Microhardness and Cutting Resistance in Enamel of Primary Molars Among Various Caries Experience Groups In Vitro

Khositphanthawong Nawaporn, Sirimaharaj Varisara, Wanachantararak Sitthichai

Published Online: Jan 27, 2022 DOI 10.14456/cmdj.2022.5

Objectives: To investigate cutting resistance, microhardness, and their correlations with primary teeth enamel, from different caries experience groups.

Methods: Forty-five extracted primary molars were divided equally into three groups using the dmft/dmft+DMFT index: low, moderate, and high caries experience groups. Each tooth was divided into 2 parts to test cutting resistance and microhardness. All data were compared statistically between groups with different caries experiences using the one-way ANOVA. The correlations were investigated using the Spearman’s and the Pearson’s correlation.

Results: The high caries experience group had significantly lower microhardness of enamel (295.8±12.73 Vickers Hardness Number (VHN)) than the moderate and low caries experience groups (315.01±16.13 VHN; p=0.001 and 325.96±9.91 VHN; p<0.001, respectively). The cutting resistance of enamel from the high caries experience group (87.23±15.06 grams) was also significantly less than those from the moderate and low caries experience groups (112.78±16.02 grams; p=0.002, and 111.67±24.75 grams; p=0.003, consecutively). There were negative correlations between caries experience and cutting resistance (r=-0.46; p=0.002) and between caries experience and microhardness (r=-0.71; p<0.001) but a positive correlation between cutting resistance and microhardness (r=0.39; p=0.009).

Conclusions: Enamel of primary teeth from the high caries experience group had less microhardness and cutting resistance than those of the moderate and low caries experience groups.

Hardness primary tooth caries experience cutting resistance enamel

1. He LH, Fujisawa N, Swain MV. Elastic modulus and stress–strain response of human enamel by nano-indentation. Biomaterials. 2006;27(24):4388-98.

2. Zhang C, Zhu P, Lin Y, Jiao Z, Zou J. Modular Soft Robotics: Modular Units, Connection Mechanisms, and Applications. Adv Intell Syst. 2020;2(6):1900166.

3. Jabbarifar SE, Salavati S, Akhavan A, Khosravi K, Tavakoli N, Nilchian F. Effect of fluoridated dentifrices on surface microhardness of the enamel of deciduous teeth. Dent Res J (Isfahan). 2011;8(3):113.

4. LeGeros RZ, Piliero JA, Pentel L. Comparative Properties of Deciduous and Permanent (Young and Old) Human Enamel. Gerodontology. 1983;2(1):1-8.

5. Zhang YR, Du W, Zhou XD, Yu HY. Review of research on the mechanical properties of the human tooth. Int J Oral Sci. 2014;6(2):61-9.

6. Xu H, Smith D, Jahanmir S, Romberg E, Kelly JR, Thompson VP, et al. Indentation damage and mechanical properties of human enamel and dentin. J Dent Res. 1998;77(3):472-80.

7. Xie Z-H, Mahoney E, Kilpatrick N, Swain M, Hoffman M. On the structure–property relationship of sound and hypomineralized enamel. Acta Biomater. 2007;3(6):865-72.

8. He LH, Swain MV. Understanding the mechanical behaviour of human enamel from its structural and compositional characteristics. J Mech Behav Biomed Mater. 2008;1(1):18-29.

9. Akkus A, Karasik D, Roperto R. Correlation between micro-hardness and mineral content in healthy human enamel. J Clin Exp Dent. 2017;9(4):e569.

10. Chuenarrom C, Benjakul P, Daosodsai P. Effect of indentation load and time on knoop and vickers microhardness tests for enamel and dentin. J Mater Res. 2009;12:473-6.

11. Hayashi-Sakai S, Sakai J, Sakamoto M, Kouda F, Noda T. The gradient of microhardness in cross-sectioned sound primary molars. JSEM. 2006;6(1):13-8.

12. Badr S, Ibrahim MA. Protective effect of three different fluoride pretreatments on artificially induced dental erosion in primary and permanent teeth. J Am Sci. 2010;6(11):442-51.

