Titanium micro-particles are commonly found in soft tissues surrounding dental implants.

BACKGROUND

Dental implants are one of the most frequently used medical devices for therapeutic purposes in dentistry. Peri-implantitis is a severe, microbial biofilm-associated condition, characterized by inflammation in peri-implant soft tissues and destruction of supporting bone. It has been suggested that metal particles originating from the implant may influence the local host response to microbial biofilms.

METHODS

Soft tissue biopsies were collected from implant sites with and without peri-implantitis in 21 patients. Micro Proton-induced X-ray Emission (µ-PIXE) analysis was used to localize, quantify and characterize titanium micro-particles within tissues. RNA sequencing was performed to evaluate potential associations between titanium micro-particles and gene expression profiles in peri-implantitis lesions.

RESULTS

Titanium micro-particles are consistent findings in soft tissues surrounding dental implants. Their occurrence varies across patients but not between sites with and without peri-implantitis within the same individual. Most particles reside in a 2-mm wide tissue portion close to the implant/tissue interface. The time in function of the implants does not influence the volumetric density of titanium micro-particles, while implant systems do. Fourteen differentially expressed genes are identified when comparing peri-implantitis samples with high and low densities of titanium micro-particles. The gene-set enrichment analysis reveals functions related to the regulation of the immune response and epithelial development.

CONCLUSIONS

The present results indicate that titanium micro-particles are commonly found in tissues surrounding dental implants and are not associated with the occurrence of peri-implantitis.