The deeper part
of the dentine caries lesion, that which is
more distant from the opening of the cavity,
is harder since the mineral content is
higher. This is called ‘inner carious dentine’
or preferably ‘affected dentine’. This often
darker and stained layer is vital, minimally
affected with bacteria and has the potential
to remineralise. It is therefore logical to
retain this layer. If rotary instrumentation
is used to clean (prepare) the cavity, tactile
feedback that enables the distinction
between the softer infected dentine and the
harder affective dentine is compromised.
This often leads to excessive cavity preparation
and unnecessary removal of sound
tooth tissue or that which has the potential
to remineralise