Organic degradation potential of a TiO₂/H₂O₂/UV-vis system for dental applications

The combination of TiO₂ and H₂O₂ under light activation constitutes a promising method for disinfection of dental prosthetics and implants, due to production of reactive oxygen species (ROS). The aim of this work was to investigate the organic degradation ability of TiO₂ particles in combination with H₂O₂ and under light activation utilizing the organic dye rhodamine B (RhB).

Five different types of TiO₂ particles, consisting of anatase, rutile, or a mixture of these crystalline phases, were combined with H₂O₂ and RhB, and subsequently exposed to UV (365nm) or visible (405nm) light at an irradiance of 2.1mW/cm².

It was found that rutile in combination with low concentrations of H₂O₂ (1.0-3.5mM) resulted in a degradation of RhB of 96% and 77% after 10min exposure to 365nm and 405nm light, respectively, which was the highest degradation of all test groups. Control measurements performed without light irradiation or irradiation at 470nm, or without TiO₂ particles resulted in little or no degradation of RhB.

Low H₂O₂ concentrations (1.0mM-3.5mM) and visible light (405nm) used in combination with rutile TiO₂ particles showed the highest RhB degradation capacity.

A combination of TiO₂ particles and H₂O₂ exposed to low energy UV or high energy visible light has an organic degradation capability that could be utilized in applications to kill or inactivate bacteria on medical devices such as dental implants for treatment against, e.g., peri-implantitis.