Teeth play a crucial role in breaking down food, with their tough enamel layer protecting them from the immense stress of chewing. However, unlike other bodily materials, enamel lacks the ability to repair itself, leaving it vulnerable to wear and tear as we age.
A research team from the University of Washington (UW) and the Pacific Northwest National Laboratory (PNNL) is delving into how enamel changes over time, aiming to develop strategies to maintain healthier teeth for longer. Their recent study, published in Communications Materials, sheds new light on enamel’s composition and how fluoride, a key protective agent, is integrated as we age.
Fluoride and Aging Enamel
The team analyzed enamel samples from two human teeth—one from a 22-year-old and another from a 56-year-old. They discovered that the older tooth contained higher concentrations of fluoride, particularly in the “shell” regions of enamel’s microscopic structures.
“Teeth tend to become more brittle with age, especially near the outer surface where cracks originate,” explained lead author Jack Grimm, a UW doctoral student in materials science and engineering and a doctoral intern at PNNL. “We know mineral composition plays a role, but understanding the changes requires looking at the atomic scale.”
Fluoride is commonly added to toothpaste and drinking water to strengthen enamel and prevent decay. This study provides the first detailed evidence of fluoride being incorporated into enamel over time, offering critical insights into its protective role.
Peering into Enamel at the Atomic Level
Enamel primarily consists of minerals arranged in highly organized structures—ten thousand times smaller than the width of a human hair. Traditional techniques have only allowed researchers to examine enamel at a much larger scale, leaving its finer details unexplored.
To overcome this limitation, the team employed atom probe tomography, a cutting-edge technique that maps each atom’s location in a sample in 3D. By comparing the atomic composition of enamel from both teeth, they identified significant differences in fluoride distribution across three regions: the core, the shell, and the space between shells.
The older tooth consistently showed higher fluoride levels, particularly in the shell regions, suggesting a cumulative integration of fluoride over time.
Interdisciplinary Collaboration Drives Innovation
The research exemplifies the power of interdisciplinary science. Materials scientist Arun Devaraj, who co-led the study, emphasized how his background in metallurgy complemented the expertise of Dwayne Arola, a UW professor of materials science and engineering.
“By combining our knowledge, we’ve been able to explore biomaterials in ways that weren’t possible before,” Devaraj said. “Interdisciplinary collaboration facilitates innovation and helps us address fascinating questions about how materials like enamel behave as we age.”
Next Steps: Understanding Protein and Organic Content
While fluoride’s role in enamel aging was a standout finding, the researchers are also investigating changes in enamel’s protein composition. Enamel contains trace amounts of organic material, and the team is curious whether these proteins degrade with age.
“Our initial goal was to understand how the organic content in enamel is distributed and whether it diminishes over time,” said Arola. “But the fluoride distribution around the crystalline structure was a surprising and compelling discovery.”
Implications for Dental Health
The study offers new perspectives on how fluoride contributes to enamel resilience. However, researchers caution that more work is needed to fully understand how aging affects enamel and tooth health.
“There’s still a lot to uncover,” Grimm noted. “But the findings underscore the importance of using fluoridated products to protect against decay and maintain enamel strength.”
For the broader public, the takeaway is clear: incorporating fluoride through toothpaste and drinking water remains one of the most effective ways to safeguard teeth against aging-related vulnerabilities. As researchers continue to unlock the secrets of enamel, their work promises to shape future innovations in dental care.
Related topics:
Harris Dental Introduces Expert Teeth Whitening Services for a Brighter Smile
Nuvia Partners with Beast Philanthropy to Donate $1 Million in Smiles Across the Nation
Greens Push for Medicare Dental Expansion to Save Richmond Residents Millions
