ABSTRACT Objectives This study investigates how titanium‐base (Ti‐base) abutment height, crown design, and force angulation affect biomechanics in an anterior single‐implant restoration, using finite element analysis. Material and Methods A three‐dimensional anterior maxilla model was constructed with linear elastic properties. Two Ti‐base heights (3.5, 5.5 mm) and two crown heights (8, 11 mm) were tested as monolithic zirconia or bilayer (zirconia core veneered with lithium disilicate). A 146 N load was applied at the cingulum at 45° or 65°. von Mises stress (VMS) was computed in the crown, abutment, and surrounding bone. Results A 3.5 mm Ti‐base with an 8 mm monolithic zirconia crown (SSZ) produced the lowest crown and abutment VMS. The highest crown VMS occurred in the 11 mm bilayer crown on a 5.5 mm Ti‐base (LLZEX) at 45°, while the highest abutment VMS occurred in the 3.5 mm Ti‐base with an 8 mm bilayer crown (SSZEX) at 65°. An increase in crown height raises crown stresses, whereas the impact of abutment height depends on configuration and angle. In bone, 45° loading increased VMS compared with 65° across all models. Conclusions In anterior single‐implant models, the lowest restoration stresses were achieved with a short crown on a 3.5‐mm Ti‐base and monolithic zirconia. Long crowns (11 mm) increased crown stresses, and abutment height should be tailored to material and anticipated loading direction rather than adjusted by a single rule. Oblique loading consistently raised bone stress compared with 65°, underscoring the need to optimize for axial force transmission.
Abtahi et al. (Sun,) studied this question.