Infection Control FAQs

Which procedures generate aerosols in dental practice?

Aerosol Generating Procedures (AGPs) in dentistry include procedures that use any of the following devices: high speed handpieces, low speed/prophy handpieces, surgical handpieces, ultrasonic and sonic devices, air polishing devices, and hard tissue lasers. The triplex when air and water are used together or when used with air on a wet surface is considered an AGP.

Why aren’t standard precautions sufficient for aerosol producing procedures in COVID-19?

The use of standard precautions (including hand hygiene, PPE, safe use and disposal of sharps, routine environmental cleaning, reprocessing of instruments and equipment, respiratory hygiene and cough etiquette, aseptic technique, and waste management) is the principal way we minimise the transmission of infections in any healthcare setting, including dental practice, and are applied to everyone, regardless of their perceived or confirmed infectious status.  They ensure a basic level of infection prevention and control.  Standard precautions are used when undertaking treatments or procedures where there is handling of blood, body fluids (e.g. saliva), non-intact skin, and mucous membranes. 
Transmission based precautions (contact, droplet or airborne) are used in addition to standard precautions when there is suspected or confirmed presence of infectious agents that are not effectively contained by standard precautions alone.  The type of transmission based precaution required is dependent on the route of transmission of  the infectious agent:
  • Contact precautions
    • are used when there is a risk of direct/indirect transmission of infectious agents e.g. highly contagious skin infections/infestations such as methicillin-resistant staphylococcus aureus (MRSA) and vancomycin resistant enterococcus (VRE)
    • Direct transmission occurs when infectious agents are transferred from one person to another, without a contaminated intermediate object or person.
    • Indirect transmission involves the transfer of an infectious agent through a contaminated intermediate object (fomite) or person.
  • Droplet precautions
    • are used when there is a risk of transmission through large respiratory droplets (>5 microns) or mucous membrane contact with respiratory secretions, generated by a patient who is coughing, sneezing, or talking. e.g. influenza, norovirus, pertussis, meningococcus.
    • Transmission via large droplets requires close contact as the droplets do not remain suspended in the air and generally only travel short distances. As the droplets do not travel over long distances, special air handling and ventilation are not required.
    • The droplets can contaminate horizontal surfaces close to the patient, and the hands of healthcare workers can become contaminated through contact with these surfaces.
  • Airborne precautions
    • are used when there is risk of transmission through small respiratory droplets (<5 microns) that remain infective over time and distance when suspended in air. e.g. measles, chickenpox, tuberculosis
    • Transmission via small droplets can result due to inhalation by susceptible individuals who have not had face-to-face contact with (or been in the same room as) the infected individual.
The WHO has confirmed that coronavirus responsible for SARSCoV2 or COVID-19 is spread primarily through droplets generated when an infected person coughs, sneezes or speaks, however transmission can also occur by touching a contaminated surface and then touching the eyes, nose or mouth before washing your hands. While this would suggest that droplet precautions are required for patients identified as positive to COVID-19, most dental treatments are identified as aerosol generating procedures, and therefore the Australian Guidelines for the Prevention and Control of Infection in Healthcare (2019)[1], states that “if a patient requires care under droplet precautions but an aerosol generating procedure is undertaken, then droplet precautions should be increased to airborne precautions for at least the duration of the procedure.”
The Center for Disease Control and Prevention advice for Dental Settings[2] states that there is currently no data available to assess the risk of SARS-CoV-2 transmission during dental treatments, or to determine whether dental healthcare professionals are adequately protected when providing dental treatment when using Standard Precautions, however they have referenced the Occupational Safety and Health Administration’s Guidance on Preparing Workplaces for COVID-19[3] which places dental practitioners in the very high exposure risk category, as their jobs are those with high potential for exposure to known or suspected sources of the virus that causes COVID-19. 

The CDC concluded that when practicing dentistry in the absence of Airborne Precautions, the risk of SARS-CoV-2 transmission during aerosol generating dental procedures cannot be eliminated, and provided the following recommendation:
  • Avoid aerosol generating procedures whenever possible. Avoid the use of dental handpieces and the air-water syringe. Use of ultrasonic scalers is not recommended during this time. Prioritize minimally invasive/atraumatic restorative techniques (with hand instruments only).
  • If aerosol generating procedures are necessary for emergency care, use four-handed dentistry, high evacuation suction and dental dams to minimize droplet spatter and aerosols. 

