Repurposing Extracted Teeth: A Bioactive Strategy for Bone Regeneration with Dr. Michal Halperin-Sternfeld

A summary of the Webinar given to Alpha Omega members on January 22^nd 2026

This lecture explores a novel approach to transforming “hopeless teeth” into an autogenous bioactive graft material for alveolar bone regeneration.

Michal started with a simple question: “What do we usually do with extracted teeth?”

We throw them away. We treat them like biological waste!

But what if I told you that an extracted tooth might actually be one of the best bone graft materials we have?

That’s the big idea behind this lecture: shifting our mindset from “discarded tooth” to autologous gold standard for bone regeneration. And I’ll walk you through it in two parts—first, what we’re already doing clinically, and second, what the lab research is showing us about where this can go next.

Bone loss

The problem we all know too well ☹

Tooth extraction is one of the most common procedures in dentistry. And we also know what follows almost every time: alveolar bone resorption.

The numbers are sobering. About 25% of bone volume disappears in the first year, and over time, that can reach 60% loss. What’s even more critical is when this happens—half of that resorption occurs in just the first three months. Most of it is horizontal, around 3–4 mm, but we also lose vertical height, especially on the buccal side.

Yet despite all of this, many extraction sockets are still left ungrafted. What starts as a simple extraction often comes back later as a complex regenerative and aesthetic nightmare.

We know that alveolar ridge preservation works. It reduces bone loss, improves implant survival, and supports healthier peri-implant tissues long-term. So the question isn’t whether to graft—it’s what should we graft with?

Why current graft materials don’t always deliver

In theory, the “perfect” graft material should be biocompatible, maintain space, resorb at the right rate, support bone growth, and ideally even induce new bone formation by delivering growth factors or cells.

But in reality, results can be inconsistent. And a big reason for that comes down to the immune response, especially the behaviour of macrophages.

Early on, you want M1 macrophages—they’re pro-inflammatory and help with cleanup. But if they hang around too long, healing stalls. For real regeneration, you need the shift to M2 macrophages, which are pro-regenerative and pro-healing.

Here’s the key point: biomaterials themselves strongly influence this immune balance. So it’s not just about filling space—it’s about how the body talks to the material.

So why teeth?

Autogenous bone is still considered the gold standard—but it comes with limited availability, donor-site morbidity and fast resorption.

Now look at dentin. 

Dentin makes up about 85% of the tooth, and structurally, it’s remarkably similar to cortical bone. It contains growth factors like BMP-2, it’s osteoinductive, and it resorbs slowly—exactly what we want in a graft.

And unlike autogenous bone blocks, teeth are:

Already there, Patient-specific, Cost-effective and otherwise thrown away So why not use them?

What does the clinical evidence say?

Clinically, extracted teeth can be used in different forms. You can section roots into blocks, or you can grind them into particulate grafts.

The processing is surprisingly simple—about eight minutes from start to finish: clean the tooth, grind it, disinfect it, rinse it. The resulting particles, usually between 300 and 1200 microns, are bacteria-free and handle beautifully.

And the data?  Well actually it’s very convincing 😊

Studies and systematic reviews show outcomes comparable to autogenous bone. Tooth-derived grafts have been used successfully in socket preservation, lateral and vertical augmentation, sinus lifts, and even periodontal defects—with less morbidity and lower cost.

Clinically, the cases show predictable regeneration and straightforward implant placement.

So clinically, this already works. But………regeneration isn’t just mechanical—it’s immunological.

This brings us to the research side.

Bone regeneration is tightly linked to osteoimmunology—the interaction between the immune system and skeletal tissues. The goal now isn’t just to place a graft, but to engineer materials that actively instruct the immune system, especially macrophages, to support regeneration.

Enter the bioactive tooth-derived scaffold

In the lab, this led to the development of an injectable hydrogel platform made from hyaluronic acid and a self-assembling peptide. Think of it as an extracellular matrix mimicking scaffold—soft, tuneable, and biologically active. The stiffness was optimized to around 45 kPa, which turns out to be ideal for osteodifferentiation of mesenchymal cells and finally bone formation.

When this hydrogel was tested alone in a critical-size calvarial defect—a defect that normally doesn’t heal—it achieved around 93% bone regeneration. In very large defects. However, a hydrogel is not enough eliminate collapse of the soft tissues therefore the addition of a bone substitute is requires. Dentin alone achieved about 80% regeneration.

But…… the real breakthrough came when the two were combined.

The “Sticky Tooth” concept

By combining dentin particles with the hydrogel, a “sticky tooth” scaffold—injectable, mouldable, easy to handle, and able to adapt to irregular defects was created.

The results were remarkable:

• Complete bone regeneration

• Enhanced remodelling of dentin particles

• Replacement by new, vital, lamellar bone

• Histology showed active osteoclasts and osteoblasts, meaning this wasn’t passive filling—it was true bone turnover and replacement resorption.

What was happening immunologically?

The scaffold actively promoted M2 macrophage polarization. Early on, M2 macrophages clustered at the scaffold–periosteum interface. Over time, they migrated deeper into the defect, supporting ongoing bone formation. Their elongated shape confirmed a pro-regenerative phenotype.

One really important takeaway here is the role of the periosteum—it’s not just a passive layer, but a critical reservoir of immune-regenerative cells.

So, where next?

The future focus is on immune-instructive biomaterials, especially for patients who don’t heal well—elderly patients, or those with chronic inflammation, impaired macrophage function, reduced angiogenesis, or low bone turnover.

The idea is no longer just to place a graft—but to direct regeneration by guiding the immune response.

Final thoughts:

Extracted teeth are not waste. They are an underused, powerful, autologous resource.

And when you combine them with bioactive, immunomodulatory scaffolds, you’re not just preserving bone—you’re redefining what regenerative dentistry can look like.

We’re literally turning something we throw away into a regenerative gold standard.

Thank you