LAUSR

Degradation of the implant surface and particle release/formation as an inflammation catalyst mechanism is an emerging concept in dental medicine that may help explain the pathogenesis of peri-implantitis. The aim of the present study was a synchrotron-based characterization of micro- and nano-sized implant-related particles in inflamed human tissues around tita-nium and ceramic dental implants that exhibited signs of peri-implantitis. Size, distribution and chemical speciation of the exogenous micro- and nano-sized particle content was evaluated using synchrotron μ-XRF, nano-XRF and μ-XANES. Tita-nium particles, with variable speciation, were detected in all tissue sections associated with titanium implants. Ceramic particles were found in five out of eight tissue samples associated with ceramic implants. Particles ranged in size from mi-cro- to nanoscale. The local density of both titanium and ceramic particles was calculated to be as high as ~40 million parti-cles/mm³. μ-XANES identified titanium in predominantly two different chemistries including, metallic and titanium dioxide (TiO2). The findings highlight the propensity for particle accumulation in the inflamed tissues around dental implants and will help guide toxicological studies to determine the biological significance of such exposures.