Researchers at New York University have developed a zinc-based compound that fights tooth decay without drilling or fillings, offering a potential alternative to silver diamine fluoride (SDF), which can permanently stain teeth.
The liquid compound reacts to the tooth’s pH and chemical environment, transforming into a solid that seals dentin tubules while slowly releasing antimicrobial zinc, according to a university news release on September 29. “If a compound does not stain, has strong antimicrobial activity, and blocks the tubules, it should stop tooth decay while being aesthetically acceptable,” said Deepak Saxena, professor of molecular pathobiology and director of research innovation and entrepreneurship at NYU.
Zinc has long been valued in dentistry for its antimicrobial properties and is commonly found in toothpaste and mouthwash. One form, zinc phosphate, is approved as a dental adhesive and could speed research into new decay treatments compared with untested materials, the release noted.
The researchers initially tested zinc phosphate to see if it could penetrate deeply into teeth. For relief from pain and sensitivity, treatments must reach the dentin, which contains about 40,000 tiny tubules per square millimeter that transmit sensation. Using thin human tooth slices, the team applied phosphate followed by zinc and observed deposits deep inside the tubules. While effective, the two-step process proved impractical for clinical use.
To simplify treatment, the team developed a new molecule called zinc tetramine difluoride. This compound begins as a liquid that solidifies into zinc oxide when absorbed, sealing the tubules and gradually releasing antimicrobial zinc. Tests showed that zinc oxide deposits remained in the dentin for at least one to two months. Researchers aim to extend the treatment’s activity further to reduce hypersensitivity and block bacterial growth.
“We know there is a need—and a market—for a product that stops tooth decay, is effective, affordable, easy to use, and non-staining, given the rise in untreated cavities worldwide,” Saxena said.
If successful, the zinc-based treatment could provide a practical, aesthetically acceptable option for millions of patients, reducing reliance on drilling and silver-based solutions while preventing further decay.