Background. Lithium disilicate has been the gold standard for esthetic restorations, but several materials have been introduced to improve the strength without compromising esthetics.

Objective. The objective of this study was to compare between chair-side pre-crystalized zirconia reinforced lithium silicate containing virgilite crystals and lithium disilicate ceramic material (LDS) regarding biaxial flexural strength and shear bond strength.

Materials and Methods. For BFS, 20 disc-shaped specimens, measuring 10 mm in diameter and 1.5 mm in thickness, were manufactured from both Tessera and LDS, with each group consisting of 10 specimens (n=10). BFS was evaluated using the piston-on-ring method on a universal testing machine. For SBS, 20 cuboid specimens (3x3mm and 5 mm thickness) were fabricated from Tessera and LDS (n=10). Specimens of both groups were bonded to natural human teeth with dual cured resin cement after appropriate surface treatment for both human natural teeth and specimen discs. SBS was assessed using a universal testing machine, and the testing was conducted at a crosshead speed of 1 mm/min.
Results. The data obtained was statistically analyzed using appropriate tests. As for BFS, difference in results was statistically significant. Mean BFS value was higher for Tessera group (274.58±22.26) compared to the LDS group (243.31±24.98), however the difference in SBS values were not statistically significant between Tessera group (20.97±1.59), and LDS group (19.18±2.99). The independent t test was used as the test of significance among the groups.

Conclusion. Zirconia reinforced lithium silicate material performed better overall than the more time-consuming lithium disilicate ceramic.