General Information for Patients
Bloodborne Disease Transmission
Barrier Precautions
Disinfection and Sterilization Practices
Handpieces
Disposal of Sharp Instruments and Infectious Waste
Management of Exposures
General Information for Patients
Cleanliness and proper sterilization techniques have been a part of dental practices for many years, but recently a number of disease causing organisms such as HIV/AIDS, hepatitis B and C, and herpes viruses have made these techniques even more important.
Dental professionals are concerned about the possibility of disease transmission and are making several visible changes in the way dental services are provided. For example,
- More dentists are using the proper infection control procedures for all patients.
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Dentists, hygienists, and assistants are routinely wearing surgical gloves, protective eye wear, and masks during treatment of patients. The use of these barriers, greatly reduces the risk of transmission of microorganisms between patients and health-care workers.
- More dental personnel are receiving vaccination against the hepatitis B virus.
- Dentists are becoming more educated about the best methods to protect their patients
These safeguards will benefit everyone - patients, families, and dental personnel.
These infection control techniques are not costly and are of great value, considering the amount of protection that is provided. Many of these techniques have been practiced in the dental office for years.
The use of these infection control techniques and practices is strongly supported by organizations such as the Centers for Disease Control and Prevention, the American Dental Association, state boards of health, schools of dentistry, and many other health agencies and professional associations.
You can help your dental health professional by reporting any changes in your health status at each dental visit. Doing so will help your dental health professional provide the best treatment based on your health needs. And if you wish to know more about infection control issues, your dentist should be able to provide you with additional information.
Bloodborne Disease Transmission
Hepatitis B (HBV) and C viruses (HCV) and HIV are important bloodborne diseases. Although the potential for HBV transmission in the workplace setting is greater than for HCV or HIV, the modes of transmission for these three viruses are similar. All have been transmitted in occupational settings. Blood is the single most important source of these viruses in the workplace setting. Protective measures against the transmission of HIV, HBV and HCV for dental workers should focus primarily on preventing exposures to blood as well as receiving the HBV vaccination.
The risk of hepatitis B infection following a parenteral (i.e., needlestick or cut) exposure to blood is directly proportional to the probability that the blood contains hepatitis B surface antigen, the immunity status of the recipient, and the efficiency of transmission. The probability of the source of the blood being positive for hepatitis B varies from l to 3 per thousand in the general population to 5% - 15% in groups at high risk for HBV infection, such as:
- Tourists from areas of high endemicity (China and Southeast Asia, sub-Saharan Africa, most Pacific islands, and the Amazon Basin).
- Sterilizing methods which use heat are preferred. However, there is a fourth sterilization method using a liquid "disinfectant/sterilant" for use on medical and dental instruments. This method is sometimes referred to as "cold sterilization". This procedure:
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Requires that the dental instruments be immersed up to 10 hours in the chemical agent
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Can not be verified by biologic monitors (ie, spore tests)
Thus indications for use of liquid germicides to sterilize instruments are limited. If this method must be used for heat sensitive instruments, follow with aseptic rinsing (using sterile water), drying, and placement in a sterile container if the instrument is not used immediately.
Alcohol is not recommended for disinfecting contaminated environmental surfaces because it evaporates quickly and does not allow sufficient contact time for effective action.
Barrier Precautions
The following information summarizes the use of gloves, masks, protective eyewear, gowns, and the protection of equipment that is hard to disinfect.
During dental procedures, dental health-care workers must wear gloves when they put their hands into any patient's mouth, and change these gloves between patients. They should also wear gloves when they touch instruments, equipment, or surfaces that may be contaminated with blood or saliva.Hands must be washed and regloved before performing procedures on another patient. Repeated use of a single pair of gloves or washing of gloves between patients is not recommended, since such practice is likely to produce defects in the glove material, which will diminish its value as an effective barrier. Surgical masks and protective eyewear or chin-length plastic face shields must be worn when splashing or spattering of blood, saliva, or oral secretions is likely, as is common during dental procedures.Reusable or disposable gowns, laboratory coats, or uniforms must be worn when clothing is likely to be soiled with blood, saliva, or oral secretions. If reusable gowns are worn, they should be washed, using a normal laundry cycle. Gowns should be changed at least daily or when visibly soiled with blood. Disposable waterproof coverings such as impervious-backed paper, aluminum foil, or clear plastic wrap may be used to wrap hard-to-clean surfaces such as light handles or x-ray unit heads, etc. These surfaces may be contaminated by blood or saliva and are difficult or impossible to clean and disinfect. To replace the covering between patients, the coverings should be removed with gloved hands and discarded. Then, after removing the soiled gloves, the coverings can be replaced with clean material.
