Simulated microbe removal around finger rings using different hand sanitation methods

Area of Science:

• Infection Control
• Microbiology
• Public Health

Background:

• Current guidelines from the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) may underestimate the risk of cross-contamination associated with wearing jewelry, such as finger rings, under examination gloves in dental clinics.
• Recommendations for hand hygiene before donning gloves, including washing for 15 seconds with soap and warm water, may not be sufficient to eliminate microbial load when jewelry is present.

Purpose of the Study:

• To evaluate the effectiveness of different handwashing procedures and the impact of finger rings on the removal of simulated microbes from gloved hands.
• To provide evidence-based recommendations for hand hygiene practices in dental settings to mitigate cross-contamination risks.

Main Methods:

• A simulated microbial contamination model using a gloved rubber hand manikin was employed.
• Washing procedures varied in duration (5, 15, 25 seconds), water temperature (20°C, 40°C), and the use of liquid hand soap.
• Fluorescent powder was used to simulate microbes, and light levels before and after washing were measured to quantify microbial removal effectiveness. Statistical analysis included a full-factorial ANOVA and Tukey's HSD test.

Main Results:

• Increased washing time with a scrub brush under flowing water effectively removed more simulated microbes, with all methods showing similar results by 25 seconds.
• Warm water combined with liquid hand soap demonstrated superior microbial removal compared to cold water.
• Simulated microbes were more difficult to remove from the palm than the back of the hand. Finger rings, especially those with stone settings, accumulated and retained microbes more effectively in crevices.

Conclusions:

• The most effective hand hygiene protocol involved washing with warm water and liquid soap for extended periods.
• Wearing finger rings under examination gloves should be discouraged due to the challenges in cleaning the sub-ring area and the significant risk of patient-to-healthcare worker cross-contamination.