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Background <p>This study aims to investigate the fracture resistance of CAD/CAM post-core restorations manufactured from different materials and to evaluate stress distribution using finite element analysis (FEA).</p> Methods <p>Root canal treatment was performed on 48 single-rooted mandibular second premolars, which were randomly assigned to four groups (<i>n</i> = 12). The experimental groups were as follows: Group PEEK (polyether ether ketone), Group Nano-hb (nanohybrid composite), Group GFR-C (glass fiber-reinforced composite), and Group Zir (zirconia). Post–core restorations were fabricated using a CAD/CAM system. Following thermocycling, the specimens were subjected to static loading in a universal testing machine. For finite element analysis, a mandibular second premolar model was constructed, and a load of 100&#xa0;N was applied at a 45° angle to the long axis. The maximum von Mises stresses were recorded. Fracture resistance values were statistically analyzed using one-way ANOVA, and post hoc pairwise comparisons were performed with the Dunnett T-test.</p> Results <p>Fracture resistance was highest in Group Zir (1240.20&#xa0;N), followed by GFR-C (993.53&#xa0;N), with PEEK (674.07&#xa0;N) and Nano hb (666.10&#xa0;N) showing significantly lower values (<i>p</i> &lt; 0.05). FEA showed the highest stress concentration in the zirconia post-core (69.230&#xa0;MPa), while the lowest was in PEEK (22.968&#xa0;MPa). However, root stress was highest in PEEK (40.390&#xa0;MPa) and lowest in zirconia (17.773&#xa0;MPa). Zirconia and GFR-C groups showed a higher incidence of catastrophic fractures, whereas PEEK and Nano hb exhibited mostly favorable fracture patterns.</p> Conclusions <p>Finite element analysis and examination of fracture types have shown that rigid zirconia post-core restorations cause severe fractures due to their mechanical properties. In contrast, materials with an elasticity modulus similar to that of dentin provide a more physiological stress distribution and result in minor fractures.</p>

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Mechanical behavior of esthetic CAD/CAM post–core restorations: a 3D finite element analysis

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2025年11月24日

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  • Leyla Tutus,
  • Ozge Parlar Oz,
  • Irem Karagozoglu

摘要

Background

This study aims to investigate the fracture resistance of CAD/CAM post-core restorations manufactured from different materials and to evaluate stress distribution using finite element analysis (FEA).

Methods

Root canal treatment was performed on 48 single-rooted mandibular second premolars, which were randomly assigned to four groups (n = 12). The experimental groups were as follows: Group PEEK (polyether ether ketone), Group Nano-hb (nanohybrid composite), Group GFR-C (glass fiber-reinforced composite), and Group Zir (zirconia). Post–core restorations were fabricated using a CAD/CAM system. Following thermocycling, the specimens were subjected to static loading in a universal testing machine. For finite element analysis, a mandibular second premolar model was constructed, and a load of 100 N was applied at a 45° angle to the long axis. The maximum von Mises stresses were recorded. Fracture resistance values were statistically analyzed using one-way ANOVA, and post hoc pairwise comparisons were performed with the Dunnett T-test.

Results

Fracture resistance was highest in Group Zir (1240.20 N), followed by GFR-C (993.53 N), with PEEK (674.07 N) and Nano hb (666.10 N) showing significantly lower values (p < 0.05). FEA showed the highest stress concentration in the zirconia post-core (69.230 MPa), while the lowest was in PEEK (22.968 MPa). However, root stress was highest in PEEK (40.390 MPa) and lowest in zirconia (17.773 MPa). Zirconia and GFR-C groups showed a higher incidence of catastrophic fractures, whereas PEEK and Nano hb exhibited mostly favorable fracture patterns.

Conclusions

Finite element analysis and examination of fracture types have shown that rigid zirconia post-core restorations cause severe fractures due to their mechanical properties. In contrast, materials with an elasticity modulus similar to that of dentin provide a more physiological stress distribution and result in minor fractures.