Chemical Erosion: Lifestyle changes among dental patients can reduce the damage from an acid attack

By Jamie Collins, RDH, CDA

A day in dental hygiene presents a melting pot of oral and systemic issues among the patients we see. No two days or two mouths are ever the same. Even the patients we've seen for years may present with different signs or symptoms at their next dental visit. With the daily focus on decay and periodontal disease, how often do you identify and counsel on other conditions? Think back to the last week of seeing patients in your hygiene chair. How many did you see that displayed evidence of acid erosion?

Acid erosion in the oral cavity is a rather common condition and seems to be becoming more prevalent. Fifty percent of dental professionals report an increase in erosion over the last five years. Erosion is caused by prolonged exposure of the tooth surface to extrinsic or intrinsic acids. Erosion is classified as loss of hard tooth structure, enamel, or dentin, by a nonbacterial acidic source. The structure of the tooth is exposed to a consistent acidic source and is not able to remineralize effectively, thus breaking down the hydroxyapatite within the enamel matrix. The tooth softens and becomes more susceptible to other forms of wear, such as abrasion and attrition.

Clinically, acid erosion appears as cupping on the occlusal surface. When I see this, I describe it as a smooth "pothole." On the facial or lingual surfaces of the posterior teeth, erosion appears as a smooth or flat surface, or the enamel layer is missing or thin, often at the cervical junction. In any area of chemical erosion, we may clinically see the yellowish hue of the underlying dentin layer since the enamel is thinner.

Acid erosion is often present on the cusp tips of posterior teeth or the lingual surface of maxillary anterior teeth. Patients may not be aware of the erosion process and may have no symptoms, especially early in the process. If the erosion is significant, patients may complain of increased sensitivity. When clinicians see evidence of erosion, we should be asking our patients the right questions in order to investigate the cause and to plan prevention so there's no further damage.

Dietary concerns

Today's American diet is much more acidic than in previous decades. This partially explains the increasing erosion prevalence in the US population. Soft drinks, juices, wine, energy drinks, and sports drinks are common staples of the American diet. Most of these drinks have a pH level less than 4.0, much lower than the pH level of 5.5 where enamel demineralization begins, or 6.5 where dentin starts to break down.

For many people, the drive for caffeine and energy develops into a habit of drinking soda, coffee, or energy drinks throughout the day. They often sip on the drinks for hours at a time. The constant bathing of the acidic drinks keeps the pH of the oral cavity lower than what is ideal and thus not only increases the incidence of decay, but also the risk of acid erosion on the teeth. Many soft drinks contain one or more of the commonly added acids used to create taste and inhibit bacterial growth-citric acid, phosphoric acid, and carbonic acid. The acids used in conjunction with the sugars of these drinks can lead to decay in susceptible areas where erosion has occurred because the enamel is weakened. Some evidence suggests that phosphoric acid may also be linked to lower bone density and an increased risk of kidney stones.

Acid erosion is not only evident in adults; many children are affected as well. Fruit juices are a common culprit for erosion in the primary dentition of children, with a pH generally in the range of 3 to 4. When combined with bruxism, which children often do as the dentition changes, obvious clinical signs of chemical erosion can be observed. Children often present with smooth dimpling on the occlusal surfaces of the molars, and sometimes the lingual of the anterior teeth are also affected. The primary dentition is not as strong as the permanent dentition and can be sensitive and wear easily. We often clinically see the yellow hue of the underlying dentinal layer in the areas of wear and erosion.

The pH of energy drinks, which have become a source of quick energy, can range from 2.53 to 3.49. I've had patients admit to drinking three or more of these drinks a day and wonder why they have decay and acid erosion accompanied by sensitivity. Most people are not aware of the dental implications of their habit, and many think a cavity will be the worst of their problems. I talked with my husband, who works in a corporate office setting, and he listed several coworkers who are never without an energy drink or soda within arm's reach throughout the day. He said one comes to work with a cooler of four to five energy drinks each day. The hygienist in me quietly screams when I hear this, and I feel the need to do some nutritional counseling for these people!

