Engineering and Work-practice Controls

Engineering and work-practice controls shall be implemented to prevent or reduce the risk of exposure to blood and OPIM and to promote safer behavior in the workplace.
  1. Background

    The unique nature of oral healthcare settings, dental procedures, and instrumentation require specific strategies to prevent the transmission of HAIs. Engineering and work-practice controls are intended to eliminate or isolate hazards and promote safer behavior in the workplace. Engineering controls take advantage of available technology to eliminate or isolate biohazards (blood or OPIM). When engineering controls are not available or are not practical, work-practice controls are implemented.

    The direct patient care setting, i.e., the dental treatment room (DTR), is central to the delivery of oral healthcare, but there are other environments within oral healthcare settings that support the delivery of clinical services, i.e., dental radiography and dental laboratory facilities. While the following recommendations primarily relate to non-surgical dental specialty areas, they are sufficiently flexible to serve as a template for developing and implementing practice-specific infection control strategies.

  2. Execution/Compliance
    1. General considerations
      1. Eating, drinking, smoking, applying cosmetics or lip balm, and handling contact lenses are prohibited in work areas where blood or OPIM may be present.
      2. Food and drink are not kept in refrigerators, freezers, or cabinets or on shelves, countertops, or benchtops in work areas where blood or OPIM may be present.
      3. All items used in patient care should be stored in closed cabinets or drawers. Mobile carts used for patient care should not be cluttered with excess materials.
      4. Bulk items should be covered to prevent contamination and caution should be exercised when retrieving such items to ensure that the remaining items are not contaminated.
      5. Begin each day with a routine handwash from fingertips to the wrist.
      6. Use water that meets Environmental Protection Agency (EPA) regulatory standards, i.e., water containing less than 500 colony forming units (CFUs/mL of heterotrophic bacteria, for handwashing and as a coolant/irrigant for nonsurgical procedures.
        1. If using water bottles, fill dental unit water bottle according to manufacturer's recommendations. Add continuous-use dental unit waterline (DUWL) cleaning product if indicated. Note: Follow dental unit and water bottle manufacturer’s instructions for products and protocols for maintenance and monitoring DUWL quality.
    2. DTR infection control
      1. Preparation
        1. Barrier protection: place protective plastic covers on clinical contact surfaces such as headrests, dental unit control switches, air and water line hoses, light handles, chairside light curing unit, and other hard-to-clean areas and equipment.
        2. Have appropriate instrument packs and supplies ready to begin treatment. This includes all necessary PPE (gloves, masks, eye protection, etc.) for the provider, assistant and the patient.
        3. Check all sterilized instrument packs and packages to ensure they are intact and the external chemical indicator has changed to the appropriate color.
          1. Do not open packs in advance of the patient's arrival.
      2. Treatment
        1. Seat the patient.
        2. Provide the patient with safety glasses.
        3. Open sterile instrument trays, pack(s) or cassettes with clean, ungloved hands and without directly touching the contents.
          1. Observe internal indicator strip(s) for color change.
          2. Leave wrapping material underneath as a barrier for the work surface.
        4. Perform hand hygiene, don gloves and other PPE.
          1. Sterile gloves are used for invasive surgical procedures.
        5. Connect hand pieces, air and water syringes, saliva ejector, and high-volume evacuation tips.
        6. Use pre-sterilized burs and files, or manufacturer’s pre-packaged single-use burs.
        7. Use expandable items, such as cotton and gauze products that have been sterilized (within instrument packs or individual packages, such as paper or plastic peel pouches).
        8. Preprocedural and intraprocedural precautions for patient treatment
          1. All procedures are performed in such a manner as to minimize splashing, spraying, spattering, and the generation of droplets (aerosols).
          2. Prior to such dental procedures, patients may rinse with chlorhexidine gluconate-, essential oil-, or povidone iodine-containing mouthwash.
          3. Use rubber dental dam, high volume evacuator (HVE) and other protective barriers, engineering and work practice controls wherever possible.
        9. Use one handed "scoop" technique or a recapping safety device to recap anesthetic needles.
        10. Use the unit dose concept for dispensing restorative and other dental materials.
          1. If additional material is needed during treatment use aseptic technique to retrieve needed items (e.g., sterile cotton forceps or pliers, an over-glove barrier, or remove gloves and perform hand hygiene).
