Hand Hygiene: Safe from the Thumb to the Pinky

The hands are the key to every dental practice. They perform the decisive part of the work, but at the same time, they are very much at risk of a microbial contamination and serve as a transport vehicle for germs. Comprehensive hand hygiene is essential for everyone who takes part in the treatment of patients. As a matter of fact, proper hand hygiene is the most important preventative measure against infections in the dental clinic. It is important to use the correct disinfectant and the right technique to avoid stressed, cracked, or porous hands.

Ignaz Semmelweis used the practice of regular hand hygiene to drastically lower the fatality rate of women who had given birth by using a disinfectant based on chlorinated lime. Since then, scientists have learned that the microorganisms on the skin are responsible for most contact infections and are a major link in the transmission of nosocomial infections.

The Skin: A Multilayered Membrane

The skin is the largest and most versatile human organ – it performs a variety of critical functions.

The skin protects us from various health hazards that include the following:

• physical injuries
• environmental influences and poisons
• UV radiation
• microorganisms
• the desiccation of the body

The skin also performs other functions including the following:

• It creates a thermal homeostasis by means of moving the cutaneous vessels and
• through the evaporation of sweat.
• It provides an equilibrium of the body‘s water supply by means of sweat.
• It functions as a sensory organ by processing temperature information and pain impulses.
• It provides interpersonal communication, for example, it provides information about the age of a person.

Beauty Is only Dermis-Deep

The skin is composed of the epidermis (outer layer), the dermis (protective layer), the subcutis (under layer), and the skin appendages.

The subcutis is embedded with fat cells and serves as energy storage and protection against the cold. The subcutis contains large blood vessels and nerves as well as receptors that resemble a type of vibration detector that can detect pressure impulses (Pacinian corpuscles).

The dermis provides stability and flexibility of the skin by means of elastic connective tissue fibers made of collagen and elastin. The fibers bind to water and regulate the moisture of the skin. The smooth musculature and the blood vessels regulate thermal homeostasis, and they are also responsible for the maintenance and the anchoring of the epidermis.

The epidermis consists of five layers (from top to bottom: stratum corneum “horn layer,” stratum lucidum “clear layer,” stratum granulosum “granule layer,” stratum spinosum “acanthocyte layer,” and stratum basale “basal cell layer”) that are together approximately 0.03 to 0.05 millimeters thick. At stressed regions on the soles of feet or hands, the epidermis can grow to be two millimeters thick. The five layers create the actual protective casing of the skin.

The two under layers that together form the germ layer are the “factory” for keratinocytes. Keratinocytes produce keratin, a horn-like structure that is water repellent and gives the skin solidity. When these cells die, they move as corneocytes (horn cells) to the outer “horn layer” and are replaced by new cells in the germ layer. These cells then flake off from the horn cell as dead skin cells. The regeneration cycle of the epidermis occurs every 28 days.

Sebaceous, sweat glands and horn-based body parts like hair or nails belong to the group of skin appendages.

When the Body’s Protection Is not Enough

The skin is populated by a resident bacterial flora with a variety of apathogenic bacteria and fungi. The bacteria create fatty acids through their metabolism, which keep the pH value of the skin acidic (pH 5.5), thereby creating a natural acidic protective coating.

However, the skin flora can provide very little against a possible invasion of pathogens during a dental treatment. During every treatment, some pathogens are transmitted through contact with bodily fluids or secretions; the number of microorganisms could even be in the millions.

When washing and disinfecting one‘s hands, it is a balancing act to try and eliminate all unwanted germs, the so-called transient germs, while not damaging the germs of the resident flora. The outcome is that the hands remain smooth and nourished. It is very important that every dental professional feels comfortable with his hands and skin.

Washing and Disinfection of Hands

  Washing of Hands

Washing one‘s hands primarily eliminates buildup of dirt. It can also physically remove partial populations of germs, although it should never be used as an alternative for the hygienic disinfection of hands. The washing of hands eliminates the germ population by a logarithmic reduction factor of 3, which means that on average only 1 out of every 1,000 pathogens survives (compare with disinfection, where only 1 of every 100,000 survives).

Healthy skin can only cope with a maximum of 20 hand washings per day. Hand soap dissolves the natural acidic coating of the skin, thereby eliminating an important protective layer of the skin. Allergic reactions are also possible, which allows the germs to penetrate the skin unchecked. Dermatitis is a possible consequence. Washing one‘s hands should therefore be limited to only the essential situations:

• At the start of work
• For visible contaminations
• Before and after long breaks (for example, lunch break)
• After every visit to the toilet
• After blowing one‘s nose, sneezing, or coughing

Washing Hands Correctly

The hands should be cleaned with a liquid soap. Alkali-free and pH neutral soaps from dispensers help protect the natural moisture and equilibrium of the skin. The dispensers should be activated with an elbow lever or be equipped with an automatic infrared sensor, as the use of conventional hand-levers increase the risk of infection. Bar soap should never be used as its moist surfaces are ideal breeding grounds for germs.

