Suitability of Direct Resin Composites in Restoring Endodontically Treated Teeth (ETT)

(1) Background: The in vitro study aimed to investigate mechanical characteristics of resin composites and their suitability in direct restauration of endodontically treated teeth (ETT). (2) Methods: 38 endodontically treated premolars with occlusal access cavities were directly restored using the following resin composites and adhesives: Tetric Evo Ceram + Syntac classic ( = 10), Venus Diamond + iBond Total-Etch ( = 10), Grandio + Solobond M ( = 9), Estelite Sigma Quick + Bond Force ( = 9). After thermocycling, the elastic modulus, shear-bond-strength, fracture load (Fmax) and fracture mode distribution were evaluated. Statistical analysis: one-way ANOVA, -test, Kruskal-Wallis test; < 0.05. (3) Results: Grandio showed the highest E-modulus (15,857.9 MPa) which was significant to Venus Diamond (13,058.83 MPa), Tetric Evo Ceram (8636.0 MPa) and Estelite Sigma Quick (7004.58 MPa). The highest shear-bond-strength was observed for Solobond M (17.28 MPa), followed by iBond (16.61 MPa), Syntac classic (16.41 MPa) and Bond Force (8.37 MPa, < 0.05). The highest fracture load (Fmax) was estimated for ETT restored with Venus Diamond (1106.83 N), followed by Estelite Sigma Quick (1030.1 N), Tetric Evo Ceram (1029 N) and Grandio (921 N). Fracture-mode distribution did not show any significant differences. (4) Conclusions: The observed resin composites and adhesives show reliable mechanical characteristics and seem to be suitable for direct restoration of endodontically treated teeth.