Acids of intrinsic and extrinsic origin are thought to be the main etiologic factors for dental erosion. There is evidence that acidic foodstuffs and beverages play a role in the development of erosion. However, the pH of a dietary substance alone is not predictive of its potential to cause erosion as other factors modify the erosive process. These factors are chemical (pK_a values, adhesion and chelating properties, calcium, phosphate and fluoride content), behavioural (eating and drinking habits, life style, excessive consumption of acids) and biological (flow rate, buffering capacity, composition of saliva, pellicle formation, tooth composition, dental and soft tissue anatomy). The interplay between erosion and abrasion (specially oral hygiene practices) may be the main driver leading to the clinical manifestation of this disorder. Recommendations for patients at risk for dental erosion such as reducing acid exposure by reducing the frequency and contact of acids will be discussed.

Dental erosion is a multifactorial condition: The interplay of chemical, biological and behavioural factors is crucial and helps explain why some individuals exhibit more erosion than others. The erosive potential of erosive agents like acidic drinks or foodstuffs depends on chemical factors, e.g. pH, titratable acidity, mineral content, clearance on tooth surface and on its calcium-chelation properties. Biological factors such as saliva, acquired pellicle, tooth structure and positioning in relation to soft tissues and tongue are related to the pathogenesis of dental erosion. 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. There is some evidence that dental erosion is growing steadily. To prevent further progression, it is important to detect this condition as early as possible. Dentists have to know the clinical appearance and possible signs of progression of erosive lesions and their causes such that adequate preventive and, if necessary, therapeutic measures can be initiated. The clinical examination has to be done systematically, and a comprehensive case history should be undertaken such that all risk factors will be revealed.

The aim of this in situ study was to test the effect of toothbrush abrasion on enamel previously exposed to a standardized artifical erosive agent. To generate moderate erosive lesions, slabs of the buccal surface of human premolars were immersed in a solution of citric acid for 3 min. Then they were attached to intraoral appliances and each one was exposed for 0 min (= toothbrushing immediately after intraoral exposure), 30 or 60 min to the oral milieu of 1 of 7 female subjects with a mean age of 22 years. Immediately thereafter the volunteers brushed the slabs for 30 s with toothpaste using their preferred brushing technique. For each test person the secretion rate of resting and paraffin–stimulated saliva, buffering capacity and pH were measured. The following mean losses of substance at the surface were registered: 0.258±0.141 μm (toothbrushing immediately after intraoral exposure), 0.224±0.087 μm (toothbrushing after intraoral exposure of 30 min) and 0.195±0.075 μm (toothbrushing after intraoral exposure of 60 min). Toothbrush abrasion in situ was significantly lower after 60–min exposure to the oral environment than after 0–min (p<0.001). Also, the 30– and 60–min values were significantly different from each other (p<0.001). Multiple linear regression analyses revealed that in this model toothbrush abrasion was associated with the intraoral exposure to saliva (p = 0.026), the severity of the erosive attack (p<0.001) and the secretion rate of resting saliva (p = 0.029). If no other preventive measures are taken we suggest that individuals at risk for erosive tooth wear wait at least 1 h before brushing their teeth after consuming erosive foodstuffs or beverages.

There is evidence that the presence of erosion is growing steadily. Due to different scoring systems, samples and examiners, it is difficult to compare the different studies. Preschool children from 2 to 5 years showed erosion on deciduous teeth in 1 to 79% of the subjects. Schoolchildren (aged from 5 to 9 years) already had erosive lesions on permanent teeth in 14% of the cases. In the adolescent group (aged between 9 and 20 years), 7 to 100% of the persons examined showed signs of erosion. Incidence data (the increase in the number of subjects presenting signs of dental erosion) was evaluated in four of these studies and presented average annual values between 3.5 and 18%, depending on the initial age of the examined sample. In adults (aged from 18 to 88 years) prevalence data ranged between 4 and 100%. Incidence data are scarce in this age group, and only one study was found analysing the increase of affected surfaces, showing an incidence of 5% for the younger and 18% for older age groups. In general, males present more erosive tooth wear than females. The distribution showed a predominance of affected occlusal surfaces (mandibular first molars) followed by facial surfaces (anterior maxillary teeth). Oral erosion was frequently found on maxillary incisors and canines. Overall, prevalence data are not homogeneous. Nevertheless, there is a trend towards a more pronounced rate of erosion in younger age groups. Furthermore, a tendency was found for more erosive lesions with increasing age and these erosions progressed with age.

The aim of this study was to investigate whether the erosive potential of a beverage on human enamel can be predicted by examining the composition of the beverage. The buccal surfaces of 84 caries-free premolars were embedded in resin and polished flat. Two hundred micrometers of the enamel surface were removed. Then the slabs were divided into 14 groups and immersed for 20 min in commercially available beverages. Surface microhardness was measured before and after immersion. Further, the phosphate concentration, the fluoride concentration, the baseline pH as well as the titrated amount of base to raise the pH to 7.0 of each beverage were determined. Surface microhardness values after immersion were calculated with an equation derived in a recent study and compared with the values measured in this investigation. Apple juice showed the greatest significant decrease (p < 0.05) in surface microhardness, followed by Schweppes, Orangina and Grapefruit soft drink. The smallest decrease in surface microhardness that was significant resulted from Fendant and Isostar orange. The mean absolute deviation of the calculated to the effective erosion was 7.1%, it ranged between 14.6% (apple juice) and 1.6% (Fendant). The data suggest the possibility of predicting erosion caused by a beverage with an accuracy of 7%. This information can be of value in the prevention of dental erosion.