Discussing the updates on the PDA Interim Guidelines on Infection Prevention for CoVid-19 Pandemic
(Part 7)
We still continue our discussion on the precaution protocols that dental
professionals and health workers need to observe to prevent the spread of the virus causing the coronavirus disease or more popularly known as Covid-19.
This week we will talk about transmission-based precaution. There is no solid scientific evidence which indicates that pre-procedural rinsing can prevent infections among the patients and the dental office staff.
However, it may reduce the viral load in the mouth. The rinse usually consists of
1% hydrogen peroxide or 0.2% povidone iodine. It is best to use the rinse in the
duration of the dental procedure as the SARS-CoV-2 may be vulnerable to oxidation.
The procedure entails rising for 60 seconds, or swab for kids or patients who are unable to rinse.
To prevent transmission of the virus, rubber dams may also be used. The rubber dams may significantly minimize the production of saliva and blood-contaminated aerosol or splattering that may happen in a procedure that produce aerosol. The virus is known to be transmitted via aerosol.
It is also best to use intra oral suction machines in dental offices that engage in dental procedures. It is preferred to use high volume evacuator. Make sure to discard the tips or disinfect after each use. For clinics using centralized high vacuum evacuator system, it is preferred for the gas to be vented out and the liquid and particulates are directed down the drain.
Generally, low volume evacuators are not preferred as backflow can be a
concern. To avoid backflow, ask the patient not to create a vacuum by sealing the lips around the ejector tip. The patient should be advised not to suck on the ejector tip. For portable low volume evacuators, evacuate the contents in an open area with flowing drainage while wearing the appropriate personal protective equipment (PPE).
When using vacuum lines, hoses should be flushed with a volume of water and
bleach for 10 minutes but not more than 15 minutes. The filters located at the junction should be removed and disinfected every day.
Due to the virulence of SARS-CoV-2 on formites and its ability to remain
suspended in air after getting aerosolized in a dental procedure, there is a need to observe extra caution when facilitating air exchange. The following pieces of equipment are recommended and dentists must learn about the manufacturer’s recommendations
regarding office set-up and size.
It is important to learn how the high efficiency particulate air (HEPA) may be able to remove the particulates in the air inside the dentist’s office. HEPA filters are designed to filter 99.97% of particulates that are 0.3 microns in size.
That size is known as the most penetrating particle size or MPPS. HEPA filters consist of interlaced glass fibers that are twisted and turned to create a fibrous maze. As the particulates move in the maze, they are taken out of circulation.
Experts advise dental clinics to consider using HEPA filters when dealing with
aerosol generating procedures. The filters may bring down the droplet and particle found during and after the aerosol generating procedure.
Also, experts say that the filters should be beside the patient’s chair and not
behind the dentist or dental health worker.
It is also recommended that use ultraviolet germicidal irradiation (UVGI) be used, which is a good way to disinfect and lower the transmission risk of the virus. The UVGI is able to kill microbes.
We will be discussing more how dentist’s office may prevent the spread of the SARS-CoV-2 when engaging in aerosol generating procedures.