Infection Control for Dental Assisting Exam Study Guide (page 5)
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Each dental professional has a responsibility to be aware of current infection control techniques and trends. Infection control is an area of dentistry that is constantly altering and evolving. Rules and regulations change yearly, and some states are more stringent than others. Infection control updates should be a regular part of a dental professional’s continuing education. In fact, this is an Occupational Safety and Health Administration (OHSA) requirement.
Concepts and Skills
Infection control is broken down into four main areas:
- Disease Transmission
- Occupational Safety and Health Administration (OSHA)/Centers for Disease Control and Prevention (CDC)
The following outline chronicles current information regarding each area of infection control.
Germs are the main causes of disease. Germs are also termed microorganisms and/or pathogens. When these germs multiply, they become diseases. Diseases can be transmitted only in a distinct pathway. This pathway is known as the chain of infection.
Chain of Infection
The chain of infection contains four links: virulence, number of microorganisms, susceptible host, and portal of entry. All of these must be present for the individual to become infected with a disease. If one of these is missing, the disease cannot be transmitted.
The virulence of an organism is its strength or ability to cause disease. The more virulent the organism, the more serious the disease. A virulent disease is also more difficult for the body to fight off and could be resistant to certain medications.
Number of Microorganisms
The number of microorganisms describes the amount of pathogens present. A large number of pathogens will overwhelm the body’s immune system and diminish the body’s ability to fight off the pathogens.
A susceptible host is someone who has a compromised immune system. This means that this person has a disease already, is currently undergoing treatment for a condition, has not been getting enough rest, and is run down or under stress. These things can suppress a person’s immune system and cause her or him to be more susceptible to an illness or disease.
Portal of Entry
A portal of entry is the way in which an infection enters the body. An infection can enter the body through various modes.
Modes of Disease Transmission
An infectious disease is one that is contagious and can be transmitted from host to host via the chain of infection. Diseases are transmitted in one of the following five modes of transmission: direct; indirect; airborne; aerosol, spray, or spatter; or blood-borne transmission.
This route of transmission occurs when there is direct contact with infected blood, saliva, or other potentially infectious materials (OPIM). Personal protective equipment (PPE) is essential in preventing transmission.
This route of transmission occurs when the dental healthcare professional comes in contact with a contaminated surface without the protection of PPE.
This route of transmission occurs through methods of inhalation. For example, a patient sneezes, and another inhales some spores that may be present in the sneeze. Many serious diseases are spread via the air.
Aerosol, Spray, or Spatter
This route of transmission is a form of airborne transmission. Aerosol is generated by the use of the high-speed hand piece in the mouth. An aerosol mist is emitted from the oral cavity, which is contaminated with the patient’s bacteria. Spray and spatter follow the same form, but are larger in size than an aerosol mist. These occur in the patient’s mouth and splash out of the oral cavity, contaminating the surrounding area.
This route of transmission occurs only from blood-to-blood contact with an infected individual. Many diseases, such as HIV/AIDS and Hepatitis C, are transmitted this way. The most common method of transmission is through a needle-stick injury. Therefore, maintaining safe practices and procedures while paying attention to details helps prevent this type of transmission.
Disease Transmission in the Dental Office
All members of the dental healthcare team should be concerned about disease transmission in the dental office. Dental professionals call this cross-contamination. Cross-contamination refers to germs within or from the dental setting being transmitted to other areas of the dental office or carried out of the dental setting. This can occur in a number of ways, including patient to patient, healthcare worker to patient, patient to healthcare worker, and healthcare worker to community.
Patient to Patient
Cross-contamination can occur from patient to patient by not changing PPE between patients, by not properly disinfecting the treatment room, and by not properly sterilizing the dental instruments. The germs and bacteria are then introduced into a new host, causing a “sharing” or “crossing” of infection. It is imperative that dental assistants understand the importance of preventing cross-contamination.
Healthcare Worker to Patient
The patient and dental healthcare worker sit in very close proximity to one another. Therefore, it is possible for the dental healthcare worker to transmit microorganisms to the patient unintentionally. It is important to don fresh PPE for each patient. This includes a new pair of disposable gloves; a new disposable mask; and clean, disinfected safety glasses. Hand washing is always an important aspect of infection control.
Patient to Healthcare Worker
The patient can also transmit microorganisms to the dental healthcare team. The same precautions as above should be followed by the dental healthcare team to prevent the transmission of microorganisms.
Healthcare Worker to Community
The dental healthcare worker may unintentionally transmit contaminants from the dental setting into the community. Care should be taken by the dental healthcare worker to avoid this by changing into street clothes prior to leaving the office, and laundering contaminated clothes properly.
