ABSTRACT
We propose a method for remote sterilization of surfaces which follows wireless power transmission principles. Using the self-steering tracking capability of retro-directive arrays (RDAs), an infected area of interest can be sterilized by radiating microwave power in a controlled and efficient manner, thus producing heat for pathogen deactivation. The employed antenna array system offers dual-circular polarization with isolation values of 55 dB which supports the co-location of the transmit and receive parts of the RDA. In particular, the paper reports the use of a 2 x 2 circularly polarized RDA system operating in the S-band, which is used to investigate the possible heat change of a water covered sample for sterilization, placed at different ranges from the transmitting point and rotated in the plane normal to the illumination. The time required to heat the area of interest up 60°C is numerically studied and the capabilities of inducing the needed temperature gradient over the samples is examined. In addition, measurements have been performed using biological samples of the coronavirus (strain Cov-229E-GFP) to demonstrate virus deactivation. The proposed methodology can also be made completely automated and with little operator interaction, representing a new and attractive option for microwave sterilization of pathogens such as those related to the severe acute respiratory syndrome coronavirus (SARS COVID-19). © 2022 European Microwave Association.
ABSTRACT
The Covid-19 pandemic over the past year has raised concern regarding the precautions needed to be taken to prevent cross-infection in the field of dentistry, as the virus is highly contagious and life-Threatening. At least half of the population above the age of 50 years are denture wearers. These dentures act as a base for the colonization of microorganisms, hence raise the chances of cross-contamination. When the patient wears contaminated dentures, the most common manifestation it may cause is oral candidiasis or denture-related stomatitis, this fungal infection leads to white or red sores, bleeding, swelling and burning sensations in the oral cavity. As the patient s oral cavity is a sterile tissue with mucous membranes, incompetent sterilisation of dentures bears the risk associated with the break of host barriers and carrying of environmental pathogens (e.g., Pseudomonas aeruginosa). The application of an improper sterilisation method in the maintenance of dental appliance mainly the complete denture concerns not only the patients but also the dental personnel and prosthesis laboratory. The first studies on microwave sterilisation of dentures were performed to confirm the potent of microwave sterilisation in preventing microorganisms attached to complete dentures prosthesis. Using different methods, definite results were obtained by studies, confirming that microwave irradiation can be an efficient technique in sterilizing the complete dentures prosthesis. Thus, executing microwave irradiation of a complete denture before it is brought to a lab, and immediately before it is placed in the patient s mouth, acts as a means of infection prevention system for all individuals. Microwave sterilisation of dentures has been recommended for denture sterilisation but its effect on the dimensional property of a complete denture still needs to be focused on. Hence, the current review presents the effect of microwave sterilisation on the physical properties, mainly the dimensional stability of the complete denture base. © (2022) Society for Biomaterials & Artificial Organs #20051922.