Mechanical behavior and weight reduction of titanium frameworks with topology-optimized lattice structures for implant-supported prostheses.

PURPOSE: This study aimed to investigate the mechanical behavior of titanium frameworks with triply periodic minimal surface (TPMS) lattice structures designed for additive manufacturing by topology optimization for complete arch implant-supported fixed dental prostheses.

MATERIALS AND

METHODS

A maxillary model supported by four implants (two posteriorly tilted and two anterior parallel) was virtually modeled using a dental computer-aided design program. Titanium frameworks for complete arch implant-supported fixed dental prostheses, which incorporated three distinct TPMS lattice structures (Schwarz, Diamond, and Lidinoid) with variable cell wall thicknesses, were designed using topology optimization software. A total of 36 optimized framework designs were analyzed by finite element analysis under vertical and oblique loading (200 N) at the canine, premolar, and molar (cantilever) regions. A solid, non-optimized titanium framework was the control group. von Mises stress (MPa), maximum displacement (µm), reaction forces (N), and weight reduction ratios (%) were analyzed. Statistical analyses were performed with ANOVA and Tukey's post hoc test (α = 0.05).

RESULTS

All topology-optimized frameworks achieved >30% weight reduction, with the Diamond lattice structure demonstrating the highest reduction of 39.92 ± 2.60 (p < 0.001). Although optimized frameworks exhibited higher displacement and stress values than solid controls because of increased flexibility, the peak stress values (190-210 MPa) remained significantly below the yield strength of titanium. Optimized frameworks generated significantly lower reaction forces than solid controls under canine and premolar loading, indicating an energy-absorbing effect.

CONCLUSIONS

Topology optimization created a semi-rigid framework that incorporates the shock-absorbing benefits of polymers while maintaining the inherent fracture resistance of metallic alloys. Topology-optimized titanium frameworks provide a clinically viable solution for reducing prosthetic weight and minimizing reaction forces at the abutment interface, particularly in complete-arch rehabilitations.