A Kid Falls Off a Bike — and That’s Where This Story Starts
A 9-year-old boy from Torrance was riding his bike down the sidewalk when he hit a crack in the pavement. He went over the handlebars. His front tooth slammed into the concrete.
His parents brought him to the dentist. The tooth looked okay on the outside — a small chip, nothing too scary. But a few weeks later, the tooth started turning dark. It wasn’t responding to cold anymore. The nerve had died.
Here’s the problem. This kid’s tooth wasn’t finished growing yet. The root was still short. The walls were still thin. The tip of the root was wide open — what we call an “open apex.” A regular root canal on a tooth like this is really tricky. You can’t pack filling material into a canal that has no bottom. And even if you manage it, you’re left with a thin, fragile root that could fracture years down the road.
So what do you do?
That’s where regenerative endodontics comes in. And it’s one of the most exciting things happening in dentistry right now.
What Is Regenerative Endodontics?
Instead of filling the canals with rubber and sealer like a traditional root canal, regenerative endodontics works with the body’s own biology. We clean out the infection, then create the right conditions for the tooth to heal itself from the inside.
The goal is simple: get the root to keep growing.
When it works — and it works a lot — the root walls thicken, the root gets longer, and the open tip closes up on its own. The tooth goes from fragile and underdeveloped to strong and functional. That’s a game-changer for a kid who still has 70+ years of chewing ahead of them.
Dr. Jason Phan performs regenerative endodontic procedures at our Torrance office for young patients across the South Bay. This is specialized work, and it takes a different skill set than a standard root canal.
How the Procedure Works
The process is straightforward, but it takes patience. It usually happens over two appointments.
Appointment One: Disinfection
We open the tooth, gently clean out the infected or dead tissue inside the canal, and place an antibiotic paste (a mix called triple antibiotic paste or sometimes calcium hydroxide). The tooth gets sealed with a temporary filling, and we send the patient home for 2-4 weeks. During that time, the antibiotic paste kills off any remaining bacteria.
Appointment Two: The Magic Part
This is where things get interesting. We remove the antibiotic paste, then intentionally irritate the tissue just beyond the root tip. This causes a small amount of bleeding into the canal. That blood carries stem cells from the surrounding bone and tissue.
The blood clot that forms inside the canal acts like a scaffold. Think of it like a framework that the body’s own cells can grab onto and start building new tissue. We place a biocompatible material (MTA) on top of that blood clot to seal everything off, then close the tooth.
And then we wait. Nature does the rest.
What Happens Next
Over the following months, the body fills in that scaffold with new tissue. The root walls get thicker. The root gets longer. The open apex starts to close. We monitor progress with X-rays and CBCT 3D imaging at regular intervals — usually at 3 months, 6 months, 12 months, and then annually.
It’s honestly pretty amazing to watch on the X-rays. You see a tooth that was basically a thin shell slowly transform into something solid and well-developed.
Who Qualifies for This Treatment?
Regenerative endodontics is mainly for kids and teenagers. Specifically, patients who have:
- Immature permanent teeth — the root hasn’t finished forming yet
- An open apex — the root tip is wide open instead of closed
- A dead or infected nerve — from trauma, deep cavities, or other injuries
- Enough remaining tooth structure to restore after treatment
Most candidates are between 7 and 18 years old. These are kids whose adult teeth came in but then got damaged before the roots had a chance to fully develop. Trauma is the most common cause — falls, sports injuries, bike accidents. Sometimes a deep cavity is the culprit.
Adults generally don’t qualify because their root tips are already closed. For adults with infected teeth, a traditional root canal or retreatment is usually the better path.
Why Not Just Do a Regular Root Canal?
Great question. Here’s the honest answer.
A traditional root canal on an immature tooth with an open apex is difficult. The canal is wide and shaped like a funnel — wide at the bottom, narrow at the top. There’s no natural stop for the filling material. Endodontists developed a technique called apexification (placing an MTA plug at the open tip) to deal with this, and it works. But the root stays thin. It stays short. It doesn’t get stronger over time.
