Root Canal Treatment

The Purpose of Root Canal Treatment

The goal of root canal treatment is not to keep the tooth alive but to preserve it in the mouth so that it can continue to function normally.

Root canal therapy becomes necessary when the dental pulp (the nerve and blood supply inside the tooth) is affected by irreversible inflammation or necrosis. In these cases, the pulp cannot be saved, but with proper treatment the tooth structure itself can be maintained, allowing the patient to chew, bite, and smile without losing the natural tooth.

What Is Root Canal Treatment?

Root canal treatment (also known as endodontic therapy) is a dental procedure in which the inflamed or dead dental pulp is removed, the root canals are disinfected, and then carefully sealed with a special filling material.

This treatment is necessary when the inflammation or necrosis of the pulp is irreversible and cannot be healed by other means.

Because root canal treatment is a highly precise and time-consuming procedure, it is often carried out over multiple appointments. The number of sessions required depends on the number, length, and shape of the root canals in the affected tooth.

Why Is Root Canal Treatment Important?

The dental pulp is the living part of the tooth, responsible for its vitality, nutrition, and sensitivity. When it becomes inflamed or infected, root canal treatment is often the only way to preserve the tooth.

Several factors can lead to pulpitis (pulp inflammation) or pulp necrosis (pulp death), including:

• Untreated deep cavities
• Tooth crown or root fractures that reach or expose the pulp
• Mechanical or thermal trauma (e.g., drilling without adequate cooling, tooth preparation for crowns)
• Loosened teeth due to periodontal disease
• Displacement or trauma from injury
• Incorrect or overly aggressive orthodontic procedures

If an inflamed tooth is left untreated, the pulp may die, and the infection can spread to surrounding tissues. In severe cases, this may even result in sepsis (blood poisoning).

As the condition progresses, bone destruction begins around the tooth root, often leading to cyst formation and further bone resorption. In extreme cases, this process can even contribute to jaw fractures.

Root canal treatment is therefore essential not only for saving the affected tooth but also for protecting overall oral and general health.

Acute Pulpitis

The most characteristic symptom of acute pulpitis is severe, often radiating tooth pain. This pain:

• Does not subside, or only briefly improves, even after taking over-the-counter painkillers
• May feel sharp, throbbing, or prolonged
• Can affect the tooth directly or radiate to neighboring teeth, and in some cases spread to the ear, cheek, or eye area
• Often worsens in response to cold stimuli or when lying down

When the inflammation spreads beyond the root canal into the surrounding soft and hard tissues near the root tip, symptoms may include:

• Redness and swelling in the area of the tooth root, extending into the face
• Formation of a dental abscess
• Bad breath or unpleasant taste in the mouth
• In severe cases: fever, chills, and general malaise

 If you experience these symptoms, you should contact a dentist immediately.

Chronic Pulpitis

Chronic pulpitis is often asymptomatic. In some cases, patients may experience:

• Sensitivity when biting down
• Occasional discomfort in response to heat

Most often, chronic pulpitis is diagnosed only through dental X-rays, as the condition may progress silently without obvious symptoms.

Prevention of Root Canal Treatment

In its early stages, pulp involvement may still be reversible (treated with pulp capping). However, once the inflammation becomes irreversible, the tooth can only be saved through root canal treatment. This is why preventing pulp infection in the first place is crucial.

Early Detection Through Regular Check-Ups

Routine dental examinations and X-ray controls are essential for detecting cavities in their initial stages, when they can still be treated without endangering the pulp. Deep, untreated cavities can lead to pulpitis that requires root canal therapy as the only solution.

Risks of Untreated Pulpitis

If pulp inflammation is left untreated, it may spread:

• Into the bone surrounding the tooth root and nearby soft tissues
• Leading to abscess formation from necrotic tissue
• In severe cases, extending to the jawbone, head, or neck regions

A persistent infection can even cause sepsis (blood poisoning), making timely dental treatment critical.

Untreated pulpitis may also lead to pulp necrosis (death of the dental pulp), which can remain symptomless for years while silently destroying the surrounding bone.

