- occurs in plaque-covered areas frequently exposed to dietary carbohydrates;
- the initial lesion is subsurface before the thin surface layer collapses;
- the initial or pre-cavitation lesion is reversible;
- saliva plays an essential part in caries prevention;
- if all plaque is removed from the surface the carious process stops.
220H
Fig. 6.1 Plot of the pH of dental plaque
against time: this is commonly known as
a Stephan curve. The curve was
produced by rinsing with a 10% glucose
solution. The dotted line represents a
typical pH value below which enamel
will dissolve (the critical pH).
(Reproduced with permission from
Jenkins 1978.).221H
Fig. 6.2 Clinical appearance of
precavitation carious lesions on the
buccal surfaces of maxillary incisor teeth
(white spot lesion).222H
Fig. 6.3 Clinical appearance of a
precavitation carious lesion on the
mesial surface of a maxillary first molar
tooth (brown spot lesion).223H
Fig. 6.4 Longitudinal ground section
through a carious lesion of the type
shown in 224HFig. 6.3 examined in water by
polarized light: ×50. (Reproduced with
permission from Soames and Southam,