Cold or lukewarm water is better for the skin than hot water. Not only does hot water dissolves the skin‘s natural oils, it also opens the pores, allowing germs to gain easy access to the body. It is also recommended to first wet one‘s hands before applying the soap, preventing the skin from drying out.

A suitable nailbrush is necessary for the cleaning of the nails and cuticles, but it should not come into contact with the skin itself. The entire washing process should take approximately 60 seconds; this should include the washing of one‘s wrists. Washing one‘s hands for a longer period of time does not lead to better results – it only damages the skin. The hands should be washed in the same motion patterns as are used during disinfection.

If seriously contaminated, the hands should be first carefully rinsed and then washed. When washing hands, precautions must be taken not to sprinkle water or soap on one‘s clothing or surroundings. In any case of doubt, all sprinkled surfaces must be disinfected and clothing must be changed after the washing of hands.

After washing one‘s hands, they must be thoroughly rinsed with water. Remains of soap could strongly affect the skin. The hands should then be dried with a disposable hand towel (paper or cloth). Recycled paper is not suitable as it often has a higher level of contamination. Drying and scrubbing the hands strongly with the towel again provide a friction that removes contamination. The hands must be dried particularly carefully between the fingers.

Hygienic Hand Disinfection

The disinfection of hands kills all existent germs on the surface of the skin but can only provide short-term protection from new germ colonies. For this reason, the hands must be disinfected after every possible new contamination.

The disinfection of hands is very different from the washing of hands:

• It is antimicrobial.
• It is not confined to the washing area.
• It is faster.
• It is possible to simultaneously do other activities, such as reviewing X-ray photographs.
• It is gentle to the skin as the protective layer of the skin stays protected and the resident flora can quickly recuperate.
• Allergic reactions are far rarer.

Manus Manum Lavat

 “One hand washes the other,” wrote the Roman playwright and philosopher Seneca. Although he was speaking quite figuratively, the quote still serves as quite a good description of what occurs during the disinfection of hands.

By activating the dispenser with one‘s elbow, foot, or by means of an infrared sensor, the disinfectant should be used in a sufficiently large amount to completely cover the hands for the contact period of 30 seconds. Approximately one teaspoon (3 ml) suffices. The hand disinfection procedure is composed of six individual steps that are codified by the European EN 1500 standard.

1. Both surfaces of the hands are rubbed against each other.
2. Each hand rubs the back of the other hand.
3. Lay the hand surfaces flat against each other, then the fingers should be spread, interlocked, and the fingers then rubbed together.
4. Interlock the hands by placing the exteriors of the fingers into each palm. Rub the exteriors of the fingers against the palm of the opposite hand.
5. Thoroughly rub one thumb with a closed fist of the other hand.

When wearing short-sleeved clothing, the forearms must also be disinfected. Drying the hands after disinfection is not necessary as the disinfectant evaporates quickly. Moreover, a physical drying of the hands rubs off the skin’s natural oils.

Techniques for Avoiding Contact Infections through Transient Germs

Surgical Hand Disinfection

Before an invasive surgery, surgical hand disinfection is required. While the hygienic hand disinfection avoids the transmission of germs, a surgical disinfection seeks to completely eliminate the hands as both a route of transmission and as a source of infection. To this end, not only the transient germs are killed but the resident germs as well. To nullify any possibility for a contact infection, it is not enough to simply wear gloves. It is proven that approximately 30 percent of all gloves leak during operations.

• Before the surgical hand disinfection, the hands and forearms up to the elbows must be washed.
• After drying, the disinfectant is to be applied in multiple portions. Hands and forearms must remain completely moistened during the entire time of disinfection. At least 2 x 5 ml of an alcohol-based preparation is required.
• The hands and forearms should be rubbed for 3 to 5 minutes.
• As soon as the disinfectant dries on the hands, sterile gloves are put on.

Keeping Your Hands Stress-Free

For the hygienic and surgical disinfection of hands, disinfectants with 60 to 80 percent concentration of alcohol as an active agent are used. Alcohol-based disinfectants denature the protein molecules of microorganisms, killing or deactivating them. Alcohols work very quickly and have a wide spectrum. Included in their spectrum are the pathogens that most often contaminate hands: HBV, HCV, HIV, influenza viruses, adenoviruses, noroviruses, bacteria including the tuberculosis bacilli, and fungi. In order to make the alcohol less aggressive to the skin, the disinfectants also include remoisturizing and nourishing substances. The skin is thereby protected from drying out and can withstand the hand disinfection procedures without being affected. Should however a skin irritation occur, choosing a new disinfectant is one possible solution.

The short exposure time of disinfectants considerably lowers the workload and is thus a great advantage to the practice. Its quick volatility also saves time as the hands do not have to be dried. Allergic reactions are rare thanks to its short exposure time.

