16 March 2023

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Local and systemic effects of the release of titanium particles after implant surgery

Lara Figini

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Commercially pure titanium (Ti) or Ti alloys are the most used metallic materials in implantology.

Although implants have proven to be an effective treatment for restoring functionality and aesthetics in edentulous patients, the growing number of peri-implant diseases raises concerns.

While it is well documented that peri-implantitis is an inflammatory condition caused by bacteria, there are other factors such as the presence of Ti metal ions that could be contributing factors.

TI-implants are biocompatible due to the formation of a protective Ti oxide layer. This stable passive film protects the dental implant surface from corrosion. However, an acidic environment or polishing of the implant can reduce the corrosion resistance of the material up to the loss of the Ti oxide layer, facilitating the release of nano debris and soluble metal ions which could induce adverse reactions.

The presence of molecules, including citrate or tartrate, in biological fluids could also generate soluble forms of Ti (Ti-citrate or Ti-tartrate) capable of triggering reactions in the body.

The main objective of this experimental study was to determine whether the accumulation of Ti metal particles from dental implants in mandibular bone defects in rats could result in significant translocation and accumulation of Ti, aluminum (Al) and vanadium (V) ions. in blood, liver, spleen and brain.

The secondary objective was to analyze the response of the peri wound bone and mucosal tissue to the presence of such metallic Ti particles.

Materials and methods

In an experimental in vitro study, published online in June 2022 in the Journal of Periodontology, the authors evaluated the ion accumulation, in blood and organs, of metallic titanium (Ti) particles in jaw defects in rats. They also provided a description of the local oral tissue reaction to this Ti alloy debris.

Researchers randomly assigned 20 Sprague-Dawley rats into three groups:

• Group 1 or experimental with a mandibular bone defect filled with metal debris obtained from implantoplasty,
• Group 2 or positive control, and
• Group 3 or negative control.

Thirty days after surgery, the rats were euthanized and subjected to peri lesion-area analysis. The tissue surrounding the jaw defect was removed, along with the lungs, spleen, liver and brain.

Researchers collected two blood samples, immediately before surgery and before euthanasia.

The periwound tissue was analyzed histologically by hematoxylin-eosin staining and the concentration of Ti, aluminum and vanadium ions was analyzed. Blood and organ Ti ion concentrations were measured by TQ-ICP-MS. Descriptive bivariate analyzes of the data were performed.

Results

All rats with metal debris implanted showed metal particles and a fracture callus in the bone defect. The metal particles were surrounded by a foreign body reaction characterized by the presence of histiocytes and multinucleated giant cells (MNGCs).

The experimental group had a significantly higher Ti ion concentration in all organs studied except lung tissue (p < 0.05). More V ions were found in the brain in the experimental group.

Conclusions

From the data of this study, researchers concluded that the presence of metal particles of Ti in the jaw might increase the concentration of metal ions in vital organs and induce a foreign body reaction.

For more information: "Ion release and local effects of titanium metal particles from dental implants: An experimental study in rats."