Accuracy of Milled Titanium Frameworks Constructed with Direct Scanning and Splinted Impression Techniques

Area of Science:

• Dental materials science
• Biomaterials engineering
• Prosthodontics

Background:

• Accurate fit of implant-supported prostheses is crucial for long-term success.
• Vertical microgaps at the implant-framework interface can lead to bacterial leakage and complications.
• Traditional impression techniques may introduce inaccuracies in framework fabrication.

Purpose of the Study:

• To compare the vertical microgap of milled titanium implant frameworks fabricated using direct model scanning (DMS) versus splinted impression (SIM) techniques.
• To evaluate the precision of framework fit associated with different digital and conventional impression methods.

Main Methods:

• Three external hex implants were embedded in a resin model.
• Titanium frameworks were milled using both DMS and SIM techniques.
• Microcomputed tomography (CT) was used to scan implant-framework interfaces.
• Vertical microgaps were measured using one-screw and two-screw tests with CT analyzer software.

Main Results:

• The DMS group exhibited significantly smaller mean maximum vertical microgaps in both one-screw (13.25 μm vs 72.40 μm) and two-screw (10.5 μm vs 36.2 μm) tests compared to the SIM group (P < .0001 and P = .0002, respectively).
• Direct model scanning demonstrated superior accuracy in framework fabrication.

Conclusions:

• Milled titanium frameworks fabricated via direct model scanning of implants show a reduced vertical microgap.
• The DMS technique offers greater precision for implant framework fabrication compared to splinted impression methods.
• This improved precision may contribute to enhanced clinical outcomes and reduced risk of complications.