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Resistência à flexão de resinas de metacrilato de metila e bisacrilato de metila submetidas à termociclagem

Flexural strength of methacrylate and bis-acrylate based resins submitted to thermo cycling

Resumos

OBJETIVO: Verificar a resistência à flexão de quatro resinas utilizadas para a confecção de restaurações temporárias submetidas à termociclagem. MÉTODO: Foram utilizadas as resinas da marcas Luxatemp e Structur 2, à base de bisacrilato de metila, e as resinas das marcas Duralay e Alike, à base de metacrilato de metila. Vinte espécimes de cada material foram confeccionados e divididos em dois grupos, para serem submetidos às seguintes condições: (I) - 24 horas de armazenagem em saliva artificial, e (II) - 24 horas de armazenagem em saliva artificial seguida de termociclagem (2000 ciclos, 5 °C-55°C). Cada amostra foi levada ao teste de resistência à flexão em uma Máquina de Ensaios Universal (EMIC DL 10000) e os dados obtidos foram analisados pelo teste ANOVA (dois fatores) e, em seguida, pelo teste Tukey (p < 0,05). RESULTADO: As resinas de bisacrilato apresentaram resultados superiores de resistência à flexão após ambos os tempos de armazenagem, não diferindo estatisticamente entre si após 24 horas (p = 0,3594). A resina Luxatemp apresentou os maiores valores de resistência à flexão após a termociclagem, sendo estatisticamente superior às demais. A termociclagem alterou as propriedades mecânicas de todas as resinas, diminuindo a sua resistência à flexão (p = 0,001). CONCLUSÃO: As resinas de bisacrilato apresentam maior resistência à flexão do que as resinas de metacrilato para os fatores estudados. Todos os materiais utilizados neste estudo tiveram sua resistência reduzida pela ciclagem térmica.

Polimetil metacrilato; prótese parcial temporária; prótese dentária


PURPOSE: This study aimed to evaluate the flexural strength of four resins used for temporary prosthesis after thermo cycling. METHOD: Luxatemp and Structur 2, bis-acryl based resins and, Duralay and Alike, methacrylate based resins, were used. Twenty specimens of each material were confectioned and divided in two groups. The specimens were submitted to the follow conditions: Group I - 24 hours of storage in artificial saliva and, Group II - 24 hours of storage in artificial saliva followed by thermo cycling (2000 cycles, 5 °C-55 °C). Each specimen was carried to flexural strength test in an Universal Testing Machine (EMIC DL 10000) and the results were statistically verified with ANOVA two-way followed by the Tukey test (p < 0.05). RESULT: The flexural strength of bis-acryl based resins was statistically superior to methacrylate based materials after both times of storage; however, they did not differ among themselves after 24 hours (p = 0,3594). The Luxatemp resin presented the higher flexural strength values after thermo cycling, being statistically superior to the others. The thermo cycling process influenced the flexural strength of all the materials evaluated, decreasing their flexural strength (p = 0,001). CONCLUSION: The bis‑acryl resins present superior flexural strength than the methacrylate ones. All materials evaluated have its flexural strength influenced by the thermo cycling process.

