Dental face masks – the dilema of supply problems

Face mask supply in Australia has been effected by supply problems out of China. We are hearing about massive opportunistic price increases anecdotally and via social media. While we can’t envisage supply drying up completely, because there is money to be made, it can cause some internal emotional angst. ¬†As a dentist it is great to make sure you’re up-to-speed with our knowledge about masks and the appropriateness of their use.

For this reason Smartdentist has added a subscriber course on facemasks. The issues this course address include:

  • Why do we wear a mask/face shield?
  • What our currrent infection control guidelines say about the use of masks.
  • Contradictions within our guidelines
  • How long does a mask ‘last’?
  • What do masks protect us from?
  • Explaining AS 4831:2015 “Single use masks in healthcare”

The course includes lots of interesting articles to read for people who value making informed decisions.

Of course for the Coronovirus we may see the panic buying of masks.

We all have a reaction to the unknown but as trained experts in infection control we have the opportunity to make sure we understand the difference between our cultural actions and evidence based decisions.

PPE
PPE is personal protective equipment. It is designed to protect the individual wearing it. PPE becomes an opportunity for the spread of infection if PPE is handled incorrectly. e.g. it should be always be considered a contaminated surface.

Masks and head coverings in surgical situations
These are used to stop the shedding of the practitioners body fluids/bacteria/viruses into open wounds in the body. In dentistry this is standard precautions for implants or surgical situations where aspetic conditions are required. The standard for surgical masks tests the bacterial filtration of a mask from the inside out. e.g. is it stopping the practitioners bacteria reaching the patient.

Masks and aerosols
Aerosols are a very complex area of science. What we know is that viruses can stay in the air for up to 40 hours. The way aerosols travel is hard to predict.
Consider the dental situation and directional air flow.

We have the following in the dental surgery:

  • A turbine releasing air and water in a fine mist that contacts a rotating bur.
  • A high speed suction unit creating directional airflow
  • A patient breathing through their nose creating a directional airflow
  • An operator and assistant breathing – around and through masks or shields
  • Droplets and splattering via the triplex air and water.
  • Air flow from airconditioning or heating – usually drawing air out of the room via a doorway

It is extremely hard to predict the resulting area or range of contaimination from treatment. The use of rubber dam and the skill of the dental assistant with the high speed suction, together with the location of the treatment are all obvious variables that would effect the resulting aerosols.

Aerosols generated in a situation where rubber dam has created a good seal and the tooth is disinfected before being drilled would logically be confined to non-infective aerosols and droplets.

What do practitioners legally need to do?
Dental practitioners, in normal practice, do not have the equipment required to treat patients who require transmission-based precautions for air borne or droplet precautions. Hence practitioners should make themselves aware of what patients would fall into this category. As far as coronavirus is concerned practitioners should avail themselves to the current information on a daily basis via the Australian Government Department of Health website.

Without these variable researchers have had difficulty studing the spread of influenza. Often theortical models have not related to clinical findings.
The ADA guidelines say that it has been recommended that medical practices move their gloves 6 ft away from the patient. This is based on a reseach project where they has a dummy coughing out virus into a closed room (much coughing). If you read the reseach procedure you may find it quite difficult to see how that relates to a dental clinic.
The ADA guidelines also say the research isn’t that good about N95 masks being that that much better than surgical masks. Interestingly a big study in China by an Australian researcher is being quoted by her as demonstrating that N95 masks are superior and should be supplied to all GP’s. When you read the actual findings the hospital workers with inferior results using normal surgical masks, only self reported wearing the masks 66% of the time and their self reported hand hygiene was about 10% worse than the N95 wearers. Hard to get good research subjects!!