IADR Abstract Archives

Influence of filler content on the viscoelasticity of dental materials

Objective: The physicochemical-mechanical properties of dental materials should be similar to enamel and dentine to guarantee good long-term behavior of the material which is well adapted to its biomechanical conditions. Therefore, composites with different filler content were investigated concerning their suitability for dental restorations.

Method: Six composites with different filler contents (w%) were selected for this study: Clearfil MajestyTM Posterior (92%, Kuraray), Grandio®SO (89%, VOCO), Arabesk Top (77%, VOCO), Tetric EvoCeram® (75%, Ivoclar Vivadent), Arabesk Flow (64%, VOCO) and Tetric EvoFlow®(62%, Ivoclar Vivadent). Resin matrices from five of six composites were additionally tested. Dental composites were processed according to the manufacturers’ instructions. Viscoelastic properties were characterized with Dynamical Mechanical Analysis (DMA, F = ± 8 N, f = 0.5 - 3.3 Hz, T = -10 to 240°C). Statistics: Kruskal Wallis H test (p < 0.05) and Spearman’s rank correlation (p < 0.05).

Result: Glass transition temperature (Tg, 86 - 144°C) increased significantly with rising filler content and was two times higher (delta Tg = 38 - 69 K) for composites in comparison to their resin matrices. High filled composites showed three times higher storage moduli than less filled composites. In comparison, damping factor (tan δ) was in the same range. In dependence of rising frequencies a shift of Tg to higher temperatures occurred. Under thermal treatment composites showed an increasing tan δ leading to a loss in damping. Hence, composites reacted more viscous and irreversible ductile deformation took place.

Conclusion: Since high filled composites have similar mechanical properties as the natural tooth, they are more suitable for dental restorations than low filled ones. Nevertheless, results showed their brittle behavior under physiological conditions leading to the risk of structural failures at an early stage of wear.

Continental European Division Meeting
2013 Continental European Division Meeting (Florence, Italy)
Florence, Italy
2013
21
Scientific Groups
  • Warkentin, Mareike  ( University Rostock, Rostock, N/A, Germany )
  • Wurm, Andreas  ( University Rostock, Rostock, N/A, Germany )
  • Schick, Christoph  ( University Rostock, Rostock, N/A, Germany )
  • Rosentritt, Martin  ( Regensburg University Medical Center, Regensburg, , Germany )
  • Ottl, Peter  ( University of Rostock, Rostock, N/A, Germany )
  • Behrend, Detlef  ( University Rostock, Rostock, N/A, Germany )
    • Oral Session
    Dental Materials III - Materials Polymerization
    09/05/2013