13. Dejsuvan S, Sirimaharaj V, Wanachantararak S. Nanohardness and elastic modulus properties of enamel and dentin of primary molars in vitro, in people with various caries experiences, using a nano-indentation technique. CM Dent J. 2021;42(1):93-100.

14. Gutiérrez-Salazar M, Reyes-Gasga J. Enamel hardness and caries susceptibility in human teeth. Rev Latin Am Met Mat. 2001;21:36-40.

15. Wongyai T, Sirimaharaj V, Wanachantararak S. Mineral comparisons of primary teeth among different caries experience groups in vitro. CM Dent J 2019; 40(3):135-45.

16. Attin T, Koidl U, Buchalla W, Schaller H, Kielbassa A, Hellwig E. Correlation of microhardness and wear in differently eroded bovine dental enamel. Arch Oral Biol. 1997; 42(3):243-50.

17. Ercoli C, Rotella M, Funkenbusch PD, Russell S, Feng C. In vitro comparison of the cutting efficiency and temperature production of ten different rotary cutting instruments. Part II: electric handpiece and comparison with turbine. J Prosthet Dent. 2009; 101(5):319-31.

18. Watson T, Flanagan D, Stone D. High and low torque handpieces: cutting dynamics, enamel cracking and tooth temperature. Br Dent J. 2000;188(12):680-6.

19. Bae JH, Yi J, Kim S, Shim JS, Lee KW. Changes in the cutting efficiency of different types of dental diamond rotary instrument with repeated cuts and disinfection. J Prosthet Dent. 2014;111(1):64-70.

20. Funkenbusch PD, Rotella M, Ercoli C. Designed experiment evaluation of key variables affecting the cutting performance of rotary instruments. J Prosthet Dent. 2015; 113(4):336-42.

21. Siegel SC, von Fraunhofer JA. Cutting efficiency of three diamond bur grit sizes. J Am Dent Assoc. 2000;131(12):1706-10.

22. Siegel SC, von Fraunhofer JA. The effect of handpiece spray patterns on cutting efficiency. J Am Dent Assoc. 2002;133(2):184-8.

23. Westland IA. The energy requirement of the dental cutting process. J Oral Rehabil. 1980;7(1):51-63.

24. Elias K, Amis AA, Setchell DJ. The magnitude of cutting forces at high speed. J Prosthet Dent. 2003;89(3):286-91.

25. von Fraunhofer J, Givens C, Overmyer T. Lubricating coolants for high-speed dental handpieces. J Am Dent Assoc. 1989;119(2):291-5.

26. Eames WB, Nale JL. A comparison of cutting efficiency of air-driven fissure burs. J Am Dent Assoc. 1973;86(2):412-5.

27. Rosenstiel SF, Land M, Fujimoto J, Cockerill J. Contemporary fixed prosthodontics. 3rd ed: Mosby, Inc; 2001.

28. National Standards Authority of Ireland. Metallic materials - Vickers hardness test - Part 2: Verification and calibration of testing machines (ISO 6507-2:2018). Dublin: NSAI; 2018.

29. Jiang H, Liu XY, Lim CT, Hsu CY. Ordering of self-assembled nanobiominerals in correlation to mechanical properties of hard tissues. Appl Phys Lett. 2005; 86(16):163901.

30. Gutiérrez-Salazar MdP, Reyes-Gasga J. Microhardness and chemical composition of human tooth. J Mater Res. 2003; 6(3):367-73.

31. Habelitz S, Marshall S, Marshall Jr G, Balooch M. Mechanical properties of human dental enamel on the nanometre scale. Arch Oral Biol. 2001;46(2):173-83.

32. Kodaka T, Debari K, Yamada M, Kuroiwa M. Correlation between microhardness and mineral content in sound human enamel. Caries Res. 1992;26(2):139-41.

33. Kelly AM, Kallistova A, Küchler EC, Romanos HF , Lips A, Costa MC, et al. Measuring the microscopic structures of human dental enamel can predict caries experience. J Pers Med. 2020;10(1): 5.

