From Simulation to Therapy: Light Guidance Through Zirconium Dental Implants for Bone-Targeted Photodynamic Inactivation.

Bacterial biofilm formations on dental implant-bone borders risk the development of periimplantitis (PI). Treatment, ranging from conservative to invasive options, is effective but associated with significant patient burden. In vitro Photodynamic Inactivation (PDI) waveguided by zirconium dioxide ceramic (ZrO2) dental implants shows promising bactericidal effects and is envisioned to function as an additive treatment reducing patient burden while maintaining therapy outcomes. To facilitate clinical application, this study mathematically quantified the expected waveguiding abilities of ZrO2 implants in a computed tomography (CT)-based Monte Carlo Simulation of Radiation Transport (MCRT). The latter implemented previously photographically determined optical properties from human and porcine jawbone tissues. ZrO2 implants displayed effective light propagation beyond the implant-bone border, with power-per-area values above a minimum baseline for effective PDI of 10 mW/cm2, thus delivering enough light power to reach bactericidal levels in a standard PDI regimen. Modifying the implant design and light-source placement influenced the topographic distribution of the light power around the implant, eventually allowing to target case-specific changes in biofilm distribution. No major interspecies difference was observed, which fosters the transferability of potential mammal testing. All findings therefore support the envisioned application of waveguiding ZrO2 dental implants in PDI to target oral health issues.