may be due to-
Poor oral hygiene
Increased mucous secretion of saliva resulting in calculus,ie,calcific deposits around the teeth.
I suggest you to get a thorough scaling and root planning done.
Use soft bristled toothbrush and fluoridated toothpaste to clean your teeth.
Tongue scrapers can be used to floss your tongue.Chlorhexidine
mouthrinse can be used to gargle.
Consistency of saliva has to be checked.
If necessary,anti-sialogogues can be administered.
Hope this helps.