Over 30 years of dentistry, Sami Dogan has treated just about every kind of tooth ailment. Cavities are simple to fill. Dental implants have become routine. But there’s one problem, he said, that annoys even the most experienced dentists: hypersensitivity, the painful sensation sparked by contact with hot, cold or acidic food.����

“We see patients with hypersensitive teeth, but we can’t really help them,” said Dogan, a . “We have all these repair options available in the market, but they’re all transient. They focus on treating the symptoms and not addressing the root cause. I see my patients after a couple of weeks, several months, again coming to my practice complaining about the same issue.”��

So a few years ago, Dogan began working with a team of UW materials engineers who had set out to develop a natural protocol to rebuild lost tooth minerals, which they believed could also become��permanent fix to this painful condition. Their solution, , builds new mineral microlayers that penetrate deep into the tooth to create effective, long-lasting natural protection.����

The ultimate goal, Dogan said, is to provide easily accessible relief for the millions of adults worldwide who suffer from tooth sensitivity.��

The painful sensation emerges when acids, like those created after saliva breaks down sugar, wear away at tooth enamel. Uninterrupted, that wear — called demineralization — can expose the pathways connecting the tooth’s hard exterior with its softer interior, dentin and pulp. Nerves and blood vessels are left defenseless, and pain ensues.  ��

The body has no way to repair or regrow worn enamel, which is the only non-living tissue in the human body. To reverse that loss, the UW researchers designed their solution to be molecularly biomimetic, meaning it closely resembles the molecular processes by which the body develops teeth.����

At the heart of that process is a peptide — a short chain of amino acids — derived from the larger protein amelogenin, which is key in the biological development of human teeth. Named sADP5, the specifically tailored peptide grabs onto calcium and phosphate ions — the main components of tooth mineral — and uses them to build new mineral microlayers.

“Our technology forms the same minerals found in the tooth, including enamel, cementum, and dentin alike, which had dissolved previously through demineralization and caused the sensitivity,” said lead author , who began this work as a postdoctoral researcher at UW and is now an assistant professor at the . “The newly formed mineral microlayers close the communication channels with the tooth nerves, and then hypersensitivity shouldn’t be an issue for you.”

The peptide can be integrated into nearly any type of oral health product. In preclinical trials, participants received a dental lozenge the size of a cough drop, with a core of calcium and phosphate coated in a layer of peptide-infused flavoring. Researchers have also designed peptide-based formulations including mouthwash, dental gels, tooth whiteners, and toothpaste.  ��

“There are lots of different design and delivery methods,” said , an assistant teaching professor of materials science and engineering at the UW and co-author of the paper. “The most important thing is the peptide, the key ingredient in the given formulation, and it’s working.” ��

This research was conducted in the at the UW under the direction of , a professor of materials science and engineering. Other authors include John Hamann and Eric Hall from the UW Department of Materials Science and Engineering. The research was funded by the National Science Foundation, the Washington State Life Sciences Discovery Fund, Gap Funds, and the UW Department of Restorative Dentistry’s Spencer Funds. ��

For more information, contact Sarikaya at sarikaya@uw.edu, Fong at hfong@uw.edu, Dogan at samido@uw.edu or Yucesoy at denizyucesoy@iyte.edu.tr. ��

Like many of life’s challenges, it turns out that dental plaque is all about how you respond.����

A team of microbiologists, immunologists and periodontists in the ����Ӱ�Ӵ�ý’s School of Dentistry are expanding upon their recent discovery that people’s gums respond to plaque with three distinct types of inflammation. The team has received a from the National Institutes of Health to better understand each of��those three responses. ��

The team discovered that people fall into three main types of responses to bacteria in plaque, including a new type of what UW microbiologist Jeffrey McLean called “slow responders.” That discovery added new depth to the field’s understanding of gingivitis — the swelling, redness and bleeding in the gums that occurs when plaque builds up on and below the gumline. ��

Left untreated, gingivitis can lead to periodontitis, an irreversible condition that eats away at gum tissue and the bone that supports teeth. Periodontitis has been linked to an increased risk of heart and lung disease and other systemic diseases in humans.��

Gingivitis research could also deepen our understanding of inflammation in the rest of the body, McLean said, which can be difficult to study in real time.����

“We think eventually, knowing someone’s responder type could also relate to their response to other things. Even, potentially, the virus that causes COVID,” said McLean, an associate professor in the Department of Periodontics. “If you’re a certain type of responder, you might have that response to other viral infections, too.” ��

The team will use the new grant to explore the specific mechanisms that control gingival inflammation. Researchers will identify the specific bacteria, fungi, viruses and metabolites associated with different responder types. Then they will attempt to understand what causes such vastly different inflammation responses.����

“We don’t know if it’s your prior history, or if that’s your response type. Those are the questions we try to answer eventually,” McLean said. “By knowing there’s three major response types, we can now dig in and find out what makes them different and what’s the basis of why they’re responding differently.”��

That research will rely upon the time-tested model of experimental gingivitis — the only model that allows researchers to create, and immediately reverse, inflammation in healthy human subjects. Participants will undergo a full dental cleaning, and then stop brushing several of their teeth for 21 days. As plaque builds up and inflammation sets in, researchers will take samples from both sides of participants’ mouths. After three weeks, participants will receive another cleaning, and the inflammation will recede.����

Previously, scientists believed there were two types of responses to plaque below the gumline: Some people’s gums responded to plaque with strong, swift inflammation and redness, while other people’s gums had a more muted response.����

In 2021, the researchers . They showed that some people accrue dental plaque much more slowly than others, meaning it takes longer for their gums to become inflamed. Once that inflammation kicks in, however, slow responders’ gums become just as inflamed as the strong responders’ gums. They also found unique molecular signatures in the other responder types.��

These discoveries open a path to develop treatments and products specifically designed for different response types — for example, a toothpaste that replicates the bacterial conditions found in slow responders’ mouths could help strong responders stave off gingivitis.��

Knowing your specific responder type might also change how you maintain good oral hygiene. Slow responders, for example, may not need to visit a dentist as often as those with stronger, quicker inflammation responses.����

Those discoveries won the 2022 , given to the year’s most outstanding research in the field.������

This trial will be led by principal investigators McLean and Rich Darveau, with co-investigators Diane Daubert and Yung-Ting Hsu, all of the UW School of Dentistry. The trial will be conducted in the UW Regional Clinical Dental Research Center in the Health Sciences Building with clinical site investigators Marilynn Rothen and Mary K Hagstrom. The award, from the National Institute of Dental and Craniofacial Research, also includes collaboration with the University of Texas Health Science Center at San Antonio.��

For more information, contact McLean at jsmclean@uw.edu.��