Adams School of Dentistry: Infection Control Manual - Chapter 11: Instrument Preparation, Sterilization, & Storage

Transporting & Instrument Inspection

ASOD has multiple clinical areas, with some solely relying on the Central Sterilization Unit (CSU) to provide sterilization services, some completing sterilization within the appropriate clinic, or a combination of both. Regardless of the above, each clinical area should minimize handling of loose contaminated instruments during transport to the instrument processing area. Use work-practice controls (e.g., carry instruments in a covered container) to minimize potential exposure (US Centers of Disease Control and Prevention (CDC), 2016).

Once transported to the appropriate area, clinical areas should remove sharps and gross debris from instruments and cassettes, then prewash to further debride. Instruments intended for processing by the CSU are then dried, packaged, or transferred to an enclosed container and placed on a cart for transport via the service elevators. CSU operating hours are 7:30 am - 6:30 pm, Monday through Friday.

Processing of Instruments

Regardless if instruments are to be processed by the CSU or an individual clinical area, the following guidelines should be followed. Modification these guidelines is permissible, provided that the modification is completed in a safe and ethical manner.

1. All soiled instruments received by the CSU must be received through the decontamination area of sterilization for inspecting, disinfecting, processing, sterilization, storing, and distribution.
2. Review video instructions on CSU specific inspection and cleaning procedures.
3. Sort instruments and if excess water is present, dispose of it before packaging.
4. Utilize an ultrasonic cleaner or instrument processor to completely debride instrument
5. Rinse and dry instruments
6. Complete final inspection of instruments to ensure instruments are not missing, no debris remains, and any other instrument specific requirements.
7. Package instruments in either a paper pouch with an integrated Class 1 BI or insert one, when wrapping instruments or a paper pouch does not contain one. Review video instructions on how to wrap an exam cassettes.
8. Follow manufacturer guidelines for all sterilization procedures including, but not limited to, loading, settings, and unloading.
9. Date stamp all instruments removed from autoclave with date sterilization was completed

Processing of Handpieces

Handpieces, including slow-speed, high-speed, and polishing, all require specific maintenance and to be sterilized, due to their classification as semi-critical devices. Appropriate maintenance requires specific equipment that may not be available in all clinical areas. If the appropriate equipment is not available, handpieces must be provided to the CSU, while clinical areas with the appropriate equipment should follow the guidelines below:

1. Repairs and maintenance of handpieces is the collective responsibility of all clinical areas, with the CSU, Dental Faculty Practice, and Graduate Clinical areas sharing equally amongst each other.
2. Handpieces may be delivered to the CSU loosely or already packaged. If the handpiece is loose, the CSU will perform the appropriate maintenance process.

• NOTE: Handpieces that are not functioning properly and are provided to the CSU should be marked with a note on sterile tap that describe the issue. CSU will attempt to inspect and repair if possible.

3. Follow manufacturer’s instructions for use on cleaning and disinfection
4. Manually wipe the external surfaces of the handpiece with intermediate-level disinfectant.
5. Clean and lubricate internally with an automatic lubricating machine and oil, insert a bur, and run machine. Alternatively, if an automatic lubricating machine is not available, manual add oil to handpiece, insert a bur, attach to the appropriate operatory hose, and run with air only for 20 seconds.
6. Wipe any excess oil off of handpiece, package, and sterilize according to manufacturer’s instructions.
7. Handpieces provided to the CSU will be returned to the appropriate clinical areas.

Identification of Instrument Level

Different types of equipment are organized into three (3) main categories, per the CDC:

1. Non-Critical;
2. Semi-Critical; and
3. Critical.

Non-Critical Instruments

• Contact intact skin only
• Barriers protect or clean and disinfect using a low to intermediate-level (i.e., tuberculocidal) disinfectant
• EXAMPLES: X-ray head or cone and blood pressure cuff

Semi-Critical Instruments

• Contact mucous membranes or non-intact skin
• Lower risk of transmission
• Should be heat sterilized or high-level disinfected
• EXAMPLES: Slow-speed/high-speed handpieces, mouth mirrors, and amalgam condensers

