Ferric sulphate and formocresol pulpotomies in baboon primary molars: histological responses.

AIM To compare pulpal reactions to ferric sulphate and formocresol pulpotomies in primary molar teeth with inflamed pulps. STUDY DESIGN An experimental study in 15 juvenile baboons (Papio ursinus). MATERIALS AND METHODS Pulpitis was induced with fresh human carious dentine or Streptococcus mutans placed into occlusal cavities in 57 primary molars; after 14 days a pulpotomy was performed on the same primary molars with the two pulp medicaments randomly allocated; the pulp was covered with IRM and the cavity filled with amalgam. After 90 days specimens were harvested and examined under the light microscope with the examiner blind to the treatment. RESULTS Reaction frequencies in the ferric sulphate-treated and formocresol-treated teeth were: recognisable pulp 52% and 50%, dentine bridges 16% and 12%, internal root resorption 12% and 4%, external resorption 28% and 31%, bacteria 12% and 23%, peri-apical abscesses 32% and 38%. STATISTICS Fisher's exact probability test showed no statistically significant differences between reaction frequencies in the two treatment groups. CONCLUSION A pulpotomy in a primary tooth may be clinically successful in the presence of adverse histological reactions.