In contrast to attrition, erosion is the loss of tooth structure due to ingested or regurgitated acids which have been either regurgitated or ingested. Regurgitated acid produces wear on the lingual and occlusal surfaces, while ingested acid produces wear on the front and biting surfaces of teeth, however, it can be present anywhere on the tooth. Erosive wear is typically not sharp and flat as seen in attrition, but rather has a soft, satin, rounded appearance. Head posture and gravity determine the appearance of the erosion.
The mechanism of erosive wear
Erosive tooth wear results from demineralization of the tooth followed by a loss of the demineralized layer through abrasion from an opposing tooth, the tongue, cheeks, food or a toothbrush. Cupping on the cusps of back teeth results when acid demineralizes the biting surface of the tooth and with the cusps receiving a greater degree of abrasion than the fossas. The erosive wear that begins on cusps eventually penetrates to dentin. As dentin wears at a faster rate than enamel, once the supporting dentin is undermined the enamel collapses and the cup enlarges. In the past, cupped lesions have been attributed to occlusal issues. If well managed, erosion can have an excellent long-term prognosis.
Common causes of erosion
- Gastric Reflux (GERD) –wear on the lingual and occlusal of all upper teeth and on the biting surface of back teeth usually with less wear on the molars then the premolars. GERD can lead of Barrett’s esophagitis, which can be a precursor to esophageal cancer.
- Bulimia produces massive wear on the back of the upper front teeth and often the lingual of the first premolars. There is much less wear on the maxillary or mandibular posterior teeth. GERD produces wear on the lingual of the maxillary anterior teeth, but may not result in them being reduced in length significantly. Bulimia destroys both length and lingual thickness of the upper front teeth.
- Citrus fruits and acidic beverages and such as carbonated beverages produce variable patterns of wear dependent upon the individual’s habits after ingesting them. Swishing the beverage before swallowing produces wear on the front of teeth. If the beverage sit in the floor of the mouth prior to swallowing, the wear will effect lower molars most.
- Other etiologies of erosive wear can mimic some of the previously discussed conditions are a lack of normal salivary buffering capacity and asthmatic inhalers. Both tend to mimic GERD.