How should impressions for appliances or models sent to labs be labeled?

Impressions for appliances or models sent to laboratories should be labeled with the indication to "treat as infectious materials." This labeling is essential because dental impressions are taken from patients' mouths and could potentially carry pathogens, including bacteria and viruses, that pose infectious risks to laboratory personnel. Therefore, correctly identifying these materials as infectious ensures that proper handling protocols, such as using personal protective equipment and following specific disposal procedures, are adhered to.

This practice aligns with safety regulations and infection control standards within the dental profession, emphasizing the importance of protecting both health care workers and patients from possible cross-contamination. By treating these materials as infectious, labs are prompted to utilize strict hygiene measures during the processing of dental impressions, thus maintaining a safe working environment.

The other options do not adequately convey the potential risks associated with handling such materials, as labeling them as non-contagious or disposable may lead to lax safety practices. Using a caution label without specifying the potential risk of infection also fails to convey the necessary urgency for careful handling.