Endodontic treatment for children

Root canal treatment for children has particular difficulties and considerations. It must be planned in light of the remaining teeth, and the need for balancing or compensating extraction borne in mind. Diagnosis may be difficult, as may prolonged treatment under local anaesthesia and rubber dam. Vital pulpotomy techniques with formocresol and/or calcium hydroxide must be carefully executed in line with the UK National Guidelines. The treatment of the avulsed tooth has been the subject of much research, and practitioners should ensure that they are up-to-date with current treatment modalities.

Although the basic aims of endodontic therapy in children are the same as those in adults, ie the removal of infection and chronic inflammation and thus the relief of associated pain, there are particular difficulties and considerations. The pulpal tissue of primary teeth may become involved far earlier in the advancing carious lesion than in permanent teeth. Exposure may also occur far more frequently during cavity preparation due to the enamel and dentine being thinner than in the permanent tooth, and the pulp chamber, with its extended pulp horns, being relatively larger, as can be seen in the extracted tooth at Figure 1. Primary molar root canals are irregular and ribbon-like in shape. Periradicular lesions associated with infected primary molars are usually inter-radicular 

(Fig. 2)

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

Non-vital pulpotomy

Fig. 6  Stainless steel crowns make ideal restorations for compromised deciduous molars.
Table 2  Paraformaldehyde devitalising paste Paraformaldehyde 1.00 g
Carbowax 1500 1.30 g Lignocaine 0.06 g Propylene glycol 0.5 ml Carmine 10 mg
This technique has been advocated where there is irreversible change in the radicular pulp, or where the pulp is completely non-vital, but where pulpectomy and root canal treatment is considered impractical. The little clinical evidence available suggests a limited prognosis of approximately 50%. At the first visit the necrotic pulp contents are removed as before, and, using small excavators, as much as possible of the radicular tissue.

Pulpectomy

Pulpectomy is indicated where the pulp is either non-vital or irreversibly inflamed. Although the technique is often considered difficult because of the complexity of the root canals in primary molars, clinical studies have shown a reasonable prognosis.The cavity preparation and removal of the necrotic coronal pulp is carried out as previously described. If the radicular pulp is necrotic, a two-stage procedure is required, but if it is found to be irreversibly inflamed a one-stage technique may be undertaken.