Indications of Pulpotomy
- This procedure is indicated where there is a pulpal exposure but the tooth is asymptomatic or exhibits signs of reversible pulpitis.
- The latter is characterised by pain of short duration or where the tooth is sensitive to temperature changes. Thus a cold drink may elicit some discomfort which disappears quickly.
- This indicates that the pulp has undergone inflammatory changes but this is probably confined to the coronal part only and the radicular pulp tissue is likely to remain unaffected.
Procedure of pulpotomy :
The vital pulpotomy therefore involves the elimination of the coronal pulp, which allows the remainder of the pulp to be retained. The tooth (Fig. 12.14a) is anaesthetised and with isolation under a dental dam, all remaining caries is removed together with the roof of the pulp chamber.
This exposes the coronal pulpal contents which then may be removed by a slowly rotating rosehead bur leaving the floor of the pulp chamber bereft of all pulp tissue except for the apertures of the root canals (Fig. 12.14b).
Care is required to avoid inadvertent perforation of the floor of the pulp chamber with the rosehead bur. The vacant pulp chamber is irrigated with water using the triple syringe and dried with a cotton pledget. The bleeding from the radicular pulp should have stopped so as to leave a clear, dry pulp chamber floor. A medicament is now applied to treat the remaining pulp; this is applied for 4 minutes with a lightly moistened cotton pledget (Fig. 12.14c).
Historically, formocresol was used to fix and disinfect the tissue. However, despite its excellent success record over almost 70 years of use in pediatric dentistry, concerns have been raised because of the formalin it contains. The latter has been associated with toxicity and potential carcinogenicity, although it has to be emphasised that there is currently no evidence linking this to dental use. For a short time in the 1990s 2% gluteraldehyde was used instead but this was found to be equally toxic. A more recent substitute is ferric sulphate and this is proving to be as effective as formocresol but without the associated problems. This is therefore currently the medicament of choice for vital pulpotomies.
After applying the ferric sulphate for 4 minutes, the pledget is removed and the floor of pulp chamber and the radicular pulp are covered with a lining of zinc oxide eugenol (Fig. 12.14d) and the tooth is restored in the appropriate way. Should a composite resin be the restorative material then an additional lining, such as zinc phosphate, is required to prevent the adverse effect of the zinc oxide eugenol on the setting of the composite resin.
In cases where there is evidence of irreversible pulpitis, characterised by constant pain exacerbated by thermal changes, the assumption is that inflammatory changes extend throughout the pulpal tissue, including the radicular pulp. Application of ferric sulphate as before would be unsuccessful as this would be placed on inflamed tissue. At one time a devitalising procedure was advocated, whereby the tooth was rendered non-vital by dressing the radicular pulp with paraformaldehyde paste for 7 days. During this period the inflamed pulp tissue would die and leave non-infected fixed tissue.
However, the same concerns regarding formocresol have been raised in relation to the use of paraformaldehyde and hence this technique is no longer advocated. Where there is an irreversible pulpitis, the coronal pulp is removed under local anaesthesia as described above, and Ledermix is placed over the radicular pulp. This is a proprietary paste which contains a corticosteroid (1% triamcinalone) and an antibiotic (3% chlortetracycline).
The former is effective in reducing the inflammation whilst the latter has bactericidal properties. A structural lining is required over the Ledermix before the tooth is restored.
The success of a pulpotomy procedure is indicated clinically by:
■ The absence of pain and swelling.
■ No tenderness to percussion.
■ No pathological mobility.
It is indicated radiographically by:
■ The absence of pathological radiolucency at the furcation area of the root.
■ Normal root resorption as part of the exfoliation process.
Should failure occur as demonstrated by these signs and symptoms, then an extraction is usually indicated.