a contralateral uninjured tooth. A duller note may indicate root fracture.
- Colour of tooth. Early colour change associated with pulp breakdown is visible on
the palatal surface of the gingival third of the crown. - Reaction to sensitivity tests. Thermal tests with warm gutta percha or ethyl chloride
(e.c.)are widely used. However, an electric pulp tester (e.p.t.) in the hands of an
experienced operator is more reliable. Nevertheless, sensibility testing, especially in
children is notoriously unreliable and should never be assessed in isolation from the
other clinical and radiographic information. Neither negative nor positive responses
should be trusted immediately after trauma. A positive response does not rule out later
pulpal necrosis and a negative response while indicating pulpal damage does not
necessarily indicate a necrotic pulp. The negative reaction is often due to a 'shock
wave' effect damaging apical nerve supply. The pulp in such cases may have a normal
blood supply. In all sensibility testing always include and document the reaction of
uninjured contralateral teeth for comparison. In addition, all neighbouring teeth to the
obviously injured teeth should be regularly assessed as they have probably suffered
concussion injuries.
669H
Fig. 12.6 Degloving injury to the lower
labial sulcus that required exploration to
remove grit.12.4.5 Radiographic examination
Periapical
Reproducible 'long cone technique' periapicals are the best for accurate diagnosis and
clinical audit. Two radiographs at different angles may be essential to detect a root
fracture. However, if access and co-operation are difficult then one anterior occlusal
radiograph rarely misses a root fracture. Periapical films positioned behind lips can be
used to detect foreign bodies.
Occlusal
To detect root fractures when used intaorally, and foreign bodies within the soft
tissues when held by patient/helper at the side of the mouth in a lateral view (670HFig. 12.5
(c)).
Orthopantomogram
Essential in all trauma cases where underlying bony injury is suspected.