Tooth Erosion

Since the early 1900’s it has been well known that soft drinks are particularly bad for your teeth, causing enamel erosion leading to dental caries if left untreated (McCay and Will, 1949).

Tooth erosion is known to be caused by the direct effect of acids in the diet – in particular from soft drinks – on the teeth and dental caries is caused by plaque bacteria via the indirect effect of acid in the diet. Most of the population assume that diet drinks, tea, coffee, and fruit choice are all better options than full fat fizzy drinks, however, it has been found that even ‘Diet Cola’ has a pH of 3.2, which is actually slightly more acidic than ‘full fat Irn Bru’ at pH 3.3. This shows that even diet drinks can have an adverse effect on the teeth

The answer to this is a major research area in dentistry and microbiology.

Unfortunately, the UK – in particular the west of Scotland, have the worst rates of enamel erosion and dental caries, especially in children with 42% of Scottish children demonstrating and experiencing dental caries, however, this is getting better due to the child smile scheme (NHSScotland, 2010).The reason behind these increased rates in the UK is due to the extensive use of refined carbohydrates in the diet, especially sucrose, which not only causes formation of dental plaque but provides specific bacteria with a substrate which is extensively converted to acids.

Streptococcus mutans is a common coloniser in the human oral cavity and is the leading contributor to tooth decay (Loesche, 1986; 1996). S. mutans, utilises glucosyl transferases (GTF) to synthesise a glucan rich extracellular polysaccharide layer from dietary sugars in particular sucrose, to promote adhesion, and formation of dental plaque (Gibbons and Houte, 1973; Ahn et al., 2008). The formation of dental plaque coupled with the acidic environment from the soft drinks can then cause caries and tooth erosion. This dental plaque obstructs the acid from escaping from the tooth surface causing the pH at the surface of the tooth to be lowered (become more acidic) adequately to cause the mineral of the enamel to gradually dissolve away – known as tooth erosion. This occurs as the plaque dos not