Contaminated aerosols in the dental office: how to reduce the risk of transmission in 2026
If you manage a dental office, a clinic, a medical center, or coordinate the activity of a unit with high patient flow, you must treat aerosol control as a clear technical protocol, not as an occasional measure.
To reduce the risk of transmission:
- limit aerosol formation at the source;
- capture particles as soon as they appear;
- control the quality of water in the dental unit;
- correctly choose protective equipment;
- ensure adequate ventilation and filtration;
- apply proper disinfection, with approved products and observed contact times.
In the following sections, you will find concrete steps and technical criteria that will help you build a solid protocol for 2026.
What are dental aerosols and why do they represent a real risk?
In the dynamics of a dental practice, airborne contamination is generated in the form of three distinct categories of particles, differentiated by biometrics (aerodynamic diameter) and kinetic behavior in the ambient environment:
- Spatter (Macroparticles > 50 µm): represent ballistic vectors with increased critical mass. Due to gravity, they exhibit a rapid sedimentation rate, macroscopically contaminating clinical surfaces within the immediate perimeter of the operating field (the patient's proximity area).
- Respiratory droplets (≤ 50 µm): particles with intermediate dynamics. They maintain a state of suspension in the short term (from a few seconds to a few minutes), subsequently undergoing a gradual sedimentation phenomenon on adjacent surfaces.
- Droplet nuclei (≤ 10 µm, frequently < 5 µm): ultrafine aerosols resulting from the partial evaporation of the carrier liquid. These possess increased buoyancy, remaining viable in airborne suspension for extended periods (between 30 and 120 minutes) and exhibiting high infectious potential through their ability to penetrate deep into the lower (alveolar) respiratory tract.
Current aerobiological evidence demonstrates that high-frequency dynamic equipment (especially ultrasonic scalers and turbine handpieces) predominantly generates bioaerosols with a diameter under 5 µm. The submicroscopic size of these particles gives them deep respiratory penetrability, making them efficient vectors for the airborne transmission of viable bacterial and viral pathogens.
What dental aerosols contain
Dental aerosols include:
- saliva and blood;
- oral microorganisms (Streptococcus spp., Actinomyces, Fusobacterium);
- bacteria from contaminated water (Legionella pneumophila, Pseudomonas aeruginosa);
- respiratory viruses.
Microorganisms can remain viable on surfaces or in the air for variable periods, depending on humidity, temperature, and exposure to UV light.
Procedures with high risk of aerosol generation
Not all interventions produce the same amount of particles.
Instruments that produce high aerosol density
- Ultrasonic scaler – produces fine particles through cavitation and pressurized water jet.
- High-speed handpieces – atomize cooling water and biological fluids.
- Air-polishing – combines compressed air, powder, and water, generating extensive dispersion.
- Rotary bur surgery – associates aerosols with tissue fragments.
In most cases, these procedures require an FFP2/FFP3 respirator and permanently active high-volume suction.
Factors influencing dispersion
Aerosol concentration depends on:
- suction efficiency;
- position of the patient and the operator;
- number of air changes per hour (ACH);
- room volume;
- degree of maintenance of vacuum systems.
An open-space office favors lateral particle dispersion. Separate cubicles limit the migration of aerosols to other areas.
Reducing aerosols at the source
Managing the risk of airborne infection requires the implementation of a systematic strategy of best practices directly at the level of the generation source. Effective source control is achieved by sequentially applying the following best practice measures:
1. Optimizing High-Volume Evacuation (HVE)
The HVE system represents the primary line of mechanical defense against bioaerosol dispersion. Its operational efficiency is conditional on the strict observance of the following technical criteria:
- Geometric configuration: The internal lumen diameter must be greater than or equal to 8 mm.
- Dynamic parameters: Volumetric flow rate specifically calibrated for the dynamic capture of ultrafine aerosol fractions.
- Clinical positioning: Placement of the cannula at a critical distance of 5-10 mm from the operating site, vectorially adapted according to the handpiece used.
2. Monitoring and maintenance of the central vacuum system
A decrease in the performance of the central vacuum system compromises fluid evacuation and may favor the reflux phenomenon, generating a major risk of cross-contamination. The mandatory technical protocol includes:
- Pressure control: Monitoring negative pressure in accordance with the manufacturer's technical specifications.
- Component integrity: Periodic verification of anti-retraction valves on handpieces and the dental unit.
- Sanitization and Maintenance: Systematic cleaning of mechanical filters and chemical decontamination (autoflush/aspiration of specific disinfectant solutions) of internal circuits.
All inspections and preventive maintenance operations must be recorded in the clinic's technical register. The absence of a documented maintenance program drastically reduces aerosol capture efficiency and escalates the risk of occupational exposure for medical staff.
3. Isolating the operating field using the rubber dam system
The use of a rubber dam isolation system is the gold standard in reducing the volume of saliva exposed to mechanical atomization. Its application is mandatory in:
- Endodontic therapies (also ensures chemical and bacterial risk management);
- Restorative dentistry and clinical procedures based on adhesive techniques.
The rubber dam does not completely eliminate aerosols, but it decreases the associated microbial load.
4. Implement pre-procedural rinsing
Before initiating any aerosol-generating procedure, it is mandatory to reduce the endogenous infectious vector by actively rinsing the oral cavity for 60 seconds, using one of the following antiseptic solutions:
- Chlorhexidine gluconate in a concentration of 0.12–0.2%;
- povidone-iodine-based solutions;
- hydrogen peroxide, diluted to an optimal clinical concentration, according to current recommendations for disinfecting mucous membranes.
Controlling water quality in the dental unit
Aerosols also include water from the unit lines. In the absence of a strict decontamination protocol, the internal surfaces of these thin tubes favor the development of a complex bacterial biofilm. During the activation of dynamic handpieces and the ultrasonic scaler, hydrodynamic shear forces detach fragments of this biofilm.
The mechanical atomization phenomenon transforms contaminated water into inhalable aerosols, causing massive airborne dispersion of opportunistic pathogens (such as Legionella pneumophila, Pseudomonas aeruginosa, and non-tuberculous mycobacteria) directly into the atmosphere of the clinical field.
Recommended microbiological standard
The microbial load of the water supplied by handpieces and the air/water syringe must be strictly below the threshold of <500 CFU/ml, equivalent to the standard of potability established for drinking water.
For interventions involving incisions, flap reflection, osteotomies, or the exposure of normally sterile deep tissues, the use of water from the conventional unit circuit is completely prohibited. In these cases, the protocol requires the exclusive use of sterile water or sterile saline solutions (physiological saline), delivered through independent sterile irrigation systems (disposable or autoclavable lines).
Protective equipment: making the right choice
Protection of staff and patients depends on the type of mask and how it is used.
Surgical masks vs. respirators
| Characteristic | Surgical mask | FFP2/FFP3 |
|---|---|---|
| Fine particle filtration | Limited | ≥94% (FFP2), ≥99% (FFP3) |
| Aerosol protection <5 μm | Insufficient | Yes |
| Requires fit test | No | Yes |
The surgical mask protects against splashes. For aerosol-generating procedures, use a respirator certified according to EN 149:2001+A1:2009.
Replace the mask if it becomes damp or after the interval recommended by the manufacturer.
Eye protection and gowns
- Glasses with side protection.
- Face shield as an additional barrier.
- Waterproof gowns for procedures with abundant spray.
Ventilation and air filtration
Ventilation directly influences the concentration of suspended particles.
Number of air changes (ACH)
- Minimum 6 ACH for standard offices.
- 12–15 ACH for frequent aerosol-generating procedures.
Natural ventilation can help temporarily, but it does not ensure constant parameters.
HEPA filters and UV-C systems
HEPA H13 filters retain ≥99.95% of 0.3 μm particles, while H14 filters retain ≥99.995%. UV-C systems (254 nm) inactivate microorganisms by degrading genetic material.
Portable devices are useful in small rooms or rooms without central ventilation. They complement source suction, they do not replace it.
Disinfection of surfaces and instruments
After each patient, treat potentially contaminated surfaces.
For surfaces and instruments, use products from the range of professional disinfectants, authorized according to national legislation regarding biocides (EU Regulation 528/2012). An example of a ready-to-use solution is Klintensiv® Alchosafe dental impression disinfectant, suitable for disinfecting surfaces and dental impressions made of various types of materials. For floors, use floor disinfectants, which possess microbiological efficacy certified by European EN standards.
For small surfaces, ethyl alcohol in a concentration of 70–85% ensures rapid disinfection if you observe the contact time.
If you want to find out how the microbiocidal efficacy of products for medical use is tested and demonstrated, read the guide: how to test and evaluate the efficacy of disinfectants: explanations based on SR EN 14885!
Aerosol control in 2026 requires technical discipline and continuous verification. You reduce the risk through source capture, microbiologically controlled water, adequate equipment, and correct disinfection.
