News & Press
John C. Chao, D.D.S., M.A.G.D
Faculty, USC School of Dentistry
Teeth are so hard you would think they would be indestructible and that they would not be adversely affected by anything. Due to the strength of enamel and bone, they should remain the same from the day the teeth come into the mouth to the day they are no longer needed. Unfortunately, this is far from true. While we would like to think of teeth as being strong and unchanging, most people know that teeth can be damaged by tooth decay-causing bacteria. We know, too, that teeth can be damaged by mechanical means - attrition caused by tooth grinding and clenching and abrasion caused by improper tooth brushing. However, few people know that there is a third factor that can destroy teeth - chemical erosion.
Chemical erosion is caused by excess acid coming in contact with a tooth for extended periods of time. The acid attack can be self-inflicted (bulimia) or more commonly from a problem with acid reflux. In acid (gastric) reflux, the acidic and partly digested contents of the stomach are returned back into the throat and oral cavity. Normally, the lower esophageal sphincter muscle (LES), connecting the esophagus with the stomach, closes once food passes into the stomach. This closure prevents the stomach contents from flowing back up into the esophagus. Acid reflux occurs when this sphincter does not work properly and allows acidic fluid to return to the esophagus and higher - the mouth.
This condition sometimes can actually be noted by a dentist long before it is acknowledged by a patient or physician. The dentist will see a characteristic smooth and circular erosion of the cusp tips of the lower first molars. The cusp tips (bumps on a tooth) lose their peak, flatten, and become concave. Soon the enamel cover is broached and the underlying dentin is exposed. Because dentin is "softer" than enamel, the erosion can progress more quickly. This acid erosion has a very different appearance from tooth loss due to a mechanical etiology. Attrition and abrasion have a very sharp, edged, and well-delineated look. Chemical erosion has a softer and more rounded presentation and is localized first to lower first molars (lower first molars are the first permanent molars to erupt into the mouth) so that the permanent teeth have the longest potential exposure. When the acid refluxes (returns) to the mouth, it pools mostly around the lower first molars. This is the site of the most erosive features.
A significant portion of the population experiences acid reflux at least once a month. About 25% of those who are affected are unaware of their problem. Infants and young children can be affected, and there may be a genetic component to this disease. Early diagnosis from erosion of the permanent lower first molars can be made as early as 7 or 8 years of age. A hiatal hernia may weaken the LES and cause reflux. Diet and lifestyle contribute to acid reflux. Chocolate, peppermint, citrus, tomatoes, fried or fatty foods, coffee (especially acidic coffee), alcoholic beverages, garlic, and onions are foods to avoid. Weight gain (also weight gain associated with pregnancy) and smoking (by relaxing the LES) may be contributing factors.
As is true with most medical and dental problems, the earlier the diagnosis is made, the easier it is to treat. Variable factors include the nature and severity of the problem, as well as frequency and type of fluid that refluxes from the stomach. Under supervision of your physician, change in diet, eating habits, and/or medication (over-the-counter or prescription) can be effective. It is recommended that you first consult your physician or a specialist (gastroenterologist) if you suspect you have gastric reflux or other gastro-intestinal ailments.
Dentally, once the enamel is broached and the dentin becomes visible, it is recommended that the affected areas be protected by covering them with an enamel replacement - a tooth-colored bonding material. This material not only protects the dentin and enamel, it may be more resistant to the acid than is naturally occurring dentin. Many times, drilling preparation is not needed. See your dentist regularly so that problems like these can be detected and treated in time.