Introduction

Is ETW really a concern for me and my patients?

Erosive tooth wear (ETW) is a public health issue with increasing prevalence in people of all ages. ETW affects a considerable part of the general population, and can be found among all categories of patients, depending on exposure to the risk factors. However, because in ETW the teeth are practically rinsed with acids, it is difficult for plaque microorganisms to tolerate the low pH level that causes ETW. For this reason, ETW-affected tooth surfaces are plaque-free, unlike caries that occur on plaque-covered surfaces, and as such, it can occur in people that maintain good oral hygiene. Furthermore, as life expectancy and dental awareness increase, people’s teeth last longer and must work harder. Wear and tears are only natural, but teeth today have more work to do over a longer period than previous generations that had teeth extracted and wore dentures. Nevertheless, there are categories of individuals that are more prone to ETW.

The people adopting healthier diets that include more fruits and vegetables, as well as their juices, many of which are acidic, are putting themselves at an increased risk of ETW. 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.

Saliva is one of our main defenses against acid attack. Yet more patients are taking an increased number of prescriptions and over-the-counter medications, more than 85% of which can reduce saliva flow, and thus decrease this line of defense. Reduced saliva flow during sleep when saliva flow rate is very low may exacerbate ETW in patients suffering from gastro-esophageal reflux disease (GERD) due to passive regurgitation causing repeated direct contact of teeth with gastric contents, the pH of which can be as low as 1, resulting to acidic dissolution of the mineralized tooth substance.

Early and minor ETW has a smooth and silky-shiny appearance without no noticeable signs or symptoms, thus patients can hardly detect it. Even when detected, patients hardly seek treatment until it gets to an advanced stage when it either becomes symptomatic (dentin hypersensitivity) or affects the esthetics of their teeth. For this reason, dentists and dental hygienists may be the first to detect it on routine dental examination. However, early or minor ETW is a call for ETW risk assessment to reveal the cause of the problem. Other indicators of ETW are yellowing and loss of whiteness, change in the surface texture, absence of Perikymata, changes in shape, and loss of occlusal contact and/or occlusal height when advanced in relation to the patient’s age.

Is erosive tooth wear the most common form of tooth wear?

Tooth wear is the cumulative surface loss of mineralized tooth substance due to physical or chemo-physical processes. Evidence of ETW can be found in almost every mouth and may co-exist with the other physical forms of tooth wear (ETW, attrition, abrasion, Non-carious Cervical Lesions). Although dental abrasion, which is the physical loss of mineralized tooth substance caused by objects other than teeth, can be distinguished from ETW, which is the chemical loss of mineralized tooth substance caused by frequent contact between acids and the mineralized tooth substance, ETW hardly occurs alone. The acidic erosive agents soften the mineralized tooth substance and decrease its wear resistance, thus rendering it more susceptible to abrasion from either the surrounding oral soft tissues, through food mastication or inappropriate use of toothbrushing/toothpaste, particularly if used immediately after an acid attack. In this case, the clinical signs often lead to an incorrect diagnosis of "toothbrush abrasion." Abrasion is commonly associated with cervical region (gingival margin). This association has been linked to Non-Carious Cervical Lesion (NCCL), which are V-shape cavities seen running horizontally along the gingival margin of some teeth in some patients. NCCL has been demonstrated to be created with horizontal toothbrushing with toothpaste. Toothbrushes without toothpaste do not create these lesions, and no correlation between firmness of toothbrush or abrasive index and the size of the NCCL. With similar process, dental attrition, which is the physical loss of mineralized tooth substance caused by tooth-to-tooth contact, as in bruxism, can be exacerbated by softening of the mineralized tooth substance by the acidic erosive agents, thus reducing its wear resistance.

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?

Following the exposure of enamel to acid (of dietary or gastric source), the surface layers of enamel is softened, making it susceptible to physical loss until it is remineralized and rehardened by the natural processes of saliva. If the oral hygiene procedure of toothbrushing with toothpaste is performed before this remineralization, the oral hygiene procedure may lead to physical removal of some of the softened material, which leads to irreversible loss of the tooth substance. With this in mind, the common practice among individuals of toothbrushing with toothpaste as either a means of refreshing their mouth after exposure to erosive agent (vomiting or regurgitation as the case with an eating disorder) should be discouraged. Routine morning oral hygiene of toothbrushing with toothpaste by patients suffering from GERD, should also be discouraged. Instead, patients should be advised to immediately use a remineralizing mouthrinse to enhance rapid remineralization of the softened tooth surface as well as serve as a mouth refresher. The use of time-delay technique, such as allowing at least 60 minutes before brushing as advised by some practitioners, to achieve remineralization by natural saliva alone may not be the best, considering it has been demonstrated that the softened tooth tissue may be worn by abrasion from the surrounding oral soft tissues and/or mastication before it can be remineralized by the slow process of saliva remineralization. Moreover, it is not feasible to obtain patients' compliance with a time-delay technique without provision of an alternative mouth refresher.