Tooth decay is the most common health problem in the world.
Billions of people live with cavities, and many suffer from the pain they cause.
While traditional dentistry relies on drilling and filling, researchers are working on easier, non-invasive ways to stop cavities before they get worse.
For the past several years, one promising option has been a liquid called silver diamine fluoride. Applied directly to the surface of teeth, it can stop small cavities from progressing and even prevent new ones from forming.
Because it is inexpensive and simple to use, it has been given in schools, rural clinics, and to patients who struggle with dental care, including those with disabilities.
But it comes with one significant drawback: silver turns the treated area black.
The dark stains are permanent, making the treatment unpopular for visible teeth, even though it works well.
Marc Walters, a professor of chemistry at New York University, wanted to solve that problem. He wondered whether another mineral might offer the same antimicrobial power as silver without leaving a stain.
His attention turned to zinc, a nutrient found naturally in foods like oysters and beef and already widely used in dental products such as toothpaste and mouthwash.
Walters and his team began testing zinc phosphate to see if it could penetrate deep into the dentin—the porous middle layer of the tooth that connects to nerves and often causes pain when exposed.
Under a microscope, they saw that the compound could travel into tiny tubules in the dentin, plugging them and blocking sensitivity. Still, the process required two steps, which Walters knew would not be practical for dentists.
Inspired by silver diamine fluoride, he developed a new single-step treatment: zinc tetramine difluoride. This compound starts as a clear liquid but transforms once it enters the tooth.
Inside the dentin tubules, it becomes a solid zinc oxide, forming long mineral cylinders that quickly seal off the tubules—much like corks in a bottle.
This not only stops pain within minutes but also creates a slow-release barrier that fights cavity-causing bacteria for months.
Walters’s research showed that zinc could remain in the tooth for at least one to two months, and possibly much longer. The hope is to create a treatment that protects against sensitivity and bacteria for years, not just weeks. Importantly, it does all this without staining the tooth.
The work has attracted interest beyond the lab. Southern Dental Industries, an Australian company that produces restorative dental materials, purchased the license for Walters’s zinc technology.
At the same time, Walters teamed up with NYU Dentistry professor Deepak Saxena, who has experience bringing dental innovations to market. Together, they are refining the formula, testing its safety, and studying how well it prevents bacterial growth.
Because zinc has already been used safely in dentistry for decades, the path toward regulatory approval may be quicker than for brand-new substances. If clinical trials are successful, dentists could soon have access to a treatment that stops cavities without drilling, avoids black stains, and is inexpensive to use.
The potential impact is enormous. Children afraid of the dentist could be treated without needles or drills. Older adults prone to root cavities would have a simple option for relief. And in underserved regions, where access to dental care is limited, this treatment could help prevent pain and tooth loss on a large scale.
Walters and Saxena see a future where zinc-based treatments make tooth decay less common and less frightening. If their work succeeds, dentistry could move beyond silver—and finally offer patients a clear, painless way to protect their smiles.
Source: KSR.
