Sterilization of dental bacteria in a flowing N/sub 2/-O/sub 2/ postdischarge reactor

Destruction processes of several dental bacteria have been analyzed in a flowing postdischarge reactor. An N/sub 2/-5%O/sub 2/ gas mixture has been chosen to produce a high quantity of oxygen atoms and a UV emission intensity of NO/sub /spl beta// bands in the whole reactor chamber. The first results obtained with Streptococcus mutans (Sm), Porphyromonas gingivalis (Pg), Fusobacterium nucleatum (Fn), Prevotella intermedia (Pi), and Escherichia coli (E. Coli) dental bacteria at initial concentrations from 10/sup 6/-10/sup 10/ colony forming unit per milliliter (CFU/ml) introduced in small cylindrical Al substrates (previously sterilized) are reported. A full destruction of Sm, Pg, and Pi bacteria was obtained after 15-20 min and of Fn after 30 min of treatment. However, the E. coli bacteria, introduced to 10/sup 10/ CFU/ml was still not destroyed after a treatment time of 30 min.