Root canal treatments are needed when a dental cavity progresses to the point where the root of the tooth has also decayed. This is a very severe problem that causes a great deal of pain. Similar to regular cavities, root canals involve the removal of bacteria and decayed tissue, and then filling of the tooth afterwards.
Root canals are a very serious problem. Not only are they more harmful and painful than regular cavities, but they are significantly harder to treat and much more expensive in terms of cost. Because of this, it is always recommended to take good care of your oral hygiene and to get dental cleanings done regularly. Doing so will keep you healthier and it will be much less of a financial burden.