IADR Abstract Archives
Fracture Behavior of Bi-structure Fiber-Reinforced Composite Restorations
Objectives: The aim of this study was to evaluate the fracture-behavior of direct composite restorations made with two different bulk composite core materials. In addition, fracture toughness (FT), flexural strength (FS) and flexural modulus (FM) of tested composites were evaluated.
Methods: Twenty groups of posterior crown restorations were fabricated (n=6/group). Test groups (n=12) were made of 4-5 mm layer of composite core materials (everX Flow, GC and SDR Flow+, Dentsply-Sirona) and covered by 2 mm layer of conventional composite (G-aenial Anterior, G-aenial Posterior, G-aenial Universal Injectable, Essentia, CeramX, Filtek Z500). Control groups (n=8) were only made of conventional composites or composite-core materials. Crowns were statically loaded until fracture. Failure modes were visually examined. FT, FS and FM were determined for each tested composite (n=6) following standards. Data were analyzed using ANOVA (p = 0.05).
Results: ANOVA revealed that crown restorations made only from everX Flow composite had significantly higher load-bearing capacity (3866 ±263 N) (p<0.05) among all the groups tested. No statistically significant difference was found in the load-bearing capacity between crowns made with different composite core materials (p>0.05). everX Flow exhibited the highest FT (2.8 MPa m1/2) and Z500 presented the highest FS values (197 MPa) (p<0.05) among tested composites. With regard to the failure mode analysis, crowns that have fiber-reinforced core material of everX Flow revealed delaminating of surface conventional composite from the substructure layer. While in crowns that have core material of SDR Flow+ or having only conventional composites with no fiber reinforcement showed a catastrophic crushing fracture pattern.
Conclusions: Restorations combining fiber-reinforced everX Flow composite core and surface layer of conventional composite displayed promising performance related to fracture-behavior. FT value of core material has prior importance, as it influences the crack arresting mechanism.
Methods: Twenty groups of posterior crown restorations were fabricated (n=6/group). Test groups (n=12) were made of 4-5 mm layer of composite core materials (everX Flow, GC and SDR Flow+, Dentsply-Sirona) and covered by 2 mm layer of conventional composite (G-aenial Anterior, G-aenial Posterior, G-aenial Universal Injectable, Essentia, CeramX, Filtek Z500). Control groups (n=8) were only made of conventional composites or composite-core materials. Crowns were statically loaded until fracture. Failure modes were visually examined. FT, FS and FM were determined for each tested composite (n=6) following standards. Data were analyzed using ANOVA (p = 0.05).
Results: ANOVA revealed that crown restorations made only from everX Flow composite had significantly higher load-bearing capacity (3866 ±263 N) (p<0.05) among all the groups tested. No statistically significant difference was found in the load-bearing capacity between crowns made with different composite core materials (p>0.05). everX Flow exhibited the highest FT (2.8 MPa m1/2) and Z500 presented the highest FS values (197 MPa) (p<0.05) among tested composites. With regard to the failure mode analysis, crowns that have fiber-reinforced core material of everX Flow revealed delaminating of surface conventional composite from the substructure layer. While in crowns that have core material of SDR Flow+ or having only conventional composites with no fiber reinforcement showed a catastrophic crushing fracture pattern.
Conclusions: Restorations combining fiber-reinforced everX Flow composite core and surface layer of conventional composite displayed promising performance related to fracture-behavior. FT value of core material has prior importance, as it influences the crack arresting mechanism.