Critical Instruments

• Penetrate soft tissue or contact bone, enter into or contact the vascular system or other normally sterilize tissue
• Greatest risk of transmitting infection
• Must be heat sterilized between use, or sterile single-use, disposable devices used
• EXAMPLES: Surgical instruments and periodontal scalers

Sterilization & Disinfection Methodologies

Sterilization is at the center of preventing cross-contamination as sterilization is a process that kills all forms of life and assists in breaking the Chain of Infection. Review this video to learn more about concepts related to the Chain of Infection. Within ASOD, sterilization is completed through the use of either a steam autoclave or vaporized hydrogen peroxide for low heat items. Sterilization of instruments is most commonly completed in ASOD via the Central Sterilization Unit, with the possibility of sterilization completed in other clinic areas. In order for any sterilization process to be effective in kills all the microorganisms, the instruments must be clean, which is why a combination of a Ultraviolet C (UVC) sanitizer, washer-disinfector, ultrasonic cleaner, and manual scrubbing techniques are utilized.

1. UVC sanitizer
   1. Individuals utilizing this equipment should ensure that:
      1. UVC sanitizer is run for the pre-set amount of time, according to the manufacturer’s guidelines.
      2. Items placed in this device are not considered critical items and are placed correctly in the UVC sanitizer (no overloading, single layer, placed away from edges, and adequate space between items).
      3. Hand hygiene is applied before retrieving items.

2. Washer-disinfector
   1. Authorized individuals utilizing a washer-disinfector should ensure that:
      1. Proper solutions are used in the washer-disinfector equipment. Improper solutions may damage the equipment and/or dental instruments.
      2. Washer-disinfector is run for the recommended period of time and according to manufacturer’s instructions.
      3. Instruments and/or cassettes are placed correctly in washer-disinfector (not too near the bottom or sides) so that the equipment can function properly.
      4. Instruments are rinsed and dried thoroughly when the washer-disinfector cycle is complete.

3. Ultrasonic cleaner
   1. Authorized individuals utilizing a washer-disinfector should ensure that:
      1. Proper solution is used in the ultrasonic cleaner. Improper solutions will damage the cleaner and are not as effective as the ones that have a detergent action.
      2. Ultrasonic cleaner is run for the recommended period of time and remains covered while in operation.
      3. Baskets are used to prevent sharps injuries.
      4. Solution is changed when recommended or if it becomes too dirty.
      5. Instruments and/or cassettes are placed in the cleaner correctly (no overloading) so that the cleaner will function properly.
      6. Instruments are rinsed thoroughly after the ultrasonic cycle is completed.
      7. Instruments are dried thoroughly, either with air-drying or clean paper.

4. Manual scrubbing
   1. Manual scrubbing should be limited to only when absolutely necessary, to reduce chances of a sharps injury. If used, the operator will:
      1. Wear full Personal Protective Equipment and utility gloves.
      2. Use a detergent that allows the instruments to be seen clearly.
      3. Cover instruments with sufficient water so that both the instrument and brush are beneath the surface of the water, in order to reduce splashing or splattering. Only hold and scrub one instrument at a time, in the sink.
      4. Rinse and dry instruments thoroughly.

Instrument Shelf Life

Sterile life of paper packaged instruments is ONE (1) YEAR from the last date of sterilization, as long as the package remains intact and has not been exposed to contamination. Instruments double wrapped in sterilization cloth are stored in a cool, dry, dark space are viable up to six (6) years from the last date of sterilization. More information is available through guidelines set by the CDC.

Storage & Usage

All instruments for intraoral use will not be stored unwrapped. Evidence of sterilization must be present on both paper and wrapped instruments; if none is present, an indicator must be inserted inside the package. If any instruments indicated for clinical use are found either unwrapped or with punctured/broken/torn packaging, the instrument(s) must be re-wrapped and re-sterilized. Only exceptions are for instruments and materials intended for non-patient care, in a simulated environment. First-in-First-out inventory control is utilized, which rotates the usage of instruments according to the stamped sterilization dates.

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