Intrinsic erosion results from the introduction of gastric acids into the oral cavity at a frequency exceeding the ability of the buffering capacity of saliva or other oral health measures to prevent it, usually several times a week for a number of years.5, 10
Stomach acids may reach the oral cavity at such frequencies by gastroesophageal reflux disorder (GERD) as well as recurrent vomiting, such as occurs in bulimia, chronic alcoholism, and pregnancy, when it is referred to as hyperemesis gravidarum.1, 3, 5, 13
- Gastroesophageal reflux. The regurgitation of stomach acids following meals, especially after overeating, is considered normal5, 10 for up to about 1 hour a day.3 However, in people with GERD, the introduction of gastric acids into the oral cavity during sleep is especially damaging to the teeth, as salivation and swallowing are reduced, and, in a supine position, the lower molars can be bathed in the acids.3 Increases in intra-abdominal pressure (i.e., from obesity or pregnancy) may also increase reflux,5 and GERD has been noted as a common comorbidity of several chronic respiratory conditions.14-16
Figures, below. Moderate to severe erosion from GERD in the primary dentition.
Photos courtesy of Martha Ann Keels, D.D.S., PhD
- Bulimia. Bulimia nervosa is an eating disorder that is characterized by intentional vomiting as a means to maintain a desired weight.3, 5, 17 It is a relatively common disorder among women in Western industrialized nations, with a prevalence of approximately 5% in 18-35 year old females.5 Among individuals with bulimia, the prevalence of erosion has been reported to be over 90%.5 Because patients with bulimia are generally of average weight, dentists are often the first to recognize the condition by the characteristic erosion of the lingual-palatal aspect of the anterior maxillary teeth (i.e., perimolysis or perimylolysis, see photos below),3, 5 caused by the forceful expulsion of stomach acids onto the front teeth during vomiting.
- Bulimia is contrasted with anorexia nervosa, in which weight gain is controlled by excessive restriction of diet,18 and non-purging bulimia which is characterized by periods of fasting and excessive exercise.
Figures, below. Characteristic erosion pattern from bulimia.
Photos courtesy of Craig Mabrito, D.D.S.
- Chronic Alcoholism. Alcoholism, with a prevalence of around 10% in Western countries,5 can result in erosion due to frequent vomiting and/or increased regurgitation.5, 19 Erosion in individuals with alcoholism can also be exacerbated by the consumption of acidic drinks.7, 13 In one study, erosion was found in 92% of 37 patients with alcoholism,5 and in a more recent study,19 49.4% of the teeth of 50 individuals with alcoholism were found to show signs of erosion.19 As in bulimia, the palatal surfaces of the anterior maxillary teeth tend to be the most affected, but erosion advances are more common to the occlusal and palatal surfaces of the posterior, and incisal edges of the anterior, maxillary teeth.5, 19
- Pregnancy. The increase in intra-abdominal pressure during pregnancy may result in an increase in reflux, but dental erosion is rare unless vomiting is chronic, as in the case of hyperemesis gravidarum.5
Unlike intrinsic factors for dental erosion, erosion due to extrinsic factors may be a combination of dietary, lifestyle, environmental or occupational factors that expose teeth to acids in beverages2, 3, 5
or inorganic acid vapors released into the environment.2, 5
- Beverages. Arguably the most significant cause of extrinsic dental erosion1, 3, 10 are soft drinks, sports drinks and fruit juices which have low pH values (2.0-3.5).3, 4 Any beverage with a low pH is a risk for erosion,3 especially with frequent consumption.3, 4, 13, 20, 21 Wine, for example, is rarely noted as a cause for erosion because it is rarely consumed as frequently as sports drinks and diet sodas.4 In 2016, a paper by Reddy et al.22 included measured pH for commercially available beverages available in the U.S. Of the 379 beverages analyzed, 93% had a pH of less than 4.0.22
A number of recent studies10, 13, 23, 24 support the hypothesis that dietary acids are a major contributing factor in dental erosion.5, 25 A 2012 meta-analysis found more than double the risk of erosion from soft drinks as well as an increase in risk from chewable vitamin C tablets.24 Many studies, including a 2015 meta-analysis, find that natural fruit juices as well as carbonated soft drinks and acidic, sweet snacks and sweet-sour candies to be significant erosion risk factors.10, 26
- Lifestyle. More frequent consumption of highly acidic fruit and sport drinks in combination with decreases of salivary flow and dehydration from athletic or strenuous activity may increase erosion risk.2 Intense workouts may also increase the possibility of gastroesophageal reflux.2 There is some evidence that a vegetarian diet and excessive use of vinegar-based dressings can lead to increased erosion.27, 28
- Industrial and Occupational Risks. Airborne industrial acids have been implicated in dental erosion among factory workers,1, 2 particularly in munitions, battery, and fertilizer plants.2 Swimmers frequenting poorly monitored chlorinated swimming pools have been reported to have increased levels of erosion, attributed to lowering of the water’s pH balance.1, 2, 7