Digital Light Processing (DLP) 3D printing technology exhibits remarkable potential in dental manufacturing due to its exceptional precision, customization capabilities, and rapid prototyping abilities. Compared to crown and bridge restorations produced through milling and sintering, resin restorations fabricated using DLP printing technology offer higher accuracy and more efficient and economical processing methods. However, the clinical application of DLP-printed tooth crowns and bridge prostheses is limited by their poor mechanical properties and biocompatibility. In this study, a light-curing resin matrix was formulated using Urethane dimethacrylate (UDMA), Poly(propylene glycol) dimethacrylate (PPGDMA), and a novel photoinitiator 2,4,6-trimethylbenzoyl bis(p-tolyl) phosphine oxide (TMO). Silane-modified nano-silica (SiO₂) was used as a reinforcing filler to achieve different solid contents in the resin matrix. Four groups of DLP-printed dental nanocomposite resins (DNRs) were prepared with varying solid contents: 16%wt, 19%wt, 22%wt, and 25%wt. Subsequently, comprehensive evaluations were conducted on the rheological properties, flexural strength, compressive strength, hardness, water absorption capacity, solubility, double bond conversion efficiency, and light transmittance of DNRs with different solid contents. The aesthetic properties and the biocompatibility of DNRs were further assessed using gingival fibroblasts. The results demonstrated that incorporating 19% wt SiO₂ nanoparticles into the resin matrix significantly enhanced both physical-mechanical properties and biocompatibility of DNRs. In conclusion, the DLP-printed dental nanocomposite with a solid content of 19%wt exhibited excellent physical-mechanical properties and biocompatibility, suggesting its potential for application in crown and bridge restorations for DLP-printed teeth.