Occupational Safety and Health Administration (OSHA)/Centers for Disease Control and Prevention (CDC)
Occupational Safety and Health Administration (OSHA) and the Centers for Disease Control and Prevention (CDC) are federal agencies that are primarily responsible for infection control measures utilized in the United States. OSHA is a regulatory agency responsible for ensuring the safety and health of employees in the United States. OSHA has developed a set of standards to provide a safe workplace in the dental office. OSHA’s main concern is the welfare of the employee, not the patient. The agency also conducts training and educational programs regarding OSHA implementation and regulations.
The CDC is an advisory agency tasked with the research and study of diseases of consequence to the American population. They make recommendations, or suggestions, regarding infection control after conducting intensive research on the topic. The CDC’s main concern is the health and protection of the overall population through preventive measures and proper treatment.
Blood-Borne Pathogens Standard
OSHA developed the Blood-Borne Pathogens (BBP) Standard, which has become the most important law governing infection control in dentistry today. The BBP Standard discusses how the dental office deals with, and its plan for, exposure to blood-borne pathogens. There are several parts to this standard that are discussed in detail in OSHA’s BBP Standard.
Universal precautions is a protocol followed by each dental office that mandates that all patients be treated as if they have a deadly disease, regardless of their health history.
Standard precautions is an expansion of universal precautions. Standard precautions outlines how the dental office will handle its infection control protocol for each patient. This means that the infection control protocol for each patient will be the same, no matter what.
Categories of Employees
OSHA has designed categories for each employee in the dental office based on his or her exposure risk to blood, saliva, or bodily fluids. Category I is the highest risk category, involving direct contact with blood, saliva, and other potentially infectious materials (OPIM). These dental healthcare members include the dentist, chairside dental assistants, and the hygienist.
Each dental office is required by OSHA to develop a written protocol outlining steps or measures to be taken after an exposure incident occurs. An example of an exposure incident is being stuck with a contaminated needle, being punctured by an instrument, or being cut with a bur.
Hepatitis B Immunization
OSHA requires that every dentist offer and pay for the Hepatitis B vaccination to all categories of employees who want to be immunized. The Hepatitis B vaccine is given in three doses over a specified period of time.
Management of Sharps Waste
Sharps, such as needles, scalpels, broken glass from an anesthetic carpule, old burs, broken instruments, etc., must be disposed of in a biohazard, non-permeable, red plastic container. Each operatory or treatment room must have its own sharps container. The office contacts a hazardous material company to dispose of the sharps waste properly, following the laws of the state.
Personal Protective Equipment (PPE)
Personal protective equipment (PPE) is required by OSHA as a means of protection for the dental healthcare worker. The dentist must supply the proper PPE for the employee. PPE consists of scrubs (overcoat, jacket, and disposable protective gown), leather shoes, lab coat, mask, safety glasses/face shield, and gloves. PPE should be donned/performed in the following manner: lab coat, mask, safety glasses/face shield, wash hands, and gloves. PPE should be removed/performed in the following manner: gloves, wash hands, safety glasses, mask, lab coat, and second hand washing.
Classifications of Waste
There are many types of waste in a dental office. OSHA classifies waste as general waste, contaminated waste, hazardous waste, infectious waste, and biohazardous waste. Each must be disposed of properly.
Waste Management for the Dental Office
OSHA requires that all dental offices have a waste management plan. This is designed to protect the environment, follow state and federal laws, and ensure the safety of those who may come in contact with the materials in the garbage. Accurate disposal records must be kept.
Disinfection is the process of killing some microorganisms, but not all. Some bacteria will form into spore colonies to protect themselves from being destroyed. Disinfection does not kill spores.
Disinfection in the Dental Office
In the dental office, most hard surface areas are disinfected with disinfectant wipes or spray. Any area that may have been contaminated during a procedure will be disinfected. Some examples of areas that would need to be disinfected following treatment include the mobile cart, lines, counter tops, dental chair, light, and any other contaminated surfaces.
Use of Surface Barriers
Surface barriers are materials used to cover equipment and surfaces to prevent cross-contamination. Any surface that may be contaminated during treatment should be covered with a disposable plastic barrier. Some examples of surface barriers include light handle covers, syringe sleeves, and chair covers.
Disposable Items Today, many dental supplies used for patient treatment are single-use disposable items. Some examples include cotton rolls, gloves, prophy angles, 2 x 2 gauze, HVE tips, and so on.
Types of Gloves for Protection
There are four main types of gloves that a dental assistant may use for protection. These are examination gloves, utility gloves, overgloves, and sterile gloves.
Examination gloves are latex, vinyl, or nitrile materials that are most often worn by members of the dental team. Examination or procedure gloves are inexpensive and disposable. They come in a variety of sizes and colors, and can be scented or flavored.
Utility gloves are similar to old-fashioned dishwashing gloves. They are used to break down a contaminated treatment room and to handle contaminated instruments. They would never be used when treating a patient. These gloves can be disinfected and/or sterilized in the autoclave.
Overgloves are used when an assistant must leave the treatment room, open a drawer during the procedure to retrieve a supply the dentist needs, or to make notes. These gloves are similar to food-handling gloves.
