Persistent bad breath
or a bad taste in the mouth may be a warning sign of gum (periodontal) disease. Gum disease is caused by the buildup of plaque on teeth.
Dry mouth also can cause bad breath.
Smoking or chewing tobacco-based products also can cause bad breath, You may need deep cleaning & fill tooth cavities
with artificial enamel filling. Rinse your mouth thoroughly with a mouth wash until then. Advance procedures can be done with laser
too. You may consult me in person.