If you’ve got a bit of a sweet tooth or are a lover of acidic foods and drinks like tomatoes, wine or meat, you owe a big thank you to your tooth enamel. Finding it isn’t hard—just crack a smile and you’ll see it.
One of the four major tissues that make up the tooth, enamel is off-white in colour and translucent, and has a ranking of 5 on the Mohs hardness scale, making it not only the hardest substance in your body but harder than steel. It owes this hardness to its composition. Composed of 96% minerals—primarily a crystalline calcium phosphate called hydroxyapatite—it’s tough enough to ensure you still have teeth after accidentally biting into your spoon. The other edge of the sword is this high minerality also makes it brittle, requiring it to be supported by a layer of the less hard but less brittle protective tissue dentin underneath.
What does tooth enamel do?
The innermost layer of the tooth—the pulp—is composed of delicate tissue. Rich in blood vessels and with an extensive number of nerves, it’s a sensitive part of the body that’s prone to inflammation. Once triggered by trauma, bacterial infection or periodontal disease, this inflammation – known as pulpitis – leads to a build-up of pressure as the pulp swells against the hard inner walls of the dentin surrounding it, compressing the delicate nerve fibres and resulting in a toothache.
Enamel prevents that from happening. The outermost layer of the tooth, it’s the protective shield that keeps the delicate inner tissue of the tooth safe from dirt, disease and bacteria. Its mineral composition makes it extremely tough and able to stand up to a lifetime’s worth of chewing, but it’s not invincible. Just like a building that survives an earthquake but falls down due to water damage, enamel is extremely susceptible to degradation.
The dangers of tooth enamel loss
This degradation can take a number of forms, including erosion, decay and abrasion amongst others. Decay and erosion are the two most common causes of degradation. Also referred to as dental carries or more commonly as cavities, tooth decay is most often caused by the interaction of mouth-borne bacteria with food debris. This interaction results in lactic acid, which decreases the pH in the mouth and contributes to a process referred to as demineralisation, dissolving the enamel.
Tooth erosion is similar in process but differs in a number of ways, key amongst them the origin of the acid. Tooth erosion refers to enamel demineralisation caused by acids not of bacterial origin, such as from foods and beverages. The same process of demineralisation and enamel dissolution occurs regardless of the source of the acid.
The dangers of these conditions are readily apparent. As we’ve discussed above, when the enamel wears away, it exposes the more delicate and easier-to-inflame parts of the tooth. Of particular concern is exposure of the sensitive pulp. Exposure to trauma, bacteria or disease results in all outcomes we’ve previously discussed, including inflammation and eventual death of the pulp. These conditions can require painful and expensive invasive procedures to remedy, including the dreaded root canal therapy in severe and/or chronic cases.
What are the environmental causes of tooth surface erosion and decay?
Much like the rest of the body, tooth enamel undergoes a gradual process of wear throughout the individual’s lifespan. Due to enamel’s hardness, the wear from normal factors is minimal. This level of wear is not a concern and will not affect the overall health of an individual’s teeth.
What is of concern are various environmental factors that can accelerate this wear to dangerous levels. While there’s a body of research that suggests that certain genetic markers were associated with higher risk of tooth decay and gum disease, environmental factors still play the largest part in determining the overall health of a person’s tooth enamel.
Key amongst them is the level of consumption of foods and drinks high in acids and sugars. These products pose a dual threat to an individual’s oral health.
Firstly, a diet high in sugar can result in tooth decay. As simple sugars are the primary energy source of these mouth-borne bacteria, increased consumption of foods high in sugar will result in the increased bacterial production of lactic acid. This will accelerate the demineralisation process, resulting in the dissolving of the enamel.
Secondly, excessive consumption of highly acidic foods and beverages including fruit juice, soft drinks, some alcohols such as wine and certain fruits and vegetables can contribute to accelerated rates of tooth erosion. Also note that erosion can be caused by long-term exposure to chlorinated swimming pool water, or by regurgitation of stomach acids resulting from acid reflux.
Does plaque cause enamel loss?
Plaque can be a contributing factor to the loss of enamel but is not a primary determinant. Plaque build-up results in a release of organic acids, while simultaneously preventing saliva from neutralising the acid. Over a lengthy period of time, this build-up can result in demineralisation of the adjacent tooth surface.
Despite this, it is important to note that plaque build-up is easily combatted by regular brushing and flossing.
What are the signs of tooth enamel loss?
There are a number of signs of tooth enamel loss that individuals can be on the lookout for. If you notice any of the following, consider scheduling a consultation with your dentist:
- Discolouration of the tooth—this is a result of the translucent enamel wearing away, revealing the opaque and yellow dentin underneath.
- Edges of the front teeth appearing transparent—this is because there is little to no underlying dentin to discolour this area of the tooth as above.
- Sensitivity on the inner and outer surfaces of the tooth—exposure of the dentin layer to bacteria and trauma can result in pain, as unlike enamel-dentin is sensitive.
How do you prevent tooth enamel loss?
Typical good dental practice will help to prevent accelerated loss of tooth enamel. Brushing twice a day, flossing and rinsing with a fluoride and antiseptic mouthwash daily can help to remove plaque and sugars from the enamel, preventing the build-up of acid that can start the demineralisation process.
Additionally, lifestyle changes such as minimising highly acidic foods and beverages in your diet, using a straw to drink acidic beverages, monitoring your sugary snack intake and chewing sugar-free gum and drinking water from a fluoridated source between meals can help to minimise your risk.
On fluoride, while many people are concerned about ingesting too much of it, dental fluorosis—as an overexposure to fluoride is called—is rare and largely cosmetic in effect, generally resulting in only mild discolouration of the teeth. Severe fluorosis generally results from exposure to quantities larger than those in artificially fluoridated water, such as long-term consumption of groundwater from wells sunk into areas containing a high level of natural fluoride-containing minerals.
How is tooth enamel loss treated?
The best way to treat enamel loss is to prevent it. Unfortunately, this narrows the field of options for patients already experiencing enamel loss. Solutions such as bonding, veneers and crowns do not restore enamel but rather replace it with an artificial protective substance such as a resin or porcelain cover. While there are products and procedures in development that aim to regrow enamel, these are still in development.