Advanced Stages and Consequences

When bone destruction becomes significant, the affected tooth may loosen, and the infection can spread to adjacent teeth. In advanced cases, odontogenic bone cysts may develop. At this stage, the tooth often cannot be saved even with root canal therapy and may require oral surgery. Importantly, even with bone involvement, the tooth may sometimes remain asymptomatic.

Importance of Monitoring Previously Treated Teeth

It is also vital to perform periodic X-ray follow-ups of previously root canal-treated teeth. In some cases, the tooth may require retreatment, which can allow the bone infection to heal. If a cyst has formed and does not resolve after retreatment, a root-end resection (apicoectomy) may be necessary to fully eliminate the lesion.

The Root Canal Procedure – Step by Step

1. Diagnosis and Treatment Planning

The process begins with a thorough dental examination, X-rays, and patient anamnesis. Based on these findings, the dentist establishes a diagnosis, prepares a personalized treatment plan, provides a cost estimate, and schedules the appointments.

2. Local Anesthesia

To ensure a completely pain-free treatment, the affected tooth and surrounding area are numbed with local anesthesia.

3. Demarcation (Crown Build-Up)

If decay extends to multiple surfaces or if significant tooth structure is missing after removing old fillings or crowns, the dentist rebuilds the crown with composite material. This step allows proper isolation of the tooth, creates a secure access cavity, and ensures a tight seal between treatment sessions to prevent contamination by saliva.

4. Access Opening (Trepanation)

The dentist opens the pulp chamber to access the root canals.

5. Determining Canal Length

The working length of the root canal(s) is measured using an apex locator and, if necessary, confirmed with an X-ray (file control).

6. Cleaning and Shaping the Root Canals

The canals are then carefully prepared through chemo-mechanical instrumentation:

• Removal of infected dentin and microorganisms from the canal walls and dentinal tubules
• Shaping the canals to create an optimal form for filling
• Disinfection with laser therapy and/or antibacterial irrigating solutions
• Placement of medication inside the canals
• Temporary closure of the tooth crown with filling material until the next session

7. Medication Change (If Needed)

If symptoms persist or further disinfection is required, the medication may be replaced, and additional laser disinfectionmay be performed.

8. Root Canal Filling (Obturation)

Once the canals are clean and symptom-free, they are permanently sealed with gutta-percha cones and sealer material. The crown of the tooth is then restored with either a long-term temporary filling or a permanent filling.

9. Final Crown Restoration

For long-term success, a root canal-treated tooth is often reinforced with a composite or porcelain inlay/onlay or dental crown. This ensures a perfect seal within the oral cavity and prevents fractures of the treated tooth.

After Root Canal Treatment

It is common for the injection site of the local anesthetic to remain slightly sensitive for 1–2 days. After the opening of the pulp chamber (trepanation), temporary sensitivity or mild pain may also occur between treatment sessions, as well as after the root canal filling has been completed.

Following the root canal obturation (final filling of the canals), the tooth will be re-evaluated after about three months. Once the root canal filling is confirmed to be stable, the tooth crown is permanently restored with either an inlay/onlay or a dental crown.

This final restoration ensures a long-term, durable solution, protecting the treated tooth and preventing fractures or reinfection.

When Do We Speak of Pulp Necrosis?

Pulp necrosis occurs when an untreated or prolonged pulp inflammation (pulpitis) leads to the death of the cells inside the dental pulp. As the infection progresses, the blood supply and nerve tissue within the pulp are irreversibly damaged and eventually die.

In addition to untreated cavities, pulp necrosis can also be caused by mechanical trauma that damages the blood vessels entering the tooth root—for example, a blow to the tooth or excessive forces during improper orthodontic treatment.

Common Characteristics of Pulp Necrosis

• Often asymptomatic for a long time, or accompanied only by dull, occasional pain that may intensify with heat
• The tooth no longer responds to external stimuli (cold or electric pulp testing)
• Possible tooth discoloration or darkening as the pulp tissue dies
• On dental X-rays, pulp necrosis typically becomes visible only once the process has spread to the surrounding tissues near the root tip, at which point it is diagnosed as periapical inflammation

Why Should I See a Dentist If the Pain Has Already Gone Away?

