Can a Root Canal Become Reinfected? Causes, Risks and Treatment

Understanding the Risk of Reinfection After a Root Canal

Getting a root canal can help save an infected or badly damaged tooth. But in some cases, a root canal tooth may become reinfected after treatment. This occurs when bacteria or infection return and continue attacking the tooth and surrounding structures.

Causes of Reinfection

There are several potential pathways for root canal reinfection:

• Residual infection - Not all bacteria were removed during the initial root canal cleaning.
• Re-entry of bacteria - Bacteria re-enter through small cracks or leaking fillings/crowns.
• Spread from adjacent teeth - Nearby infected teeth spread bacteria through shared blood or tissues.

Without proper treatment, reinfection allows damage to continue until it leads to abcess, bone loss, tooth fracture, or even tooth loss.

Signs of Reinfected Root Canal Tooth

Some signs your root canal tooth may be reinfected include:

• Tooth pain or sensitivity - Especially to temperature changes.
• Swollen gums near the tooth.
• Darkened tooth.
• Sinus pain, drainage, pressure.
• Bad taste/breath related to the tooth.
• Visible pimples or abscess on the gums.

The only way to confirm reinfection is through x-rays and examination by your dentist.

Risk Factors for Reinfected Root Canal

Unfortunately reinfection occurs fairly often. About 10-15% of root canals fail after a few years. The risk rises to over 50% by 8-10 years after treatment.

Some factors that raise chances of root canal reinfection include:

Complicated Tooth Structure or Root System

Teeth with more complex anatomy are harder to fully access, disinfect, and seal:

• Narrow canals - Difficult to open canals makes complete cleaning unlikely.
• Curved roots - Bends prevent access to the full root length.
• Extra canals - Undiscovered hidden or branching canals may harbor remnants of infection.

History of Trauma or Prior Failed Treatments

Past injury or unsuccessful treatments increase susceptibility:

• Cracked tooth - Fissure lines can harbor bacteria while also letting new microbes back inside the tooth.
• Failed previous root canal - More difficult to fully disinfect a tooth with prior infection or inflammation history.
• Damaged crown - Ill-fitting or leaking crowns allow re-entry after the initial root canal treatment.

Chronic Grinding, Clenching, or Chewing Stress

Excess force stresses the tooth structure and seals over time:

• Bruxism - Chronic teeth grinding or clenching puts extreme pressures on teeth.
• Tough diet - Constant chewing of very hard, sticky foods stresses the restored tooth.

This pressure can cause microscopic cracks or let filling materials spring a leak where bacteria creep back inside.

Gum Disease

Gum bacteria can infect root canals in a few ways:

• Directly invade the inner tooth if gum pockets contact the root.
• Release toxins that dissolve protective cementum from root surfaces.
• Cause inflammation that destroys nearby bone and supportive tissues.

As gums bleed, recede, or develop abscess, they grant problematic bacteria access.

Preventing Root Canal Reinfection

While sometimes unavoidable, you can take these steps to help prevent a root canal tooth from becoming reinfected:

Get an Initial Post-Treatment Crown

A protective crown helps block reinfection pathways like cracks or breakdown of the temporary filling. It also withstands chewing forces better to prevent leakage or cracks.

Practice Excellent Oral Hygiene

Brush gently 2x daily, floss once daily, and use antiseptic rinses to reduce overall mouth bacteria and prevent gum disease. See your dentist for cleanings and exams every 6 months.

Eat a Tooth-Friendly Diet

Avoid very hard, crunchy, chewy, sticky, or acidic foods. Stay hydrated and limit sugary snacks and acidic drinks that promote damage.

Ease Bruxism and Clenching

Get custom nightguards and consider Botox injections, stress management, and physical therapy to ease grinding/clenching if needed.

Don't Delay Follow-Up Exams

See your dentist promptly if any suspicious symptoms arise for early detection of potential problems.

Get Protective Sports Mouthguards

Wear custom mouthguards during contact sports or vigorous exercise.

Treating Reinfected Root Canal Teeth

If a root canal tooth does become reinfected, treatment falls into 3 main options:

Root Canal Retreatment (RCT Retreatment)

The dentist reopens the tooth, cleans it again thoroughly with disinfectants, seals it again with filling material, and places a new crown.

This aims to fully remove infection that persisted or reentered the inner canals and tooth roots that were previously treated.

Root Canal Surgery (Apicoectomy)

If infection is isolated at the bottom root tip, the infected tip can sometimes be removed through root end surgery, sealing off that problematic area.

Tooth Extraction

In cases of severe infection, significant structural damage or crack lines, failed retreatments, or advanced decay, extracting the tooth may ultimately be necessary.

Outlook for Reinfected Root Canals

Prognosis depends greatly on multiple factors like tooth location, level of structural damage, gum health, patient habits, and speed of treatment.

Through prompt treatment and good home care, many reinfected root canals can still be salvaged and retain usefulness for years. But some may fail again quickly or require extraction if too severely compromised.

Work closely with your endodontist and dentist if a previous root canal treatment fails for best chances of tooth preservation or efficient replacement.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.