Soares CJ, de Carvalho RM. Ultimate tensile strength of tooth structures. Dent Mater. 2004;20(4):322–9.CrossRefGoogle Scholar
  29. 29.
    Konishi N, Watanabe LG, Hilton JF, Marshall GW, Marshall SJ, Staninec M. Dentin shear strength: effect of distance from the pulp. Dent Mater. 2002;18(7):516–20.CrossRefGoogle Scholar
  30. 30.
    Watanabe LG, Marshall GW Jr, Marshall SJ. Dentin shear strength: effects of tubule orientation and intratooth location. Dent Mater. 1996;12(2):109–15.CrossRefGoogle Scholar
  31. 31.
    Nalla RK, Kinney JH, Ritchie RO. On the fracture of human dentin: is it stress- or strain-controlled? J Biomed Mater Res A. 2003;67(2):484–95.CrossRefGoogle Scholar
  32. 32.
    Lertchirakarn V, Palamara JE, Messer HH. Anisotropy of tensile strength of root dentin. J Dent Res. 2001;80(2):453–6.CrossRefGoogle Scholar
  33. 33.
    Trustrum K, Jayatilaka ADe-S. Applicability of Weibull analysis for brittle materials. J Mat Sci. 1983;18(9):2765–70.CrossRefGoogle Scholar
  34. 34.
    Dickens SH, Cho BH. Interpretation of bond failure through conversion and residual solvent measurements and Weibull analyses of flexural and microtensile bond strengths of bonding agents. Dent Mater. 2005;21(4):354–64.CrossRefGoogle Scholar
  35. 35.
    Burrow MF, Thomas D, Swain MV, Tyas MJ. Analysis of tensile bond strengths using Weibull statistics. Biomaterials. 2004;25(20):5031–5.CrossRefGoogle Scholar
  36. 36.
    Xu HHK, Kelly JR, Jahanmir S, Thompson VP, Rekow ED. Enamel subsurface damage due to tooth preparation with diamonds. J Dent Res. 1997;76(10):1698–706.CrossRefGoogle Scholar
  37. 37.
    Banerjee A, Kidd EA, Watson TF. Scanning electron microscopic observations of human dentine after mechanical caries excavation. J Dent. 2000;28(3):179–86.CrossRefGoogle Scholar
  38. 38.
    Mannocci F, Pilecki P, Bertelli E, Watson TF. Density of dentinal tubules affects the tensile strength of root dentin. Dent Mater. 2004;20(3):293–6.CrossRefGoogle Scholar
  39. 39.
    Pashley DH. Smear layer: physiological considerations. Oper Dent. 1984;suppl 3:13–29.Google Scholar
  40. 40.
    Miguez PA, Pereira PN, Atsawasuwan P, Yamauchi M. Collagen cross-linking and ultimate tensile strength in dentin. J Dent Res. 2004;83(10):807–10.CrossRefGoogle Scholar
  41. 41.
    Kinney JH, Nalla RK, Pople JA, Breunig TM, Ritchie RO. Age-related transparent root dentin: mineral concentration, crystallite size, and mechanical properties. Biomaterials. 2005;26(16):3363–76.CrossRefGoogle Scholar
  42. 42.
    Arola D, Bajaj D, Ivancik J, Majd H, Zhang D. Fatigue of biomaterials: hard tissues. Int J Fat. 2010;32(9):1400–12.CrossRefGoogle Scholar
  43. 43.
    Jameson MW, Hood JA, Tidmarsh BG. The effects of dehydration and rehydration on some mechanical properties of human dentine. J Biomech. 1993;26(9):1055–65.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • H. Ryou
    • 1
  • N. Amin
    • 1
  • A. Ross
    • 1
  • N. Eidelman
    • 2
  • D. H. Wang
    • 3
  • E. Romberg
    • 4
  • D. Arola
    • 1
    • 5
  1. 1.Department of Mechanical EngineeringUniversity of Maryland Baltimore CountyBaltimoreUSA
  2. 2.Paffenbarger Research Center, American Dental Association FoundationNational Institutes of Standards and TechnologyGaithersburgUSA
  3. 3.School of Mechanical Engineering and AutomationKyungnam UniversityMasanSouth Korea
  4. 4.Department of Health Promotion and PolicyBaltimore College of Dental Surgery, University of MarylandBaltimoreUSA
  5. 5.Department of Endodontics, Prosthodontics, and Operative DentistryBaltimore College of Dental Surgery, University of MarylandBaltimoreUSA

Personalised recommendations