Infection Control Manual

Section IX: Disinfection of Impression Materials and Dental Laboratory Procedures

1. REQUIRED CLINICAL PROCEDURES

   IMPRESSIONS, BITE REGISTRATIONS, APPLIANCES, PROSTHETIC DEVICES AND CASTINGS: After removing any attached cotton materials from the item, rinse with running water to remove saliva, blood, and debris. Disinfect item prior to leaving the operatory, pouring in die stone, or sending to the dental laboratory by soaking as follows:

   1. Most impression materials and dental items may be soaked as described later in this section. Do not soak polyether elastomeric impressions or reversible and irreversible hydrocolloid impressions.

   2. Soaking: Rinse item well under running water and then soak item with 1:10 Clorox, ProPhene Plus ,or other suitable disinfectant. Leave for 10 minutes. Rinse thoroughly under running water, shake gently to remove water. The item may be rinsed and considered disinfected.

   3. BAGGING: Place disinfected impression or other dental item in a biohazard-labeled plastic zip-lock or heat-sealed (leak-proof) plastic bag before leaving the operatory. Avoid contaminating the outside of the bag. Wipe the bag with disinfectant if contaminated. For impressions, label the bag as to whether it is merely disinfected (DIS), or has been disinfected and rinsed (OK to pour). (Note that improper rinsing of the disinfectant inhibits the set of the dental stone.)

   4. SUBMISSION GUIDELINES: Remove gloves and wash hands prior to carrying or submitting materials to the dental laboratory.

   5. RE-ADMISSION GUIDELINES: All prosthetic items to be returned to the patient's mouth from the laboratory are considered clean. Items may be rinsed in a small amount of mouth wash to improve their taste.

   6. INTERIM-USE GUIDELINES: See Section VII. All re-usable instruments in high-risk use, such as burs, Tofflemire or other matrix bands and retainers, scissors, hemostats, etc., contaminated during patient treatment, must be sterilized.

      1. The previously-described disinfectant techniques must be used for such items which either cannot be sterilized or are in a low-risk usage category, such as shade guides, laboratory pliers, laboratory knives, etc.. If these 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 shall be disinfected prior to being returned to storage.
      3. Contaminated dentures, castings, appliances, 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.

2. LABORATORY CONSIDERATIONS:

   1. Laboratory personnel are required to wear a clean uniform or laboratory jacket/coat. Personnel receiving cases must also wear disposable treatment gloves. A disposable mask and protective eyewear are also required when there is the potential for exposure to dust or spatter. Wash hands after removing gloves and whenever changing gloves.

   2. Prior to arrival at the dental laboratory, all incoming cases must be properly disinfected and labeled. If there is a question about contamination, the case may be disinfected by soaking.

      1. SOAK: 10 minute soak in 1:10 dilution of Clorox, ProPhene Plus or other acceptable disinfectant. Polyether materials should not be soaked, but rather sprayed, rinsed, sprayed, and rinsed again after 3 minutes as previously described.
      2. Case containers must also be disinfected, and packing materials discarded to avoid cross-contamination.

      3. Soak gypsum casts and articulators with disinfectant when contaminated.

   3. All out-going cases must be properly cleaned and placed in a zip-lock bag or appropriate container prior to leaving the laboratory.

   4. Contaminated countertops and work surfaces must be cleaned of debris and disinfected daily. After cleaning, wipe surfaces with disinfectant, wipe dry with paper towels, and re-wipe with disinfectant. Leave surfaces wet.

   5. Contaminated ragwheels must be washed thoroughly and sterilized or disinfected in Clorox 1:20 for 20 minutes daily. Use Clorox (1:10) to wet the pumice daily. Caution should be used to avoid spatter on clothes.

   6. Contaminated provisional and permanent appliances or prostheses which require ultrasonic cleaning and/or ragwheel polishing must be immersed in Clorox (1:20) for 10 minutes preceding cleaning/polishing.

   7. Solid waste materials that are contaminated with blood or saliva must be placed in heavy-duty trash bags and sealed for disposal.

Last modified: