Revista de Odontologia da UNESP
https://revodontolunesp.com.br/article/588018d07f8c9d0a098b4e2c
Revista de Odontologia da UNESP
Original Article

Effect of specimen size on flexural strength of restorative composites

Efeito das dimensões dos corpos de prova na resistência à flexão de compósitos restauradores

Santos, Sybilla Cristine do Couto; Abi-Rached, Filipe de Oliveira; Almeida-Júnior, Antonio Alves de; Cruz, Carlos Alberto dos Santos

Downloads: 0
Views: 546

Abstract

The aim of this study was to evaluate the influence of specimen size, in comparison with the ISO Standard, on the three point flexural strength of resin composite restorative materials Filtek Supreme and Filtek Z-250. Forty specimens were fabricated for each material with the following length, width and thickness measurements (n = 10): 1) 20 × 2 × 2 mm (ISO 4049); 2) 10 × 2 × 1 mm; 3) 10 × 1 × 1 mm; 4) 8 × 0.8 × 0.8 mm. The composites were inserted in a single increment into two-piece metal device and light-polymerized. The specimens were dry stored at 37 ± 1 °C and protected from light for 7 days. After this period, flexural strength was measured by three-point flexure test using MTS 810 equipment, with a load cell of 10 kN at a speed of 0.5 mm/min. For the evaluated sizes, the results showed significant variability (p = 0.00) with values when compared with the ISO Standard (116.700 MPa), being statistically higher for the test specimens measuring 10 × 1 × 1 mm (142.530 MPa), similar for those of 10 × 2 × 1 mm (115.815 MPa) and lower for those of 8 × 0.8 × 0.8 mm (86.650 MPa). There was statistical equality (p = 0.08) for the studied composites (Filtek Supreme, 125.270 MPa; Filtek Z-250, 108.130 MPa). Specimens measuring 10 × 2 × 1 mm provided flexural strength values equivalent to those obtained in the sizes recommended by the ISO 4049 standard, with lower consumption of material, energy and time.

Keywords

Specimen size, flexural strength, restorative composites

Resumo

O objetivo deste estudo foi avaliar, em relação à norma ISO, o efeito da redução das dimensões dos corpos de prova na resistência à flexão, em três pontos, dos compósitos restauradores de nanopartículas (Filtek Supreme - 3M ESPE) e micro-híbrido (Filtek Z-250 - 3M ESPE). Foram confeccionados 40 corpos de prova para cada material com as seguintes dimensões de comprimento, largura e espessura (n = 10): 1) 20 × 2 × 2 mm (ISO 4049); 2) 10 × 2 × 1 mm; 3) 10 × 1 × 1 mm; 4) 8 × 0,8 × 0,8 mm. Os compósitos foram inseridos em único incremento em matrizes metálicas bipartidas, correspondentes a cada dimensão avaliada, e fotoativados. Os corpos de prova foram armazenados a 37 ± 1 °C, em ambiente seco e protegido de luz, durante 7 dias. Posteriormente, foi realizado o ensaio de resistência à flexão, em três pontos, usando o equipamento MTS 810, com célula de carga de 10 kN e velocidade de 0,5 mm/min. Os resultados mostraram variabilidade significativa para as dimensões avaliadas (p = 0,00), com valores, em relação à norma ISO (116,700 MPa), estatisticamente superiores para os corpos de prova de 10 × 1 × 1 mm (142,530 MPa), semelhantes para os de 10 × 2 × 1 mm (115,815 MPa) e inferiores para os de 8 × 0,8 × 0,8 mm (86,650 MPa). Houve igualdade estatística (p = 0,08) para os compósitos estudados (Filtek Supreme, 125,270 MPa; Filtek Z-250, 108,130 MPa). Corpos de prova de 10 × 2 × 1 mm proporcionaram, com menor consumo de material, energia e tempo, valores de resistência à flexão equivalentes àqueles obtidos nas dimensões preconizadas pela norma ISO 4049.

Palavras-chave

Dimensão de corpos de prova, resistência à flexão, compósitos restauradores

References



1. Ferracane JL, Greener EH. The effect of resin formulation on the degree of conversion and mechanical properties of dental restorative resins. J Biomed Mater Res. 1986; 20: 121-31.

2. Ferracane JL, Mitchem JC. Properties of posterior composite: results of round robin testing for a specification. Dent Mater. 1994; 10: 92-9.

3. Gregory WA, Berry S, Duke E, Dennison JB. Physical properties and repair bond strength of direct and indirect composite resins. J Prosthet Dent. 1992; 68: 406-11.

4. Nambu T, Watanabe C, Tani Y. Influence of water on the transverse strength of posterior composite resins. Dent Mater J. 1991; 10: 138-48.

5. Asmussen E, Peutzfeldt A. Influence of UEDMA, BisGMA and TEGDMA on selected mechanical properties of experimental resin composites. Dent Mater. 1998; 14: 51-6.