Regenerative endodontics gives the tooth a chance to actually finish developing. The root walls thicken. That means the tooth is way less likely to fracture during normal use. For a kid who needs this tooth to last a lifetime, that difference matters a lot.
Results: What the Research Shows
Studies on regenerative endodontics show success rates between 75-95%, depending on how you define success. Most treated teeth show at least some continued root development. Many show full closure of the open apex and significant thickening of the root walls.
The American Association of Endodontists has published clinical guidelines supporting regenerative procedures for immature teeth with necrotic pulp. This isn’t experimental anymore. It’s evidence-based treatment with a growing body of research behind it.
Dr. Phan follows up with every regenerative case closely. We track root development with periodic imaging and adjust our approach if things aren’t progressing as expected.
Management of Dental Cysts
While we’re talking about things that happen around tooth roots — let’s talk about dental cysts.
What Is a Dental Cyst?
A dental cyst is a fluid-filled sac that forms at the tip of a tooth root, usually because of a long-standing infection. The body walls off the infection with a lining of tissue, and that pocket slowly fills with fluid. Over time, it can grow and start pressing on surrounding bone, other teeth, or even nerves.
A lot of patients don’t even know they have one. Dental cysts are often painless until they get big enough to cause problems.
How We Diagnose Them
Our CBCT 3D imaging is the best tool for spotting and measuring dental cysts. A regular 2D X-ray can show a dark shadow at the root tip, but CBCT tells us the exact size, shape, and relationship to nearby structures. That information drives the treatment plan.
Treatment Options
Small cysts (and many periapical lesions that look like cysts) often resolve on their own once the source of infection is treated. A root canal or retreatment removes the bacteria, and the body reabsorbs the cyst over several months. We see this happen regularly at our Torrance office.
Larger cysts — or true cysts that have a complete epithelial lining — sometimes need surgical removal. That’s where endodontic microsurgery comes in. Dr. Phan can remove the cyst surgically through a small incision while also addressing the root tip at the same time.
The key is accurate diagnosis. Not every dark shadow on an X-ray is a cyst. And not every cyst needs surgery. Dr. Phan takes the time to figure out which situation you’re actually dealing with before recommending a treatment path.
Why an Endodontist Should Do This
Regenerative endodontics requires specialized training, specialized equipment, and a lot of patience. This isn’t a procedure most general dentists are set up to perform.
Here’s what Dr. Phan brings to the table:
- Endodontic specialty training — 2+ years of advanced training beyond dental school, focused entirely on the inside of teeth
- Surgical microscope — 25x magnification for precise canal disinfection and material placement
- CBCT imaging — 3D views to assess root development, measure open apices, and track healing over time
- Experience with young patients — kids need a different approach, both clinically and in terms of chair-side manner
- Backup plan — if regenerative treatment doesn’t progress as expected, Dr. Phan can pivot to apexification or other approaches without starting over from scratch
The Future of Regenerative Endodontics
This field is moving fast. Researchers are working on better scaffolds, growth factors that speed up root development, and even lab-grown pulp tissue. The day may come when we can fully regenerate the nerve and blood supply inside any tooth — not just immature ones.
We’re not there yet. But the progress in just the last 10-15 years has been remarkable. What used to be an experimental concept taught in a few dental schools is now a standard part of endodontic practice. Dr. Phan stays current with the latest research and techniques so that families in Torrance and the South Bay have access to these treatments close to home.
Serving Torrance and the South Bay
Our office sees young patients from all over — Torrance, Redondo Beach, Manhattan Beach, Hermosa Beach, Palos Verdes, Gardena, Carson, and Lomita. Many are referred by pediatric dentists and general dentists in the South Bay who recognize that regenerative endodontics requires a specialist.
If your child has an injured or infected permanent tooth that hasn’t finished growing, don’t wait. The sooner we treat it, the better the chances for successful root development.
Schedule a Consultation
Call our Torrance office or contact us online to schedule an appointment. Dr. Phan will take a CBCT scan, evaluate the tooth, and walk you through every option — including whether regenerative endodontics is the right fit for your child’s situation.
A damaged tooth doesn’t have to stay damaged. Sometimes the body just needs a little help to finish what it started.