An appropriately reestablished tooth following root canal therapy yields long-term achievement rates near 97%. In a large-scale investigation of over 1.6 million patients who had root canal therapy, 97% had retained their teeth 8 years following the procedure, with most untoward events, for example, re-treatment, apical medical procedure or extraction, occurring during the initial 3 years after the initial endodontic treatment. The US Dental Association asserts that any risks can be adequately controlled. An appropriately performed root canal treatment successfully expels the infected part of the pulp from the tooth.
An infected tooth may endanger other parts of the body. People with special vulnerabilities, for example, an ongoing prosthetic joint replacement, an unrepaired congenital heart imperfection, or immunocompromisation, may need to take antibiotics to shield from infection spreading during dental procedures. The book's author, George Meinig, has been a strong advocate against endodontic therapy for years; he has since lost his dental permit for gross carelessness and Root Canal Conceal Uncovered has gone under great criticism. In the early 1900s, several researchers theorized that bacteria from teeth which had necrotic pulps or which had gotten endodontic treatment could cause chronic or local infection in areas distant from the tooth through the transfer of bacteria through the bloodstream.
Bacteremia (bacteria in the bloodstream) can be caused by many everyday activities, for example brushing teeth, however may also happen after any dental procedure which involves bleeding. It is particularly likely after dental extractions because of the development of the tooth and force expected to dislodge it, yet endodontically treated teeth alone don't cause bacteremia or foundational disease. This was called the "focal infection theory", and it drove a few dentists to advocate dental extraction. In the 1930s, this theory was discredited, however the theory was as of late resuscitated by a book entitled Root Canal Conceal Uncovered which used the early discredited research, and further complicated by epidemiological examinations which discovered correlations between periodontal disease and heart disease, strokes, and preterm births.