Transient apical internal resorption is another form
of trauma induced non-infective root resorption which
was identified by Andreasen in 1986.
This resorptive process can follow luxation injuries and may be
associated with a transient apical breakdown –
recognized by a confined periapical radiolucency which
resolves within a few months. It is considered to be a
positive response, with the internal apical resorption
allowing ingress of a greater vascular network to aid in
the healing of a traumatized pulp. Often there is an
associated colour change due to intra-pulpal
haemorrhage and this may resolve spontaneously if
revasularization to the coronal pulp chamber occurs. In
the longer term, as this is a transient process, the
internally resorbed apex will close uneventfully.
An example of transient apical internal root
resorption is shown in Fig 5. This case illustrates the
resorptive process following a luxation injury, tooth
discolouration and resolution, and then apical closure.
The resolution of discolouration which may accompany
transient apical internal resorption does not occur in
all cases. In the experience of the author it is estimated
that colour resolution will occur in approximately 50
per cent of cases despite other radiographic signs of a
satisfactory healing response. This poses an aesthetic
problem which on occasions may be resolved by
external bleaching, but more often elective pulpectomy,
root filling and intra-coronal bleaching are required. If
internal apical resorption is still present, the endodontic
treatment is somewhat complicated and should extend
only to the position of the resorption. These aesthetic
complications and the difficulty posed for dental
practitioners in monitoring this healing response have
led some to question the advisability of recommending
this conservative approach as opposed to pulpectomy,
root filling and intra-coronal bleaching as soon as
discolouration is observed. However, the author
remains of the opinion that this healing process should
be recognized and implemented in clinical practice and
teaching.