There are few things worse than having to avoid eating your favorite ice cream because you don’t want to experience the pain caused by sensitive teeth. That may soon be a thing of the past, with researchers developing a novel way of rebuilding lost tooth minerals, offering a long-term solution to the problem.
Tooth sensitivity, also called dentin hypersensitivity, occurs when a tooth's inner dentin layer and the tubules within it get exposed, most often due to the loss of protective enamel at the crown and cementum on the tooth’s root, a process called demineralization. With the softer interior of the tooth exposed, nerves and blood vessels are prone to react to heat, cold, touch, pressure, or acidic foods, causing pain.
Enamel can be worn away by abrasion, decay or teeth-grinding, and it can’t be repaired by natural processes as it’s the only non-living tissue in our bodies. In recent years, the rise in peroxide-based dental whitening products has exacerbated the issue of enamel wear. The only way to treat dentin hypersensitivity currently is to treat the symptoms.
But researchers at the University of Washington have developed a novel treatment that can rebuild lost tooth minerals, offering a permanent fix to the problem of dentin hypersensitivity.
“We [dentists] see patients with hypersensitive teeth, but we can’t really help them,” said Sami Dogan, one of the study’s co-authors. “We all have these repair options available in the market, but they’re all transient. They focus on treating the symptoms and not addressing the root cause.”
The researchers’ goal was to develop a biomimetic, something that closely resembles or mimics the natural biochemical processes that occur in the body. So they focused on a peptide – a short chain of amino acids – that’s key to the biological development of human teeth. Called sADP5, the peptide latches on to calcium and phosphate ions, the main minerals found in teeth, and uses them to build new mineral microlayers.
In preclinical trials, the researchers created a lozenge the size of a cough drop with a core of calcium and phosphate coated in a sADP5-infused flavoring, which they tested on dentin discs extracted from human teeth. Each of the discs had exposed dentin tubules. After three rounds of peptide-guided remineralization treatment, the researchers accomplished the formation of a new mineral layer on the exposed dentin, which extended into the dentin tubules, occluding them.
“Our technology forms the same minerals found in the tooth, including enamel, cementum, and dentin alike, which had dissolved previously through demineralization,” said Deniz Yücesoy, lead author of the study. “The newly formed mineral microlayers close the communication channels with the tooth nerves, and then hypersensitivity shouldn’t be an issue for you.”
Measuring the hardness of the newly created mineral layer, the researchers found that it was significantly higher than that of demineralized and normal human dentin. Testing it using thermal aging, the mineral layer did not separate from the tooth. Both suggest that it could withstand the long-term mechanical and thermal stresses encountered in the natural oral environment.
In addition to the lozenge, the researchers have incorporated their biomimetic peptide-based formulation into mouthwash, dental gels, tooth whiteners and toothpaste.
“There are lots of different design and delivery methods,” said Hanson Fong, a co-author of the study. “The most important thing is the peptide, the key ingredient in the given formulation, and it’s working.”
Further research is needed to investigate the permeability and chemical stability of the mineral layer to achieve an effective, easy-to-apply treatment for dentin hypersensitivity, including implementing the peptide-guided approach under in vivo conditions.
The study was published in the journal ACS Biomaterials Science & Engineering.
Source: University of Washington