Aim: This study aimed to compare the fracture resistance of endodontically treated
premolars restored by Ceram x SphereTEC one composite resin, bioactive restorative
material (ACTIVA BioACTIVE Restorative), Alkasite restorative material (Cention-N)
and Zirconia reinforced glass ionomer (Zirconomer). Subjects and Methods: Forty
maxillary premolars were assigned into four equal groups according to the restorative material used . Group A: Teeth restored with Ceram x SphereTEC one. Group B:
Teeth restored with ACTIVA BioACTIVE Restorative. Group C: Teeth restored with
Cention-N and group D: Teeth restored with Zirconomer. Standardized flat MOD cavities after root canal treatment were prepared for all groups. Restorative materials were
applied according to manufacture instructions. The teeth were mounted in universal
testing machine and subjected to compressive force till fracture. Fracture patterns were
evaluated under a stereomicroscope at magnification of 12×. Data was statistically
analyzed. Results: For all groups, the mean fracture resistance values were 1447.82
N, 1452.28 N, 1250.42 N, and 920.39 N, respectively. Statistical analyses showed no
significant differences in the mean fracture resistances between group A, group B and
group C (p < 0.05). There were significant differences between group D and the other
groups (p > 0.05). Conclusions: Ceram x SphereTEC one, Activa Bioactive Restorative
and Cention-N have a high similar fracture resistances values in restoration of endodontically treated teeth, while Zirconomer has the lower value.