Can lithium carbonate cause a lot of tooth decay?

Yes: The exact process of lithium causing tooth decay is not known. But health professionals have observed an increase of amount of tooth decay in some patients on lithium. The most probable cause is due to the side effect of the medication, poor oral hygiene and bad dietary habits.

It's possible: Lithium itself will not cause tooth decay, but some of its side effects might. One side effect is dry mouth which can cause excessive tooth decay. You need saliva to cleanse the mouth and buffer plaque acids. You must have impeccable oral hygiene, avoid sweets, and see the dentist every 6 months to avoid this type of decay. Also vomiting is a side effect which causes acid in your mouth.

Dry Mouth: Lithium doesn't cause the decay but it leads to severe dry mouth. This leads to increased decay. It can also lead to increased carbohydrate consumption. The behavior patterns which lithium is prescribed for can also contribute to increased decay.