12. Meds
Certain over the counter medicines can indirectly harm teeth. Some, like cough syrups or drops, are high in sugar; others, like antihistamines, inhibit the production of saliva, which can lead to tooth decay.

13. Breaking Bad
The use of crystal methamphetamine, a highly addictive illegal drug, causes users to clench and grind, dries out the mouth and also leads to craving sweets, all of which are enough to destroy a set of teeth.