Gloves
You are most likely to contact blood with your hands. If the skin of your hands is intact, it provides good protection from microorganisms that may be in blood. Frequently, however, there may be small unapparent breaks in the skin on your hands.
Wearing gloves will provide an extra barrier against the entry of microorganisms through any breaks in your skin.
Wear gloves whenever you put your hands into any patient's mouth or touch instruments, equipment, or surfaces that may be contaminated with blood. Use a new pair of gloves for every patient.
NEVER reuse surgical or examination gloves. Washing these gloves may damage them and actually cause "wicking," which increases the flow of liquid through undetected holes in the gloves.
Utility gloves may be reused if they are not punctured or torn. They should be properly decontaminated before reuse.
If your gloves are torn, cut, or punctured, remove then immediately and dispose of them properly. Then wash your hands thoroughly with soap and water and put on a new pair of gloves.
As a barrier, there is no difference between an intact vinyl glove and an intact latex glove. However, any type of glove may be defective. It would be prudent, therefore, to make sure your gloves are intact before using them.
As a public health measure, it is not necessary to double-glove, as long as the glove is intact.
Eyewear
Wear either a mask and protective glasses or goggles, or a chin-length face shield that protects your eyes, nose, and mouth from spatter. Wear facial protection whenever blood or oral fluids contaminated by blood may be spattered, for example during patient treatment, while cleaning instruments, or when disposing of contaminated fluids.
Use a new surgical mask for every patient. If the mask becomes wet during the single treatment of a patient, the mask should be replaced.
Gowns
Protect your street clothes from contamination by covering them with a gown or coat or wearing a uniform. The sleeve length of these work clothes may be long, medium, or short. Long sleeves will provide the most protection, but may become soiled and need to be changed more often during the course of the work day. If medium or short sleeves are used, be sure to wash your arms up to the sleeve length, while washing your hands before gloving.
Change these work clothes at least daily, or more often if soiled, especially if they become visibly contaminated with blood.
Work clothes soiled by blood, saliva, or oral secretions should be placed and transported in bags that prevent leakage. Wash soiled linens in hot or cold water with detergent and, if possible, chlorine bleach. Normal washing and drying cycles will remove or kill potentially harmful micro-organisms, including viruses. Be sure to follow the instructions of the detergent and machine manufacturers.
Disinfection and Sterilization Practices
Cleaning, disinfection, and sterilization are all decontamination processes. These processes differ in the number and types of microorganisms killed. By knowing the differences between these processes, your will know how to choose the right way to reprocess reusable instruments and equipment.
Cleaning is the basic first step for all decontamination. When you clean, you physically remove debris and reduce the number of microorganisms present. You always need to clean before you disinfect or sterilize.
Disinfection is a process that kills disease-causing microorganisms, but not necessarily all microorganisms. There are three levels of disinfection: low, intermediate, and high.
- Low-level disinfection is the least effective disinfection process. It does not kill bacterial spores or Mycobacterium tuberculosis var. bovis, a laboratory test microorganism that is used to classify the strength of disinfectant chemicals.
- Intermediate-level disinfection is a disinfection process that does kill M. tuberculosis var. bovis, but not bacterial spores. If you use a process that kills M. tuberculosis var. bovis, you will also kill organisms that are easier to kill, such as the ones that cause hepatitis B and AIDS.
- High-level disinfection is a disinfection process that kills some, but not necessarily all, bacterial spores. This powerful process will also kill M. tuberculosis var. bovis, as well as other bacteria, fungi, and viruses.
Sterilization is a process that kills all microbial life, including bacterial spores, which are the most difficult form of microorganism to kill.
The choice of how to decontaminate anything should be based on how it will be used.
Instruments that will touch bone or penetrate tissue are called CRITICAL. Forceps, scalpels, and scalers are examples of critical items. Sterilize these critical instruments. Heat sterilization methods are preferable.
Instruments that will touch mucous membranes but will not touch bone or penetrate tissue are called SEMI-CRITICAL. Mirrors and amalgam condensers are examples of semi-critical items. Sterilize these semi-critical instruments in an autoclave if they will not be damaged by heat. If they will be damaged by heat, USE HIGH-LEVEL DISINFECTION.
Equipment and environmental surfaces that will come into contact only with intact skin are called NON-CRITICAL. For non-critical equipment and surfaces that will touch only intact skin, USE INTERMEDIATE OR LOW-LEVEL DISINFECTION.
