“How do you get rid of tooth decay?”

Tooth decay starts with plaque accumulation on your tooth surfaces and the acid destruction of the tooth enamel or dentin produced by the bacteria in the plaque. Once damage occurs a restoration (filling) may be necessary to restore the tooth. If you are consistent in brushing AND flossing thoroughly everyday or twice a day and reduce your intake of sugary and sticky plaque-feeding foods, you can avoid a cavity. If you must eat such foods, you just need to work harder in removing plaque. Just remember that the bacteria in the plaque doubles every 20 min. Tooth decay will happen as long as you have a natural tooth to decay and you don't remove the plaque regularly. You cannot stop the plaque from developing even if you stop eating but you can keep removing it before it does significant damage or slow its metabolism by choosing healthier food choices.

If you have existing decay in a tooth, the way to get rid of it is to visit a dentist and have them remove decay and do a filling. If that seems unappealing, you can have the tooth extracted. Once a tooth has decay, it is not reversible.

This question is easy to answer: Contact your dentist to confirm that you have decay and they will discuss your options on how to restore your tooth or teeth after the decay is removed. It would be wise to also discuss ways to prevent future decay with this professional.
Good luck!

Have your dental provider restore (fix) the tooth/teeth.