[Dental application of superplastic forming for titanium complete denture bases]

Area of Science:

• Biomaterials Engineering
• Dental Materials Science
• Materials Forming

Background:

• Titanium and its alloys are biocompatible materials with potential for dental prosthetics.
• Traditional methods for fabricating dental prostheses can have limitations in terms of accuracy and material integrity.

Purpose of the Study:

• To investigate the feasibility of using superplastic forming for creating complete denture bases from titanium and its alloy.
• To evaluate the properties and surface characteristics of titanium denture bases formed via superplasticity.

Main Methods:

• Sheets of pure titanium and Ti-6Al-4V alloy were deformed using a hot press and a trial ceramic die under vacuum conditions.
• The ceramic die was prepared by sintering a CaO-TiO2-ZrO2-MgCl2 system.
• Deformation parameters included speeds from 1 x 10(-3) to 3 x 10(-2) mm/sec at temperatures up to 900°C.

Main Results:

• Successful deformation of titanium sheets into complete denture bases was achieved at 850°C and 10(-3) Torr.
• The ceramic die exhibited a compressive strength of 11 kg/cm², thermal expansion of 0.8%, and surface roughness (Ra) of 1.4 microns.
• The formed denture bases retained the metallic color of the raw material and accurately replicated the die's surface details.
• Electron Probe Microanalysis (EPMA) revealed a significantly thinner oxygen-enriched layer compared to dental castings.

Conclusions:

• Superplastic forming is a viable technique for fabricating dental prostheses from titanium and its alloys.
• This method offers precise replication of die details and results in a superior surface quality with minimal oxidation.
• The developed process holds promise for producing high-quality, durable, and aesthetically pleasing titanium-based denture bases.