How does cementum change with age?

With age, the cellular renewal rate in human bodies, including dental tissues, slows down. This physiological change significantly impacts cementum, the bone-like tissue covering the tooth root. Understanding how does cementum change with age is crucial for maintaining good oral health throughout the lifespan.

Quick Summary

Over a lifetime, cementum progressively thickens, especially near the root tip, as a protective biological response to the forces of chewing and age-related changes, but this thickening can also expose the tissue to new vulnerabilities like root caries and increased sensitivity.

Key Points

• Cementum Thickens with Age: The tissue continuously deposits new layers throughout life, leading to a thickening of the tooth root, particularly at the apex.

• Gum Recession Exposes Cementum: Age-related gingival recession can expose the root's cementum to the oral environment, as it is no longer covered by protective gum tissue.

• Increased Risk of Root Caries: Exposed cementum is softer and less resistant to acid than enamel, significantly increasing the risk of cavities on the root surface.

• Tooth Sensitivity May Increase: The erosion of exposed cementum can reveal underlying dentin, leading to increased tooth sensitivity to temperature and sugar.

• Forensic Tool: The incremental rings of cementum deposition can be used in forensic anthropology to help estimate an individual's age.

• Stiffer Tooth Response: Cementum thickening can cause a stiffer response to chewing loads, which may protect the tooth from fracture in some cases.

• Manage with Regular Dental Care: Proactive strategies like regular cleanings, fluoride treatments, and addressing dry mouth are crucial for protecting aging cementum and preventing dental problems.

Continuous Apposition and Thickening of Cementum

Cementum is a vital tissue that helps anchor the tooth to the jawbone via the periodontal ligament. Unlike other mineralized tissues that undergo constant remodeling, cementum experiences continuous, lifetime deposition, or apposition. This means that new layers of cementum are added over time, much like the rings of a tree. This continuous buildup results in a progressive thickening of the cementum layer, most noticeably around the root apex.

This thickening is largely considered a protective, compensatory mechanism. As the biting surfaces of teeth wear down from years of mastication, the tooth naturally erupts or migrates slightly to maintain occlusal contact with its opposing tooth. The ongoing cementum apposition at the root apex helps to fill the space created by this migration, maintaining a stable anchor for the tooth. This adaptation helps the aging tooth better withstand decades of mechanical stress from chewing.

Acellular vs. Cellular Cementum

Cementum is composed of two main types: acellular and cellular.

• Acellular Cementum: Found mainly on the coronal and middle portions of the root, this type forms first and lacks embedded cells. It is responsible for the initial anchoring of the periodontal ligament fibers.
• Cellular Cementum: Predominantly located around the root apex, this type continues to form throughout life and contains embedded cells called cementocytes. It is the cellular cementum that contributes most significantly to the age-related thickening of the tooth root.

This distinction helps explain why the apex thickens most dramatically, as it is the site of continuous cellular cementum deposition that responds to normal occlusal forces.

Comparison of Young vs. Aged Cementum

Feature	Young Cementum	Aged Cementum
Thickness	Relatively thin, especially at the apex.	Continuously thickens over time, particularly at the apex.
Incremental Lines	Less numerous and prominent annual layers.	More numerous and denser annual layers, used in forensic age estimation.
Permeability	More permeable than aged cementum.	Becomes less permeable with age, but can still be exposed.
Clinical Exposure	Typically remains protected by healthy gums.	Often exposed due to age-related gum recession.
Resistance to Acid	Protected by surrounding gums.	Low resistance when exposed, increasing risk of root caries.
Structural Response	More mobile and flexible under masticatory load.	Stiffer and less mobile, potentially to protect against fracture.

Implications of Age-Related Cementum Changes

The changes to cementum with age are not without clinical consequences for senior care.

