Taking on the Challenge

The demand for hygiene is a pervasive issue in every dental office. This is because of three quintessential reasons. Firstly, the incidence of infection during the practice of dentistry is unavoidable and there are numerous possible paths of transmission. Secondly, the evolution of multiresistant pathogens and a widespread number of parents who do not vaccinate their children require the dental community to constantly adapt their hygienic measures. Thirdly, the legal obligations regarding hygiene must be consistently fulfilled, particularly because of the dental professional’s responsibility for his patients and staff. The result is a contemporary and proper handling of this “challenge” of hygiene.

Hygieia was worshiped in Greek mythology as the goddess of health, cleanliness, and sanitation alongside her father Asklepius, the god of medicine, and her sister Panacea, the goddess of healing. In the temple of her father, she welcomed the sick, who were ritually cleansed by her priestesses. Medicinal therapy and healthy practices were already then connected as a sisterly harmony. Hygieia serves as the namesake for our contemporary concept of hygiene, which the Oxford English Dictionary describes as a “system of principles or rules for preserving or promoting health.”

Just one century ago, 50 percent of all causes of death were related to infectious diseases and the average lifespan was only 45 years. Today’s life expectancy has risen to over 80 years, and infectious diseases no longer reign on the list of the most common causes of death. The medical advances of the last hundred years are responsible for this, particularly the implementation of antibiotics as well as developments in hygiene and public health. Additional reasons are the sanitation of cities, health education, comprehensive immunizations, and raised hygiene awareness in daily life. The costs of prevention total to a small fraction of the costs of treatment. It is fully understandable that hygiene is given such attention by resident doctors and dentists in particular at-risk places such as dental offices, hospitals, medical practices, old person homes, and nursing homes.

Discovery of Anthrax Spores

In 1876, a young doctor from the small town of Wollstein published his discovery of anthrax spores. The young doctor was the local physician Robert Koch, who had set up a laboratory in his simple four-room apartment. With his discovery of the anthrax spores, the dormant state of the pathogen, Koch was able to describe the chain of infection and account for the bacteria’s resistance. He was the first to be able to prove that an infections disease can only appear if its specific pathogen is present—the birth of modern bacteriology.

Koch left Wollstein in 1880 to be appointed to the Imperial Health Office in Berlin. Here he turned his attention to the bacteriological methodology, which allowed him to research on diseases and to develop preventative measures such as disinfection practices. He standardized the culture medium for breeding bacteria and introduced microphotography. Koch’s scientific fame was most definitively established in March 24, 1882, when he delivered his famous lecture on the “Etiology of Tuberculosis.”

In 1885, Koch was appointed to a professorship for hygiene in Berlin, a position created specifically for him. In the same year, Koch became the director of the new Institute for Hygiene. Koch’s bacteriological discoveries eventually lead to revolutionary changes regarding the cautious handling of dirt and infectious material.

War and Peace: A War of Infections or a Pax Hygienica?

The word pathogenicity signifies the ability of certain factors to provoke abnormal changes to the body. The object triggering the disease is classified as a pathogen. Pathogens are normally in agents such as bacteria, viruses, fungi, and prions. Pathogens elicit infections that clinically manifest themselves in various ways. Meanwhile, it is also known that infections can be the pathogenetical cause of sicknesses that are not necessarily associated with infections at a first glance, including cancer, stomach ulcers, bronchial asthma, or multiple sclerosis to name a few.

It would be quite exaggerated to compare Tolstoy’s epic novel to today’s hygienic situation. Nevertheless, the catchwords war and peace can concisely capture the situation in which the modern practice of dentistry finds itself. A growing number of parents who do not vaccinate their children, the appearance of new pathogens, and the evolution of antibiotic resistant strains are the reasons for this still complicated and difficult situation. The increasing degree to which the average person travels also contributes to the geographic spread of diseases. “Diseases do not come upon us out of the blue, but rather from minor daily sins against nature. When enough of these have accumulated, illnesses will suddenly appear,” said Hippocrates, the most famous doctor of the antiquity (460–370 BC). The constant advancement of hygienic strategies due to new scientific findings makes it possible to keep up with the blitzkrieg pace of this “War’s” development. “Peace” will only be reached once we are able to eliminate the presence and transmission of pathogens on a large scale.

Crime Scene Investigation: The Dental Office

The pathogen’s natural habitat is the source of infection in which it lingers and reproduces. The most important of these sources of infection is the human being. We identify germ-containing populations as a natural reservoir in which pathogens can gather and turn into a source of infection. Natural reservoirs can be found in humans (e.g., in the throat) as well as on contaminated surfaces and materials.

Contaminatus (stained) is the Latin root of the word contamination. In a medical sense, contamination can be understood as a defilement of objects or materials with pathogenic microorganisms. In the practice of dentistry, this could pertain to the surfaces of fixtures, instruments, waste, and materials such as fluids or medications. Buttons, lamp handles, turbine heads, suction nozzle holsters, and the instrument table are particularly at risk of a possible infection. Additionally, pieces of clothing, especially long-sleeved clothing, are further possibilities for a pathogenic contamination. Following a contamination, the possibilities arise for a cross-contamination. In such a case, the pathogens are retransmitted from an already-contaminated surface or material onto an uncontaminated surface or material.

