What This Guide Covers
This guide explains regenerative endodontic procedures, a biologically based treatment that helps immature permanent teeth heal and continue developing after infection or trauma.
If your child or teenager has a permanent tooth that was injured or became infected before the root finished forming, this guide is for you. You will learn how the procedure works, what qualifies a tooth for treatment, what happens during each visit, potential side effects such as tooth discoloration, and how outcomes compare to traditional alternatives.
Regenerative endodontics is a specialty procedure typically performed by an endodontist, a dentist who specializes in treating the inside of teeth. You can learn more about this specialty on the endodontics page.
Understanding Regenerative Endodontics
Regenerative endodontic procedures (REPs) replace damaged or dead tissue inside a tooth with new living tissue, allowing the tooth root to keep growing.
What Is a Regenerative Endodontic Procedure?
A regenerative endodontic procedure, sometimes called revascularization, is a treatment that encourages new blood vessels, nerve fibers, and pulp-like tissue to grow inside a tooth. The word "pulp" refers to the soft tissue inside your tooth that contains blood vessels and nerves. When this pulp dies, usually from infection or injury, the tooth loses its blood supply.
In a mature adult tooth, root canal therapy removes the dead pulp and fills the empty space. But in an immature tooth, the root has not finished forming. The root walls are thin. The tip of the root, called the apex, is still wide open. A traditional root canal in this situation would leave the tooth permanently weak because the root would never thicken or close. [4]
REPs solve this problem by creating conditions that allow the body's own stem cells to move into the tooth. These stem cells, found in the tissue around the root tip, can generate new tissue that resembles pulp. This new tissue brings blood flow back to the tooth. With blood flow restored, the root walls can continue to thicken and the open apex can narrow or close. [2]
How the Biology Works
The key to regenerative endodontics is a structure called the blood clot scaffold. During the procedure, the endodontist intentionally causes a small amount of bleeding from the tissue beyond the root tip. This blood clot fills the empty canal space and acts like a scaffold, a framework that stem cells and growth factors can attach to.
Growth factors are natural proteins that signal cells to multiply, specialize, and build new tissue. The blood clot is rich in these proteins. Stem cells from a region called the apical papilla, the developing tissue at the root tip, migrate into the scaffold and begin forming new tissue. [7]
Over time, this process can produce increases in root length, root wall thickness, and narrowing of the open apex. A 2024 systematic review and network meta-analysis found that REPs led to statistically significant increases in both root length and root wall thickness compared to baseline measurements. [2]
Success Rates and Outcomes
Research demonstrates strong healing rates for regenerative endodontic procedures. A 2024 systematic review analyzing treatment outcomes found periapical healing, meaning resolution of infection around the root tip, in approximately 91% of treated immature teeth. The same review reported that most teeth showed measurable increases in root length and wall thickness after treatment. [2]
A 2023 systematic review and meta-analysis based on randomized controlled trials compared REPs to apexification (the traditional approach). The results showed that REPs achieved comparable rates of periapical healing. However, REPs were associated with greater increases in root length and root wall thickness compared to MTA apexification. [3]
A 2021 systematic review examined long-term outcomes and concluded that both REPs and MTA apexification had high healing success rates. The reviewers noted that REPs offered the additional benefit of continued root development, which may improve the long-term survival of the tooth. [4]
It is worth noting that outcomes vary by case. Factors that can influence results include the type and duration of infection, the degree of root development at the time of treatment, and the patient's overall health. Not every tooth will show the same degree of continued root growth. [5]
Tooth Discoloration: A Common Side Effect
One potential side effect of regenerative endodontic procedures is tooth discoloration. The crown of the treated tooth may darken or develop a grayish or yellowish tint after treatment. A 2022 systematic review and meta-analysis published in the Journal of Endodontics found that the pooled prevalence of tooth discoloration after REPs was approximately 44.5%, making it a relatively common occurrence. [10]
The discoloration is often linked to the triple antibiotic paste used to disinfect the canal during the first visit. Specifically, minocycline, one of the three antibiotics in the standard mixture, is a known cause of staining. The antibiotic can be absorbed into the tooth structure and cause a color change over time. [10]
Endodontists are aware of this risk and may take steps to reduce it. Common strategies include replacing minocycline with a different antibiotic (such as clindamycin or amoxicillin) in the paste, sealing the inside walls of the pulp chamber with a bonding agent before placing the antibiotic, or using calcium hydroxide paste instead of triple antibiotic paste. These modifications can lower the risk of staining, though they may not eliminate it entirely. [10]
If discoloration does occur, it can often be treated with internal bleaching or cosmetic dental procedures after the tooth has healed. Discuss this possibility with your endodontist before treatment so you understand the options available.