1. Gum Recession and Root Exposure: One of the most significant issues is the widespread occurrence of gingival recession in older adults. As gums recede, the cementum-covered root surface, normally protected, becomes exposed to the oral environment. Unlike enamel, cementum is compromised and has a lower resistance to the acidic environment of the mouth.

2. Increased Risk of Root Caries: The exposure of less-resistant cementum makes the tooth root highly susceptible to decay, known as root caries. This is a major dental problem for older adults, compounded by other age-related factors like dry mouth caused by certain medications.

3. Tooth Sensitivity: The microscopic tubules in dentin, the layer beneath the cementum, can become exposed when cementum is lost. This can lead to increased sensitivity to hot, cold, and sweet stimuli.

4. Forensic Age Estimation: The continuous, rhythmic deposition of cementum results in incremental lines, or annulations, similar to tree rings. In forensic science, these annulations can be counted to provide a moderately reliable estimate of an individual's age at death, especially when skeletal remains are involved.

How to Manage Cementum-Related Issues in Senior Care

Good oral hygiene and regular dental care are paramount for managing age-related changes in cementum and preserving dental health in older adults.

• Proper Brushing Technique: Using a soft-bristled toothbrush and a gentle, non-abrasive technique is important to avoid further gum recession and damage to the exposed root surface.
• Fluoride Application: The use of fluoride toothpaste, and potentially professionally applied fluoride treatments, can help strengthen the exposed cementum and make it more resistant to acid attacks.
• Addressing Dry Mouth: For individuals with dry mouth (xerostomia), which is common among seniors, products like artificial saliva and consistent hydration can help.
• Preventative Dental Visits: Regular check-ups allow dentists to monitor for signs of gum recession and root caries, enabling early intervention.
• Dietary Adjustments: Limiting acidic foods and beverages can reduce the risk of further damage to exposed root surfaces.

The integrity of the cementum is critical for the overall health and longevity of a tooth, especially in the face of periodontal disease. By understanding how cementum changes over time, seniors and their caregivers can take proactive steps to mitigate risks and maintain a healthy, functional smile. For more information on geriatric dentistry, consider visiting the American Dental Association's Oral Health Topics section.

Frequently Asked Questions

Why does cementum thicken as people get older?

Cementum thickens with age due to continuous, lifelong deposition of new layers, especially cellular cementum at the root apex. This is a natural physiological process that compensates for the gradual wear and tear on the tooth's biting surface over time.

What is the primary risk associated with aging cementum?

The main risk is that age-related gum recession can expose the cementum to the oral cavity. Unlike enamel, exposed cementum is more vulnerable to acid erosion, which significantly increases the risk of root caries (cavities on the tooth root).

Can exposed cementum cause tooth sensitivity?

Yes, it can. When the protective cementum layer is eroded, the underlying dentin, which contains microscopic tubules leading to the tooth's nerve, can be exposed. This exposure makes the tooth more sensitive to hot, cold, and sweet foods and drinks.

How can I protect my teeth from the effects of aging cementum?

Maintaining excellent oral hygiene is key. This includes using a soft-bristled toothbrush, fluoride toothpaste, and seeking regular dental check-ups. Your dentist can also recommend specific treatments like fluoride applications or addressing gum recession.

Does cementum thickening affect tooth mobility?

Yes, studies have shown that the thickening of cementum can lead to a stiffer response to masticatory (chewing) forces, which reduces overall tooth mobility. This is considered a protective adaptation to prevent fracture in the aging tooth.

Is there a difference between acellular and cellular cementum?

Yes. Acellular cementum forms first and is found on the middle and upper parts of the root, while cellular cementum, which contains cells called cementocytes, is deposited continuously at the root apex throughout life.

Can a dentist reverse damage to aging cementum?

While eroded cementum cannot be regenerated easily, a dentist can perform various procedures to mitigate damage. These include applying restorative materials to fill root caries, providing fluoride treatments to strengthen the exposed surface, or performing soft tissue grafts to cover exposed root surfaces.