Should titanium miniplates be removed after bone healing is complete?

Area of Science:

• Biomaterials Science
• Oral and Maxillofacial Surgery
• Tissue Engineering

Background:

• Titanium and stainless steel are common materials for miniplates in orthopedic and maxillofacial surgery.
• Soft tissue reactions to implanted materials can affect patient outcomes and aesthetics.
• Pigmentation in overlying soft tissues is a potential concern for certain implant materials.

Purpose of the Study:

• To compare the incidence and characteristics of soft tissue pigmentation associated with titanium miniplates versus stainless steel plates.
• To investigate the elemental composition and cellular deposition of pigments in tissues covering these implants.

Main Methods:

• A prospective study involving 32 patients who underwent miniplate removal after 8 months.
• Macroscopic and microscopic examination of soft tissues covering titanium and stainless steel miniplates.
• Energy-dispersive X-ray analysis (EDX) and electron microscopy of pigmented tissues.

Main Results:

• Macroscopic pigmentation observed in 25.6% of titanium miniplate sites, none in stainless steel sites.
• Microscopic pigmentation detected in 71.8% of titanium sites and 65.3% of stainless steel sites.
• EDX confirmed titanium dioxide in tissues near titanium plates; stainless steel sites showed chromium, nickel, iron, and molybdenum. Electron microscopy revealed titanium dioxide between collagen fibers and stainless steel particles within giant cells.

Conclusions:

• Titanium miniplates can cause visible soft tissue pigmentation, primarily due to titanium dioxide deposition.
• Stainless steel plates are associated with different elemental compositions in surrounding tissues, with particles localized in giant cells.
• Material-specific tissue reactions and pigment characteristics should be considered in the selection of fixation devices.