Other factors linked to erosion
The principal intrinsic factor is gastric acid. Although less common in young people, indigestion occurs in about a fifth of adolescents and 15% report getting an acid taste in their mouth; the former is associated with an increased prevalence of tooth wear, while the latter may not.39 A much smaller proportion, 3%, have reported regularly suffering stomach upsets or vomiting which does present a significant risk factor.39
In infants, reflux is common, but declines through their first year.41 As primary dentition usually starts to emerge at around 6 months, erosion may be possible.
Tooth erosion can be drug-induced - both from medicines as well as illicit use. A number of factors may be relevant here. Some drugs may have the potential to induce GERD, such as theophylline, anticholinergics, progesterone, anti-asthmatics, and calcium channel blockers.42 Acidic drugs such as aspirin (suitable for use in those over 12 years), especially if taken in a chewable format, present a clear erosive challenge.
Asthma medication is sometimes mentioned in relation to dental erosion, particularly with reference to orally inhaled medication.42 People with asthma should drink some water after using an inhaler, to wash away any drug residue in the mouth. However, the problem may be small, as a UK survey of adolescents found no significant differences in tooth wear between the 16 per cent claiming to have asthma and the rest of the cohort.39
Drugs that decrease salivary flow may make teeth more prone to caries, but as the protective effects of saliva are removed erosion should also be considered.42 These can include antihistamines, anticholinergics, antidepressants, antipsychotics and proton pump inhibitors.42
An in situ study suggests tooth brushing can adversely affect remineralization, if carried out too soon after the erosive challenge.31 Subjects were asked to wear an intraoral appliance with human enamel specimens which was then subjected to a demineralization process with an acidic drink. The time between the demineralization process and brushing the enamel samples varied from immediately afterwards, through 10 minute intervals to 60 minutes.
After three weeks, enamel wear was analyzed using a laserprofilometer which showed a significant influence of remineralization period on abrasive wear. But even after 60 minutes, the wear was significantly increased as compared to the demineralized but not brushed control.31
The authors concluded: resistance to the abrasion improves the longer the softened enamel is given to remineralize; and, at least 60 minutes should elapse before brushing after an erosive attack.31
Other research supports this view that enamel softened by erosion is readily susceptible to abrasion through tooth brushing, and abrasive enamel loss correlated with drink corrosive potential.43
Influence of mouthwashes
Certain mouthwashes may be acidic and should not be used long term or continuously.44 Teeth whitening with hydrogen peroxide may be associated with cervical root resorption, and a reduction in the microhardness of dentin and enamel.42
Exposing teeth to extrinsic minerals may also influence erosion. A lack of exposure to fluoride may increase susceptibility to erosion. In one study, children who didn't rinse regularly with a fluoride mouthwash had a higher prevalence of erosion compared to children who did.45
Influence of toothpaste
Toothpaste containing fluoride and potassium nitrate has been found to offer a degree of protection if the tooth is exposed to the paste before and after the acid challenge.46 The in vitro research used teeth extracted from people living in an area with unfluoridated water.
Further research found that exposure to fluoride improves resistance to enamel erosion, with the degree of acid protection positively correlating with the extent of fluoride uptake.47 The researchers noted that fluoride uptake is not necessarily directly related to fluoride concentration or free fluoride availability, but may be related to how the fluoride dentifrice is formulated.