Thermal behavior of various direct resin composites: glass transition temperature and initial degradation analyses

Authors

  • Ivone Lima Santana Federal University of Maranhão
  • Letícia Machado Gonçalves Piracicaba Dental School, State University of Campinas
  • Jacqueline Jady Soares Ribeiro Federal University of Maranhão
  • Joaquim Rodrigues Mochel Filho Federal University of Maranhão
  • Aluísio Alves Cabral Júnior Federal University of Maranhão

Keywords:

Dental composite, thermal treatment, DSC, TGA

Abstract

Purpose: The association of direct resin composites with simple thermal treatments may improve the mechanical properties of these materials. However, the ideal temperature for heat application depends on the thermal behavior of each material, such as glass transition (Tg) and initial degradation temperatures. To propose a heat treatment methodology, this study evaluated the thermal behavior of five commercial direct resin composites using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Methods: Photo-irradiation was achieved in cylindrical specimens (3 x 2 mm) using a photo-activator source (600 mW/cm² for 40 s). Thermal analyses were performed by DSC and TGA using a temperature range from 25 °C to 900 °C. Results: Tg values obtained by DSC were 130.6 °C for FillMagic, 129 oC for Glacier, 143.5 oC for Te-Econom, 147.5 °C for Prisma APH and 143.7 oC for Natural Look. A moderate weight loss began at around 270 oC for all materials, which represented the initial degradation temperature. Conclusion: Regarding the heat treatment itself, it was concluded that the effective temperature for heat treatment is material dependent.

Author Biographies

Ivone Lima Santana, Federal University of Maranhão

Department of Odontology I, Federal University of Maranhão, São Luís, MA, Brazil

Letícia Machado Gonçalves, Piracicaba Dental School, State University of Campinas

Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil

Jacqueline Jady Soares Ribeiro, Federal University of Maranhão

Department of Odontology I, Federal University of Maranhão, São Luís, MA, Brazil

Joaquim Rodrigues Mochel Filho, Federal University of Maranhão

Department of Odontology I, Federal University of Maranhão, São Luís, MA, Brazil

Aluísio Alves Cabral Júnior, Federal University of Maranhão

Post-Graduation Section of Materials Engineering, Federal University of Maranhão, São Luís, MA, Brazil

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Published

2010-12-06

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Section

Original Article