Under current minimally invasive treatment regimes, minor tooth preparation and thinner biomimetic ceramic restoration are used to preserve the restored tooth's vitality, aesthetics, and function. New computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic-like material are now available. To guarantee longevity, a dental clinician must know these newly launched product's mechanical strength compared to the relatively brittle glass-matrix ceramic. Furthermore, a tooth substitute has been promoted for laboratory investigation, especially after the pandemic, and more evidentiary support is required for its application. This study developed a laboratory protocol for a monotonic load-to-fracture test to determine the fracture strength of 1 mm-thick CAD/CAM occlusal veneers. Master dies were milled from high-pressure fiberglass laminate, which has similar elastic modulus and bond strength as hydrated dentin. They were mounted into polyvinyl chloride (PVC) end caps with cold-curing epoxy resin. Occlusal veneers, also called tabletop restorations, were milled from lithium disilicate (LD) and resin nanoceramic blocks (RNC) and cemented to prepared master dies using dual-cured adhesive resin cement. They were allowed to cure fully by storing in distilled water for 48 h at 37 °C. All samples were then placed in a universal testing machine and loaded via a non-fixed 5.5 mm stainless-steel ball that allows lateral movement as would occur against the antagonist teeth. Compression was applied at a 1 mm/min rate, and the load-displacement graph was generated. The average maximum load-bearing capacity of restorations in the RNC group (3,212.80 ± 558.67 N) was significantly higher than in the LD group (2727.10 ± 472.41 N) (p < 0.05). No debonding was found during the test. Both CAD/CAM materials may have a similar flaw distribution. Hertzian cone crack was found at the loading site, whereas radial cracks propagating from the cementation surface were found close to the margin in both groups.