Microorganisms protein degradation through photocatalysis using nanoparticles for instrumental sterilization

Objective: nanotechnology, the science of miniscule, has developed products which are able to manipulate atoms and molecules in order to cause the sterilization process of dental instruments, which is the objective of the present work. A study on the self-cleaning action of the Tio2 and Ag nanoparticles coating on dental instruments originated by the photocatalysis process through ultraviolet light was done.

Material and Method: Eighteen (18) cement spatulas for each microorganism, Micrococcus luteus and Salmonella typhi, were used for microbiologic tests. After 5-minute contamination, they were placed in a wooden box, covered with aluminum foil, exposed to ultraviolet light for 15, 30, and 60 minutes, respectively, and stored in test tubes in BHI (Brain Heart Infusion) for 20 minutes. Checking times for bacterial growth were at 24 and 48 hours. Results: Salmonella typhi proved inactive under 60-minute ultraviolet light exposure. Bacterial growth was observed at 24, 48, and 72 hours under 15- and 30-minute exposure, respectively. No Micrococcus luteus growth was observed at 24, 48, and 72 hours under 15-, 30-, and 60-minute exposure, respectively. Conclusion: By means of heterogeneous photocatalysis process using Tio2 and Ag nanoparticles in the anastase phase and after 60-minute ultraviolet light exposure, inactivation of both Micrococcus luteus and Salmonella typhi was observed, and occurrence of the bactericidal process was proved effective.