Titanium Base-Free Multi-Unit Abutment Connections: A Critical Review of Prosthetic Screw Design, Biomechanical...

Area of Science:

• Biomaterials Science
• Dental Implantology
• Biomechanics

Background:

• Titanium base-free multi-unit abutment (MUA) restorations aim to streamline implant prosthetic workflows.
• Eliminating titanium bases alters the biomechanics of the prosthesis-abutment-implant complex.
• Limited evidence synthesizes the biomechanical consequences of omitting titanium bases.

Purpose of the Study:

• To critically review the influence of prosthetic screw design on titanium base-free MUA restorations.
• To evaluate screw effects on preload maintenance, load transfer, and mechanical stability.
• To synthesize current evidence on the biomechanical behavior of these restorations.

Main Methods:

• Critical literature review.
• Focus on studies investigating prosthetic screw design parameters.
• Analysis of biomechanical outcomes: preload, load transfer, stability, and fatigue.

Main Results:

• Preload loss, screw loosening, and fatigue are key factors in mechanical performance.
• Screw material, surface, and geometry may influence preload and stability, but evidence is limited.
• Short-term clinical outcomes are acceptable with proper protocols, but long-term data is scarce.

Conclusions:

• Titanium base-free MUA restorations are technique-sensitive.
• Optimized screw selection, prosthetic fit, and controlled loading are crucial.
• Further long-term studies are necessary to confirm predictability.