6. Peutzfeldt A, Sahafi A, Asmussen E. Characterization of resin composites polymerized with plasma arc curing units. Dent Mater. 2000; 16: 330-6.

7. Li J, Nicander I, von Beetzen M, Sundström F. Influence of paste temperature at curing on conversion rate and bending strength of light‑cured dental composites. J Oral Rehabil. 1996; 23: 298-301.

8. Munksgaard EC, Peutzfeldt A, Asmussen E. Elution of TEGDMA and BisGMA from a resin and a resin composite cured with halogen or plasma light. Eur J Oral Sci. 2000; 108: 341-5.

9. Palin WM, Fleming GJ, Burke FJ, Marquis PM, Randall RC. Monomer conversion versus flexure strength of a novel dental composite. J Dent. 2003; 31: 341-51.

10. Eliades GC, Vougiouklakis GJ, Caputo AA. Degree of double bond conversion in light-cured composites. Dent Mater. 1987; 3: 19-25.

11. Hansen EK, Asmussen E. Visible-light curing units: correlation between depth of cure and distance between exit window and resin surface. Acta Odontol Scand. 1997; 55: 162-6.

12. Hirabayashi S, Hood JA, Hirasawa T. The extent of polymerization of Class II light-cured composite resin restorations; effects of incremental placement technique, exposure time and heating for resin inlays. Dent Mater J. 1993; 12: 159-70.

13. Park SH. Comparison of degree of conversion for light-cured and additionally heat-cured composites. J Prosthet Dent. 1996; 76: 613-8.

14. Park SH, Lee CS. The difference in degree of conversion between light-cured and additional heat-cured composites. Oper Dent. 1996; 21: 213-7.

15. International Organization for Standardization Dentistry – resin-based filling materials. Switzerland: ISO; 1988. 11p. (ISO 4049:1988).

16. Blackham JT, Vandewalle KS, Lien W. Properties of hybrid resin composite systems containing prepolymerized filler particles. Oper Dent. 2009; 34: 697-702.

17. Catelan A, Padilha AC, Salzedas LM, Coclete GA, dos Santos PH. Effect of radiotherapy on the radiopacity and flexural strength of a composite resin. Acta Odontol Latinoam. 2008; 21: 159-62.

18. Miyazaki M, Oshida Y, Moore BK, Onose H. Effect of light exposure on fracture toughness and flexural strength of light-cured composites. Dent Mater. 1996; 12: 328-32.

19. Rocha SS, Adabo GL, Vaz LG, Vido RN. Resistência à flexão de compósitos diretos utilizados em restaurações posteriores. ROBRAC: Rev Odontol Brasil Central. 2004;13:24-7.

20. Yesilyurt C, Yoldas O, Altintas SH, Kusgoz A. Effects of food-simulating liquids on the mechanical properties of a silorane-based dental composite. Dent Mater J. 2009; 28: 362-7.

21. Firoozmand LM, Pagani C. Influence of bleaching treatment on flexural resistance of hybrid materials. Acta Odontol Latinoam. 2009; 22: 75-80.

22. Muench A, Correa IC, Grande RH, João M. The effect of specimen dimensions on the flexural strength of a composite resin. J Appl Oral Sci. 2005; 13: 265-8.

23. Peutzfeldt A, Asmussen E. Mechanical properties of three composite resins for the inlay/onlay technique. J Prosthet Dent. 1991; 66: 322-4.

24. Huysmans MC, van der Varst PG, Lautenschlager EP, Monaghan P. The influence of simulated clinical handling on the flexural and compressive strength of posterior composite restorative materials. Dent Mater. 1996; 12: 116-20.

25. Hinoura K, Miyazaki M, Onose H. Effect of irradiation time to light-cured resin composite on dentin bond strength. Am J Dent. 1991; 4: 273-6.

26. Peutzfeldt A, Asmussen E. Effect of temperature and duration of post-cure on selected mechanical properties of resin composite containing carboxylic anhydrides. Scand J Dent Res. 1992; 100: 296-8.

27. Peutzfeldt A, Asmussen E. The effect of postcuring on quantity of remaining double bonds, mechanical properties, and in vitro wear of two resin composites. J Dent. 2000; 28: 447-52.

28. Condon JR, Ferracane JL. In vitro wear of composite with varied cure, filler level, and filler treatment. J Dent Res. 1997; 76: 1405-11.

29. Venhoven BA, de Gee AJ, Werner A, Davidson CL. Influence of filler parameters on the mechanical coherence of dental restorative resin composites. Biomaterials. 1996; 17: 735-40.

30. Xu HH, Schumacher GE, Eichmiller FC, Peterson RC, Antonucci JM, Mueller HJ. Continuous-fiber preform reinforcement of dental resin composite restorations. Dent Mater. 2003; 19: 523-30.
588018d07f8c9d0a098b4e2c rou Articles
Links & Downloads

Rev. odontol. UNESP

Share this page
Page Sections