• Yu.V. Lakhtin Sumy State University
  • Yu.V. Smeyanov Sumy State University
  • B.V. Nishta Sumy State University
Keywords: stress state, tooth, carious cavity, tooth restoration, dentine, enamel, finite elements method.


A number of problems, worsening restorative material retention in carious cavities and resulting in reduction of restorations working lifespan, occur while dental preparing and restoration. It concerns technical errors during treatment, methods of forming carious cavities. Internal stress arises in the enamel and dentine of both intact and restored teeth, which may cause secondary decay.

Purpose of research is to study stress in dental hard tissues in computer modeling of restored I class carious cavities, which were prepared with classic method.

Methods. Three-dimensional model «enamel-dentine-restoration» was created in SolidWorks program and based on mandibular molar radiograph, it was exported in software complex ANSYS Workbench, and finite element model was formed. Von-Mises equivalent stress was calculated on the condition that dental root was rigidly fixed, all the model components were isotropic, vertical uniaxial load on tooth centre was 500 Н.

Results. A masticator surface stresses in enamel corresponds topographically to projection of molars fissures in an intact tooth. Several stress fields, spreading concentrically from maximum values in the point of load action to minimum values to fissures perimeter, occur there. The first field appears in the point of vertical load action, maximum stress is 74.2 MPa. The second field is located around the first one, its values are lesser up to 50 MPa. Indices of the third field reduce to 25-30 MPa. In the area of medial and distal edge isolated stress zones are noticed up to 35 MPa. The fourth stress field has the lowest indices 10-20 MPa.

Enamel stress nature in a restored tooth is equal to the nature in an intact tooth. But the first field starts around the dental filling, maximum stress value in an enamel is 119 MPa, which is 60% higher than in an intact tooth. The second stress field is about 100 MPa (100% higher than then intact tooth).

Stress in full enamel thickness, in a sagittal section of an intact tooth in a load point, is equal to 52-55 MPa, and in the area of dentine-enamel junction reaches a maximum (74 MPa). Indices in a dentine decrease to 10 MPa. The same stress force is noticed in precervical area of enamel and dentine.

The same stress arises in the top filling layers of restored tooth, as in an enamel of an intact tooth (52-55 MPa). However, a stress is increased to about 120 MPa in the area of direct contact of a filling and enamel. In the thickness of mantle dentine, and in precervical area stress force of hard tissues decreases to 10-15 MPa.

Conclusions. Stress in hard tissues of intact and restored tooth has different value. In unidirectional vertical stress on restored tooth in molar of lower teeth caries of I class maximum stress arises in enamel on the boundary of direct contact with restoration.


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1. Боровский Е. В. Качество препарирования полостей класса I и II / Е. В. Боровский, С. Н. Носикова // Сборник научных трудов SWorld : Материалы междунар. науч.-практ. конф. «Современные направления теоретических и прикладных исследований ‘2012». – Вып. 1, т. 30. – Одесса : КУПРИЕН- КО, 2012. – С. 27-29.

2. Загорский В. А. Частичные съемные и перекрывающие протезы / В. А. Загорский. - М.: Медицина, 2007. - 360 с.

3. Ремизов С. М. Микромеханические характеристики реставрационных стоматологических материалов, эмали и дентина зубов человека / С. М. Ремизов // Стоматология. - 2001. - №4. - С. 28–32.

4. Трехмерное математическое моделирование напряженно-деформированного состояния зуба и пломбы / Е. Ю. Шелковников, А. И. Кириллов, С. М. Ефремов [и др.] // Ползуновский альманах. - 2014. - №2. - С. 54-58.

5. Ausiello Р. Mechanical behavior of post-restored upper canine teeth: A 3D FE analysis / Р. Ausiello, Р. Franciosa, М. Martorelli // Dental Materials. – 2011. – Vol. 27, № 12. – P. 1285–1294.

6. Chun K. J. Comparison of mechanical property and role between enamel and dentin in the human teeth / K. J. Chun, H. H. Choi, J. Y. Lee // J. Dent. Biomech. - 2014. - Vol. 5. - doi: 1758736014520809.

7. Class I and Class II restorations of resin composite: An FE analysis of the influence of modulus of elasticity on stresses generated by occlusal loading / E. Asmussen, A. Peutzfeldt // Dental Materials. - 2008. - Vol. 24, № 5. - P. 600–605.

8. Dejak B. Three-dimensional finite element analysis of molars with thin-walled prosthetic crowns made of various materials / B. Dejak, A. Mlotkowski, C. Langot // Dental Materials. - 2012. - Vol. 28. - P. 433-441.

9. Effect of occlusal restoration on stresses around class V restoration interface: A finite-element study /[ G. Vasudeva, P. Bogra, V. Nikhil, V. Singh] // Indian J. Dent. Res. - 2011. - Vol. 22. - P. 295-302.

10. Factors influencing marginal cavity adaptation of nanofiller containing resin composite restorations / H. Takahashi, W. J. Finger, K. Wegner [et al.] // Dental Materials. – 2010. - Vol. 26, № 12. – P. 1166–1175.

11. Fracture simulation of restored teeth using a continuum damage mechanics failure model /[ L. Haiyan, L. Jianying, Z. Zhenmin, A.S.L. Fok] // Dental Materials. – 2011. – Vol. 27. – Р. 125-133.

12. Fusayama T. Total etch technique and cavity isolation / T. Fusayama // J. Esthet Dent. – 1992 (4). – P. 105- 109.

13. Influence of C-factor and light-curing mode on gap formation in resin composite restorations / G. O. Santos, M. Е. Santos, E. M. Sampaio [et al.] // Oper Dent. – 2009. – Vol. 34. – P. 544-550.

14. Monoblocks in root canals: a finite elemental stress analysis study / [S. Belli, O. Eraslan, G. Eskitascioglu, V. Karbhari] // International Endodontic Journal. - 2011. - Vol. 44. - Р. 817-826.

15. The influence of different restorative materials on secondary caries development in situ / F. H. Sande, Niek N. J. M. Opdam [et al.] // Journal of Dentistry. - 2014. - Vol. 42, № 9. - P. 1171–1177.
How to Cite
Lakhtin, Y., Smeyanov, Y., & Nishta, B. (2018). MODELLING OF STRESS STATE OF DENTAL HARD TISSUES WHILE CARIOUS CAVITIES OF I CLASS RESTORATION. Ukrainian Dental Almanac, (4), 9-12. Retrieved from