Tooth pulp inflammation (pulpitis) can only be treated conservatively in its early, reversible stages, when the vitality of the tooth may still be preserved. This is why regular dental check-ups are essential, and why you should schedule a consultation at the first sign of tooth sensitivity or pain.

Only a dentist can determine whether a root canal treatment or, in some cases, even a tooth extraction is necessary.

It is important to understand that when pain associated with pulpitis decreases or disappears, it does not mean that the tooth has healed on its own. In many cases, the loss of pain is actually a sign that the pulp has died, which can allow the infection to spread silently to surrounding tissues.

Why Are Dental X-Rays Essential Before, During, and After Root Canal Treatment?

Since the dental pulp, tooth roots, and root canals are invisible to the naked eye, dental X-rays are indispensable throughout the root canal procedure. They provide crucial diagnostic and follow-up information that ensures treatment success.

Before Root Canal Treatment

X-rays help the dentist evaluate:

• The depth of cavities or defects under old fillings
• The number of roots and their curvature
• The number, path, and possible obstructions of the root canals
• The extent of inflammation and periapical lesions
• Possible fractures of the tooth crown or root

During Root Canal Treatment

X-rays are used to assess:

• The exposed part of the root canals and any anatomical curvatures
• The correct working length of the canals
• The position and length of the root canal filling during “file control”

After Root Canal Filling

X-rays confirm:

• The quality of the final root canal filling, including its length and density

Follow-Up Control X-Rays

Periodic check-ups with X-rays ensure that:

• No periapical pathology has developed around the treated canals
• Any pre-existing periapical lesion is healing, shrinking, or has disappeared completely in advanced cases

What Does Root Canal Treatment Involve? Modern Techniques and Tools in Endodontics

Modern root canal therapy goes beyond traditional methods, using advanced technology to ensure precision, effectiveness, and long-term success.

Dental Microscope

A dental operating microscope provides high magnification and illumination, allowing the dentist to see even the most complex pulp systems. This is especially useful in cases of narrow, calcified, or severely curved root canals, where precision is essential.

Laser Therapy

Dental lasers are highly effective in root canal disinfection. They help eliminate bacteria and pathogens inside the canals, enhancing sterilization and supporting long-term healing.

CBCT Imaging (Cone-Beam CT)

Cone-Beam Computed Tomography (CBCT) provides a three-dimensional X-ray view, making it easier to visualize the exact course, curvature, and possible anatomical variations of root canals. This technology significantly increases the accuracy of diagnosis and treatment planning.

Possible Complications During Root Canal Treatment

Although modern technology has made root canal treatment highly predictable and successful, certain challenges and complications can still occur. With the use of advanced tools such as microscopes, lasers, and CBCT imaging, most of these can be effectively managed.

Narrow or Blocked Root Canals: Common in older patients or in cases of chronic, long-standing infections. These canals can often be successfully treated with the help of special irrigating solutions and advanced instruments.

Severely Curved or “S-Shaped” Root Canals: Complex root anatomy, including extreme curvatures, can complicate treatment. Here, microscopic magnification and 3D CBCT scans provide essential guidance for safe and effective cleaning.

Broken Instruments: In rare cases, a file or instrument may fracture inside the canal, especially in narrow or highly curved roots. Often, the fragment can be removed, allowing the treatment to continue successfully.

Mild Pain Despite Anesthesia: In severely inflamed teeth, some patients may feel short-lived discomfort when the pulp chamber is first opened, even under local anesthesia.

Sensitivity or Pain Between Appointments: Occasionally, inflammation extending beyond the root tip may require more time to heal. Patients may experience temporary tooth sensitivity or mild pain between visits, which usually resolves as the treatment progresses.

What Defines a Successful Root Canal Treatment?

The hallmark of a successful root canal treatment is that the tooth becomes symptom-free and remains that way over time.

A key factor in long-term success is ensuring that the root canal filling is properly sealed, both inside the root canals and at the crown level. This prevents bacteria from the oral cavity from reinfecting the tooth. For this reason, the treated tooth is permanently restored with an inlay/onlay or, in many cases, a full crown to provide complete protection.

