Dr. Arvind B

Inside every tooth root is a tiny channel called the root canal that holds the nerve and blood vessels. Over time — especially with age, repeated dental work, or after an injury — your body lays down extra layers of dentin that gradually narrow these canals. When the canal becomes very narrow or completely blocked with hardened dentin, it's called a calcified canal.

Calcification makes root canal treatment more challenging because:

• The canal is hard to locate — it may not be visible on X-rays
• Standard files cannot pass through; specialized ultrasonic instruments are needed
• Risk of perforation (creating a false channel) is higher
• Treatment takes longer and often requires the use of a dental operating microscope

This is why specialist endodontic care matters for these cases — general dental clinics often refer such cases out because they require microscopic precision.

A periapical lesion is an infection or inflammatory area at the tip of a tooth root. It typically appears on X-rays as a dark shadow near the root tip. It happens when bacteria from a deeply decayed or previously infected tooth spread out beyond the root and trigger your body's immune response, causing bone destruction in that area.

Good news: Most periapical lesions heal completely after a properly performed root canal treatment. Your body's natural healing fills the bone back in over 6–12 months once the source of infection (the bacteria inside the canal) is removed.

However, large lesions or those that don't heal after a routine RCT may need:

• Multi-visit treatment with intracanal medication
• Endodontic retreatment (Re-RCT)
• Apicoectomy (a small surgical procedure to remove the lesion directly)

Follow-up X-rays at 3, 6, and 12 months confirm the healing.

This is one of the most common patient questions. The honest answer:

Single-visit RCT works well for:

• Vital teeth (nerve still alive but irreversibly inflamed)
• Teeth without infection or visible periapical lesion
• Front teeth and most premolars with simple anatomy
• Cases where complete cleaning and shaping can be achieved comfortably in one sitting

Multi-visit RCT is preferred when:

• There's significant infection (pus drainage, swelling, abscess)
• A periapical lesion is present and intracanal medication is needed to disinfect over time
• The tooth has complex anatomy (calcified canals, curved roots, multiple molars)
• Re-treatment of a previously failed root canal

Most of my cases are completed in a single visit when conditions allow. Multi-visit is chosen specifically for predictability and long-term success in the more complex cases — never for convenience.

RCT (Root Canal Treatment) is the first-time treatment of a tooth where the inflamed or infected pulp tissue is removed, the canals are cleaned and disinfected, and then sealed with a biocompatible material.

Re-RCT (Endodontic Retreatment) is performed on a tooth that had RCT done before but has either:

• Developed a new infection (failed healing)
• Persistent pain or swelling months/years after the original RCT
• A new lesion visible on X-ray
• Inadequately filled canals from the original treatment

Re-RCT involves carefully removing the old filling material from inside the canals, re-cleaning, treating any missed canals, and re-sealing. It's technically more difficult than original RCT and often requires a microscope and specialist training. The good news: many teeth that were recommended for extraction can be saved through retreatment — that's the central philosophy of endodontics.

Often, yes. Failed root canals are not the end of the road. The treatment options, in order of preference:

1. Endodontic Retreatment (Re-RCT): The most common option. Re-cleaning and re-sealing the canals with current techniques.
2. Apicoectomy (apical surgery): When retreatment isn't possible (e.g., a crown is in place that cannot be removed), the infected root tip is surgically removed and sealed from below.
3. Intentional replantation: Rare cases where the tooth is gently extracted, treated outside the mouth, and put back.
4. Extraction + implant/bridge: Last resort when none of the above are feasible.

I always evaluate the tooth carefully before recommending extraction. In many cases, what looks like a "lost cause" can be saved with the right specialist approach.

A root canal-treated tooth is structurally weaker than a natural tooth for several reasons:

• Significant tooth structure is removed during access and cleaning
• The tooth no longer has its blood supply and becomes more brittle over time
• Daily chewing forces — especially on molars — can cause vertical fractures

A crown (cap) protects the tooth from fracture and seals it against future bacterial leakage. Without a crown, even a perfectly performed root canal can fail within 1–2 years due to the tooth cracking. With a crown, treated teeth routinely last 15+ years.

The crown should ideally be placed within 4–6 weeks of completing the root canal. Skipping this step is one of the most common reasons RCTs fail long-term.