Immediate and delayed direct pulp capping with the use of a new visible light-cured calcium hydroxide preparation.

The pulpal response to mechanical exposure and capping either immediately or after 24 hours was investigated in 64 teeth of four cynomolgus monkeys with the use of Dycal, VLC Dycal, or Prisma-Bond. All overlying amalgam restorations were surface-sealed with zinc oxide-eugenol cement. After 2 months the teeth were removed and prepared for histologic examination; dentine bridges were present in almost all teeth filled with Dycal or VLC Dycal, and pulpal inflammation was observed in only one tooth that showed evidence of infection. Dentine bridges were usually incomplete when Prisma-Bond was used, although pulpal inflammation was only observed in 2 of 22 teeth. The success rate of pulp capping delayed for 24 hours was as high as that for immediate capping.