I admit to needing my caffeine boost each day, and I'm pretty sure my patients like me better because of it. Discussing these habits with patients is often similar to discussing tobacco use. Many people are very reluctant to change habits and might be afraid you're asking them to give up a habit they feel gets them through the day. I never ask my patients to give up their caffeine habit, but I instead ask them to change how they consume it. If people sip acidic drinks slowly, they expose their teeth to acid attack for longer periods of time. I would rather see them drink it down and be done with it, and then drink water afterward to allow the saliva to buffer the acid and return the oral cavity to a normal pH level. The salivary glands naturally increase flow, and bicarbonates and urea in saliva clear acid from the oral cavity and return the pH to a normal range if given time between exposures.

Drinks are not the only cause of chemical erosion. The foods we eat play a part as well. We've become a society of convenience, and with the ease of processed foods and frequent snacking, the risk of chemical erosion has increased. Grazing throughout the day, even on healthy alternatives such as fruits and berries, puts the teeth under acid attack.

Acid reflux

Diet is not always to blame for chemical erosion-it may be the result of an intrinsic factor. Gastroesophageal reflux disease (GERD) is a common cause of chemical erosion of the teeth. The acid of the stomach and related fumes enter the oral cavity and can be highly acidic and erosive. The hydrochloric acid produced in the stomach has a pH of 1.0 to 3.0. GERD can develop slowly and continue for years before a patient seeks medical help. It often occurs when lying flat at night sleeping, and people often are not aware it's happening until they have severe discomfort.

At least once a month my office sends a patient to his or her medical doctor for a GERD evaluation due to evidence of chemical erosion along the posterior teeth, and extrinsic sources of diet or habits are not indicated as a cause. When these patients return to the office months later, many say they did not realize the symptoms were present, but have since resolved the issue with medication.

We all learned about the risk of chemical erosion due to bulimia, which involves vomiting multiple times daily over a prolonged period of time. The incidence of chemical erosion is usually severe and widespread, and portions of the teeth may be missing. The topic of bulimia is a delicate one and should be broached with caution and compassion. Frequently patients are not willing to admit their problem and gaining control of it may require professional help.

The widespread use of medications can also contribute to the increased incidence of chemical erosion. Medications used to treat health conditions such as depression can slow the salivary flow and cause xerostomia. Without adequate saliva to wash away and buffer the acidic exposures of the oral cavity, the risk of erosion increases along with the risk of decay. Acidic erosion is also associated with recreational drug use. Look for smooth exposure and cupped surfaces along the gingival margins and occlusal surfaces of the posterior teeth. Systemic health conditions such as Sjogren's syndrome affect the function of the salivary glands and cause xerostomia. Asking patients right questions can help you understand the reasons behind chemical erosion and decide the causes, whether habits, xerostomia, GERD, or a combination.

Treating chemical erosion involves prevention of further damage as well as treatment of existing eroded areas. The first step is to identify the cause of the chemical erosion. The easiest way to start treatment is with diet and better habits. If the patient consistently consumes acidic drinks or foods, nutritional counseling may be helpful. Having a patient keep a log of food and drink over a few days may shed light on their habits and frequency. Small changes can make a big difference in the dental erosion process.

When symptoms of GERD are present, refer the patient to a physician for evaluation. Untreated GERD is erosive to the esophagus and teeth, and gastric juices can affect overall health and increase the risk of esophageal cancer if left untreated.

No matter the cause of chemical erosion, treatment options are the same. Use of high fluoride treatments both in office and at home are effective in protecting the eroded surfaces and can increase acid resistance. Encourage patients to use a straw when drinking acidic beverages to limit the contact with tooth structure. In addition, counsel patients on the frequency of acid exposure and recommend limiting the time teeth are exposed to an acidic episode.

In instances where areas of chemical erosion, such as concavities, are significant, a small filling to replace the lost tooth structure may be indicated. In severe cases of chemical erosion, restorations such as crowns may be necessary to repair the damaged structures. When teeth are exposed to acid, they are more susceptible to abrasion, such as from a stiff toothbrush or highly abrasive toothpaste. A mild toothpaste should be recommended, and brushing should be delayed until the saliva has had a chance to buffer the pH level, which is sometimes as long as 30 minutes after acid exposure.

Remember, prevention is always the best medicine. Take time to educate your patients about the causes and effects of acid erosion. RDH

Jamie Collins, RDH, CDA, resides in Idaho with her husband, Cory, and their four children. She currently works as a full-time hygienist as well as an educator at the College of Western Idaho. In addition, she acts as a content expert and contributor in multiple upcoming textbooks. She can be contacted at [email protected].