Tissue response to surface-treated tantalum implants: preliminary observations in primates

Area of Science:

• Biomaterials Science
• Materials Science
• Tissue Engineering

Background:

• Tantalum is a biocompatible metal used in medical implants.
• Surface properties significantly influence the biological response to implanted materials.
• Understanding tantalum surface-tissue interactions is crucial for developing advanced medical devices.

Purpose of the Study:

• To investigate the effect of various surface treatments on tantalum's tissue response.
• To evaluate the role of surface-free energy in tantalum-tissue bioadhesion.
• To characterize the morphological and ultrastructural tissue reactions to implanted tantalum.

Main Methods:

• Tantalum samples underwent surface treatments: mill-finished, polished, oxidized, sintered, and glow-discharged.
• Surface characterization utilized contact angle, SEM, EDX, and IRS.
• Surgical implantation in Macaca speciosa (stumptail monkey) at mandible, buccal mucosa, and subcutaneous sites.
• Tissue reaction assessment at intervals up to three weeks via morphological and ultrastructural evaluation.

Main Results:

• Glow-discharge treatment resulted in distinct tissue responses compared to lower surface energy samples.
• Two zones observed adjacent to glow-discharge treated implants: Zone 1 (active mesenchymal cells, potential bioadhesion) and Zone 2 (fibroblastic cells).
• Other treatments showed multinucleated giant cells and reduced cellularity in Zone 1, with both zones becoming less cellular over time.

Conclusions:

• Surface-free energy of tantalum significantly influences differential tissue response.
• Glow-discharge treatment may promote bioadhesion and unique cellular interactions.
• These findings are critical for optimizing tantalum-based biomaterials for medical applications.