Teeth may look simple on the outside, but inside they are complex structures made of minerals, proteins, and tiny channels that allow them to be both strong and sensitive.
A new study has revealed an unexpected detail about this inner structure: the amount of zinc inside teeth increases dramatically as you move closer to the nerve.
Scientists say this discovery could influence how dentists choose fillings and other treatments in the future.
Researchers from Charité Berlin, TU Berlin, and Helmholtz-Zentrum Berlin used advanced imaging techniques to study the three-dimensional structure of teeth.
Their work, published in the journal VIEW, mapped how zinc — a trace element found in small amounts in the body — is distributed within dentin, the hard tissue that lies beneath enamel and surrounds the dental pulp.
Dentin is full of microscopic channels called tubules that carry sensations such as heat and cold to the nerves inside the tooth.
These tubules become more numerous toward the center, making the inner dentin more porous.
The scientists discovered that zinc levels increase five to ten times in these more porous regions near the pulp compared with the outer layers of the tooth.
Until now, little was known about how zinc is arranged inside healthy teeth.
Most discarded human teeth available for research had been exposed to toothpaste, dental treatments, or fillings that contain zinc, making it difficult to measure natural levels.
To avoid this problem, the team studied cattle teeth, which are very similar to human teeth but had not been treated.
Using microscopes and 3D X-ray imaging, the researchers mapped the tooth structure and measured the distribution of elements such as calcium, phosphorus, and zinc. While calcium and phosphorus were evenly spread throughout the dentin, zinc showed a sharp increase toward the inner part of the tooth.
This finding could have practical importance for dentistry. Many dental materials, including some fillings and pastes used in root canal treatments, contain zinc. Knowing that natural zinc levels are already higher near the pulp may help dentists decide when high-zinc materials are beneficial and when they might cause unwanted effects.
Scientists also believe zinc may play a role in how teeth respond to damage or acid exposure from cavities. In healthy teeth, zinc is locked inside the dentin, but acids could release it and activate enzymes that might weaken the tooth structure. More research on human teeth is needed to confirm these effects.
Beyond dental care, the discovery suggests zinc could serve as a marker for tooth density and strength. Because zinc levels closely follow changes in dentin porosity, measuring zinc may help scientists understand how teeth age and how treatments influence their durability over time.
The study highlights how much remains to be learned about the microscopic structure of teeth. What seems like a tiny trace element may turn out to be an important factor in tooth health. In the future, dentists may use this knowledge to design better fillings and treatments that protect teeth more effectively and last longer.
Source: KSR.