        11. Complete charting and computer entries after removing gloves and performing hand hygiene.
        12. Remove PPE and perform hand hygiene before leaving the treatment area.
        13. Wear appropriate attire outside the DTR, e.g., a clean lab coat when exiting DTR to conduct business elsewhere in the clinic or administrative spaces.
      3. DTR turn-around procedures between patients
        1. Wear heavy-duty utility gloves and other PPE while handling contaminated instruments and cleaning contaminated surfaces.
        2. Place all disposable sharps in designated sharps container in the DTR.
        3. Dispose of all non-sharp, regulated medical waste following local policy.
        4. Place instruments in cassette tray (or properly labeled and approved container) for transport to the central sterilization room (CSR).
        5. Flush water and air lines for 20-30 seconds after each patient from any device connected to the dental water system that enters the patient’s mouth (e.g., hand pieces, ultrasonic scalers, air and water syringes).
        6. Remove dental hand piece(s), including slow speed hand piece motors, and other intraoral instruments that can be removed from air and waterline couplings of dental units.
        7. Follow manufacturer’s instructions for cleaning, lubrication, and sterilization of hand pieces and other intraoral instruments and devices removed from dental units.
        8. Remove and dispose of all disposable barriers.
        9. Clean and disinfect clinical contact surfaces that were not barrier protected with an EPA-registered hospital disinfectant with a tuberculocidal claim (i.e., intermediate-level disinfectant).
        10. Remove gloves and perform hand hygiene.
        11. Don a fresh pair of gloves and transport instrument trays, packs, and cassettes to the receiving side of CSR or another designated holding space.
        12. Return to the DTR without touching any surfaces while enroute to remove PPE and perform hand hygiene.
        13. Prepare the DTR for the next patient.
      4. Securing the DTR at the end of the day
        1. Wear appropriate gloves, face protection, and eye protection while cleaning contaminated surfaces.
        2. Clean and disinfect all contact surfaces, dental unit surfaces, and countertops with an EPA-registered disinfectant.
          1. To facilitate cleaning, treatment rooms should be free of all unnecessary equipment and supplies.
        3. Empty and clean amalgam trap container per dental unit manufacturer’s recommendations.
        4. Flush and clean the HVE system per manufacturer’s recommendations.
        5. Flush and clean each water line and suction hoses, follow manufacturer’s instructions if waterline treatment products are used. Follow manufacturer’s instructions for cleaning and maintenance of dental unit water bottles.
        6. Dispose of regulated waste per local policy.
        7. Clean and disinfect sink area.
        8. Ensure only DTR cleaning materials and no patient care items are stored under the sink.
        9. Inventory consumable unit dose packs, replenish as necessary per local policy. Note: Routinely check for expiration dates on solutions, materials and dispensable items per command policy.
        10. Remove PPE (clean and disinfect reusable PPE) and perform hand hygiene.
    3. Disposition of single use patient-care items
      1. Unregulated waste
        1. Generally, blood and/or saliva-tinted items (e.g., clinic gowns, gloves, and patient bibs) are not considered regulated waste and are placed in the regular trash receptacle.
      2. Regulated waste
        1. Regulated waste is disposed of according to the requirements established by local and state environmental agencies.
        2. Disposable sharps (e.g., needles, local anesthetic cartridges, orthodontic wires, scalpel blades, suture needles, endodontic file, and broken instruments) are removed from cassettes, tray sets, or packs; and are placed in a rigid, puncture-resistant, leak-proof container with a secure lid for storage and transportation.
        3. Other regulated waste (e.g., items that drip when held vertically, release fluid when compressed, have dried on fluid that could flake off in transit) is placed in small biohazard bag and are disposed of into a centralized Regulated Waste Receptacle after each appointment.
        4. Biohazard labels (fluorescent orange or orange red, with lettering or symbols in a contrasting color) are affixed as close as feasible to containers of regulated waste by string, wire, adhesive, or other method to prevent their loss or unintentional removal.
        5. Regulated waste that has been decontaminated is not labeled or color-coded and is placed in the regular trash receptacle.
    4. Disposition of reusable patient-care items
      1. Immediately, or as soon as possible after use, all cassettes, tray sets, or packs containing contaminated instruments and reusable sharps are transported to the central instrument processing area in a manner that minimizes the risk of exposure to persons and the environment.
      2. Receiving, cleaning, and decontamination
        1. Items are first cleaned with a hands-free process using an ultrasonic system with a strainer-type basket.
        2. Wearing heavy-duty gloves, protective eyewear, and protective clothing the instruments are visually inspected for residual debris and damage.
