Operative dentistry aje qualtrough, jd satterthwaite la morrow, pa brunton

Indications for use
Dentine itself is an excellent insulator; therefore, in preparations 
estimated to have more than 2 mm of remaining dentine thickness,
there is generally no requirement for any pulp protective material
beneath the restorative material. However a preparation sealer
should be placed to seal dentinal tubules and thus prevent post-
operative sensitivity and bacterial contamination of dentinal tubules.
In the case of simple amalgam restorations two coats of a dentine
desensitiser (such as a HEMA/glutardialdehyde combination, avail-
able as a proprietary product) may be used. Current research would
seem to suggest that cavity varnish will be replaced by dentine bond-
ing agents in the near future. However, there is insufficient evidence,
at present, to support the routine use of dentine bonding agents under
amalgam restorations. There is growing evidence that compound or
complex amalgams would benefit from the application of a dentine
bonding agent. Dentine bonding agents should be used routinely
used under all resin composite restorations.
For deeper cavities in which there is less than 2 mm of remaining
dentine a preparation liner should be placed in the deepest aspects of
the preparation. Traditionally, calcium hydroxide was used routinely
as a liner but is now reserved for use in deeper cavities or for ‘capping’
procedures (Fig. 2.3).
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Chapter 2
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Table 2.2 provides a guide to the use of pulp protection materials,
indicating suitable combinations of sealers, liners and bases to be used
in resin composite and amalgam preparations.
Principles of direct intervention


41
Fig. 2.3
Features of a restored deep lesion (RmGIC 
= resin-modified glass-ionomer
cement).