A root canal infection is treated by removing the infected tissue inside the tooth, disinfecting the hollow canals, and sealing them to prevent bacteria from returning. This procedure, called root canal treatment (or endodontic therapy), is the standard approach and has a high success rate when followed by proper restoration. Antibiotics alone won’t resolve the problem because the blood supply to the inner tooth is compromised, meaning medication can’t reach the source of infection effectively.
Signs You’re Dealing With an Infection
The most common symptoms of a root canal infection include persistent toothache, sensitivity to hot or cold food and drinks, swelling around the face or neck, gum swelling near the affected tooth, and sometimes a visible hole in the tooth. Pain often intensifies when you bite down or apply pressure. Some people notice a bad taste in their mouth from drainage if an abscess has formed.
Your dentist will start with dental X-rays to assess how far the damage extends. They may also tap on the tooth to check for pain on percussion and test its response to temperature. These steps help determine whether the inner tissue (the pulp) is still alive but inflamed, or whether it has died and become infected.
What Happens During a Root Canal
The procedure itself is more straightforward than most people expect. After numbing the area, the dentist or endodontist (a specialist in treating tooth interiors) makes a small opening in the crown of the tooth. Using very small instruments, they remove the infected or dead pulp tissue from the inner chamber and the root canals that extend down into your jawbone. The canals are then carefully shaped and disinfected.
Once the space is clean, the canals are filled with a rubber-like biocompatible material called gutta-percha, which is placed with an adhesive cement to completely seal the canals and block bacteria from re-entering. A temporary filling usually covers the opening until you return for a permanent restoration, typically a crown.
That crown matters more than you might think. Research from Indiana University School of Dentistry found that a tooth receiving both a filling and a crown after a root canal lasts about 20 years on average. A tooth with only a filling or only a crown lasts around 11 years. Without any restoration at all, the tooth survives just 6.5 years. The treated tooth becomes more brittle without its living pulp, so the crown acts as structural reinforcement.
Do You Need Antibiotics?
Probably not. ADA treatment guidelines state that antibiotics are not needed for the urgent management of most dental pain and swelling from pulp infections in otherwise healthy adults. The reason is simple: removing the infected tissue (the actual source of bacteria) is what solves the problem. Antibiotics offer limited benefit and carry risks like allergic reactions and contributing to antibiotic resistance.
There are two situations where antibiotics do come into play. If you can’t get dental treatment right away and have a localized abscess, antibiotics may be prescribed as a temporary bridge. And if the infection has spread beyond the tooth, causing fever, significant facial swelling, or swollen neck glands, antibiotics are recommended alongside urgent dental care. Signs of spreading infection warrant same-day evaluation.
Recovery After Treatment
As the numbing medication wears off, you can expect some tenderness around the treated tooth for a few days. Mild jaw soreness is also normal from keeping your mouth open during the procedure. Over-the-counter pain relievers typically handle this well. Most people return to normal activities the next day, though you should avoid chewing on the treated side until your permanent restoration is placed.
If pain worsens significantly after the first few days rather than improving, or if swelling develops, contact your dentist. These can be signs that the infection hasn’t fully resolved.
What Happens If You Don’t Treat It
Ignoring a root canal infection doesn’t just mean losing the tooth. Untreated infection can spread to surrounding bone in the jaw, a condition called osteomyelitis. It can also spread into the soft tissues of the head, neck, and chest. In rare but serious cases, these infections become life-threatening. The progression typically starts with worsening pain and abscess formation, then moves to fever and swollen lymph nodes in the neck as the body fights a spreading infection.
When a Root Canal Fails
The median survival time of a tooth after root canal treatment is 11.1 years across the general population, and many last far longer with good restoration. But sometimes treatment doesn’t fully resolve the infection. This can happen if a canal was missed (some teeth have unusually complex anatomy), if the original seal leaked, or if new decay developed under a crown and allowed bacteria back in.
Retreatment
The first option is usually endodontic retreatment. The endodontist reopens the tooth, removes the old filling material, cleans and disinfects the canals again, then reshapes and reseals them with fresh material. This is a good option when the tooth structure is still healthy and the issue was incomplete cleaning or a compromised seal. It’s nonsurgical and less invasive than the alternative, though it can be technically challenging in teeth with complex root anatomy.
Apicoectomy
If retreatment isn’t possible or has already failed, an apicoectomy is often the last step before extraction. This is a minor surgical procedure where the endodontist makes a small opening in the gum, removes the tip of the infected root along with the surrounding inflamed tissue, and seals the end of the root from the outside. It’s typically recommended when canals are blocked, too narrow or curved to access from above, or when a previous instrument fragment is lodged inside the canal. Recovery takes longer than a standard root canal, with mild swelling and soreness expected for several days, but it can save a tooth that would otherwise need to be pulled.