This course establishes the concept of dental erosion as a condition that is distinct from caries, and as an emerging public health issue with increasing prevalence in people of all ages. Although often generalized under the heading of “tooth wear,” there are actually two distinct tooth surface loss processes that must be taken into account. Tooth surface loss can be the result of physical mechanisms, such as attrition and abrasion, or chemical mechanisms triggered by acid. Both of these mechanisms are discussed, as well as the chemical, biological, and behavioral factors that increase or reduce risk of tooth surface loss. For the purpose of this discussion, the impact of physical processes on tooth surface loss, such as attrition and abrasion, will be referred to as tooth wear. The process related to chemical acid attack resulting in tooth surface loss will be referred to as dental erosion. In addition, diagnosis and prevention measures related to dental erosion are introduced.

Clinical Significance Snapshots

Is dental erosion really a concern for me and my patients?

Erosion is more frequently found in ‘healthy’ patients, and this is where the greatest number of cases now occur. Although people adopting healthier diets and caring more for their oral health improve their overall well-being, they are also putting themselves at increased risk of dental erosion. Healthier diets include more fruits and vegetables, as well as their juices, many of which are acidic. In addition, increased consumption of carbonated beverages, with sugar, or sugar-free, and a concurrent decrease in milk consumption has led to increased acid intake and a reduced calcium intake.

Taking all the above into account, patients today have many more perfect, unrestored teeth, all of which are susceptible to acid attack, more acid exposures through changes in diet and lifestyle, and an increased frequency of toothbrushing with (mildly abrasive) toothpaste. A consequence of all these factors is erosive tooth wear. Also, the teeth our patients have must work harder and last longer as life expectancy increases. Wear and tear is only natural, but teeth today have more work to do over a longer period than previous generations that had teeth extracted and wore dentures.

Saliva is one of our main defenses against acid attack. Yet more patients are taking an increased number of prescription and over-the-counter medications, more than 400 of which have the ability to reduce saliva flow, and thus decrease this line of defense.

Minor erosion can be found in nearly every mouth, and should be regarded as a normal response to a healthy lifestyle. If minor, erosion has no noticeable signs or symptoms for the patient. However, minor dental erosion is an indicator of more significant signs (yellowing and loss of whiteness, dullness and loss of luster, changes in shape) and symptoms (dentin hypersensitivity and loss of occlusal contact and/or occlusal height) when advanced in relation to the patient’s age.

Is erosion the most common form of tooth wear?

Evidence of erosion can be found in almost every mouth, and may co-exist with the other physical forms of tooth wear. Erosive tooth wear may be exacerbated by physical wear from inappropriate use of toothpaste, particularly if used immediately after an acid attack, when the surface of the enamel is soft and vulnerable to wear. In this case, the clinical signs often lead to an incorrect diagnosis of "toothbrush abrasion." Incidentally, nylon toothbrush bristles will not wear away enamel – they are too soft! However, the action of aggressive brushing places greater pressure on the abrasive cleaning particles in toothpaste that can wear enamel, especially if already softened by dietary acids. Soft brushes hold more abrasives against the surface of the tooth and are thus more harmful to the hard tissues than a hard brush.

It is imperative to assess erosive risk factors in all patients demonstrating signs or symptoms of tooth wear, no matter how obvious the diagnosis may be. Seldom does any one element of tooth wear occur alone.

How is dental erosion linked to my patient’s oral hygiene?

After any acid (dietary or stomach) has softened the surface layers of enamel, that enamel is vulnerable to physical loss until the natural forces of saliva have remineralized and thus rehardened it. If oral hygiene is conducted while the enamel is still softened, the oral hygiene procedure may lead to physical removal of some of the softened material, which leads to irreversible loss. Used as directed, most toothpastes are safe. However, if used aggressively or abusively – too much force, too much paste, too frequently – the detergents and abrasive particles essential for cleaning under normal circumstances have the potential to increase physical loss of the softened enamel.