Tooth Regrowth Drug Enters Phase 2 Human Trials, Promising End to Cavities and Implants

Losing a permanent tooth has historically meant a lifetime of synthetic replacements—titanium screws, porcelain crowns, or removable dentures. For millions of adults and children missing teeth due to decay, injury, or genetics, the jawbone becomes a construction site rather than a biological foundation. But a new class of medicine is shifting dentistry from mechanics to biology, promising to wake up dormant tooth buds hidden in the human jaw.[3]

In August 2026, Japan's Pharmaceuticals and Medical Devices Agency cleared the clinical trial notification for Phase 2 human trials of TRG-035, an experimental intravenous drug designed to regrow natural teeth. Developed by Kyoto University spin-out Toregem BioPharma, the drug recently secured $5.3 million in fresh funding to test its efficacy. This milestone follows a successful Phase 1 safety trial involving 30 adult men, which concluded earlier this year with no serious adverse events reported.[1][2]

The therapy targets a specific protein called USAG-1 (uterine sensitization-associated gene-1). In healthy adults, USAG-1 acts as a biological brake, suppressing vestigial tooth buds from developing into a third set of teeth once the permanent adult set has erupted. TRG-035 is a monoclonal antibody that binds to and neutralizes this protein, effectively releasing the brake and allowing the dormant buds to grow into fully functional teeth.[1]

While the ultimate goal is to treat adults who have lost teeth to decay or injury, the Phase 2a trial will focus on a highly specific population: 24 children aged two to seven with severe congenital hypodontia. This rare genetic condition leaves patients missing six or more permanent teeth from birth. Because children's jawbones are still growing, traditional implants are often impossible, leaving them reliant on poorly fitting dentures that impede nutrition, speech, and jaw development.[1][2]

The biological premise is heavily supported by preclinical evidence. A landmark 2021 study demonstrated that blocking USAG-1 successfully stimulated whole-tooth regeneration in mice and ferrets. The newly grown teeth possessed normal enamel, dentin, and pulp, and integrated naturally with the surrounding jawbone and blood vessels. Moving from animal models to human safety trials in just a few years marks an unusually rapid translation for regenerative medicine.

However, researchers caution against overselling the immediate results for average dental patients. While animal models grew structurally sound teeth, human trials must still prove that a chemically stimulated tooth will align correctly with the existing bite and form proper neural connections. Furthermore, waking up a dormant tooth bud in a child with a genetic defect is biologically different from regenerating a tooth in a 60-year-old jaw where the socket has been empty for decades.[1]

Despite the excitement, clinical reality requires patience. The drug remains investigational, and researchers at Kitano Hospital estimate a commercial rollout by 2030 at the earliest, assuming all trials succeed. Early cost projections sit around $11,000 per regenerated tooth—a steep initial price that developers expect will fall as the technology scales, eventually positioning it as a viable third option alongside dentures and implants.[1]

For patients weighing their future dental options, the landscape is splitting into two distinct paths: the established mechanical reliability of titanium implants versus the emerging biological promise of regenerative medicine. Understanding the trade-offs between these approaches is crucial for anyone managing long-term oral health, as the choice dictates not just the immediate procedure, but decades of bone and tissue health.[3]