Regenerative Endodontics: Options for an Immature Permanent Tooth

Name: Regenerative Endodontics: Young Permanent Teeth
Creator: Silicon Valley Endodontics editorial team

Regenerative endodontic procedures (REPs) may help a permanent tooth whose pulp has died before its root finished forming. The first aim is to control infection and support healing; further root growth is possible, but not guaranteed.

Prepared by the Silicon Valley Endodontics editorial team from published sources. The full guide in English, Spanish, Persian, Hindi, Korean, Vietnamese, Simplified Chinese and Traditional Chinese was clinically reviewed by Jason Kung on 2026-10-07, including translated medical meaning. This review does not cover linked pages or separate articles. This is general education, not an individual treatment plan or an AAE endorsement of this practice.

What does the AAE Winter 2026 issue explain?

The main clinical use discussed is a necrotic immature permanent tooth: the pulp has died, the root walls may be thin, and the root tip (apex) remains open. After disinfection, a scaffold such as a blood clot and a sealed restoration may support tissue ingrowth and continued root development. This is not treatment for baby teeth. Extensions to fully developed permanent teeth remain under investigation.

The primary goal is relief of symptoms and healing of bone around the root. The secondary goal is increased root-wall thickness and/or root length. A positive response to cold or electrical testing is a tertiary goal. A tooth may heal and function with little additional root growth; test responses alone do not prove that normal pulp has regenerated.

Avina Paranjpe’s AAE newsletter is professional educational guidance, not a new clinical trial. Human tissue findings vary: tissue inside the canal may be pulp-like or repair tissue rather than normal pulp. No procedure can promise lifetime tooth retention.

Read Paranjpe’s Regenerative Endodontics — AAE Winter 2026 (English PDF) [9]

Browse the AAE newsletter archive (English)

Learn about dental-trauma assessment and care

Who May Be a Candidate?

An endodontist assesses root development, pulp status, the cause of injury or infection, and whether the tooth can be restored. Root maturity matters more than an age cutoff.

Features that may support REP

An immature permanent tooth with an open apex
Necrotic pulp after trauma, decay or a developmental defect
Enough remaining tooth structure for a reliable restoration
Ability to attend staged treatment and long-term follow-up

Situations needing another approach

Baby teeth: treatment decisions are different
Mature permanent teeth: regenerative extensions remain investigational
A tooth that cannot be restored or has an unfavorable fracture
Allergies or other factors that make the proposed materials unsuitable

What Does Treatment Involve?

REPs commonly require two or more visits. This overview is not a clinical protocol; timing and materials depend on the tooth and its response.

Disinfection

Under local anesthesia and dental-dam isolation, the clinician disinfects the canal while limiting damage to thin root walls. An intracanal medicament may be calcium hydroxide or an antibiotic paste. Calcium hydroxide is not an antibiotic.

Reassessment

A temporary seal protects the tooth between visits. The clinician checks symptoms and infection control before continuing; persistent symptoms may require further treatment or a different plan.

Scaffold for tissue ingrowth

When appropriate, bleeding is stimulated from tissues near the root tip to create a blood-clot scaffold. Other scaffolds are also studied. This aims to support tissue ingrowth, not guarantee replacement of the original pulp.

Seal and restoration

A barrier material and a well-sealed restoration help protect the canal from reinfection. Material selection must balance sealing, biological effects and discoloration risk.

Follow-up is part of treatment

Clinical examinations and X-rays assess symptoms, bone healing and possible root changes over months and years. Keep the follow-up schedule recommended for your tooth, including early reassessment and longer-term annual checks. Report new pain, swelling or drainage rather than waiting for the next visit.

REP Versus Apexification

Apexification manages an open root tip by inducing a hard-tissue barrier or placing a bioceramic apical plug so the canal can be filled and sealed. It is not simply another name for ordinary root canal treatment. Both options aim to control infection; suitability depends on the individual tooth.

Apexification

Creates or places an apical barrier for canal filling
Does not aim to lengthen the root or thicken its walls
Thin walls may remain vulnerable to fracture
May be an alternative initially or after an unsuccessful REP

Regenerative endodontic procedure

Supports healing and possible tissue ingrowth
May increase root length and/or wall thickness
Root development varies and may be minimal despite healing
Does not guarantee normal pulp, fracture prevention or lifelong retention

Frequently Asked Questions

How long does regenerative treatment take?

Usually two or more treatment visits are needed, often weeks apart. Healing and possible root development are assessed over months and years. Follow-up is essential even when the tooth feels comfortable.

Is it painful?

Treatment is performed with local anesthesia. Discomfort can occur afterward. New or worsening pain, swelling or drainage needs reassessment; absence of pain alone does not confirm healing.

What risks should we discuss?

Risks include persistent or recurrent infection, tooth discoloration, little or no further root development, and fracture of a still-fragile tooth. Calcification within the canal may complicate future treatment. Material allergies and other individual risks should be discussed before consent.

What if the tooth does not heal?

The clinician reassesses infection, the seal and the remaining tooth structure. Further treatment may include an apical barrier procedure or another endodontic approach. Extraction may be necessary if the tooth cannot be saved. Limited root growth alone is not the same as failure when symptoms resolve and bone heals.

Is REP established care or experimental?

REP is a recognized option for selected immature permanent teeth with necrotic pulp and open apices. It does not reliably recreate normal pulp. Extensions to mature permanent teeth remain investigational and should not be presented as a routine substitute for conventional root canal treatment. Baby teeth need a different assessment.

Is calcium hydroxide an antibiotic, and which medicament is best?

Calcium hydroxide is an alkaline intracanal medicament, not an antibiotic. Antibiotic pastes are a separate option. Alovisi and colleagues’ 2026 review reported similar pooled one-year outcomes for calcium hydroxide and triple antibiotic paste, but used a naïve indirect comparison across studies, not a definitive head-to-head trial. These results do not establish a universally best medicine or a personal success rate. Disinfection, effects on cells, allergies and staining all matter.

What counts as success, and will the root always grow?

Relief of symptoms and healing around the root are the primary goals. More root length or thicker walls are secondary goals; a response to pulp sensibility testing is a tertiary goal. Not every tooth achieves all three. A positive test does not prove true pulp regeneration, and no blanket percentage predicts an individual tooth’s outcome.

What the Evidence Can and Cannot Tell Us

Case selection, infection control, the restoration and follow-up all matter. Published studies use different methods and outcome definitions.

Reviews describe REP mainly for necrotic immature permanent teeth. Healing and continued root development are possible, but normal pulp regeneration is not assured.
Compared with apexification, REP offers the possibility of increased root length or wall thickness. Those changes are variable and do not establish lifelong fracture protection.
Protocols and materials vary. The AAE considerations and the ESE position statement provide clinical context; neither replaces individual assessment or guarantees a fixed result.
Zhang and colleagues’ 2025 meta-analysis of nine studies reported comparable clinical success, radiographic healing and survival between REP and conventional root canal treatment, with differences in sensibility and root maturation. Mixed populations and protocols limit what this comparison can predict for a particular immature or mature tooth.

Financial-bias disclosure: Dr. Kung has no financial relationship — paid consulting, royalty, equity or promotional — with any biomaterial, scaffold or device manufacturer, implant system or laboratory. This guide discusses evidence and limitations rather than endorsing a product.

Sources and further reading

These sources informed this editorial guide. Bibliographic titles are retained in their original language; source authors have not reviewed this clinic’s interpretation.