Bloody Impressions

Based on OSHA, DOT and CDC guidelines, it is Safelink’s recommendation that dental practices and dental laboratories work together to protect each other and ultimately the patient from contamination by items that are processed between the office and the laboratory. These items include impressions, prostheses and extracted teeth. Safelink’s recommendations are based on the following information. 

DOT informed us of the need to comply with ß173.196 Infectious substances (etiologic agents) which states:

“(a) Authorized packagings and components are as follows:
(1) Inner packagings comprising:
(i) A watertight primary receptacle;

(ii) A watertight secondary packaging; and

(iii) An absorbent material must be placed between the primary receptacle and the secondary packaging.”

“(e)(2) Liquid or solid substances. (i) Substances shipped at ambient temperatures or higher.  Primary receptacles include those of glass, metal or plastic. Positive means of ensuring a leakproof seal, such as heat seal -must be provided.”

Two concerns here are impressions and extracted teeth. Because impressions can contain blood and, if broken during shipment, could be handled by someone not knowledgeable of the potentially infectious item, we interpret that an impression, even if disinfected in the dental office, falls under this requirement. Receipt of grossly contaminated impressions with retraction cords and cotton rolls are not an uncommon occurrence in dental laboratories.

Extracted teeth shipped to dental laboratories must be packaged properly (see information below relating to the CDC guidelines). Therefore, the container used for shipping or transport must have a leakproof seal and meet the DOT requirements stated above. We consider the impression itself the primary receptacle and the bag it is shipped in the secondary packaging.

Under OSHA’s Bloodborne Pathogen Standard  29 CFR 1910.1030 Subpart Z, (d) Methods of Compliance states under paragraph (d)(2)(xiii): “specimens of blood or other potentially infectious materials shall be placed in a container which prevents leakage during collection, handling, processing, storage, transport or shipping.

(d)(2)(xiii)(A) the container for storage, transport, or shipping shall be labeled or color-coded according to paragraph (g)(1)(i) and closed prior to being stored, transported or shipped -Labeling or color-coding in accordance with paragraph (g)(1)(i) is required when such specimens/containers leave the facility.”

Here again, as with the DOT requirements, we consider dental impressions and extracted teeth as potentially infectious and therefore need to be packaged properly to meet OSHA requirements. The Guidelines for Infection Control in Dental Health-Care Settings published by the Centers for Disease Control and Prevention (CDC) in 2003 addresses the proper handling and packaging of extracted teeth. They state that “extracted teeth sent to a dental laboratory for shade or size comparisons should be cleaned, surface-disinfected with an EPA-registered hospital disinfectant with intermediate-level activity (i.e., tuberculocidal claim) and transported in a manner consistent with OSHA regulations.”

The guidelines further state that, “when a laboratory case is sent off-site, DHCP should provide written information regarding the methods (e.g., type of disinfectant and exposure time) used to clean and disinfect the material (e.g., impression, stone model, or appliance). Clinical materials that are not decontaminated are subject to OSHA and U.S. Department of Transportation regulations regarding transportation and shipping of infectious materials.”

CDC further recommends that, “the best time to clean and disinfect impressions, prostheses or appliances is as soon as possible after removal from the patient’s mouth before drying of blood or other bioburden can occur.” Dental laboratories frequently receive items containing visible blood and bioburden. Dental staff can prevent this from occurring by following these CDC recommendations for cleaning.

The guidelines go on to address final disinfection of appliances and prostheses delivered to the patient. It states that, “communication between the laboratory and the dental practice is also key at this stage to determine which one is responsible for the final disinfection process. If the dental laboratory staff provides the disinfection, an EPA-registered hospital disinfectant (low to intermediate) should be used, written documentation of the disinfection method provided and the item placed in a tamper-evident container before returning it to the dental office. If such documentation is not provided, the dental office is responsible for final disinfection procedures.”

Coordination and communication between the dental office and dental lab can prevent cross-contamination for the safety of dental staff, technicians and patients.