Bacterial aerosols in dental practice - a potential hospital infection problem?

Area of Science:

• Oral microbiology
• Infectious disease control in dentistry
• Dental aerosol research

Background:

• Modern dental instruments generate microbial aerosols from patients' oral cavities.
• Increased oro-nasal colonization by meticillin-resistant Staphylococcus aureus raises concerns about dental surgery contamination.

Purpose of the Study:

• To quantify the spread distance and contamination levels of airborne bacteria during dental restorative procedures.
• To assess the extent of bacterial contamination in dental surgeries using high-speed rotating instruments.

Main Methods:

• Collection of fallout samples on blood agar plates at various distances (0.5-2m) from the patient.
• Sampling from personnel masks and room surfaces before and after disinfection.
• Incubation of samples and classification of bacterial colonies by Gram stain.

Main Results:

• Significant room contamination (mean 970 CFU/m²/h) was observed with high-speed instrument use.
• Bacterial density increased at more remote sampling points, indicating widespread contamination.
• Gram-positive cocci, including viridans streptococci and staphylococci, were predominant findings.

Conclusions:

• Dental aerosol contamination extends throughout the entire treatment room, exceeding previous estimations.
• New strategies are essential for preventing microbial aerosols and protecting surfaces in dental settings.
• Enhanced precautions are crucial in hospital dental surgeries, particularly for immunocompromised or generally ill patients.