generally acceptable. Cavity design is usually a modified approximal design with
bevelling of the margins to increase the amount of enamel available for etching and
bonding.
The use of rubber dam is essential if a dry field is to be achieved. This fact together
with the material's relative expense probably reflects the lack of widespread use of
composite resin in many countries.
Glass ionomer cement
More studies have been conducted using glass ionomer cements than composite
resins. However, the cavity designs used in the different studies vary considerably and
it is difficult to draw firm conclusions. Certainly, glass ionomer cement will undergo
significantly more loss of anatomical form than amalgam in the approximal area, and
as such conventional glass ionomers have not been shown to be as durable as
amalgam. However, the operator will need to balance this fact with the obvious
mechanical and chemical advantages of the cement⎯namely its ability to bond to
enamel and dentine, thus requiring a more conservative preparation, and its ability to
act as a reservoir of fluoride.
Compomers
Compomers are now widely used in general dental practice for the restoration of
approximal lesions in primary teeth. After good initial results, longer follow-up
periods have shown that this material indeed lived up to its early promise and good
survival rates have been reported for restorations in primary molars. However, it must
be placed in cavities prepared to the usual principles of cavity design for a most
favourable outcome.
357H
Fig. 8.12 (a)-(f) Technique sequence for the placement of two-surface amalgam
restorations in lower primary molars. The first molar could have been restored with a
stainless-steel crown.