12.7.4 Resorption
Root resorption is a serious and destructive complication which may follow trauma to
primary and permanent teeth. Primary teeth which develop pathological resorptive
lesions are not good candidates for conservative treatment and should be extracted.
Permanent teeth on the other hand may often be successfully treated provided tissue
destruction has not advanced to an unrestorable state.
Two general forms of pathological root resorption are recognized, inflammatory and
replacement.
INFLAMMATORY ROOT RESORPTION
Internal and external root surfaces injured as a result of trauma are rapidly colonized
by multinuclear giant cells. If giant cells are continuously stimulated, most commonly
by microbial products from an infected root canal or periodontal pocket, progressive
inflammatory root resorption may follow with catastrophic consequences.
Inflammatory root resorption may be classified according to its site of origin as
external root resorption, cervical resorption (a special form of external resorption), or
internal root resorption.
EXTERNAL INFLAMMATORY ROOT RESORPTION
Teeth affected by external inflammatory root resorption are invariably non-vital with
infected pulp canals. Resorptive activity is initiated by damage to p.l. in trauma but
propagated by infected root canal contents seeping to the external root surface through
patent dentinal tubules, and may be extremely aggressive. However, if the infected
canal contents are removed, the propagating stimulus is lost and the lesion will
predictably arrest.
- Diagnosis. External inflammatory root resorption is usually detected as a chance
radiographic finding, and is characterized by change of the external contour of the
root, which is often surrounded by a bony lucency (751HFigs. 12.40 and 752H12.41). Sometimes
it may present as a radiolucency overlying the root, and can be distinguished from
internal resorption by its asymmetrical shape, by the superimposed contour of the
intact root canal walls, and by the fact that it moves in relation to the root canal on
periapical films of different horizontal angle. - Treatment. Provided the tooth is still restorable, external inflammatory root
resorption should be treated without delay. Following access cavity preparation, the
root canal should be cleaned and shaped, taking care not to weaken the root
excessively, or to risk perforation into the resorbed area. It is common practice to
dress the root canal with non-setting calcium hydroxide paste and to monitor the tooth
for several months prior to definitive obturation to ensure that the lesion has arrested.
Nevertheless, control of intracanal infection is the key determinant of success, and
there is good evidence to suggest that if the canal is adequately prepared, it may be
filled without protracted calcium hydroxide treatment.
Periodic clinical and radiographic review should be arranged.
CERVICAL RESORPTION