This is not the first coronavirus pandemic this century. In 2003 we had Sudden Acute Respiratory Syndrome caused by SARSCoV1. A retrospective review[4], outlined measures to reduce the risk of cross infection with coronavirus in the dental setting, including the identification of patients with SARS through targeted screening questions, pre-procedural rinsing, hand hygiene, PPE, rubber dam isolation and recommended that “aerosol-generating procedures should be avoided as much as possible if rubber dam isolation is not feasible. Some of these procedures include ultrasonic scaling, root-surface debridement, and high- or low-speed drilling with water spray.” These measures were adopted in both the ADA Managing COVID-19 Guidelines and ADA Dental Service Restrictions documents. A conclusion of this article was that while no dental healthcare worker was affected in either a nosocomial or dental setting, this was thought to be due to the use of universal infection control measures and/or the low degree of viral shedding in the prodromal phase of SARSCoV1.

While both SARSCoV2 and SARSCoV1 demonstrate high viral loads in posterior oropharyngeal saliva samples, SARSCoV1 viral load was found to peak at 10 days after symptom onset.  In comparison, SARS CoV2 has the highest viral load on presentation, suggesting that SARS-CoV-2 can be transmitted easily, even when symptoms are relatively mild. This finding could account for the fast spreading nature of this pandemic, with efficient person-to-person transmission noted in community and health-care settings.[5]
[4] Samaranayake L, Peiris M
Severe acute respiratory syndrome and dentistry. A retrospective review
JADA 2004; 135: 1929-1302.
[5] To KK-W, Tsang O T-K et al
Temporal profiles of viral load in posterior oropharyngeal saliva samples and serum antibody responses during infection by SARSCoV2: an observational cohort study
The Lancet Infec Dis 2020; 20: 565-74

Do I have to use a dental dam?

A dental dam substantially decreases the risk of producing dangerous aerosols, particularly for procedures where aerosol producing instruments are necessary e.g. endodontic access.  It should be used in conjunction with other layered measures.  Whether you need to use a dental dam is dependent on the applicable level of restriction for your location and the type of procedure.

Can I charge an item number for consulting over the phone?

The ADA has recently issued a new item number for teleconsultations.  Please refer to the Guidelines for Teledentistry for further details on the use of this item number.

919 Teleconsultation
The remote provision of a consultation to a patient in exceptional circumstances which prevent face to face consultation. It may include the provision of oral health or treatment information and referral.

Should I turn off the air-conditioner while undertaking aerosol generating procedures?

There is no need to turn off the air-conditioning. No additional precautions with respect to air-conditioning or air filtration need to be taken if treating a low risk patient. Under levels 2 and 3, NHMRC transmission based precautions recommend "resting" the room for 30 minutes or more after use. 

Should I make the treatment room negative pressure?

The use of a negative pressure room is just one part of a suite of measures for treating patients under full airborne precautions. Other parts of airborne transmission based precautions include:

  • Annual fit-testing of P2/N95 respirator masks which is undertaken by a trained and validated fit-tester
  • Specific processes for patient entry and exit from the surgery e.g. appointment time, entering and exiting the building, restriction contact with other patients and staff.   
  • Specific donning and doffing protocols of PPE
  • Environmental cleaning

The design of a negative pressure room is also important such as including bulkheads to eliminate areas where things can settle on and build upon, making surfaces much easier to clean, designing the room's airflow patterns correctly.  Expert advice should be sought to ensure all issues have been considered.

Should I be asking my patients to complete hand hygiene when entering the practice?

Yes, you should be directing patients to perform hand hygiene by using alcohol-based hand rub, or by washing their hands with soap and water. This needs to be done when they enter the practice, and when they leave the practice.

What additional measures are required that may not have been implemented before COVID-19 pandemic?

All aspects of patient interaction within the practice should be considered including alcohol-based hand-rub or hand-washing for patients when they enter and leave the practice, wiping down of door handles and benches that the patients touch, and the inclusion of a pre-operative patient mouth rinse such as 1% hydrogen peroxide. Additional precautions will also be required depending on the COVID-19 risk of the patient and the dental procedure being performed. Frequent environmental cleaning is a requirement for high patient touch areas (4 or more times per day).

