is no overt or open cavity, diagnosing the status of a discoloured or stained fissure can
be incredibly difficult if not impossible on occasions. Many methods have been
proposed, both alone and in combination. These include:
- visual methods (dry tooth);
- probe/explorer;
- bitewing radiographs;
- electronic;
- fibre optic transillumination;
- laser diagnosis.
When two or three methods are used in combination, there is greater accuracy and
higher rates of detection of caries. The most widely used combination is visual
inspection under a good light, to examine a dry tooth for stains, opacities, etc., along
with a good quality bitewing radiograph. Drying the tooth to be examined is essential
as early lesions will only become visible, where the demineralization is minimal,
when there is a dry surface. Different recommendations are made for the timing of
bitewing radiographs and these are discussed in 414HChapter 3. Bitewing radiographs will
show dentinal caries in teeth that are designated as clinically sound but there will also
be teeth visually designated as carious in which there are no radiological signs of
caries, hence the need for more than one method of diagnosis.
In making a diagnosis of caries, the operator has to decide, not only that there is a
lesion present but also:
- Whether or not demineralization is present.
- The depth of the lesion.
- The rate of progression of the lesion.
- Whether it is an arrested or active lesion.
It would be nice to have a method of quantifying these factors. Measurements of
electrical conductance and laser fluorescence have the potential to chart lesion
progression/retardation as they provide a quantitative record, which if repeated over
several appointments will demonstrate whether the lesion is active or arresting. They
can be repeated safely more frequently than radiographs. However, it should be
remembered that the electrical conductance and laser fluorescence methods would
incorrectly interpret hypomineralization as caries and that similarly the laser-based
instrument will routinely interpret staining to be caries.
Key Point
Diagnosis of early caries is important to be able to plan the whole treatment package.
9.5 FISSURE SEALING
9.5.0 Introduction
Fissure sealants cannot be discussed in isolation from caries diagnosis or treatment of
pit and fissure caries. The authors discuss use of these materials both preventively and
therapeutically.