- When treating an approximal lesion on one tooth with an adjacent neighbour, the
operator will almost certainly damage the latter. The important surface layer of the
neighbouring tooth, which contains the highest level of fluoride is the most resistant,
so damage inflicted increases the chances of the adjacent surface of the neighbouring
tooth becoming carious. It also creates an area of roughness on that surface, which in
turn will accumulate more plaque, thereby increasing the risk of further
decalcification. - When placing an interproximal restoration it is inevitable that there is some damage
to the periodontal tissues. There is the transient damage caused by placement of the
matrix band and wedge, and there is also an enduring effect caused by the presence of
the restoration margin. The very presence of the new restoration results in a contour
change of the interstitial space. However smooth the operator attempts to make it, the
altered state will increase plaque accumulation.
Key Point
Every time a restoration is placed, more of the original tooth structure will be
destroyed, thereby weakening the tooth.
9.3.2 Important points in relation to remineralization
- Early smooth surface lesions are reversible in the right conditions.
- There is little evidence to suggest that remineralization occurs in lesions already
into dentine. - The rate of caries progression is usually slow but can be rapid in some individuals,
particularly younger children. In general, the older the child is at diagnosis of a
carious lesion the slower the progress of the lesion, assuming constancy of other risk
factors. - The remineralized tissue of early caries is less susceptible to further caries.
- Small restorations are generally more successful than large, so a balance has to be
struck, allowing preventive procedures adequate time to function, against the risk of
lesion enlargement.
The progression rate of approximal caries can vary from tooth to tooth within the
same mouth. It is thought that if the circumstances for remineralization are
favourable, clinicians should use the modality, as opposed to a restoration that has a
finite but limited lifespan (410HFigs. 9.2 and 411H9.3).
Remineralization sources available are:
- fluoride rinse,
- fluoride varnish,
- chlorhexidine thymol varnish,
- oral hygiene measures,
- adjacent glass ionomer restorations.