What is the difference between dental suction and medical suction?

Medical suction, particularly those units used by paramedics are aerosol producing, while dental suction is aerosol reducing.

Dental suction is designed to collect all aerosols in the oral cavity, when the suction airflow is greater than 250 L/min.  When the aerosols enter the suction cannula they combine to form droplets, which are then trapped either in the chairside suction separator or by the suction machine in the plant room.

In comparison, medical suction is designed to trap small amounts of contaminated fluids in a single-use container using high negative pressure, rather than airflow.  Suction units used by paramedics are small self contained units that don't require any external plumbing, therefore the exhaust air, which is released next to the paramedic using the suction unit, contains moisture.

Source: Bill Clark, Director at Cattani Australia

Is temperature testing beneficial during COVID-19?

The Australian Government Department of Health has stated that while in places like hospitals and aged care facilities, temperature checks may be useful as an extra precaution to protect vulnerable people, temperature checks are not as useful in other settings. This is because people with COVID-19 don’t always develop fever, or may be on medication that reduces their temperature. It is also possible that the person may have a temperature for another reason unrelated to COVID-19.  Also bear in mind that body temperature measurement is affected by the method used, the site, the time of day and the patient’s age, as well as their medical condition.
If you decide to undertake temperature testing of staff and/or patients, the healthdirect Coronavirus (COVID19) symptom checker references a fever as 37.5oC or more. (
The Coronavirus Disease 2019 CDNA National Guidelines for Public Health Units (version 3.9) published on 9 October 2020 identifies clinical criteria for COVID-19 as “Fever (≥37.5°C), or history of fever (e.g. night sweats, chills) OR acute respiratory infection (e.g. cough, shortness of breath, sore throat) OR loss of smell or loss of taste.

Date of document: 12 October 2020


Treating older adults during COVID-19

The Australian Government has stated that people aged 70 years and over, people aged 65 years and over with chronic medical conditions, people with compromised immune systems, and Aboriginal and Torres Strait Islander people over the age of 50, are at greater risk of more serious illness if they are infected with coronavirus
Detailed advice specifically for this vulnerable group is available at
The National Cabinet recommended older Australians stay at home except for essential purposes like food shopping, medical appointments and exercise.  While tele-health may be an option for some health-related appointments, for oral health related issues this may not be as useful, and it is important that any problems are addressed in a timely manner to reduce the risk of a poor outcome, or potentially  contribute to systemic disease.
It is recommended that your older patients attend necessary dental appointments however remind them when leaving home, to practice physical distancing as well as good hand and respiratory hygiene, which may include wearing a mask.  In addition, some older patients may have developed an individual COVID-19 action plan with their GP, which outlines behaviors they will take dependent on the number of COVID-19 infections in their community.

Which disinfectants can we use in dental practice for the 2 step cleaning process?

Any disinfectant on the TGA list (irrespective of where you purchased it) may be suitable. None the less, please check against the purpose for which you are using the disinfectant, as some products may not be suitable for use in clinical practice and particularly if there is the risk of contact with other medical devices or the disinfectant has residues that might contact with mucosal surfaces. It is also important that all safety directions are appropriate for clinical use and that the product Safety Data Sheet is read and safety directions followed prior to any use in a workplace setting.

Faecal-Oral Spread

The coronaviruses that cause SARS, MERS and COVID-19 can all infect cells in the gastrointestinal tract. These viruses have been found in biopsy specimens of the gut wall, and in the faeces of infected people, including those who had cleared the infection from the respiratory tract but who continued to shed it in their faeces. In COVID-19, the SARS-CoV-2 virus may be shed for prolonged periods of time (often several weeks) after respiratory symptoms have subsided. Nevertheless, there is not compelling evidence for spread from faeces via the faecal-oral route. An enteric source of the virus could explain some cases of transmission where the source is “unknown”. In some cases, respiratory symptoms of COVID-19 infection are preceded by gastrointestinal tract symptoms, including abdominal discomfort, nausea, vomiting and diarrhoea. Of note, a similar pattern was seen in up to 73% of cases of SARS in 2003, and 25% of cases of MERS. In these coronavirus infections, gastrointestinal symptoms occurred before subsequent manifestation of more severe respiratory symptoms. This indicates that pulmonary infection occurs after intestinal infection.

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