This study evaluated the feasibility of cantilever and fixed bridge restorations through finite element analysis of narrow-diameter implants (NDls) in a 4-unit anterior mandibular bridge. A total of five restoration models were analyzed using static, modal, and dynamic analyses. Results showed that the fixed bridge supported by three NDIs exhibited the lowest stress (crown: 27.429 MPa, implant: 58.608 MPa) and optimal stability (resonance frequency: 8653 Hz). The maximum stresses in cantilever bridge implants (crowns: 78.803 MPa, implants: 146.27) were 2–3 times higher than those in fixed bridges. Dynamic loading generated the highest stresses during the second phase of the masticatory cycle, with overall stress 10%–30% higher than under static loading. Fixed bridges supported by three NDIs are recommended for optimal stress distribution, while cantilever bridges should be used with caution.

The purpose of this study was to use finite element analysis (FEA) to evaluate the mechanical effects of eight different anti-rotation structures in fin-ty