Hypersensitivity to titanium: clinical and laboratory evidence.

Area of Science:

• Biomaterials Science
• Immunology
• Medical Device Research

Background:

• Titanium is widely used in dental and endoprosthetic implants due to its biocompatibility.
• However, concerns exist regarding its potential to elicit adverse immune responses in susceptible individuals.

Purpose of the Study:

• To investigate the potential of titanium to induce hypersensitivity reactions.
• To assess the clinical relevance of titanium-induced hypersensitivity in patients with implants.

Main Methods:

• Fifty-six patients with symptoms post-titanium implant placement were tested using the lymphocyte transformation test MELISA (Mixed Eosinophil Lymphocyte Stimulation Assay).
• Patch testing with titanium and other metals was performed on 54 patients.
• Implant removal was undertaken in 54 patients, with 15 undergoing retesting.

Main Results:

• MELISA revealed titanium hypersensitivity in 37.5% of patients; 28.6% had ambiguous results.
• Patch tests were negative for titanium in all patients, but some reacted to other metals like nickel.
• Following implant removal, 54 patients experienced significant clinical improvement, correlating with normalized MELISA reactivity in retested individuals.

Conclusions:

• Titanium can induce clinically relevant hypersensitivity in a subset of patients exposed to titanium-based implants.
• These findings highlight the importance of considering titanium allergy in patients experiencing adverse reactions to implants.
• Implant explantation can lead to substantial clinical recovery.