Does Having Crowns Cause Bad Breath?

Crowns can cause halitosis (bad breath) when there is an underlying health issue with the tooth in question or an ill fitting crown. Often times bad breath emanating from a crown can be sensed by the patient as the malodor permeates into the nasal cavity, in worse cases, the bad breath projects to others around you. This type of bad odor coming from a crown usually results from decay that may be occurring on the tooth underneath the crown or from infected gums around the crown. Crowns can also act as food traps if they do not fit well, trapped food subsequently rots and gives off a bad smell. If you suspect a bad smell coming from a crown, it's time to see your doctor and get it examined very carefully before the infection progresses and gets worse. 

Crowns, in and of themselves, do not cause bad breath but bacteria does.  If one is experiencing bad breath after crown placement, it can possibly due to poor oral hygiene.  Make sure your crowns are properly cleaned at the gumline.  If the crown margins are not closed and finished properly, food and bacteria might collect causing a bad odor as toxins are released from the bacteria and decay.  It is recommended that you have your teeth cleaned professionally at least 2 times per year.  

Bad breath is not due to dental crowns but it is due to poor oral hygiene. The dental crowns require additional care and thorough brushing and flossing as there may be some food lodgement around them or under the pontics that may cause bad breath. So, Crowns or not, regular brushing, flossing and mouthwash will keep the bad breath away.