Pathogens in the Fast Lane

Humans move around by whatever means of transportation they desire, be it by plane, train, or automobile. Normally we are able to reach our destination. The means by which pathogens arrive in a host organism are just as versatile as our choices of transportation. The transmission of a pathogen from one human to another is referred to as anthroponosis, while the transmission of a pathogen from an animal to a human is referred to as zoonosis. The infection carriers are predominantly sick humans and animals but also include expulsion during incubation, expulsion during sickness, expulsion over three years after the infection, as well as germ carriers. The path of transmission can also either be direct or indirect, depending on whether or not direct contact with the infection carrier was made.

The Most Important Paths of Infection 

he dangers of infection are constantly present in the dental office. The risk of an aerosol infection is present when using high-speed hand pieces and contra angles with spray cooling. The aerosol that develops contains germs and disperses conically from the oral cavity of the patient. The highest germ density of the aerosol is 60 centimeters from the dental chair, approximately the distance between the patient’s mouth and the attending dentist. A widespread accumulation of aerosol can contaminate the entire environment of the dental chair within a radius of up to 1.5 meters.

An airborne infection, generated by expelling infected saliva while talking, sneezing, or coughing, can put both patients and the dental team at risk. The transmission of the pathogen is possible at a radius of up to 3 meters.

Contact infections are the result of improper sanitation and disinfection of contaminated surfaces and materials. Poor hygiene practices after using the toilet dramatically increase the risk of a smear infection.

Keep Your Eye on the Goal

An infection is defined as an adhesion, either an active or passive intrusion, and the reproduction of pathogens in a host. According to the type of pathogen, various kinds of infections may occur; some of the more common infections include bacterial infections, viral infections, fungal infection, and prion infections. Other infections such as parasitic or worm infections are less commonly found in the dentist’s office.

The transmission of an infection can occur endogenically or exogenically. An endogenic infection refers to an autoinfection, during which the body’s own microorganisms overwhelm the weakened immune system and thus become the pathogens themselves (e.g., from the intestines or stomach). An exogenic infection is the transmission of pathogens from the environment.

Pathogens are able to infiltrate an organism without showing any symptoms of sickness. This colonization is different than an infection, which is characterized by a sickness with clinical symptoms. To the same degree, a settlement of mucous is referred to as colonization in terms of desirable resident flora (e.g., in the intestinal flora).

Offense and Defense

The human body makes a stand against invading pathogens with a more or less strong immune potential. This immune potential is comprised of the body’s own barriers as well as its specific and nonspecific defenses (see table below). A specific defense can also be supported by an active or passive immunization. An active immunization is accomplished by inserting into the host weakened pathogens (live vaccine) or dead pathogens or pieces of dead pathogens (dead vaccine) in order to encourage the development of an immunity. A passive immunization is when antibodies are administered to the organism so that they do not need to be produced by the organism itself. The effectiveness of a passive immunization is immediate, but the period of effectiveness is limited. These applied defensive measures are usually rejected by the body after a few weeks.

The Human’s Defenses Against Infection

The Resilience of an Organism to Outside Forces

Such is the dictionary‘s medical definition of resistance. The human being can develop resistance against pathogens, mostly on account of active and passive immunizations. Pathogens are likewise able to develop resistance against certain medications.

Bacteria can possess or are able to develop a natural (primary) or acquired (secondary) resistance. The secondary resistances in particular can create serious problems. Antibiotics exert an evolutionary selective pressure on the bacteria and only allow conformed pathogens to survive. This conformation of the bacteria takes place through changes in the genetic material, which are passed on to the bacteria‘s offspring. Bacteria reproduce between every 10 and 30 minutes on the average. If one compares that with the generation rate of humans, approximately 20 years, bacteria would only require 111 days to complete the evolutionary leap between a Neanderthal and a human. This just shows how great a potential for mutation this organism has.

Multiresistant pathogens are resistant against many different antibiotics (bacteria) or antivirals (virus). An example of multiresistant development is the MRSA (methicillin-resistant Staphylococcus aureus), which spawns in hospitals, old person homes, nursing homes, ambulances, and can also be widely found in dental offices. In recent years, the percentage of MRSA infections has multiplied. Because of its continual appearance and the difficult treatment for the disease, it is now considered an epidemic (see table below).

The preventative measures for this developing situation of resistance must be consistently adapted. Other factors that are challenging our current hygiene standards are new pathogens and the increasing appearance of prion diseases.

The Spread of Infectious Diseases 

Taking on the Challenge: Our Personal Responsibility

The cost of healthcare for infectious diseases in the United States alone is estimated at over $120 billion. In Europe, billions are also being invested. The morbidity rate of infectious diseases in developed nations is however still high. Every year in Switzerland approximately 70,000 people, of its 7 million people, suffer from infectious diseases; 5,000 of these do not survive.

Definitions 

As pathogens are increasingly difficult to treat, attention should be give to the prevention of infection and disease. Infection control plays the vital role. The dental professional strives for hygienic perfection because of the medical necessity, his judicial duty, his legal obligation to provide care, and his responsibility for his patients, his staff, and for himself.

“If man were a body, there would be no other moral than Hygiene,” said Théodore Jouffroy, the French philosopher (1796–1842). Recognizing the problems and understanding the causes and paths of transmission are the first steps to successful infection control procedures.