        3. Wearing heavy-duty gloves, protective eyewear, and protective clothing the instruments are visually inspected for residual debris and damage.
        4. Residual blood, OPIM, cement and other visible debris are removed using a long-handled brush.
        5. Damaged instruments are replaced.
      3. Non-critical items, i.e., items that contact only intact skin during their intended use.
        1. Disinfected with an EPA-registered intermediate-level hospital disinfectant with tuberculocidal claim (e.g., products containing chlorine, quaternary ammonium compounds with alcohol, phenolics, or iodophors).
      4. Semi-critical items, i.e., items that touch, but do not penetrate, nonintact skin or mucous membranes; and critical items, i.e., items that penetrate soft tissues and bone during their intended use.
        1. Heat-sensitive items are sterilized with ethylene oxide or an FDA-registered sterilant (e.g., products containing glutaraldehyde, glutaraldehyde with phenol, hydrogen peroxide, or hydrogen peroxide with peracetic acid).
          1. After sterilization, all items are rinsed with sterile water to remove toxic or irritating residues.
          2. Handled using sterile gloves and dried with sterile towels.
          3. Delivered to the point of use in an aseptic manner.
        2. Heat-tolerant items are heat sterilized in an FDA cleared device.
          1. Preparation and packaging
            1. The cleaned and inspected instruments are assembled into cassettes, tray sets, or packs with hinged instruments open and unlocked.
            2. An internal chemical indicator is placed in each cassette, tray set, or pack.
            3. If the internal indicator is not visible from the outside of the wrapped and sealed package, an external chemical indicator is placed on each cassette, trays set, or pack to monitor sterilization process.
        3. Sterilization
          1. The sterilizer is loaded according to manufacturer’s recommendation, in single layers or in racks to increase circulation around the instruments.
          2. The cycle time, temperature, and pressure are set according to the manufacturer’s recommendation.
          3. Upon completion of the sterilization cycle, the packages are allowed to dry and cool before removing them from the sterilizer.
        4. Storage
          1. Sterilized items are stored in a clean, enclosed, and dry environment.
          2. Sterilized packages remain sterile indefinitely, unless an event causes it to become contaminated (e.g., torn or wet packages).
        5. Monitoring of the sterilization process
          1. Mechanical - Confirm cycle time, temperature, and pressure by observing the gauges or displays on the sterilizer for each load.
          2. Chemical - Note color changes of time and temperature sensitive internal and external chemical indicators, which reflect physical conditions during the sterilization process.
          3. Biological - Monitor weekly the sterilization process by an appropriate spore test (according to manufacturer’s time, pressure, and temperature recommendation).
            1. Spore strip or vial is placed inside the cassette, tray set, or pack.
            2. Cassette, tray set, or pack containing the biological indicator is placed in the center of the load (hardest area to penetrate).
            3. A control strip (which is not heat processed) is used as a control with each spore test.
            4. A record is maintained of the weekly spore testing results.
          4. Additional biological monitoring is performed whenever there is a change in the packaging process, following equipment repair, and when training new employees.
          5. Quality assurance procedures following a positive mechanical, chemical, or biological monitoring test.
            1. Secure sterilizer from further use.
            2. Make proper log entries.
            3. Review operating procedures.
            4. Take corrective action (repair or replacement).
            5. Retest sterilizer using biological monitors (CDC recommends to retest 3 times using an empty chamber).
            6. Loads dating back to the last negative biological indicator should be recalled, rewrapped, and resterilized.
    5. Handpieces
      1. All handpieces (i.e., high- and slow-speed motors, nose cones, contra-angles, motor-to-angle adapters and prophylaxis angles), unless disposable, are heat sterilized between patients.
