Adams School of Dentistry: Infection Control Manual - Chapter 12: Equipment, Impressions, & Laboratory Considerations

Digital Impression Scanner - Disinfection & Use

Digital impressions, also referred to as 3-D intraoral scanning, utilizes a wand-like device that is connected to a computer and with advanced software, a virtual model of the hard and soft tissues is replicated. Follow manufacturer guidelines on use, disinfection, setup, and storage requirements to ensure appropriate aseptic techniques are followed. Specific setup for this device depends upon clinical area and ability to ensure appropriate aseptic practices. Summary of the most commonly adhered to steps are found below:

1. Tips for the impression scanner are re-usable and must be sterilized between each patient.
2. Tips are generally stored within each clinical dispensary area.
3. Disinfect the wand, cord, and keyboard with a intermediate-level disinfectant utilizing the wipe/discard/wipe technique. Do not use disinfectant on the lens.
4. Avoid the lens portion of the scanner as this is to be cleaned with a lint-free glass wipe.
5. Open packaging and place sterilized tip on digital impression wand.
6. When finished with digital impression scanner, remove tip for sterilization and repeat disinfection process of wand and cord, with care taken in cleaning lens.

Intraoral Camera - Disinfection & Use

Intraoral cameras are cameras designed specifically to take pictures of a patient’s mouth, with captured images ranging from a patient’s full face to a single surface lesion and beyond. Follow manufacturer guidelines on use, disinfection, setup, and storage requirements to ensure appropriate aseptic techniques are followed. Specific setup for this device depends upon clinical area and ability to ensure appropriate aseptic practices. Summary of the most commonly adhered to steps are found below:

1. Disinfect the handle and cord of the intraoral camera with an intermediate-level disinfectant utilizing the wipe/discard/wipe technique. Do not use disinfectant on the lens.
2. Avoid the lens portion of the scanner as this is to be cleaned with a lint-free glass wipe.
3. Place new plastic barrier on intraoral camera between each patient. Do not use if plastic barrier is not available as unit cannot be appropriately disinfected with the use of an additional barrier.
4. When finished with intraoral camera, remove plastic barrier, squeeze out excess disinfectant, and repeat the disinfection process of the intraoral camera handle and cord.

Impression Materials & Dental Appliances Disinfection

Dental impressions and appliances are a common source for transmission of infection between dental clinics and dental labs due to cross-contamination. Ensuring that appropriate disinfection of impression materials and dental appliances is required so that the chain of infection may be broken. Follow manufacturer instructions on appropriate disinfection procedures, if available, and adhere to the guidelines below. Modifications to this process is acceptable to fit each situation and clinic, provided that any modification is completed in a way that maintains aseptic technique, does not endanger any individual, and the quality of the produced impression or appliance is maintained.