There may be ways to avoid having to decontaminate items with irregular surfaces that cannot be cleaned and disinfected easily. Some, such as saliva ejectors, are available in a disposable form and can be thrown away after a single use. Others, such as light handles and hand-operated chair controls, can be covered to avoid contamination altogether. Still others, however, such as light-curing wands, are not disposable and cannot be covered. Your dental supplier and the manufacturer of a particular piece of equipment or material are the best sources of information for decontaminating these items.
Handpieces
Handpieces should be sterilized by heat.
Water lines connecting to the handpieces should be thoroughly flushed between patients, and at the beginning and end of each day.
Because handpieces come in contact with mucous membranes, and because the structure of handpieces limit cleaning and disinfection or sterilization of both the internal and external surfaces, handpieces should be cleaned and then treated between patients by a heat sterilization process (i.e. steam under pressure [autoclaving], dry heat, or heat/chemical vapor). Manufacturer's instructions for cleaning, lubrication, and sterilization procedures should be followed closely to ensure both the effectiveness of the process and the longevity of handpieces. Virtually all high-speed and low-speed handpieces in production today are claimed by manufacturers to be heat-tolerant, and most older models that are damaged by heat can be retrofitted with heat-stable components. Surface disinfection by wiping or soaking in liquid chemical germicides is not an acceptable method for reprocessing handpieces or other intraoral dental instruments that are attached to air/water lines of dental units.
To further reduce the potential risk of transfer of infective material from one patient to another, the water lines attached to handpieces should be handled as follows:
1. Because water retraction valves in dental-unit water lines may aspirate patient materials back into the handpiece and water lines, check valves should be installed to prevent fluid aspiration. Routine maintenance of check valves is necessary to ensure effectiveness; the dental-unit manufacturer should be consulted to establish an appropriate maintenance routine.
2. After each patient use, high-speed handpiece water lines should be thoroughly flushed to aid in removal of patient material. It is prudent for water-cooled handpieces to be run and to discharge water and air into a sink or container for a minimum of 20-30 seconds after use on each patient is completed. This is intended to aid in physically flushing out patient material that may have been aspirated into the handpiece or water line. Additionally, there is evidence that overnight or weekend microbial accumulation in water lines can be significantly reduced by removing the handpiece and allowing open water lines to run and to discharge water for several minutes at the beginning of each clinic day.
3. Sterile saline or sterile water should be used as a coolant/irrigator when performing surgical procedures involving the cutting of bone.
Disposal of Sharp Instruments and Infectious Waste
Sharp items (e.g., needles, scalpel blades, wires, and other sharp instruments) contaminated with patient blood and saliva should be considered as potentially infective and must be handled with care to prevent injuries.
To prevent needlestick injuries, needles should not be recapped by hand using a two-handed recapping technique; needles should not be purposely bent or broken by hand, removed from disposable syringes, or otherwise manipulated by hand. After they are used, disposable syringes and needles and other disposable sharp items should be placed in puncture-resistant containers for disposal. The puncture-resistant containers should be located as close as practical to the use area. All needles should be placed in a puncture-resistant container.
Disposal of Solid or Liquid Waste
Solid waste such as blood contaminated gauze, cotton rolls, disposable gowns, and masks should be placed and secured in a leakproof plastic bag. When putting waste in the bag take care not to contaminate the outside of the bag. Dispose of the bag as outlined by your state, local, or institutional requirements.
The risk of transmission of any microorganism from clothing is extremely low. Therefore, good cleaning rather than sterilization is the proper method of treating soiled linens. Wash soiled linens in hot or cold water with detergent and, if possible, chlorine bleach. Use normal washing and drying cycles. Handle the soiled linens as little as possible. Wash your hands after handling soiled linens.
Whenever blood, suctioned fluids, or other liquid waste is handled, wear gloves. Pour liquids down a drain that is connected to a sanitary sewer. Be careful not to spill or splash any liquid.
Management of Exposures
An occupational exposure that may place a worker at risk of HIV or HBV infection is defined as follows:
Contact with blood, tissues, or other body fluids to which universal precautions apply, including laboratory specimens that contain HIV or HBV with: -
An injury to the skin (e.g., a needlestick or cut with a sharp object).
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Mucous membranes, or
- Skin (especially when the exposed skin is chapped, abraded, or afflicted with dermatitis, or the contact is prolonged or involves an extensive area).
After an occupational exposure, the source patient should be informed of the incident and tested for serologic evidence of HIV infection and hepatitis B surface antigen after consent is obtained.
See also:
Periodontal Disease & Diabetes
What is Plaque?
Source: Your Health Encyclopedia, 4-rd Edition, 2002
Last Revised at December 4, 2007 by Harutyun Medina, M.D.
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