Dr Susan Cartwright of Colgate Oral Care gives us a lesson in the daily habits that may be causing dental erosion and the steps we should take to prevent it.
1. The acidity of food/fluids: tooth enamel is composed of minerals, such as calcium and phosphate. Both enamel and dentine are weakened and dissolved by acid (pH less than 5.5). The enamel layer in primary teeth (the first set of teeth in children) is thinner making them particularly vulnerable.
2. The frequency and duration of exposure to acidic products: salivary flow neutralises acids and provides calcium and phosphate to remineralise tooth enamel within a 20-30min “recovery” phase.
3. The sugar content: Cola drinks, sports drinks, gels and energy drinks (and any other type of food which may be “sticky” e.g. honey, glucose syrup, etc) are sources of carbohydrate in the form of sugar for the purpose of easy digestibility and delivery to working muscles. However, these foods provide sugar in a form that adheres to teeth more than saliva and provide a substrate for additional acid production by oral bacteria.
4. Decreased salivary flow: Saliva plays a vital role in protecting teeth. It dilutes and clears liquids at the tooth surface. It neutralises acids in the mouth and provides a mineral source including calcium and phosphate for remineralisation (enamel hardening). Dehydration causes the mouth to become dry, reducing salivary flow which increases the time of tooth surface damage.
RESCU: Can you tell us exactly what dental erosion is, and how it differs from decay?
Dr Susan Cartwright: Tooth enamel is a very hard substance but the minerals that it is made up of are dissolved by strong acids. There are two different ways this can occur- tooth decay and dental erosion. Tooth decay and dental erosion have different causes, mechanisms of action and outcomes.
Tooth decay is the result of a build-up of plaque bacteria and their by-products on your teeth. Some of these bacteria produce acids which can dissolve tooth mineral. The surface of the tooth stays intact for a period of time allowing this process to be reversed if it is recognised early enough.
Erosion is mainly caused by acids from the diet or from the gastro-intestinal system which act directly on the tooth surface. Layers of tooth tissue are lost and the teeth become thinner and/or shorter over time and may become sensitive. This loss of tooth structure is not reversible.
RESCU: We understand dental erosion is caused by an imbalance in acid in the mouth — what exactly does this mean and how does the acid imbalance start?
Dr Susan Cartwright: Erosion is caused by strong acid coming into direct contact with tooth tissue. The minerals in the tooth’s enamel are dissolved by acids. These acids are contained in foods and beverages such as fruit juices, wine, pickles, citrus fruit, and soft drinks to name a few.
Alternatively, the acids may arise from gastrointestinal origin in cases of GORD (gastro-oesophageal reflux disease) or Bulimia, for example.
RESCU: We understand the prevalence of drink bottles is one of the causes of dental erosion. Why is this?
Dr Susan Cartwright: Drink bottles allow us to sip drinks continually. Sipping from a drink bottle can be a damaging habit depending on what is in the bottle. If an acidic beverage is in the bottle sipping slowly will extend the period of time acid is in contact with the teeth. Increased frequency and duration of acid exposure increases the risk of erosion.
Sports people are at particular risk since their mouths can be dry due to dehydration from exertion. Dehydration affects the flow of saliva. Saliva contains, amongst other things, bicarbonate which helps to neutralise acids and calcium and phosphate ions which help to remineralise acid softened enamel. When saliva flow is diminished and acidic drinks are sipped the likelihood of tooth erosion occurring is heightened.
RESCU: Fresh juices have become extremely popular over the last couple of years and are touted as a healthy alternative to soft drinks. When it comes to teeth, are they really all that much healthier?
Dr Susan Cartwright: Not when it comes to teeth. Commercial fruit juices naturally contain a lot of sugar which can promote tooth decay in those who are vulnerable to decay and can be quite acidic and so increase the potential for erosion in those who do not accumulate much dental plaque.
RESCU: Can you tell us a little about the medications that can cause dental erosion?
Dr Susan Cartwright: Acidic medications such as Vitamin C tablets and Aspirin can cause dental erosion if they are frequently chewed or sucked.
Medications that cause a dry mouth can contribute to erosion since protective saliva flow is diminished and these individuals often sip fluids frequently to make their mouths’ more comfortable. If these drinks are acidic this greatly increases risk.
RESCU: What are some of the non-dietary causes of dental erosion?
Dr Susan Cartwright: Non-dietary causes include gastric acids from reflux and regular vomiting e.g. bulimia, some medications e.g. Vitamin C tablets and aspirin that are chewed or sucked and some oral hygiene habits e.g. vigorous brushing directly after acid exposure.
RESCU: If we already have some dental erosion, is there any way to reverse or repair the damage?
Dr Susan Cartwright: Tooth tissue that has been lost to erosion cannot easily be restored. Prevention is the best defence. If you have lost significant amounts of tooth tissue you may be able to get some white dental restorations (filling material or veneers or crowns) to restore the teeth but as damage is usually widespread in the mouth this is a very expensive exercise.
RESCU: What steps should we take to prevent dental erosion, and how can we help prevent dental erosion in kids?
Dr Susan Cartwright: Some steps to take to prevent dental erosion:
- Use tap water to maintain hydration
- Only sip water from a bottle
- Use a straw to drink acidic drinks
- Eat cheese and drink milk to help neutralise acids
- Wait for 30 minutes before brushing teeth if you are prone to dental erosion
- Always use a soft toothbrush
- Check with your dental professional to see if you have any signs of erosion