Polymethyl methacrylate; denture partial temporary; dental prosthesis


  • 1
    Ha JY, Kim SH, Kim KH, Kwon TY. Influence of the volumes of bis-acryl and poly(methyl methacrylate) resins on their exothermic behavior during polymerization. Dent Mater J. 2011; 30:336-42. PMid:21597212. http://dx.doi.org/10.4012/dmj.2010-188
  • 2
    Patras M, Naka O, Doukoudakis S, Pissiotis A. Management of provisional restorations'deficiences: a literature review. J Esthet Rest Dent. 2011; 24(1):26-38. PMid:22296692. http://dx.doi.org/10.1111/j.1708-8240.2011.00467.x
  • 3
    Yap AUJ, Mah MKS, Lye CPW, Loh PL. Influence of dietary simulating solvents on the hardness of provisional restorative materials. Dent Mater. 2004; 20:370-6. PMid:15019452. http://dx.doi.org/10.1016/j.dental.2003.06.001
  • 4
    Rutkunas V, Sabaliauskas V, Mizutani H. Effects of different food colorants and polishing techniques on color stability of provisional esthetic materials. Dent Mater J. 2010; 29:167-76. PMid:20379027. http://dx.doi.org/10.4012/dmj.2009-075
  • 5
    Koumjian JH, Nimmo A. Evaluation of fracture resistance of resins used for provisional restorations. J Prosthet Dent. 1990; 64: 654-7. http://dx.doi.org/10.1016/0022-3913(90)90290-S
  • 6
    Galindo D, Soltys JL, Graser GN. Long term reinforced fixed provisional restorations. J Prosthet Dent. 1998; 79: 698-701. http://dx.doi.org/10.1016/S0022-3913(98)70078-2
  • 7
    Haselton DR, Diaz-Arnold AM, Vargas MA. Flexural strength of provisional crown and fixed partial denture resins. J Prosthet Dent. 2002; 87: 225-8. PMid:11854681. http://dx.doi.org/10.1067/mpr.2002.121406
  • 8
    Manak E, Arora A. A comparative evaluation of temperature changes in the pulpal chamber during direct fabrication of provisional restoratios: an in vitro study. J Indian Prosthodont Soc. 2011; 11:149-55. PMid:22942574 PMCid:3175240. http://dx.doi.org/10.1007/s13191-011-0073-x
  • 9
    Small BW. Provisional restorations for veneers. Gen Dent. 2008; 56: 608-10. PMid:19014018.
  • 10
    Knobloch LA, Kerby RE, Pulido T, Johnston WM. Relative fracture toughness of bis-acryl interim resin materials. J Prosthet Dent. 2011; 106:118-25. http://dx.doi.org/10.1016/S0022-3913(11)60106-6
  • 11
    Jo LJ, Shenoy KK, Shetty S. Flexural strength and hardness of resin for interim fixed partial dentures. Indian J Dent Res. 2011; 22(1):71-6. PMid:21525681. http://dx.doi.org/10.4103/0970-9290.79992
  • 12
    ANSI/ADA Specification No. 27: Direct filling resins. American National Standards Institute, American Dental Association. Revised 1993.
  • 13
    Powers JM, Sakaguchi RL. Craig's restorative dental materials. 12th ed. St Louis: Mosby Elsevier; 2006.
  • 14
    Nejatidanesh F, Momeni G, Savabi O. Flexural strength of interim resin materials for fixed prosthodontics. J Prosthodont. 2009; 18: 507‑11. PMid:19689710. http://dx.doi.org/10.1111/j.1532-849X.2009.00473.x
  • 15
    Kamble VD, Parkhedkar RD, Mowade TK. The effect of different fiber reinforcements on flexural strength of provisional restorative resins: an in-vitro study. J Adv Prosthodont. 2012; 4:1-6. PMid:22439093 PMCid:3303914. http://dx.doi.org/10.4047/jap.2012.4.1.1
  • 16
    Lang R, Rosentritt M, Behr M, Hendel G. Fracture resistance of PMMA and resin matrix composite-based interim FPD materials. Int J Prosthodont. 2003;16:381-4. PMid:12956492.
  • 17
    Ireland MF, Dixon DL, Breeding LC, Ramp MH. In vitro mechanical property comparison of four resins used for fabrication of provisional fixed restorations. J Prosthet Dent. 1998; 80: 158-62. http://dx.doi.org/10.1016/S0022-3913(98)70104-0
  • 18
    Rosentritt M, Behr M, Lang R, Handel G. Flexural properties of prosthetic provisional polymers. Eur J Prosthodont Restor Dent. 2004;12:75‑9. PMid:15244011.
  • 19
    Young HM, Smith CT, Morton D. Comparative in vitro evaluation of two provisional restorative materials. J Prosthet Dent. 2001;85:129‑32. PMid:11208201. http://dx.doi.org/10.1067/mpr.2001.112797
  • 20
    Gale MS, Darvell BW. Thermal cycling procedures for laboratory testing of dental restorations. J Dent. 1999; 27: 89-99. http://dx.doi.org/10.1016/S0300-5712(98)00037-2
  • 21
    Pinto JRR, Mesquita MF, Henriques GEP, Nóbilo MAA. Evaluation of varying amounts of thermal cycling on bond strength and permanent deformation of two resilient denture liners. J Prosthet Dent. 2004; 92: 288-93. PMid:15343166. http://dx.doi.org/10.1016/j.prosdent.2004.06.005
  • 22
    Ban S, Anusavice KL. Influence of test method on failure stress of brittle dental materials. J Dent Res. 1990, 69: 1791-9. PMid:2250083. http://dx.doi.org/10.1177/00220345900690120201
  • 23
    Yap AUJ, Teoh SH. Comparison of flexural properties of composite restoratives using the ISO and mini-flexural tests. J Oral Rehabil. 2003; 30: 171-7. http://dx.doi.org/10.1046/j.1365-2842.2003.01004.x
  • 24
    Oliveira AG, Panzeri H. Resistência à flexão e à fadiga da resina acrílica quimicamente ativada acrescida de fibras híbridas. Biosci J. 2004; 20: 103-12.

Datas de Publicação

  • Publicação nesta coleção
    08 Fev 2013
  • Data do Fascículo
    Out 2012

Histórico

  • Recebido
    06 Ago 2012
  • Aceito
    17 Out 2012
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