Regular dental check-ups and X-ray follow-ups are essential to monitor healing and prevent future complications.

We consider root canal treatment successful when:

• The tooth is symptom-free (no pain, no sensitivity)
• X-rays show no pathological changes around the root tip
• The infected pulp has been completely removed
• The root canal filling perfectly seals the canal, preventing reinfection

Advanced Cases

Sometimes patients only seek treatment once the infection has already spread to the periapical area (due to neglected or untreated teeth). On an X-ray, this appears as a lesion around the root tip (such as a granuloma or cyst). In these cases, treatment is considered successful if, after the root canal filling, the pathological lesion fully heals and disappears.

What Is Root Canal Retreatment (Revision)?

Root canal retreatment—also called revision—is a procedure in which an old, inadequate root canal filling is removed and replaced with a new, hermetically sealed filling that covers the entire root canal system.

The procedure is similar to conventional root canal treatment, with one main difference: the tooth has already been trepanned (opened), so the old root canal filling must first be carefully removed using solvents, hand files, and rotary instruments before a new filling can be placed.

Root canal retreatment is often considered a last attempt to save a tooth before extraction, and it can be technically challenging for the dentist.

When Is a Root Canal Filling Considered Inadequate?

A root canal filling may require revision in the following cases:

• The treated tooth remains sensitive or painful
• The filling was exposed to saliva for an extended time (due to a broken tooth, lost filling, or fallen inlay), causing reinfection
• The filling does not seal hermetically, does not fully occupy the root canal system, or appears non-homogeneous on X-ray
• The filling extends beyond the root tip, maintaining chronic inflammation
• The filling is too short, leaving untreated space where bacteria multiply
• A broken instrument remains in the canal, preventing proper filling and causing persistent infection
• In multi-rooted teeth (or teeth with multiple canals in one root), not all canals were filled
• Despite an apparently adequate filling on X-ray, periapical inflammation does not heal

Surgical Supplement: Apicoectomy

In cases of large or persistent periapical lesions, root canal retreatment may be combined with a surgical procedure called apicoectomy (root-end resection). This involves removing the tip of the root and surrounding infected tissue to fully eliminate the source of infection.

Are Root Canal-Treated Teeth Less Durable Than Natural Ones?

Yes. Since a root canal-treated tooth no longer has blood supply, it becomes more brittle and fragile compared to vital teeth. This makes it more prone to fractures under the pressure of everyday chewing forces.

To ensure long-term durability, it is highly recommended to protect the tooth with a permanent restoration, such as an inlay, onlay, or a full dental crown. These restorations strengthen the tooth structure and help it withstand significant biting and chewing forces.

Should I Choose Extraction and an Implant/Bridge Instead of Root Canal Treatment?

While root canal treatment may sometimes be complex, time-consuming, or relatively costly, our primary goal in dentistry is always to preserve your natural tooth whenever possible.

When a tooth is extracted, the bone around the extraction site gradually deteriorates. Replacing the missing tooth with a dental implant requires time—typically 4–6 months for the implant screw to fully integrate with the bone. In addition, the procedure can involve significant extra costs, such as bone grafting materials, sinus lift surgery, autologous blood membranes, CBCT scans, or surgical guides.

If a patient chooses a dental bridge instead, healthy neighboring teeth often need to be ground down to serve as abutments. In many cases, more than two supporting teeth are required. Bridges also present hygiene challenges, as they demand special oral care and cleaning techniques.

It is important to remember that no replacement—whether implant or bridge—will ever be exactly the same as your natural tooth. For this reason, our main objective remains the same: to save and preserve your own teeth whenever possible.

Fiber Posts in Dentistry: Purpose and Indications

A fiber post is used exclusively in root canal-treated teeth to reinforce the tooth when there is insufficient healthy tooth structure remaining—for example, in cases of extensive decay, removal of a large old filling, or a fractured crown.

The fiber post is inserted into approximately two-thirds of the root canal and securely bonded in place. A composite core build-up is then placed around it, creating a stable foundation. This allows the tooth to be restored with an appropriate dental crown or other permanent restoration, ensuring both strength and long-term durability.