A root canal hollows out a tooth's living core and refills it with tree latex
Inside every tooth runs a hollow of nerves and blood vessels. When that pulp becomes infected, root canal treatment drills in, scrapes the channels clean with tiny files, floods them with disinfectant and packs them with gutta-percha, a rubbery polymer from the latex of the percha tree. The goal is saving the tooth.
Also called endodontic therapy, the procedure targets an abscessed pulp, usually when decay is too extensive for an ordinary filling. Before starting, the endodontist diagnoses the pulp and surrounding tissue with tests such as tapping the tooth for tenderness, pressing over the root tip for swelling, checking for looseness, shining light through it to reveal cracks, or asking the patient to bite on a small plastic tool to pinpoint the sore tooth. For pulp that is irreversibly inflamed, the options are extraction or removing the pulp.
Work begins with an opening through enamel and dentin. A rubber dam is compulsory: it keeps saliva and its microbes out, allows harsh cleaning chemicals, and stops the patient swallowing or inhaling tiny instruments. Canals are then shaped with hand files or engine-driven rotary files. Methods have multiplied since Ingle's standardised technique of 1961, which risked ledges and perforations; later variants such as step-back and crown-down shape the canal from opposite ends, and rotary systems spread from the early 1990s.
Irrigants do the killing. Sodium hypochlorite, used at 0.5% to 5.25%, and chlorhexidine are effective antimicrobials in the lab, though a systematic review found no good evidence that any single rinse gives a better long-term result. Lidocaine has been the usual anaesthetic since 2000, but numbing can fail because the acidity of an abscess inactivates it, so the abscess may be drained first. Gutta-percha shows up on X-rays, letting dentists confirm the canals are filled without gaps.
Treatment can stretch over several visits across weeks. Some dentists leave calcium hydroxide paste inside for a week or more to disinfect the canal, but multi-visit treatment shows no advantage, and single sittings produced slightly better though not statistically significant outcomes. Removing only the crown portion of the pulp, which holds 90% of its nerve tissue, usually stops the pain until the job is finished. One discredited approach, the Sargenti method, used a paraformaldehyde filling called N2.
Source: Root canal treatment
