IADR Abstract Archives
Finite Element Analysis and Fracture Resistance Testing of Multilayered Woven Fiber and Sonically Inserted Resin Composites
Objectives: The purpose of the present study was to evaluate the stress distribution and fracture type of teeth restored with sonically inserted resin composites (SIRC) reinforced by single or multiple layers of polyethylene woven fiber (PWF).
Methods: Following the Class II (MOD) cavity preparation in nighty-six double rooted mandibular molar teeth, they were divided into eight groups; Group-1: the teeth were restored only with SonicFill2 (SF2), Group-2: one layer of PWF+SF2; Group-3: two layers of PWF+SF2; Group-4: four layers of PWF+SF2; Group-5: the teeth were restored only with Resin Composite inserted with a sonic instrument Compothixo (RCC), Group-6: one layer of PWF+RCC; Group-7: two layers of PWF+RCC; Group-8: four layers of PWF+RCC. Finally, the test specimens were subjected to compressive strength testing until fracture in an EMIC universal testing machine. The data were statistically analyzed using one-way ANOVA followed by post-hoc Tukey test. Specimens also were scored based on the occurrence of vertical root fracture (VRF) and the scores were analyzed using chi-square test. For the finite element method, specimens of the fracture resistance test were simulated by computer modeling to determine the stress distribution pattern in the teeth and resin composite combinations studied.
Results: The highest fracture strength was observed in Group 3, followed by Group 7 and Group 4, respectively. However, there were no statistically significant differences between SF2 and RCC groups combined with same amount of PWF (p= 0.527). In addition, frequency of VRFs in Group 5 was significantly higher than all groups (p= 0.012).
The FEA model for Groups 3 and 4 demonstrated lowest stress values and highest fracture strength, being in agreement with the ex vivo study.
Conclusions: Reinforcing the coronal restoration with two layers of PWF gave most favorable results. While four layers of PWF and stand-alone SIRC increase the stress distribution and decrease the fracture resistance.
Methods: Following the Class II (MOD) cavity preparation in nighty-six double rooted mandibular molar teeth, they were divided into eight groups; Group-1: the teeth were restored only with SonicFill2 (SF2), Group-2: one layer of PWF+SF2; Group-3: two layers of PWF+SF2; Group-4: four layers of PWF+SF2; Group-5: the teeth were restored only with Resin Composite inserted with a sonic instrument Compothixo (RCC), Group-6: one layer of PWF+RCC; Group-7: two layers of PWF+RCC; Group-8: four layers of PWF+RCC. Finally, the test specimens were subjected to compressive strength testing until fracture in an EMIC universal testing machine. The data were statistically analyzed using one-way ANOVA followed by post-hoc Tukey test. Specimens also were scored based on the occurrence of vertical root fracture (VRF) and the scores were analyzed using chi-square test. For the finite element method, specimens of the fracture resistance test were simulated by computer modeling to determine the stress distribution pattern in the teeth and resin composite combinations studied.
Results: The highest fracture strength was observed in Group 3, followed by Group 7 and Group 4, respectively. However, there were no statistically significant differences between SF2 and RCC groups combined with same amount of PWF (p= 0.527). In addition, frequency of VRFs in Group 5 was significantly higher than all groups (p= 0.012).
The FEA model for Groups 3 and 4 demonstrated lowest stress values and highest fracture strength, being in agreement with the ex vivo study.
Conclusions: Reinforcing the coronal restoration with two layers of PWF gave most favorable results. While four layers of PWF and stand-alone SIRC increase the stress distribution and decrease the fracture resistance.