Infection Control and Sterilization

Key Points

  • Since 1993, the ADA and the Centers for Disease Control and Prevention (CDC) have updated and supplemented their infection control recommendations to reflect new scientific knowledge and growing understanding of the principles of infection control.
  • A 2016 CDC document, “CDC Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care” brings together recommendations from the CDC 2003 guidelines on infection control with tools and checklists to help dental health care personnel follow infection prevention guidelines.
  • The ADA urges all practicing dentists, dental auxiliaries and dental laboratories to employ appropriate infection control procedures as described in the 2003 CDC Guidelines, and 2016 CDC Summary and to keep up to date as scientific information leads to improvements in infection control, risk assessment, and disease management in oral health care.
  • Along with the proper sterilization of instruments and materials, sterilizer monitoring is an essential part of any in-office infection control program.
  • The CDC advises that dentists use only FDA-cleared dental handpieces and sterilize them according to manufacturers' instructions; follow manufacturer instructions for sterilization and processing of all dental instruments and materials.
  • Along with the proper sterilization of instruments and materials, sterilizer monitoring is an essential part of any in-office infection control program.

ADA COVID-19 Safety and Clinical Resources:

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Introduction
In the 1980s, the ADA Foundation’s Health Screening Program helped identify hepatitis B virus as an occupational hazard in dentistry. The ADA responded by being the first entity to recommend that dentists and dental offices follow standard infection control procedures. The ADA subsequently worked with the Centers for Disease Control and Prevention (CDC) to develop CDC’s own infection control recommendations for dentistry, which were originally issued in 1993.1 Since then, the CDC has updated and supplemented their recommendations to reflect new scientific knowledge and growing understanding of the principles of infection control.2, 3

In addition to the standard infection control procedures discussed on this page, the CDC recommends the following nonpharmaceutical interventions (NPIs) to help limit the spread of influenza,4 urging dental staff and patients to always:

  • Stay home when ill.
  • Practice good respiratory etiquette: cough or sneeze into a tissue or a shirt sleeve and immediately wash your hands with soap and water or use an alcohol-based hand sanitizer (at least 60% ethanol or isopropanol) to disinfect them.
  • Routinely clean all frequently touched surfaces, using standard infection control procedures as directed in the CDC 2003 guidelines on infection control2 where appropriate.

During influenza pandemics, CDC recommends more stringent NPIs:4

  • People living with a person who has influenza should stay home for up to three days after their initial contact with the ill person.
  • Persons who are ill should wear a face mask if they must go out of the house.

CDC Infection Control Recommendations for Dentistry
In December 2003, the CDC published a major consolidation and update of its infection control recommendations for dentistry.2 The 2003 document incorporated relevant recommendations that were previously published in several other CDC documents and contained an extensive review of the science related to dental infection control. In March 2016, the CDC issued the new “CDC Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care.”3 Although not intended as a replacement for the 2003 Guidelines document, the new CDC Summary is targeted to “anyone who seeks information about basic infection control in dental settings and includes several new recommendations as well as an assessment checklist.” Although the primary content is essentially unchanged, the new Summary document brings together recommendations from the 2003 CDC guidelines as well as other recommendations published in CDC guidance documents since 2003.

The 2003 CDC Guidelines and 2016 Summary are comprehensive and evidence-based sources for infection control practices relevant to the dental office that have been developed for the protection of dental care workers and their patients. The new resource includes tools to help dental health care personnel follow infection prevention guidelines, including:

  • a summary of basic infection prevention principles and recommendations for dental settings;
  • a checklist to help evaluate dental staff compliance with administrative and clinical practice infection prevention recommendations; and
  • key references and resources for each area of focus including sterilization, safe injection practices and hand hygiene in dental settings.

The new recommendations3 emphasize the importance of having one person in every dental practice assigned to be the infection prevention coordinator. The coordinator would develop written infection prevention policies based on evidence-based guidance outlined in the new resource. The coordinator can help ensure that dental health care personnel are aware of the equipment and supplies necessary to address infection prevention issues with all staff members.

