Review Ch 18, 20, 21, 23, 24 Flashcards
(36 cards)
Why is it necessary to study microbiology in dentistry?
To understand the nature of pathogens (disease-producing microorganisms) and ways to prevent the transmission of disease in the dental office.
What are the groups of microorganisms studied, what group is the benchmark for sterilization?
The four major groups are: bacteria, viruses, protozoa, and fungi.
1. Bacteria: single-celled organisms that can be found in various environments
2. Viruses: infectious agents that require a host cell to replicate
3. Protozoa: single-celled eukaryotes that can cause diseases like malaria
4. Fungi: includes yeasts, molds, and mushrooms.
Spores represent the most resistant form of life known. They can survive extremes of heat and dryness and even the presence of disinfectants and radiation. Because of this, they are used to test the effectiveness of techniques used to sterilize dental instruments.
What are the shapes used to describe various microorganisms?
Bacteria shapes are spherical (cocci), rod (bacilli) and spiral (spirochetes). Chains of cocci are streptococci and irregular groups or clusters are called staphylococci.
What is oral candidiasis?
fungi - candida is a common yeast found in the oral cavity of about half the patient population. Oral candidiasis is caused by the year candida albicans. It is an opportunistic infection, especially those that affect very young, very old, and very ill patients. It’s characterized by white membranes on the surface of the oral mucosa, on the tongue, and elsewhere in the oral cavity. Th lesions may resemble thin cottage cheese; wiping reveals a raw, red, and sometimes bleeding base. It’s treated with topical antifungal preparations.
How are antibiotics used to treat various infections? What groups of microorganisms are antibiotics ineffective?
Antibiotics are used to treat bacterial infections by targeting bacterial processes such as cell wall synthesis, protein synthesis, nucleic acid synthesis, etc.
Viruses: antibiotics do not work against viral infections
Fungi: antifungal medications are required
Protozoa: antiprotozoal drugs are used instead
What are the differences between aerobic, anaerobic, and facultative anaerobic bacteria?
Aerobic bacteria: require oxygen for growth and survival
Anaerobic bacteria: cannot tolerate oxygen and grow in its absence
Facultative anaerobic bacteria: can grow in both the presence and absence of oxygen
Who is at risk for the Zika virus?
Zika virus can be spread from a pregnant woman to her fetus and has been linked to a serious birth defect of the brain called microcephaly in babies.
How is SARS CoV2 transmitted?
It is spread by droplets when the infected person breaths, talks, coughs, or sneezes.
What types of surfaces are found in a dental office?
Touch surfaces: directly touched and contaminated during treatment procedures. Ex: dental light handles, dental unit controls, etc.
Transfer surfaces: may not be directly touched but are in contact with contaminated items and instruments. Ex: trays, handpiece, suction receptors, etc.
Splash, spatter, and droplet surfaces: housekeeping surfaces that are not actually in contact with members of the dental team, contaminated instruments or supplies. Ex: floors, walls, sinks, etc.
What are the purposes of surface barriers?
Surface barriers are used to manage surface contamination to prevent the surface from becoming contaminated. Surface barriers are important for areas that are difficult to clean. They should be resistant of fluids. To prevent contamination of surfaces, to reduce the risk of cross contamination, and to speed up the process of preparing the operatory for the next patient.
What is precleaning and what is its purpose in clinical areas?
Precleaning means cleaning before disinfecting. All contaminated surfaces must be precleaned before they can be disinfected.Even a bit of saliva or blood might decrease the effectiveness of the disinfectant. Precleaning reduces the number of microbes and removes body fluids, called bioburben. Precleaning techniques are most effective when used on contaminated surfaces that are smooth and easily accessible.
What are the purposes of disinfectants?
Disinfection is intended to kill disease-causing microorganisms that remain on the surface after precleaning. Spores are not killed during disinfecting procedures. The term disinfectant is ised for chemicals that are applied to inanimate surfaces, such as countertops and dental equipment.
How long is the soak time to sterilize with a surface disinfectant?
Immersion disinfectants are chemicals on the market that can be used for sterilization or high-level disinfection. The time for sterilization can range from 6 minutes to 30 hours.
What information is found on label of a chemical agent?
Active ingredients, instructions for use, warning and precautions, EPA registration number and expiration date.
What are synthetic phenol compounds?
Synthetic phenol compounds are EPA-registered intermediate-level hospital disinfectants with broad-spectrum activity, meaning that they kill a wide range of microbes. When diluted properly, phenols are used for surface disinfection, provided the surface has been thoroughly cleaned first.
Where are Green infection control protocols not appropriate
PPE - single-use, disposable items. Gloves and masks are not reusable. Washable gowns are an alternative to disposable gowns, but they require energy, chemicals and water to wash.
What are critical, semi-critical and non-critical items?
Critical instruments: items used to penetrate soft tissue or bone. Great risk of transmitting infection and must be sterilized by heat.
Semi-critical instruments: touch mucous membranes or nonintact skin. Lower transmission risk. Sterilized by heat or receive minimum high-level disinfection if not heat tolerant.
Noncritical instruments: contact only intact skin. Low risk of infection transmission. Cleaned and processed with EPA registered intermediate or low-level disinfectant.
Describe an ideal instrument processing area?
Instrument processing area or sterilization area should be centrally located in the office to allow easy access from all patient care areas. This minimizes the need to carry contaminated items through clean areas of the office, where sterilized instruments, fresh disposable supplies, and prepared trays are stored.
Describe ultrasonic cleaners and their use in dentistry?
Used to loosen and remove debris from instruments. These cleaners also reduce the risk for hand injury from cuts and punctures that occur during the cleaning process. When using, always wear puncture-resistant utility gloves, mask, protective eyewear, and protective gown. Process until visibly clean.
Why are instruments bagged before sterilization?
Before sterilization, the instruments should be wrapped or packaged to protect them from becoming contaminated after sterilization. Can also be grouped into special setups, such as crown/bridge, amalgam, prophylactic, or composite. Never store sterilized instruments open in a drawer or storage container. Once the sterilization container has been opened, the sterilization of the instrument is compromised.
What is sterilization?
Sterilization destroys all microbial forms, including bacterial spores. Sterile is an absolute term; there is no partially sterile, or almost sterile. There are three most common forms of heat sterilization in the dental office: steam, chemical vapor, dry heat.
What are the difference types of sterilization used in dentistry? What is most common?
There are three most common forms of heat sterilization in the dental office: steam sterilization, chemical vapor sterilization, and dry heat sterilization.
Steam: an autoclave is used to sterilize dental instruments and other items by means of steam under pressure. This involves heating water to generate steam to produce a moist heat that rapidly kills microorganisms. Four cycles: heat up, sterilize, de pressure, drying. The heat, not the pressure, kills the microorganisms.
Chemical Vapor: similar to autoclaving, except that the combination of chemicals (alcohol, formaldehyde, ketone, acetone, and wtaer) is used instead of water to create a vapor for sterilization. OSHA requires a SDS on the chemical vapor solution.
Dry Heat: operate by heating up the air and transferring that heat from the air to the instrument. This form of sterilization requires higher temperatures than are needed for steam or chemical vapor sterlization.
What is the purpose of biological monitoring?
It’s the only way to determine whether sterilization has occurred and all bacteria and endospores have been killed.
What is the purpose of a process indicator?
Process indicators are placed outside of instrument packages before sterilization. Examples include autoclave tape and color-change markings on packages or bags. They simply identify instrument packs that have been exposed to a certain temperature; they do not measure the duration or the pressure. They are also known as single-parameter indicators. They are useful in distinguishing between packages that were processed and those that were not processed.