        1. Cleaning, sterilization and maintenance procedures described by the handpiece manufacturer are followed to ensure proper sterilization and maximum longevity for the handpiece. For most handpieces, the following generic protocol is appropriate:
          1. Before removing handpiece from hose the lines are flushed for 20-30 seconds.
          2. Handpiece (with the bur removed) is scrubbed thoroughly under running water, rinsed thoroughly, and dried.
          3. Handpiece requiring pre-sterilization lubrication is lubricated.
          4. After lubrication, the handpiece is reattached to hose (with bur or blank reinserted) and the rheostat is activated to remove excess lubricant. – CRITICAL
          5. Fiberoptics are cleaned with a cotton swab, dampened with isopropyl alcohol to remove excess lubricant.
          6. Handpieces are packaged and sterilized in a steam autoclave.
    6. Saliva ejectors
      1. Prevent backflow in low-volume suction lines.
        1. Position the section of the suction tubing holding the tip above the patient’s mouth.
        2. Instruct patient not to create a seal around the suction tip.
        3. Avoid the simultaneous use of other evacuation devices, i.e., high-volume suction.
    7. Dental radiography
      1. Preparing the operatory.
        1. Cover clinical contact areas with a protective barrier before seating the patient.
      2. Exposing and processing films.
        1. Hand hygiene and PPE before initiating the process.
        2. Use disposable or heat-sterilized film-holding and positioning devices.
        3. Use FDA-cleared film barrier pouches.
          1. After exposure, remove the film packet from pouch and place in a clean container.
            1. Transport/handle exposed radiographs in an aseptic manner to prevent contamination of developing equipment.
      3. Digital radiography sensors and other high-technology instruments are cleaned and heat-sterilized or high-level-disinfected according to manufacturer’s recommendation.
      4. Panoramic radiography.
        1. Place disposable plastic cover over bite guide before the patient is positioned in the machine.
          1. If no barrier is used, use a sterile bite guard.
    8. Oral surgical procedures
      1. Perform surgical hand asepsis.
      2. Use appropriate PPE.
        1. When using laser or electrosurgical units, the thermal destruction of tissue creates laser plumes or surgical smoke, which may contain aerosolized infectious material.
      3. Use only sterile saline or sterile water as a coolant/irrigant.
        1. Use specifically designed irrigating devices (e.g., bulb syringe, single-use disposable products, or sterilizable tubing).
    9. Biopsy specimens
      1. Specimens are placed in leak-proof, puncture-resistant container with a secure lid for storage and transportation.
      2. If the outside of the container becomes visibly contaminated, it is cleaned and disinfected or placed in an impervious bag.
      3. The container is labeled with the biohazard symbol.
    10. Extracted teeth
      1. Potentially infectious and are disposed as regulated waste.
      2. Teeth sent to the laboratory for shade and size comparisons.
        1. Cleaned and disinfected with an EPA-registered, intermediate-level hospital disinfectant with tuberculocidal claim (e.g., products containing chlorine, quaternary ammonium compounds with alcohol, phenolics, or iodophors).
      3. Teeth containing dental amalgam are disposed of according to local and state regulations.
      4. Extracted teeth can be disinfected and returned to patients, upon request.
      5. Extracted teeth in an educational setting.
        1. The teeth are cleaned of visible blood and gross debris and maintained in a hydrated state (e.g., water or saline) in a well-constructed closed container.
        2. Before clinical exercises or study, the teeth are heat-sterilized (autoclave cycle for 40 minutes).
          1. Teeth with amalgam restorations are disinfected by immersion in 10% formalin solution for 2 weeks.
            1. Review MSDS for occupational safety and health concerns.
    11. Laboratory asepsis
      1. Environmental surfaces are barrier-protected or cleaned and disinfected.
      2. Use PPE when handling items received in the laboratory until they have been decontaminated.
        1. Impressions, prostheses, and other devices.
          1. Rinse under running tap water to remove blood and OPIM.
          2. Disinfect with an EPA-registered intermediate-level hospital disinfectant with tuberculocidal claim (e.g., products containing chlorine, quaternary ammonium compounds with alcohol, phenolics, or iodophors).
          3. Thoroughly rinse under running water before handling.
        2. Laboratory case is sent off-site.
          1. Written information is provided regarding the method used to clean and disinfect the material (i.e., type of disinfectant used and exposure time).
        3. Burs, polishing points, rag wheels, or laboratory knives.
          1. Heat-sterilized, disinfected, or discarded between cases following manufacturer’s recommendations.
        4. Metal impression trays and face bow forks are:
          1. Heat sterilized between patients.
        5. Articulators, case pans, lathes, pressure pots, and water baths
          1. Cleaned and disinfected between patients according to manufacturer’s recommendation.
        6. Unless waste generated in the laboratory falls under the category of regulated waste, it is discarded with general waste.
    12. Dental records
      1. Charts are notated and radiographs viewed before gloving or after the gloves are removed and the hands are washed, unless cover gloves are worn.