Sterilization of dental bacteria in a N₂-O₂ microwaves post-discharge, at low pressure: influence of temperature

¹ CPAT, University Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France
² GREMI, University Paul Sabatier, 118 route de Narbonne, 31062 Toulouse, France

Corresponding author: svilleger@voila.fr

Received: 30 October 2003
Revised: 28 December 2003
Accepted: 12 March 2004
Published online: 11 May 2004

Abstract

Recently, plasmas have been largely studied to develop a new cold and safe sterilization process. The plasma efficiency on bacteria destruction has been proved at low or near atmospheric pressure. In our investigation we used a N₂-O₂ post discharge at low pressure, where the experimental conditions allowing the optimal production of active species have been determined: 100 Watt, 1 L_n.min⁻¹, 5 Torr. By exposing E. coli to these plasma conditions, it is demonstrated a synergy of N and O active atoms on substrate temperature: a reduction of 6 log was achieved after a treatment time of 20 minutes at 80 °C and of 12 log after 5 minutes at 120 °C.