The treatment is carried out using local anaesthesia and adequate isolation. Following cavity preparation in the normal manner, the deep caries is removed and the coronal pulp chamber opened, such that there is no overhanging dentine inhibiting the complete removal of the pulp tissue. The coronal tissue is removed using a large excavator or sterile rosehead bur. If a high-speed diamond bur is used it should be cooled with sterile water or saline. Sterile cotton wool is applied to the radicular pulp tissue to achieve haemostasis. A small pledget of cotton wool is dipped in a 1:5 dilution of Buckley’s formocresol (Table 1) and squeezed to remove excess liquid. It is placed over the radicular pulp stump for 5 minutes in order to fix the inflamed tissue and bacteria and thus allow healing of the unaffected pulp. If the haemorrhage has completely stopped, a layer of zinc oxide–eugenol or glass-ionomer cement is applied, and the tooth restored, preferably with a preformed stainless steel crown to prevent subsequent fracture of the weakened tooth (Fig. 6).
Other materials have been considered as an alternative to formocresol.
Concerns about the safety of formocresol led to investigations of pulpotomies employing a 2% glutaraldehyde solution as an alternative dressing, but research has shown a lower clinical success rate than with formocresol. Concern about hypersensitivity to and handling of glutaraldehyde have largely led to its abandonment as a treatment alternative.
Other materials have been considered as an alternative to formocresol.
Concerns about the safety of formocresol led to investigations of pulpotomies employing a 2% glutaraldehyde solution as an alternative dressing, but research has shown a lower clinical success rate than with formocresol. Concern about hypersensitivity to and handling of glutaraldehyde have largely led to its abandonment as a treatment alternative.
Recent work by Waterhouse et al. has shown that very favourable results have been achieved with calcium hydroxide when it has been applied in carefully controlled circumstances.
Following haemostasis, calcium hydroxide powder was delivered to the pulp chamber using a small, sterile, endodontic amalgam carrier. The powder is condensed over the pulp stumps with an amalgam condensor and small pledgets of cotton wool. Failure of this technique is explained by the presence of an extra-pulpal clot separating the calcium hydroxide from the pulpal tissue and thus impairing healing.
Both the calcium content and alkaline properties of the dressing are important to achieve healing. An initial layer of necrotic tissue develops, which becomes associated with an inflammatory reaction. Subsequently, a matrix forms and mineralises to become a hard tissue barrier of dentine-like material.