The ADA has long advocated the use of infection control procedures in dental practice and provided dentists with resources to help them understand and implement them. The ADA urges all practicing dentists, dental auxiliaries and dental laboratories to employ appropriate infection control procedures as described in the 2003 CDC Guidelines and 2016 CDC Summary and to keep up to date as scientific information leads to improvements in infection control, risk assessment, and disease management in oral health care.

Infection Control: Instrument and Equipment Sterilization
In April, 2018, the CDC released a Statement on Reprocessing Dental Handpieces stressing that handpieces (both low-speed and high-speed) and other intraoral instruments that can be removed from the air lines and waterlines need to be heat sterilized between patients,5, 6 and that reusable devices made prior to 20156 may not meet current FDA reprocessing guidance.7 The CDC Statement reaffirmed and clarified 2003 CDC recommendations2 and emphasized three key points:6
  1. Clean and heat sterilize handpieces and other intraoral instruments that can be removed from the air lines and waterlines of dental units.
  2. For handpieces that do not attach to air lines and waterlines, use FDA-cleared devices and follow the validated manufacturer’s instructions for reprocessing these devices.
  3. If a dental handpiece cannot be heat sterilized and does not have FDA clearance with validated instructions for reprocessing, do not use that device.

If a dentist is concerned about the validity of the manufacturer’s reprocessing instructions, or believes that the instructions are not consistent with basic infection prevention and control principles, they can contact the manufacturer to request documentation of FDA clearance of the device in question. If the manufacturer is not able to provide sufficient information, dentists can contact FDA’s Office of Compliance for assistance, at OCMedicalDeviceCo@fda.hhs.gov or 1-240-402-7675.

Infection Control: Monitoring Sterilizers

Along with the proper sterilization of instruments and materials, sterilizer monitoring is an essential part of any in-office infection control program.

Many factors can cause sterilization to fail—from procedural errors that are easily remedied, like overloading, to mechanical problems that can take a sterilizer out of service until repairs can be made. Since this variety of factors can influence successful sterilization, the ADA and CDC encourage dentists to regularly assess the efficiency of their in-office sterilizers.2, 8, 9 In addition, state or local regulations may exist regarding frequency and record-keeping issues related to sterilizer monitoring. Check with your state dental board for regulatory information.

Sterilization is best monitored using a combination of mechanical, chemical, and biological indicators.8 The CDC has provided the following recommendations:2, 3, 9

Mechanical Indicators

  • Record cycle time, temperature, and pressure as displayed on the sterilizer gauges for each instrument load.

Chemical Indicators

  • Use chemical indicators, such as indicator tapes, with each instrument load. These indicators change color after exposure to the proper sterilization environment.
  • Failure of the indicator to change color indicates that it was not exposed to the proper sterilization environment (e.g., proper pressure or temperature). In such cases, the instrument load should be re-sterilized.
  • Indicator tapes are sterilizer-specific (i.e., tapes for steam sterilizers cannot be used to test chemical vapor sterilizers).
  • Chemical indicators should not replace biological indicators, as only a biological indicator consisting of bacterial endospores can measure the microbial killing power of the sterilization process.

Biological Indicators

  • The CDC recommends monitoring sterilizers at least weekly with biological indicators.2, 3 Check to see whether your state dental board has different requirements.
  • Biological monitoring can be done in two ways:
    1. In-office incubator and spore monitoring strips (contact your dental supplier for a list of products). This method usually gives results in 24-48 hours.
    2. Mail-in spore monitoring programs. This process usually takes a week. Although it takes longer to get results using a service, third-party monitoring programs may provide more accuracy than in-house monitoring.
  • A positive spore test result indicates that sterilization failed.  According to CDC recommendations:1, 3
    1. Take the sterilizer out of service.
    2. Review the sterilization process being followed in the office to rule out operator error as the cause of failure.
    3. Correct any identified procedural problems, and retest the sterilizer using biological, mechanical, and chemical indicators.
  • If the repeat biological indicator test is negative and the other test results fall within normal limits, the sterilizer can be returned to service.
  • Maintain a log of spore test results. Check with your state dental board to determine how long you need to keep spore testing records.

What to Do When Results Confirm Sterilization Failure

If the biological indicator test is positive, or the mechanical or chemical test results indicate failure, the sterilizer should not be used until the reason for failure has been identified and corrected.

