Do dentists sterilize those suction hoses in their offices?

Yes: All equipment in the dental office is either disposable or sterilized. The suction tips (that go directly in the mouth) are disposable. The internal portion of the hose is cleaned with a solution that is "sucked" through. The outer portion is sterilized with the same room sterilant as the other equipment.

No, but...: The plastic tips used in saliva ejectors and high-volume evacuators are single-use disposable items, and sterilization is not required to prevent cross-infection. It is customary to clean the flexible tubes that connect to the disposable tips with a high-level surface disinfectant and use disposable polyethylene barrier sleeves on their working ends. This is sufficient to prevent infection.

Yes: Disposable suction tips, the part that goes in your mouth. Surface disinfectant through the hose. Surface disinfectant to wipe the outside of the hose. All in all much cleaner than the drain in your bathroom sink.

Yes: The 'hoses' are cleaned by sterilizing solutions which are run through the lines. The suction tips are all disposable.

Plastic disposibles: The tips that enter patients mouths are usually disposable plastics that are used for one patient only. Some offices will use metal parts that are sterilized. The suction hoses are cleaned with cleaning solution regularly, but are not and cannot be sterilized from the inside out. The outside are usually wiped with prescription strength medicines that kill 99.9% of germs after each patient.