Japanese Scientists Advance Human Trials for Drug That Regrows Lost Teeth

A Japanese biotech company, Toregem BioPharma, has successfully advanced the world's first tooth-regrowing drug into Phase II human trials after raising $5.3 million in new funding.[1][2]

The drug, known as TRG035, works by blocking a specific protein that suppresses tooth development, effectively waking up dormant tooth buds that humans naturally possess.[3]

While the prospect of regrowing a lost molar sounds like science fiction, the clinical reality is moving rapidly. Phase I trials at Kyoto University Hospital, which began in late 2024 with 30 healthy adult men, have concluded their initial safety windows without serious adverse events.[4]

Now, the medical community is evaluating how this biological approach will eventually stack up against the gold standard of modern dentistry: the titanium dental implant.[5]

To understand the trade-offs, we have to look at how TRG035 actually works. Humans naturally grow two sets of teeth: baby teeth and adult teeth. But we also possess the genetic blueprints for a "third set" of teeth, which are kept permanently suppressed by a protein called USAG-1.[3]

By administering an intravenous antibody that neutralizes USAG-1, TRG035 removes this biological roadblock. In animal models, including mice, ferrets, and dogs, a single injection was enough to trigger the development of fully functional teeth.[4]

The immediate clinical target for this drug is not the average adult with a cavity, but children suffering from congenital tooth agenesis—a rare condition where individuals are born missing some or all of their permanent teeth.[1][2]

For these children, traditional implants are often impossible because their jawbones are still developing. A biological solution that grows natural teeth alongside the developing jaw would be a life-changing intervention.[5]

However, Toregem BioPharma has explicitly stated its long-term goal: bringing the drug to the broader adult market by 2030 to treat tooth loss caused by decay, gum disease, or injury.[3]

This timeline means that adults currently facing tooth loss must weigh the immediate, proven benefits of dental implants against the future promise of biological regeneration.[5]

Dental implants have a decades-long track record, boasting success rates of over 95%. They provide immediate structural support to the jawbone, preventing the bone loss that typically follows an extraction.[5]

Yet implants are invasive, requiring surgery to drill a titanium post into the bone, and they lack the natural periodontal ligament that gives real teeth their shock-absorbing micro-mobility.[5]

TRG035 promises a tooth that is biologically yours, complete with natural nerves, blood vessels, and ligaments. But it comes with profound uncertainties: we do not yet know how long a chemically induced tooth takes to grow in a human, or if it will align perfectly with the existing bite.[4]

Furthermore, early cost estimates for the biological treatment hover around $11,000 per tooth, making it significantly more expensive than a standard implant, which typically costs between $3,000 and $5,000.

For patients, the decision ultimately comes down to timing and anatomy. Waiting for a drug that is still in trials means living with a missing tooth, which can lead to adjacent teeth shifting and jawbone deterioration in the meantime.[5]

The practical takeaway for readers is reassuring but grounded: if you need a tooth replaced today, traditional implants remain the safest, most effective choice. But for the first time in medical history, a biological alternative is visibly on the horizon.[5]