REPs Compared to Traditional Apexification
The traditional treatment for an immature tooth with dead pulp is called apexification. In this approach, the endodontist places a biocompatible material, typically MTA (mineral trioxide aggregate), at the open root tip to create an artificial barrier. The rest of the canal is then filled, similar to a standard root canal.
Apexification is effective at resolving infection. However, it does not promote further root development. The root walls remain thin, and the root stays short. This means the tooth may be more prone to fracture over time. [4]
REPs, by contrast, aim to restore the biological potential for root growth. A 2017 survey of endodontists and pediatric dentists found that the majority of providers favored regenerative procedures over apexification for immature necrotic teeth, citing the potential for continued root development as a primary advantage. [6]
Neither treatment is universally superior. A 2023 meta-analysis of randomized controlled trials found similar periapical healing rates between the two approaches. The decision often depends on the specific clinical situation, the tooth involved, and the child's ability to cooperate through multiple visits. It is also worth noting that tooth discoloration is more common with REPs than with apexification, which may be a consideration for front teeth where appearance matters. [3] [10]
Who Qualifies and When to Act
The best candidates for regenerative endodontics are children and teenagers with immature permanent teeth that have lost vitality due to infection or trauma.
Age and Candidacy
Regenerative endodontic procedures are most commonly performed on patients between the ages of 6 and 18. This age range corresponds to the period when permanent teeth are erupting but roots have not yet fully formed. Full root formation typically takes about three years after a tooth erupts into the mouth.
The ideal candidate has an immature permanent tooth with an open apex and a diagnosis of pulp necrosis (dead pulp tissue), usually with signs of infection such as a periapical lesion (an area of bone loss visible on X-ray around the root tip). The tooth should have enough remaining structure to be restored after treatment. [2]
Regenerative procedures have also been explored for some challenging cases. A 2024 case series described successful REPs in immature teeth affected by regional odontodysplasia, a rare developmental condition that causes abnormal tooth structure. This suggests the approach may have applications beyond typical trauma and infection cases. [1]
Why Timing Matters
Treating an infected immature tooth promptly is important. The longer the infection persists, the more damage it can cause to the stem cells in the apical papilla. These stem cells are essential for the regenerative process. If they are destroyed by prolonged infection, the tooth may lose its ability to regenerate tissue.
Research has examined whether the timing of the induction step (the visit where bleeding is stimulated) affects outcomes. A 2017 review found that both immediate and delayed induction protocols showed favorable results, though the evidence was limited. The standard protocol uses two visits, with antibiotic disinfection at the first visit and the blood clot induction at a follow-up visit. [7]
If your child has a tooth that was knocked out, pushed into the gum, or cracked due to trauma, seek evaluation within a few days. If there are signs of infection such as swelling, pain, or a pimple-like bump on the gum near the tooth, prompt evaluation by an endodontist is advised.
How to Prepare
Before the procedure, the endodontist will take detailed X-rays and possibly a cone-beam CT scan (a 3D X-ray) to evaluate the tooth's root development, the size of the open apex, and the extent of any infection.
Let the endodontist know about any allergies, especially to antibiotics or latex. The procedure involves placing antibiotic paste inside the tooth, so allergy information is critical. Also share any medications your child takes and any relevant medical history.
Your child should eat a normal meal before the appointment. The procedure is done under local anesthesia (numbing), so there is no need to fast. For anxious patients, some offices offer sedation options; ask about these during the consultation.
What Happens During Treatment
Regenerative endodontic procedures typically involve two office visits spaced one to four weeks apart, plus follow-up appointments to monitor root development.
First Visit: Disinfection
The endodontist numbs the area around the tooth with local anesthesia. A rubber dam, a thin protective sheet, is placed over the tooth to keep the treatment area clean and dry.
The endodontist creates a small opening in the top of the tooth to access the pulp chamber and root canal. Any dead or infected tissue is gently removed. The canal is then carefully irrigated (rinsed) with a low-concentration sodium hypochlorite solution to kill bacteria. Unlike a traditional root canal, the endodontist avoids scraping or filing the canal walls. Preserving the canal walls protects the stem cells in the surrounding tissue. [7]
After cleaning, the endodontist places a triple antibiotic paste or calcium hydroxide paste inside the canal. This medication stays in the tooth for one to four weeks to eliminate any remaining bacteria. A temporary filling seals the opening. Your child can return to normal activities, though soft foods may be recommended for a day or two.
