Do teeth get thicker with age? A look at dentin and enamel changes

An estimated 90% of people between 80 and 90 years old have experienced some degree of gum recession, which is just one of many changes that occur in the mouth as we get older. This raises the question: do teeth get thicker with age? The answer is more complex than a simple yes or no and involves a fascinating interplay between the tooth's different layers.

Quick Summary

As we age, the inner layer of our teeth called dentin naturally thickens, while the outer protective enamel layer thins. This process alters the tooth's appearance, making it look more yellow, and can increase brittleness. Other age-related factors like gum recession also change tooth appearance.

Key Points

• Internal dentin thickens with age: The yellowish dentin layer under the enamel continuously grows, making the pulp chamber smaller.

• Outer enamel thins over time: Years of chewing, brushing, and acid exposure cause the protective enamel to wear down.

• Teeth appear yellower as a result: The translucent, thinning enamel reveals more of the darker yellow dentin underneath.

• Increased sensitivity is a common side effect: Thinner enamel provides less insulation, exposing the dentin and increasing sensitivity to temperature changes.

• Other factors also affect tooth appearance: Gum recession can make teeth look longer, while grinding can shorten and flatten tooth surfaces.

The Internal Thickening of Dentin

While teeth don't grow larger after they have fully erupted, the dentin, which is the calcified tissue beneath the enamel, thickens throughout life. Dentin is yellowish, porous, and softer than enamel. Dentin-forming cells called odontoblasts continuously produce secondary dentin, gradually reducing the size of the pulp chamber containing nerves and blood vessels. This thickening of yellow dentin contributes to teeth appearing darker or more yellow as they age, as it shows through thinning enamel.

The External Thinning of Enamel

In contrast to dentin, enamel, the outer layer of the tooth, thins with age. Despite being the hardest substance in the human body, enamel wears down over time due to chewing, grinding, and exposure to acids.

Thinning enamel has several effects:

• Increased Yellowing: Thinner enamel becomes more translucent, making the thicker, yellower dentin more visible.
• Greater Sensitivity: Less enamel protection means more exposure for the dentin's microscopic tubules, leading to increased sensitivity to hot, cold, and sweet stimuli.
• Higher Risk of Cavities: As enamel thins, teeth are more vulnerable to decay, particularly near the gumline where recession may expose softer root surfaces.

A Tale of Two Tissues: Dentin vs. Enamel

Dentin thickening and enamel thinning are key age-related tooth changes. Here's a comparison:

Feature	Dentin (Inner Layer)	Enamel (Outer Layer)
Changes with Age	Thickens gradually due to secondary dentin deposition.	Thins gradually due to wear from chewing, abrasion, and erosion.
Primary Composition	A living tissue with a yellowish hue.	The hardest mineralized substance in the body, primarily white but translucent.
Impact on Appearance	Thickening makes teeth appear more yellow or dark from the inside.	Thinning makes the underlying yellow dentin more visible.
Effect on Tooth Health	Thicker dentin and smaller pulp chamber can make teeth more brittle and less sensitive over time.	Thinner enamel increases sensitivity and susceptibility to cavities and damage.
Protecting Against Damage	Responds to injury by creating reactionary dentin to protect the pulp.	Protects the tooth but cannot regenerate itself once lost.

Other Factors Influencing Tooth Shape and Size Perception

Other age-related factors also change tooth appearance:

• Gum Recession: Gums receding expose more of the tooth's root, making teeth appear longer, not thicker, and exposing vulnerable root surfaces.
• Attrition and Erosion: Chewing and dietary acids can wear down biting surfaces, making teeth look shorter or chipped.
• Crowding and Shifting: The dental arch can narrow, causing teeth to crowd and shift, affecting smile symmetry.

Protecting Your Smile as You Age

Understanding these changes allows for proactive dental care. Regular checkups and cleanings are vital for early detection of issues like enamel wear or gum recession. A nightguard can help prevent grinding, and limiting acidic/sugary foods helps preserve enamel.

Conclusion

While permanent teeth don't grow after erupting, they change with age. Dentin thickens and enamel thins, altering structure and appearance. This can lead to yellower teeth that are more prone to sensitivity, cracking, and decay. Good oral hygiene is essential to maintain a healthy smile throughout life.

Optional outbound link

For more detailed information on age-related oral health, consult the resources from the National Institutes of Health or other reliable dental institutions.

Optional one outbound Markdown link National Institutes of Health (NIH) on Aging and Oral Health

Frequently Asked Questions

Do teeth get bigger or longer as you age?

No, permanent teeth do not get bigger or longer. The appearance of longer teeth is actually due to gum recession, a process where the gum tissue pulls back and exposes more of the tooth's root.

Why do teeth become more yellow with age?

Teeth appear more yellow with age for two main reasons: the yellowish inner dentin layer thickens, and the outer, more transparent enamel layer thins, allowing the dentin's color to show through more prominently.

What is the difference between dentin and enamel?

Enamel is the hard, protective, white outer layer of the tooth, while dentin is the softer, yellowish, porous tissue beneath the enamel that makes up the bulk of the tooth.

Does thinner enamel mean more cavities?

Yes, thinner enamel offers less protection against bacteria and acids. This increases the risk of tooth decay and cavities, especially as the gums recede and expose softer, unprotected root surfaces.

Can enamel be rebuilt or thickened?

No, once enamel is lost, it cannot be regrown or thickened naturally. However, early-stage damage can be repaired through remineralization, often aided by fluoride.

Is it possible to stop dentin from thickening with age?

No, the thickening of dentin is a natural, physiological process known as secondary dentin formation that occurs throughout life. It is the tooth's way of protecting the inner pulp.

How can I protect my teeth from age-related changes?

You can protect your teeth by maintaining excellent oral hygiene, using a soft-bristled toothbrush, avoiding abrasive toothpastes, limiting acidic and sugary foods, and wearing a nightguard if you grind your teeth.