Alcohol-based Disinfectants: Passed the Test with Flying Colors

Although institutions such as the Robert Koch Institute recommend exclusively hand disinfection with alcohol-based disinfectants, antimicrobial disinfectants that are based on chlorhexidine or PVP-iodine are currently on the market.
Various studies have compared the alcohol-based disinfection of hands (rub) with the use of chlorhexidine-based disinfectants (scrub). These studies have determined the following results:

• Rubbing with alcohol-based disinfectants leads to a significantly higher and faster reduction of bacteria.
• Alcohol-based disinfectants are better armed to fight problematic germs such as MRSA and VRE (vancomycin-resistant enterococcus).
• Chlorhexidine is not always effective against mycobacteria, fungi, and some viruses.
• When interacting with water, chlorhexidine has an allergenic potential.
• Chlorhexidine can cause skin irritations that actually increase the number of pathogens.
• Chlorhexidine is less tolerated than alcohol-based disinfectants as they increase the stress on the skin
• Hand washing with chlorhexidine preparations is more time-consuming.
• Saving time by using alcohol-based disinfectants can decrease hand washing costs by up to 50 percent.
• Alcohol-based hand disinfectants are less prone to error and far more flexible.

Hand disinfectants: An overview

 (Outstanding = ++ , Good = +, Mediocre = - , Poor = --)

The Dental Practice Is Not a Beauty Pageant

Watches and jewelry (including a wedding ring) must never be worn in the dental clinic. Fingernails must be cut short and must not have any nail polish; fake fingernails are also forbidden. Wearing jewelry, watches, and fake or overgrown fingernails unnecessarily complicate a reliable disinfection of the hands.

• Rings are great hiding places for germs where disinfectants cannot reach them.
• Disinfectants that do land under a ring will dry more slowly. This can result in irritations of the skin or other damage.
• Artificial or overgrown fingernails are ideal breeding grounds for germs, are difficult to clean and disinfect, and they can damage gloves.
• Rings and watches can also damage gloves.
• Rings create a risk of injury for the patient during the treatment.
• The surfaces of jewelry can be damaged by disinfectants, discouraging staff from disinfecting their hands.

Treat Your Hands Right

The hands should perceive as little as possible from the daily stress of hand washing and disinfection. Only a healthy and smooth skin can be cleaned and disinfected unproblematically. As soon as they are injured, cracked, or porous, disinfection is only somewhat possible and would be painful. The desire to disinfect one‘s hands would be considerably decreased.

Hand creams should be applied at the end of the workday and before long breaks. Creams from dispensers or from personal tubes are preferred over lotions taken from jars or other containers. The ideal lotion is one that contains non-oily remoisturizing agents. These provide the skin with long-lasting moisture. That is particularly important in the winter when the artificial heating air damages the hands.

Studies have shown that many alleged allergies against disinfectants are actually a result of insufficient skin care. Allergic reactions against moisturizing agents or a fragrance ingredient are rare.

Lotions and creams should never be administered right before and after the disinfection of hands and immediately before putting on gloves.

Avoiding Mistakes

Mistakes put the success of the hand disinfection at a high risk. Some of these risks include the following:

• Wet hands (alcohol-based disinfectants should be put on dry hands so that the antimicrobial effectiveness is not reduced by being diluted by water)
• Hands that are contaminated with dirt, oil, or sweat
• Wearing rings and watches
• Fingernails that extend beyond the fingertips
• Paying insufficient attention to hard-to-reach spots, especially around the fingernails
• Insufficient rubbing of hands or improper motion patterns
• Insufficient application time
• Rinsing with water (this cancels the effect of the hand disinfection)
• Insufficient removal of cleaning agents that were applied earlier
• Applying lotion to the hands immediately before or after the disinfection

Disinfection of Disposable Gloves

The question of whether or not to disinfect disposable gloves is controversially debated in professional circles. There are many arguments in favor of disinfection, and some against. Opponents of the glove disinfection argue that the medical personnel could thereby be misled to believe that the gloves can be used multiple times. That must be absolutely avoided as the thin-walled gloves are not engineered for more than a single use.

The proponents of glove disinfection have various arguments in favor of glove disinfection:

• Gloves can already be contaminated when they are removed from the packaging. This is often the case when they come out of open boxes that are stored in areas near the patients.
• Gloves do not offer a full protection as they are somewhat permeable. Examinations have shown that 1 to 4 percent of all gloves have holes before they are used.
• There can be an particularly high number of germs on gloves surfaced.
• Gloves can be easily disinfected thanks to their smooth structure.

In common practice, it has become standard to disinfect gloves immediately after putting them on. The disinfection occurs according to the exact principles. In fact, even the same product used as for hand disinfection. The manufacturer of the disinfectant should provide reference to the compatibility with gloves.