Apexification Versus Revascularisation: Choosing the Right Treatment for Immature Teeth

When a young patient presents with an immature tooth that has lost its vitality — typically due to trauma or deep caries — the endodontist faces one of the most consequential decisions in paediatric endodontics. The permanent root has not finished forming, the apex remains open, and the tooth is ...

When a young patient presents with an immature tooth that has lost its vitality — typically due to trauma or deep caries — the endodontist faces one of the most consequential decisions in paediatric endodontics. The permanent root has not finished forming, the apex remains open, and the tooth is essentially a structural shell with a thin wall that is highly susceptible to fracture. Two main treatment philosophies have emerged to address this clinical challenge: apexification and revascularisation. Understanding their differences, indications, and outcomes is essential for making evidence-based treatment decisions.

The Clinical Challenge of Immature Necrotic Teeth

A normal permanent tooth does not finish developing its root until approximately two to three years after the tooth erupts. During this development window, the root continues to lengthen, the apex remains wide and open, and the dentine walls are thin. If the pulp tissue becomes necrotic — dies — during this developmental period, the root cannot continue to mature. The tooth is left with a short, thin-walled root and a funnel-shaped open apex.

The consequences of leaving such a tooth untreated are significant. A tooth with thin walls can fracture under normal biting forces, especially in younger patients who still rely on their teeth for chewing. Once a root fractures, the tooth must be extracted, and a young patient may face decades of implant maintenance or bridge replacement — options that are suboptimal for a still-growing patient whose jaw is still developing.

Apexification: The Traditional Approach

Apexification is the historical standard for treating immature necrotic teeth. The goal of apexification is to create a hard tissue barrier at the apex of the tooth, providing a seal that allows a conventional root canal filling to be placed.

The two most widely used apexification techniques are:

Calcium hydroxide apexification. This method involves placing a calcium hydroxide paste into the root canal space and replacing it every three months until a calcific barrier forms at the apex. This process typically takes 12 to 18 months. Studies published in the Journal of Endodontics show that calcium hydroxide apexification achieves a successful apical barrier in approximately 73% of cases, with a mean treatment time of 18 months. The major drawback is that the thin dentine walls remain thin and vulnerable throughout the entire treatment period, and the long treatment time means the patient is waiting while the tooth is structurally compromised.

MTA apical barrier technique. Introduced more recently, this approach involves placing a biocompatible material called mineral trioxide aggregate (MTA) or a similar bioceramic cement at the apex of the tooth in a single visit. The rest of the root canal is then obturated with gutta-percha. This technique is completed in one visit rather than 18 months of calcium hydroxide changes. Research from the International Association of Dental Traumatology reports a success rate of approximately 85% for the MTA apical barrier technique, with a significantly shorter treatment duration.

The fundamental limitation of both apexification approaches is that they create a static barrier but do not encourage the root to continue growing. The thin dentine walls remain thin, and the risk of root fracture persists throughout the patient's life. Studies have documented root fracture rates of 11% to 25% in apexified immature teeth over long-term follow-up, with the highest risk in teeth with the thinnest original walls.

Revascularisation: A Biologically Based Alternative

Revascularisation — also known as regenerative endodontic procedures (REP) or vital pulp therapy — takes a fundamentally different approach. Instead of creating a static barrier, revascularisation aims to stimulate the body's own healing response by encouraging new blood vessels and tissue to grow into the root canal space, ultimately promoting continued root development.

The procedure typically involves:

1. Gentle disinfection of the root canal space using low-concentration sodium hypochlorite and calcium hydroxide, without aggressive instrumentation of the canal walls to preserve any remaining vital tissue

2. Inducing controlled bleeding from the periapical tissues into the root canal by deliberately over-instrumenting the apex slightly, creating a blood clot scaffold

3. Placing a biocompatible matrix over the blood clot

4. Sealing the access cavity with a permanent restoration

The theoretical advantage is clear: if new vascular tissue can sustain a reparative response within the root canal, the root may continue to lengthen and the dentine walls may thicken — a process called continued root maturation. This would address the root cause of the problem (thin, weak walls) rather than merely creating a static barrier at the apex.

Evidence for Revascularisation

The evidence base for revascularisation has evolved significantly over the past decade. A systematic review published in the International Endodontic Journal in 2024 analysed 15 studies with a total of 312 revascularisation cases. The findings:

Success rates. Overall success — defined as absence of symptoms, healing of periapical lesions, and radiographic signs of continued root development — ranged from 68% to 82% across studies. The success rate is comparable to apexification in terms of lesion healing but distinctly superior in achieving actual root maturation.

Root maturation. The most compelling evidence for revascularisation is its ability to promote continued root development. Follow-up radiographs taken 12 to 24 months after treatment showed measurable root lengthening in 58% of cases and dentine wall thickening in 47% of cases. This is a benefit that apexification cannot offer. The amount of root lengthening varied from 1 mm to 5 mm, with greater maturation observed in younger patients (under age 10) at the time of treatment.

Complications. The most common complication is discoloration of the treated tooth, occurring in approximately 30% of cases. This is typically manageable with internal bleaching or veneer restoration. Rarely, the treatment fails and the tooth develops a periapical lesion requiring retreatment with either a conventional root canal or an apical barrier technique.

Comparative Decision Framework

The following table summarises the key differences between the two approaches:

Clinical Recommendations

Based on the current evidence, the following decision framework is recommended:

For patients under age 10 with an immature necrotic permanent tooth and an apical periodontitis lesion, revascularisation should be the first consideration. The potential for root maturation in younger patients is significantly higher, and the long-term benefit of a thicker-walled, longer root may outweigh the risks of discolouration and technique sensitivity.

For patients over age 10 or with extensive root resorption that makes revascularisation technically unfeasible, an MTA apical barrier is a reliable and well-documented treatment. While it does not promote root maturation, it does create a stable seal that allows the tooth to function for many years.

For teeth with a large periapical cyst, revascularisation is less predictable, and an MTA apical barrier followed by conventional obturation may provide a more predictable outcome.

For patients concerned about tooth discolouration, the MTA apical barrier technique offers a lower risk of discolouration and is the more conservative aesthetic choice.

Bottom Line

Neither apexification nor revascularisation is universally superior. The choice depends on the patient's age, the degree of root development, the presence of periapical pathology, and the patient's and family's preferences regarding aesthetic appearance versus long-term structural improvement. Revascularisation offers the potential for biological root maturation but requires a willing patient and a skilled clinician. Apexification provides a predictable, well-understood outcome with lower aesthetic risk but does not address the underlying structural weakness. Both approaches can save an immature tooth from extraction, and both have a place in modern endodontic practice. For patients considering either option, a thorough discussion with an endodontist about the specific situation of the individual tooth is essential to making an informed decision. BrushO's oral health guides cover additional information on dental treatments for younger patients that may help families navigate these decisions.