Tooth Erosion and Abrasion are terms which refer to the loss of external tooth structure(enamel), but erosion means loss of the tooth structure by means of chemical agents and abrasion due to mechanical friction of the tooth structure with any external agent.
Erosion: Tooth erosion is referred to as the loss of tooth structure due to chemical agents such as acids which erode the surface layers of the tooth which is mainly the protective enamel but some times in severe cases the dentin may also be affected and cause severe sensitivity of the tooth.
Most common agents which cause tooth erosion are aerated/carbonated drinks such as soft drinks which are not usually soft on the tooth,Gastric juices when regurgitated into the oral cavity in case of severe vomiting, some citric juices, wine also has been seen to cause erosion due to its low pH, Chlorine mixed in swimming pools, sugars which on fermenting turn into acid and erode the tooth. The erosive potential of erosive agents like acidic drinks or foodstuffs depends on chemical factors, e.g. pH, acidity, mineral content, clearance on tooth surface and on its calcium-chelation properties.
Furthermore, behavioural factors like eating and drinking habits, regular exercise with dehydration and decrease of salivary flow, excessive oral hygiene and, on the other side, an unhealthy lifestyle, e.g. chronic alcoholism, are predisposing factors for dental erosion.
Tooth erosion can be prevented by maintaining good oral hygiene, using straws while drinking soft drinks, rinse with water after eating sweet foods. . .etc.