  • If no procedural errors are identified or failures persist after procedural errors are corrected, the sterilizer should not be used until the reason for failure has been identified and corrected.

Before the sterilizer can be returned to service, the biological indicator should return negative results for tests conducted during three consecutive empty-chamber sterilization cycles to ensure that the problem has been corrected.

  • To the extent possible, reprocess all instruments that were sterilized since the last negative spore test.
  • Record the positive test results and all actions taken to help ensure proper functioning of the sterilizer in the monitoring log.
     

ADA Policy on Infection Control
INFECTION CONTROL IN THE PRACTICE OF DENTISTRY

(Trans.2012:470; 2019:XXX)


Resolved, that it be ADA policy to support the implementation of standard precautions and infection control recommendations appropriate to the clinical setting, per the 2003 Guidelines for Infection Control in Dental Health Care Settings and the 2016 Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care from the Centers for Disease Control and Prevention (CDC), and be it further

Resolved, that the ADA urges practicing dentists, dental auxiliaries and dental laboratories to keep up to date as scientific information leads to improvements in infection control,

and be it further

Resolved, that this policy includes implementation of CDC recommendations for vaccination and the prevention and management of exposures involving nonintact skin, mucous membranes and percutaneous injuries.


American Dental Association

Adopted 2012; Amended 2019


References
  1. Centers for Disease Control and Prevention. Recommended infection-control practices for dentistry, 1993. MMWR Recomm Rep 1993;42(RR-8):1-12.
  2. Centers for Disease Control and Prevention Guidelines for Infection Control in Dental Health-Care Settings — 2003 (December 19, 2003 / Vol. 52 / No. RR-17). U.S. Department of Health and Human Services 2003. Accessed September 21, 2018.
  3. Centers for Disease Control and Prevention. Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care. In: Services DoHaH, editor. Atlanta, GA: Centers for Disease Control and Prevention; 2016.
  4. Qualls N, Levitt A, Kanade N, et al. Community Mitigation Guidelines to Prevent Pandemic Influenza - United States, 2017. MMWR Recomm Rep 2017;66(1):1-34.
  5. Centers for Disease Control and Prevention Dental Handpieces and Other Devices Attached to Air and Waterlines.  2018. Accessed September 27, 2018.
  6. Centers for Disease Control and Prevention Statement on Reprocessing Dental Handpieces.  2016. Accessed June 11, 2019.
  7. U.S. Food & Drug Administration. Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling. Guidance for Industry and Food and Drug Administration Staff: U.S. Department of Health and Human Services; 2015.
  8. ADA Professional Product Review Back to Basics: Sterilization Monitoring in the Dental Office. American Dental Association November 15, 2015. Accessed September 12, 2016.
  9. Kohn WG, Harte JA, Malvitz DM, et al. Guidelines for infection control in dental health care settings--2003. J Am Dent Assoc 2004;135(1):33-47.
     

Other Resources
The CDC website has a section on infection control that is designed for dental professionals. Following are relevant links to additional information from the CDC and other agencies and organizations.

CDC Statement on Reprocessing Dental Handpieces


CDC Boil Water Advisory Information

CDC “DentalCheck” mobile application for iOS (to assist dental facilities with monitoring compliance with recommended infection prevention practices)

CDC Vaccination Recommendations:
Organization for Safety, Asepsis and Prevention (www.OSAP.org): The Safest Dental Visit™ Infection Control Educational Program

OSHA: Best Practices for the Safe Use of Glutaraldehyde in Health Care

Postexposure obligations, protocols, resources (for needlesticks and other sharps injuries):
Safe use of needles and other sharps:
Topic Updated: January 5, 2021.

Prepared by:

Department of Scientific Information, Evidence Synthesis & Translation Research, ADA Science & Research Institute, LLC.


Disclaimer

Content on the Oral Health Topics section of ADA.org is for informational purposes only.  Content is neither intended to nor does it establish a standard of care or the official policy or position of the ADA; and is not a substitute for professional judgment, advice, diagnosis, or treatment.  ADA is not responsible for information on external websites linked to this website.