Devitalisation pulpotomy

This is a two-stage procedure, used when local anaesthesia cannot be obtained to permit extirpation of the pulp, or when haemorrhage is uncontrolled before or following the application of formocresol. This technique mummifies and fixes the coronal pulp tissue, whilst the major part of the radicular pulp remains vital, but it carries a lower success rate.

If the tooth is not anaesthetised, cavity preparation is carried out as far as possible and access is gained to the pulpal exposure. A small amount of paraformaldehyde devitalising paste (Table 2) on a pledget of cotton wool is applied to the exposed pulp tissue. Formaldehyde vapour liberated from the dressing permeates through the pulpal space, producing fixation of the tissues. A soft layer of zinc oxide–eugenol temporary dressing is then placed, without applying pressure, to seal the medicament in position. The child and parent must be warned of possible discomfort, for which analgesics are recommended. After one to two weeks the tooth is checked for signs and symptoms. The devitalised coronal pulp may now be removed, without the need for local anaesthesia. A hard setting layer of zinc oxide–eugenol, which may be mixed with formocresol, is then placed over the radicular stumps and

the tooth restored. If some vital tissue remains in the coronal pulp chamber, a further dressing of paraformaldehyde paste is required.