You could see another dentist. It sounds like you might have some decay under the crown and this needs to be addressed.
I had a gross odor when flossing around my crown & it seemed loose as well. This turned out to be an abscessed tooth. The pain is unbearable, I am currently on antibiotics & pain med. having the tooth extracted next week & an implant put in 3000.00 later. Ugh what a headache. If their is a smell that means decay under the crown or something else brewing. Crowns should always feel tight & not smell when flossing between.
Nightmare to say the least until now.read carefully and respond back.first buy peroxide and dental floss get a small plastic cup pour peroxide inside the cup and let it soak for a few minutes.place the dental floss between your
teeth for a few seconds repeat three times a day.remember
to brush your tongue twice a day as well as floss between