34. Simmer JP, Papagerakis P, Smith CE, Fisher DC, Rountrey AN, Zheng L, et al. Regulation of dental enamel shape and hardness. J Dent Res. 2010;89(10):1024-38.

35. Vieira AR, Gibson CW, Deeley K, Xue H, Li Y. Weaker dental enamel explains dental decay. PLoS One. 2015;10(4):e0124236.

36. Simmer JP, Hu JCC. Dental enamel formation and its impact on clinical dentistry. J Dent Educ. 2001;65(9):896-905.

37. Shimizu T, Ho B, Deeley K, Briseño-Ruiz J, Faraco IM Jr, Schupack BI, et al. Enamel formation genes influence enamel microhardness before and after cariogenic challenge. PLoS One. 2012;7(9):e45022.

38. Bayram M, Deeley K, Reis MF, Trombetta VM, Ruff TD, Sencak RC, et al. Genetic influences on dental enamel that impact caries differ between the primary and permanent dentitions. Eur J Oral Sci. 2015; 123(5):327-34.

39. Song XF, Jin CX, Yin L. Quantitative assessment of the enamel machinability in tooth preparation with dental diamond burs. J Mech Behav Biomed Mater. 2015;41:1-12.

40. Fagrell TG, Dietz W, Jälevik B, Norén JG. Chemical, mechanical and morphological properties of hypomineralized enamel of permanent first molars. Acta Odontol Scand. 2010; 68(4):215-22.

41. Mollica FB, Camargo FP, Zamboni SC, Pereira SMB, Teixeira SC, Nogueira Junior L. Pulpal temperature increase with high-speed handpiece, Er: YAG laser and ultrasound tips. J Appl Oral Sci. 2008; 16:209-13.

42. Ercoli C, Rotella M, Funkenbusch PD, Russell S, Feng C. In vitro comparison of the cutting efficiency and temperature production of 10 different rotary cutting instruments. Part I: Turbine. J Prosthet Dent. 2009;101(4):248-61.

43. Declerck D, Leroy R, Martens L, Lesaffre E, Garcia-Zattera MJ, Vanden Broucke S, et al. Factors associated with prevalence and severity of caries experience in preschool children. Community Dent Oral Epidemiol. 2008;36(2):168-78.

44. Maciel S, Marcenes W, Sheiham A. The relationship between sweetness preference, levels of salivary mutans streptococci and caries experience in Brazilian pre‐school children. Int J Paediatr Dent. 2001;11(2):123-30.

Khositphanthawong N, Sirimaharaj V, Wanachantararak S. Microhardness and Cutting Resistance in Enamel of Primary Molars Among Various Caries Experience Groups In Vitro: Original articles. CM Dent J [Internet]. 2022 Jan 27 [cited 2024 Nov 18];43(1):49-56. Available from: https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=161

Khositphanthawong, N., Sirimaharaj, V. & Wanachantararak, S. (2022). Microhardness and Cutting Resistance in Enamel of Primary Molars Among Various Caries Experience Groups In Vitro. CM Dent J, 43(1), 49-56. Retrieved from: https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=161

Khositphanthawong, N., Sirimaharaj Varisara and Wanachantararak Sitthichai. 2022. "Microhardness and Cutting Resistance in Enamel of Primary Molars Among Various Caries Experience Groups In Vitro." CM Dent J, 43(1), 49-56. https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=161

Khositphanthawong, N. et al. 2022. 'Microhardness and Cutting Resistance in Enamel of Primary Molars Among Various Caries Experience Groups In Vitro', CM Dent J, 43(1), 49-56. Retrieved from https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=161

Khositphanthawong, N., Sirimaharaj, V. and Wanachantararak, S. "Microhardness and Cutting Resistance in Enamel of Primary Molars Among Various Caries Experience Groups In Vitro", CM Dent J, vol.43, no. 1, pp. 49-56, Jan. 2022.

Khositphanthawong Nawaporn, Sirimaharaj Varisara, Wanachantararak Sitthichai "Microhardness and Cutting Resistance in Enamel of Primary Molars Among Various Caries Experience Groups In Vitro." CM Dent J, vol.43, no. 1, Jan. 2022, pp. 49-56, https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=161