Advertisement

Oral Radiology

, Volume 35, Issue 1, pp 29–34 | Cite as

Evaluation of permanent and primary enamel and dentin mineral density using micro-computed tomography

  • Sachiko Hayashi-Sakai
  • Makoto Sakamoto
  • Takafumi Hayashi
  • Tatsuya Kondo
  • Kaito Sugita
  • Jun Sakai
  • Junko Shimomura-Kuroki
  • Makiko Ike
  • Yutaka Nikkuni
  • Hideyoshi Nishiyama
Original Article
  • 182 Downloads

Abstract

Objectives

The present study was performed to investigate the mineral density distribution in enamel and dentin for both permanent and primary teeth and to establish the standard density per tooth type using micro-computed tomography (CT).

Methods

Fifty-seven extracted human teeth (37 permanent, 20 primary) were evaluated in the present study. The enamel and dentin mineral densities in the extracted teeth were measured using micro-CT. Cubic regression curves were used to determine the mineral density distribution in the enamel and dentin for each tooth type.

Results

The mean values, distributions, and regression equations of the mineral densities were obtained. The mean mineral density values for permanent enamel and dentin were significantly higher than those for their primary counterparts for each tooth type.

Conclusions

In the present study, we demonstrated the distribution of mineral density in sound enamel and dentin and attempted to determine the standard mineral density for each tooth type using micro-CT. The mineral density distributions found in this study contribute to our understanding of the mechanical properties of enamel and dentin. A positive correlation suggests that the systemic bone mineral density could be predicted based on the analysis of exfoliated teeth, such as in patients with hypophosphatasia. The present results may be useful in establishing a numerical standard for the mechanism involved in root fracture and for early detection of root fracture risk.

Keywords

Mineral density Micro-computed tomography Enamel Dentin Primary teeth 

Notes

Acknowledgements

This study was supported in part by a Grant-in-Aid for Scientific Research (C) (no. 17K11665) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

Compliance with ethical standards

Conflict of interest

Sachiko Hayashi-Sakai, Makoto Sakamoto, Takafumi Hayashi, Kaito Sugita, Jun Sakai, Junko Shimomura-Kuroki, Makiko Ike, Yutaka Nikkuni and Hideyoshi Nishiyama declare that they have no conflict of interest.

Human rights statement and informed consent

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. Informed consent was obtained from all patients for being included in the study.

References

  1. 1.
    Hayashi-Sakai S, Sakai J, Sakamoto M, Kouda F, Noda T. The gradient of microhardness in cross-sectioned sound primary molars. J JSEM. 2006;6:13–8.Google Scholar
  2. 2.
    Hayashi-Sakai S, Sakai J, Sakamoto M, Endo H. Determination of fracture toughness of human permanent and primary enamel using an indentation microfracture method. J Mater Sci Mater Med. 2012;23:2047–54.CrossRefGoogle Scholar
  3. 3.
    Marshall GW, Balooch M, Gallagher RR, Gansky SA, Marshall SJ. Mechanical properties of the dentinoenamel junction: AFM studies of nanohardness, elastic modulus, and fracture. J Biomed Mater Res. 2001;54:87–95.CrossRefGoogle Scholar
  4. 4.
    Park S, Wang DH, Zhang D, Romberg E, Arola D. Mechanical properties of human enamel as a function of age and location in the tooth. J Mater Sci Mater Med. 2008;19:2317–24.CrossRefGoogle Scholar
  5. 5.
    Craig RG, Gehring PE, Peyton FA. Relation of structure to the microhardness of human dentin. J Dent Res. 1959;38:624–30.CrossRefGoogle Scholar
  6. 6.
    Bowen RL, Rodriguez MM. Tensile and modulus of elasticity of tooth structure and several restorative materials. J Am Dent Assoc. 1962;64:378–87.CrossRefGoogle Scholar
  7. 7.
    Xu H, Zheng Q, Shao Y, Song F, Zhang L, Wang Q, et al. Effects of ageing on the biomechanical properties of root dentine and fracture. J Dent. 2014;42:305–11.CrossRefGoogle Scholar
  8. 8.
    Zou W, Hunter N, Swain MV. Application of polychromatic µCT for mineral density determination. J Dent Res. 2011;90:18–30.CrossRefGoogle Scholar
  9. 9.
    Davis GR, Wong FS. X-ray microtomography of bones and teeth. Physiol Meas. 1996;17:121–46.CrossRefGoogle Scholar
  10. 10.
    Hayashi-Sakai S, Sakai J, Kitamura T, Sakamoto M, Taguchi Y. The clinical oro-facial findings of an 11-year-old boy with 47,XYY: a case report. Pediatr Dent J. 2008;18:179–86.CrossRefGoogle Scholar
  11. 11.
    Hayashi-Sakai S, Numa-Kinjoh N, Sakamoto M, Sakai J, Matsuyama J, Mitomi M, et al. Hypophosphatasia: evaluation of size and mineral density of exfoliated teeth. J Clin Pediatr Dent. 2016;40:496–502.CrossRefGoogle Scholar
  12. 12.
    Hayashi-Sakai S, Hayashi T, Sakamoto M, Sakai J, Shimomura-Kuroki J, Nishiyama H, et al. Nondestructive microcomputed tomography evaluation of mineral density in exfoliated teeth with hypophosphatasia. Case Rep Dent. 2016;2016:4898456.Google Scholar
  13. 13.
    Feldkamp LA, Davis LC, Kress JW. Partial cone-beam algorithm. J Opt Soc Am A. 1984;1:612–9.CrossRefGoogle Scholar
  14. 14.
    Montgomery J, Beaumont J, Mackenzie K. Timelines in teeth: using micro-CT scanning to investigate mineralization in developing human enamel. In: Bruker microCT Academy Newsletter; 2011. p. 219–21.Google Scholar
  15. 15.
    Neves AA, Vargas DO, Santos TM, Lopes RT, Sousa FB. Is the morphology and activity of the occlusal carious lesion related to the lesion progression stage? Arch Oral Biol. 2016;72:33–8.CrossRefGoogle Scholar
  16. 16.
    Alajaji NK, Bardwell D, Finkelman M, Ali A. Micro-CT evaluation of ceramic inlays: comparison of the marginal and internal fit of five and three axis CAM systems with a heat press technique. J Esthet Restor Dent. 2016;29:49–58.CrossRefGoogle Scholar

Copyright information

© Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  • Sachiko Hayashi-Sakai
    • 1
  • Makoto Sakamoto
    • 2
  • Takafumi Hayashi
    • 1
  • Tatsuya Kondo
    • 2
  • Kaito Sugita
    • 2
  • Jun Sakai
    • 3
  • Junko Shimomura-Kuroki
    • 4
  • Makiko Ike
    • 1
  • Yutaka Nikkuni
    • 1
  • Hideyoshi Nishiyama
    • 1
  1. 1.Division of Oral and Maxillofacial RadiologyNiigata University Graduate School of Medical and Dental SciencesNiigataJapan
  2. 2.Department of Health Sciences, Faculty of MedicineNiigata UniversityNiigataJapan
  3. 3.Department of System and Automotive EngineeringNiigata College of TechnologyNiigataJapan
  4. 4.Department of Pediatric DentistryThe Nippon Dental University, School of Life Dentistry at NiigataNiigataJapan

Personalised recommendations