Step 4. Gaining adequate
access to the caries lesion
In small caries lesions, where the opening
into the cavity is small, it is often necessary
to widen the access. A dental hatchet
is used ensuring that the instrument is
correctly stabilised using an appropriate
finger rest. The corner of the hatchet is
placed in the entrance of the cavity, usually
in the deepest part of the pit or fissure
for the occlusal surface, and the instrument
tip rotated backwards and forwards
while maintaining slight pressure (Fig. 8).
This fractures off the weak demineralised
enamel surrounding the cavity entrance,
permitting adequate access to the dentine
caries for the smallest excavator. As mentioned
above, an EAC can also be used
to improve access to a caries lesion. This
instrument is placed in the cavity opening
and rotated in a similar way as the hatchet
to fracture off weak demineralised enamel.
The EAC has two pyramidal shaped working
tips, one large and one small. The
largest tip can be used when the cavity
opening is relatively wide, but needs to be
opened further; the smaller tip being used
in small openings where there might be
difficulty in using the hatchet.
Note: the EAC should not be used for
creating cavities where they do not exist.
If in doubt about the presence of a possible
lesion it is better to place a therapeutic
sealant without any mechanical
preparation