Journal of Dental Sciences
Volume 5, Issue 1 , Pages 14-20, March 2010

Comparison of the microstructure of crown and root dentin by a scanning electron microscopic study

  • Chia-Yi Chu

      Affiliations

    • Department of Dentistry, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
    • ,
  • Tien-Chun Kuo

      Affiliations

    • Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan
    • Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
    • ,
  • Shu-Fang Chang

      Affiliations

    • Department of Dentistry, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
    • ,
  • Yow-Chyun Shyu

      Affiliations

    • Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
    • ,
  • Chun-Pin Lin

      Affiliations

    • Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan
    • Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan
    • Corresponding Author InformationCorresponding author. Department of Dentistry, National Taiwan University Hospital, 1, Chang-Te Street, Taipei 10048, Taiwan

Received 1 November 2009; accepted 28 January 2010.

Article Outline

Background/Purpose

Detailed information of the dentin microstructure is essential in order to interpret data from investigations on dentin adhesive materials. Most studies of dentin microstructure focused on the crown dentin, and few compared microstructures of the crown and root dentin. The purpose was to compare the density and diameter of dentinal tubules and the thickness of peritubular dentin at the crown, and coronal and middle root.

Materials and methods

Ten caries-free human lower first molars were sectioned into four parts as the chamber roof, chamber wall, coronal root, and middle root. After being immersed in 5.25% NaOCl solution for 30 minutes, sectioned surfaces were examined under a scanning electron microscope. Data of tubule density, diameter, and peritubular dentin thickness in the inner, middle and outer portions were collected. Friedman's nonparametric related sample test and Wilcoxon nonparametric signed rank post hoc test were used for data analyses.

Results

Tubule densities of the inner and middle dentin of the root were significantly lower than that of the crown. Peritubular dentin width in the chamber roof was significantly higher than those in other areas of the tooth.

Conclusion

Our findings show that the proportion of the tubular area is lower, and there is less peritubular dentin in the root dentin than in crown dentin. To achieve good bonding of resin to root dentin, it is potentially beneficial to focus on improving the quality of the hybrid layer rather than that of resin tags.

Key Words:  dentinal tubule , intertubular dentin , microstructure of dentin , root dentin , scanning electron microscopy

No full text is available. To read the body of this article, please view the PDF online.

 

Back to Article Outline

References 

  1. Bath-Balogh M , Fehrenbach MJ . Tooth development and eruption . In:  Bath-Balogh M ,  Fehrenbach MJ editor. Illustrated Dental Embryology, Histology, and Anatomy . Philadelphia: WB Saunders Co; 1997;p. 62–80
  2. Hanazawa K . A study of the minute structures of dentine, especially of the relationship between dentinal tubules and fibrils . Dent Cosmos . 1917;59:374–405
  3. Symons NBB . A histochemical study of the intertubular and peritubular matrices in normal human dentine . Arch Oral Biol . 1961;5:241–250
  4. Aubin JE . New immunological approaches to studying the odontoblast . J Dent Res . 1985;64:515–522
  5. Hals E . Polarized light study of giant tubules in human and red deer coronal dentin . Scand J Dent Res . 1983;91:105–111
  6. Kaye H , Herold RC . Structure of human dentin, I: phase contrast, polarization, interference and bright field microscopic observations on the lateral branch system . Arch Oral Biol . 1966;11:355–368
  7. Mjör IA , Shackleford JM . Microradiography of human pulp tissue and decalcified coronal dentine . Arch Oral Biol . 1966;11:1307–1316
  8. Schroeder L , Frank RM . High-resolution transmission electron microscopy of adult human peritubular dentine . Cell Tissue Res . 1985;242:449–451
  9. Tronstad L . Ultrastructural observations on human coronal dentin . Scand J Dent Res . 1973;81:101–111
  10. Mjör IA , Nordahl I . The density and branching of dental tubules in human teeth . Arch Oral Biol . 1996;41:401–412
  11. Schwartz RS . Adhesive dentistry and endodontics, part 2: bonding in the root canal system-the problems: a review . J Endod . 2006;32:1125–1134
  12. Fosse G , Saele PK , Eide R . Numerical density and distributional pattern of dentin tubules . Acta Odontol Scand . 1992;50:201–210
  13. Garberoglio R , Brännström M . Scanning electron microscopic investigation of human dentinal tubules . Arch Oral Biol . 1976;21:355–362
  14. Bouillaguet S , Troesch S , Wataha JC , Krejci I , Meyer JM , Pashley DH . Microtensile bond strength between adhesive cements and root canal dentin . Dent Mater . 2003;19:199–205
  15. Reeh ES , Messer HH , Douglas WH . Reduction in tooth stiffness as a result of endodontic and restorative procedures . J Endod . 1989;15:512–516
  16. Lang H , Korkmaz Y , Schneider K , Raab WH . Impact of endodontic treatments on the rigidity of the root . J Dent Res . 2006;85:364–368
  17. Barjau-Escribano A , Sancho-Bru JL , Forner-Navarro L , Rodrìguez-Cervantes PJ , Pérez-González A , Sánchez-Marín FT . Influence of prefabricated post material on restored teeth: fracture strength and stress distribution . Oper Dent . 2006;31:47–54
  18. Wu X , Chan ATT , Chen YM , Yip KHK , Smales RJ . Effectiveness and dentin bond strengths of two materials for reinforcing thin-walled roots . Dent Mater . 2007;23:479–485
  19. Nakabayashi N , Kojima K , Masuhara E . The promotion of adhesion by the infiltration of monomers into tooth substrate . J Biomed Mater Res . 1982;16:265–273
  20. Gaston BA , West LA , Liewehr FR , Fernandes C , Pashley DH . Evaluation of regional bond strength of resin cement to endodontic surfaces . J Endod . 2001;27:321–324
  21. Muniz L , Mathias P . The influence of sodium hypochlorite and root canal sealers on post retention in different dentin regions . Oper Dent . 2005;30:533–539
  22. Yoshiyama M , Matsuo T , Ebisu S , Pashley D . Regional bond strengths of self-etching/self-priming adhesive systems . J Dent . 1998;26:609–616
  23. Gwinnett AJ . Quantitative contribution of resin infiltration/ hybridization to dentin bonding . Am J Dent . 1993;6:7–9
  24. Yoshida Y , Nagakane K , Fukuda R , et al.   Comparative study on adhesive performance of functional monomers . J Dent Res . 2004;83:454–458
  25. Kanca JA . Improving bond strength through acid etching of dentin and bonding to wet dentin surfaces . J Am Dent Assoc . 1992;123:35–43

PII: S1991-7902(10)60003-7

doi:10.1016/S1991-7902(10)60003-7

Journal of Dental Sciences
Volume 5, Issue 1 , Pages 14-20, March 2010

Article Tools