of these purchases. Pure fruit juices do contribute to this figure, but, increasingly,
carbonated drinks make up a large part of the younger population's intake and are now
widely available in vending machines located in schools, sports centres, and other
public areas. Both normal and so-called 'diet' carbonated drinks have very low pH
values and are associated with tooth surface loss. While there is no direct relationship
between the pH of a substrate and the degree of tooth surface loss, pH does give a
useful indication as to the potential to cause damage. Other factors such as titratable
acidity, the influence on plaque pH, and the buffering capacity of saliva will all
influence the erosive potential of a given substrate. In addition, it has been shown that
erosive tooth surface loss tends to be more severe if the volume of drink consumed is
high or if the intake occurs at bedtime.
Key Points
The degree of erosive, tooth-surface loss may be related to:
- the frequency of intake;
- the timing of intake;
- toothbrushing habits.
The pattern of dietary, erosive tooth surface loss depends on the manner in which the
substrate is consumed. Carbonated drinks are not uncommonly held in the mouth for
some time as the child 'enjoys' the sensation of the bubbles around the mouth. This
habit may result in a generalized loss of surface enamel (564HFig. 10.16 (a) and (b)). Note
the chipping of the incisal edges of the upper anterior teeth in 565HFig. 10.16⎯this is an
example of attrition contributing to the overall pattern of tooth surface loss. A
generalized loss of the surface enamel of posterior teeth is often evident particularly
on the first permanent molars, and characteristic saucer-shaped lesions develop on the
cusps of the molars. This phenomenon is known as perimolysis. More peculiar habits
are not uncommon; 566HFig. 10.17 shows the dentition of a young cyclist who very
frequently consumed a lemon drink via a straw in his bicycle's drink bottle. 567HFigure
10.18 is an example of a young adult who, for many years, daily consumed 2 lbs
(almost 1 kg) of raw Bramley cooking apples. The extent of tooth surface loss has left
his amalgam restorations 'proud'.
Gastric regurgitation and tooth surface loss
The acidity of the stomach contents is below pH 1.0 and therefore any regurgitation or
vomiting is potentially damaging to the teeth. As many as 50% of adults with signs of
tooth surface loss have a history of gastric reflux. The aetiology of gastric
regurgitation may be divided into two categories: (1) those with upper gastrointestinal
disorders; and (2) those with eating disorders.
In young patients, long-term regurgitation is associated with a variety of underlying
problems (568HTable 10.6).
In addition, there are a group of patients who suffer from gastro-oesophageal reflux
disease (GORD). This may be either symptomatic⎯in which case the individual
knows what provokes the reflux⎯or, more insidiously, asymptomatic GORD, where
the patient is unaware of the problem and continues to ingest reflux-provoking foods.
Unexplained, erosive tooth surface loss is one of the principal signs of an eating