If the endodontist uses triple antibiotic paste, they may take extra steps to reduce the risk of tooth discoloration. These steps can include applying a bonding agent to the inside walls of the pulp chamber before placing the paste, or substituting minocycline with a less staining antibiotic. Ask your endodontist which disinfection approach they plan to use and how they manage discoloration risk. [10]
Second Visit: Blood Clot Induction
At the second appointment, the endodontist reopens the tooth and removes the antibiotic paste. The canal is irrigated again to clear any remaining medication.
The critical step comes next. The endodontist uses a small instrument to intentionally irritate the tissue just beyond the root tip. This causes bleeding into the canal space. The blood fills the canal and forms a clot. This blood clot is the scaffold that will attract stem cells and growth factors. [7]
Once the blood clot reaches the desired level inside the tooth, the endodontist places a biocompatible material, typically MTA or Biodentine, over the clot to seal it in place. A permanent filling or crown is then placed on top to protect the tooth. The entire second visit typically takes 30 to 60 minutes.
Follow-Up and Monitoring
After treatment, the endodontist will schedule follow-up X-rays at regular intervals, typically at 3, 6, 12, and 18 months, and then annually. These X-rays track three key signs of success: resolution of any infection, thickening of the root walls, and narrowing or closure of the open apex. [5]
Some teeth show visible root development within six months. Others take a year or longer. In many cases, the tooth may also regain some sensitivity to cold or electric pulp testing, suggesting that nerve fibers have grown back into the regenerated tissue. However, not all teeth regain sensation, and this does not necessarily indicate failure.
During follow-up visits, the endodontist will also monitor the color of the tooth. If discoloration develops, it is typically noticeable within the first few months. Your endodontist can discuss cosmetic options such as internal bleaching if staining becomes a concern. [10]
Your child should avoid biting hard foods on the treated tooth for the first few weeks. Normal brushing and flossing can continue. Contact the endodontist if there is new swelling, persistent pain, or any signs of re-infection.
Cost and Insurance Considerations
Regenerative endodontic procedures typically cost more than a standard root canal but are comparable in cost to other complex endodontic treatments.
Cost ranges for REPs generally fall between $800 and $2,500 per tooth. Costs vary by location, provider, and case complexity. Factors that can increase cost include the need for a 3D scan, sedation, additional visits for complex infections, and the type of final restoration placed on the tooth.
Dental insurance may partially cover regenerative endodontic procedures, though coverage varies widely between plans. Some insurers classify REPs under the same billing codes as traditional root canals or apexification procedures. Others may consider them experimental. Ask your insurance provider for a pre-treatment estimate. Your endodontist's office can typically submit a predetermination request to clarify coverage before treatment begins.
When evaluating cost, consider the long-term value. A successful REP can allow an immature tooth to continue developing, potentially strengthening it enough to last for decades. The alternative, losing the tooth or having a weakened tooth that fractures later, may lead to more expensive restorative work such as implants or bridges down the road. If tooth discoloration occurs after treatment, cosmetic correction such as internal bleaching may add additional cost, so factor this possibility into your planning.
When to See an Endodontist
A child or teenager with signs of infection or trauma in an immature permanent tooth should be evaluated by an endodontist as soon as possible.
Your general dentist or pediatric dentist may be the first to identify a problem. Common signs include a tooth that has darkened in color, swelling or a pimple-like bump on the gum near a permanent tooth, pain that lingers after hot or cold exposure, or an X-ray showing an infection at the root tip of a tooth with an open apex.
A 2017 survey of dental providers found that endodontists and pediatric dentists were the specialists most likely to offer regenerative endodontic procedures. General dentists in the same survey were less likely to perform REPs and more likely to refer patients to a specialist for this treatment. [6]
Seek specialist evaluation in these situations:
The American Association of Endodontists recognizes regenerative endodontic therapy as a biologically based treatment option for immature teeth with necrotic pulp. [8] If your child's dentist has mentioned an open apex, incomplete root formation, or the need for apexification, ask about whether a regenerative procedure might be an option.
- Your child's permanent tooth was knocked out, loosened, or cracked from an injury
- A permanent tooth has turned dark gray or yellow
- There is swelling, a draining bump, or persistent pain near a permanent tooth
- An X-ray shows infection at the tip of a tooth with an open (immature) root
- Your dentist has recommended apexification or extraction of an immature permanent tooth
Find a Regenerative Endodontics Specialist
If your child has an injured or infected immature permanent tooth, an endodontist with experience in regenerative procedures can evaluate whether revascularization is a good option. Use the My Specialty Dentist directory to search for an endodontist in your area. You can filter by specialty and location to find a provider who offers regenerative endodontic treatment. Visit the endodontics page to start your search and learn more about what endodontists do.
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