Infection through sprays in medical devices for dentistry. A controllable epidemiological impact

The risk of infections via dental sprays has been confirmed once again by the detection, inside dental unit waterlines, of bacterial and viral contaminations, both from water supplies and from the oral cavity of patients. Conventional means of prevention, flushing of the ducts before any dental treatment and anti-retraction devices intended to avoid contamination originating from the patient, evaluated in laboratory and clinical conditions, have been shown to be ineffective in controlling the risk. Tests carried out in vitro, with circuit models, and with the dental unit in service, have confirmed the efficacy of a method to disinfect the waterlines with a disinfecting solution based on TAED and Peroxidant, which in aqueous solution develop peracetic ions (Autosteril method). Zero bacterial count, zero viral charge and a complete biofilm demolition were achieved both in lab conditions and in service units. After hygienic treatment, the same disinfection method, once installed on old units that had been in service for years and without any hygienic device, allowed us to restore and to maintain the microbiological quality of the irrigant also in dental units of old design, and significantly reduced biofilm formation inside the waterlines. Therefore, on the basis of scientific findings, a microbiologic monitoring protocol is proposed in order to verify the hygienic conditions of units which are in service.