1. Complete the following guidelines before leaving the operatory, pouring in die stone, or sending to a dental laboratory.
2. Generally speaking, most impression materials and dental items may be either sprayed or soaked, as described below. If unsure, consult with a colleague or faculty member for immediate guidance and contact Director of Clinical Compliance to provide guidance for future cases.
3. Do not soak polyether elastomeric or reversible/irreversible hydrocolloid impressions.
4. Disinfection Procedure:
   1. After removing any attached cotton materials from the item, rinse thoroughly under running water to remove saliva, blood, debris, and other other potentially infectious materials (OPIM).
   2. Spray item with intermediate level disinfectant, ensuring that all surfaces are exposed to the disinfectant, and remains wet for a minimum of three (3) minutes or level of time per manufacturer’s guidelines.
   3. Rinse item thoroughly under water to remove excess disinfectant; item may be considered disinfected at this point.
   4. NOTE: Improper rinsing inhibits the set of dental stone and may negatively impact the result of the casting, for impressions.
5. Bagging / Packaging Procedure:
   1. Place disinfected item in a biohazard-labeled, plastic zip-lock or health sealed (leak-proof) bag, before leaving the operatory.
   2. Avoid contaminating the outside of the bag, which may require assistance from another clinical individual. If outside of bag becomes contaminated, disinfect the outside of the bag using the wipe/discard/wipe methodology.
   3. For impressions, label the bag as to whether it is merely disinfected (DIS) or it has been disinfected AND rinsed (OK to pour).
6. Submission Guidelines:
   1. Remove gloves and wash hands.
   2. Verify that the bag containing the item is appropriately marked.
   3. Received items that have not been properly disinfected and/or marked will not be accepted for submission and provider may be subject to disciplinary action.
   4. Individual receiving submitted items has the authority to determine what is considered “acceptable” as a single standard does not fit all situations. However, any individual denying the receipt of a submitted item may be required to provide some proof of their decision.
7. Re-Admission Guidelines:
   1. All prosthetic items to be returned to the patient’s mouth from the laboratory are considered clean.
   2. Items may be rinsed in a small amount of mouth wash to improve their taste, if the patient would like.
8. Interim-Use Guidelines:
   1. Items that cannot be sterilized or are in the “Non-Critical” category, such as shade guides, laboratory pliers, laboratory knives, and so forth, also must be disinfected per the above-mentioned guidelines. If these items are handled by gloved hands in the operatory, they must be disinfected prior to being returned to storage.
   2. Other items, such as amalgamators, activators, curing lights, brushes, and polycarbonate crowns should be disinfected prior to being returned to storage
   3. Contaminated dentures, castings, appliance, or other prosthetic devices being taken by the provider to a remote site for further adjustment must be disinfected prior to leaving the operatory.
   4. Articulators, facebows, and other re-usable items handled by soiled gloved hands, but not stored in the operatory, must be disinfected prior to removal.

On-Site Laboratory Considerations

While working within an on-site laboratory, laboratory personnel are required to adhere to the following:

1. Wear a clean laboratory jacket, coat, gown, and/or uniform.
2. When receiving items, laboratory personnel are expected to wear disposable treatment gloves and monitor actions to reduce chances of cross-contamination.
3. While working on received items, laboratory personnel are expected to wear a disposable mask, protective eyewear, and gown (if a laboratory jacket or coat is not being worn). Each are necessary to protect laboratory personnel from potential exposure to dust, spatter, and OPIM.
4. Perform appropriate hand hygiene after removing gloves, whenever changing gloves, and any time the integrity of gloves has been compromised.

Incoming Laboratory Considerations

Incoming and received items should be appropriately disinfected and labeled. However, if a received item is suspected to be contaminated, the item may be disinfected utilizing the same disinfection procedure discussed earlier. Summary of the procedure is as follows:

1. Rinse the item well and utilizing an intermediate level disinfectant, spray the item so it remains wet for three (3) minutes or for the amount of time indicated by the manufacturer, and rinse well again.
2. Item containers must also be disinfected and packing materials discarded to avoid cross-contamination.
3. Spray gypsum casts and articulators with an intermediate level disinfectant when suspected of contamination.

Outgoing Laboratory Considerations

Outgoing items and laboratory areas should also be appropriately disinfected utilizing the following guidelines:

1. Outgoing items must be properly cleaned and placed in a zip-lock bag or appropriate container prior to leaving the laboratory.
2. Contaminated surfaces must be cleaned of debris and disinfected daily. After cleaning, spray surfaces with disinfectant, wipe dry, and spray again with disinfectant so surfaces remain wet; do not dry second time.
3. Contaminated ragwheels must be washed thoroughly and sterilized daily.
4. Contaminated provisional and permanent appliances, or prosthesis which require ultrasonic cleaning, are to be placed in a sealed plastic bag prior to the cleaning procedure. For these same type of items that require polishing via ragwheel, each item must be disinfected as outlined in the prior section before polishing.
5. Solid waste materials that are contaminated with visible blood, saliva, or OPIM must be placed in a heavy-duty biohazardous trash bags and sealed for disposal.

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