Sterile gloves are utilized during surgical procedures involving the bone or periodontium. These gloves are supplied in a protective pouch. When the protective pouch is opened, the gloves can clearly be seen labeled for the right or left hand.
Disinfectants are used to kill some of the microorganisms prior to sterilization. Dental assistants use disinfectants to wipe down treatment rooms or other contaminated surfaces following a procedure. The two most popular disinfectants utilized in the dental office are iodophors and gluteraldehydes.
Iodophors are used in the dental treatment rooms to disinfect the hard surface areas and equipment, but they have a tendency to stain. They are supplied in either a spray or a wipe.
Gluteraldehydes are interesting due to their ability to be both a sterilant and a disinfectant. In the dental office, gluteraldehydes are used as the holding bath or “cold sterile.” Some instruments cannot withstand heat sterilization and must be sterilized in the cold sterile. For this to occur, the instrument must be immersed in the solution for ten hours. Anything less than that time, and the instrument is considered to be disinfected, but not sterilized.
Procedural Steps in Disinfection
All contaminated items are removed from the treatment room and properly disposed of or taken to the sterilization area in a closed, covered container. Begin disinfection using the desired method selected by the dental office. The wipes method of disinfection is most popular. Wipe the entire operatory thoroughly while wearing proper PPE. After the room is disinfected, wash hands, and place new barriers.
Sterilization is the process that completely destroys microorganisms (including bacteria and spores) on instruments, equipment, and surfaces.
Dental instruments are grouped into three categories, according to their function: critical, semi-critical, and non-critical.
Critical instruments are those that contact or penetrate soft tissue or bone. These include scalpels, burs, scalers, and other dental tools that penetrate bone and tissue.
Semi-critical instruments are instruments that come in contact with the oral cavity but do not penetrate soft tissue or bone. These include amalgam carriers, condensers, and other items that touch tissue and are contaminated by blood and saliva.
Non-critical instruments are those that pose the least risk of spreading infection because they do not come in contact with soft tissue, membranes, or broken skin. These include items such as the X-ray unit position indicator device or X-ray film holder (Snap-A-Ray).
Instrument processing involves seven steps: transport, cleaning, packaging, sterilization, storage, delivery, and quality assurance of all dental instruments. Personal protective equipment must be worn at all times during the sterilization process. All instruments are packaged after cleaning and before sterilization to group them in sets and to protect them from contamination after sterilization.
Methods of Sterilization
Four of the leading methods of sterilization are autoclave, chemiclave, flash sterilization, and cold sterilization.
An autoclave sterilizes instruments by converting water to steam and pressurizing it. This is known as steam under pressure. High heat and pressure kills any remaining microorganisms or spores. The average cycle of an autoclave is 30 minutes: 20 minutes at 250° F (121° C) at 15–20 pounds per square inch (psi) for sterilizing, and ten minutes venting time for drying.
The chemiclave converts chemical vapor into steam and pressurizes it. The odor emitted is unpleasant, and the office should be equipped with a special vent for use with this type of sterilizer. The average cycle of a chemiclave is 30 minutes: 20 minutes at 270° F (132° C) at 20 psi for sterilizing, and ten minutes for drying.
Flash sterilization is utilized in an office when a particular instrument is needed right away. The average cycle of a flash sterilizer is three minutes at 270° F (132° C) at 15 psi for unwrapped instruments. The instrument needs to be used right away since it is unwrapped.
Forms of Sterilization Monitoring
Whatever type of sterilizing is used, it must be monitored to ensure that the dental instruments are properly sterilized. There are three forms of monitoring: physical, chemical, and biological.
Physical monitoring of the sterilization process involves checking the readings on the indicators on the sterilizer, along with checking if the color-changing pouch or tape has in fact changed color to denote that a certain temperature level was reached.
Chemical monitoring of sterilization uses heat-sensitive chemicals that change color under certain conditions. Process indicators are placed outside the instrument packs, while process integrators are placed inside.
Biological monitoring involves spore testing to establish whether the sterilization process was successful. Weekly testing is mandated by OSHA for every sterilization device utilized in the office. The spores utilized are bacillus stearothermophilus for steam and chemical vapor sterilizers, and bacillus subtilis for dry heat and ethylene oxide sterilizers.
Dental hand pieces must be carefully sterilized to avoid cross-contamination.
Before the actual sterilization begins, wipe down the hand piece with disinfectant wipes or alcohol-soaked gauze 2 x 2s to remove any bioburden. It is recommended that the hand piece be flushed for 20–30 seconds prior to disconnecting to remove any contaminated water. Hand pieces should never be immersed in any type of liquid. Follow the manufacturer’s directions regarding lubrication of the dental hand piece.
There are only two ways to properly sterilize hand pieces: steam or chemical vapor sterilizers. As with other dental instruments, hand pieces should be packaged before being sterilized.
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