Pulpal response of four
calcium hydroxide liners, MPC 10, MPC 12,
Dycal and
Pulpdent were tested on primary and permanent teeth with
zinc oxide and
eugenol (ZOE) and
silicate as controls. Responses of the pulps were evaluatedi in Rhesus monkeys, utilizing Class V cavity preparations at 3 days, 5 and 8 weeks. An equivalent number of anterior and posterior teeth were studied for all compounds. The Ca(
OH)2 liners,
zinc oxide and
eugenol (ZOE) and
silicate controls were placed in 80 primary and 80 permanent teeth. Following perfusions the teeth were prepared utilizing routine histological procedures. The 3 day response of the
calcium hydroxides was moderate with some disruption in the odontoblasts, vacuolization and mild
inflammation underlying the cavity except
Pulpdent which was more severe. At 5 weeks a decrease in inflammatory response and the formation of reparative dentin was similar for all
calcium hydroxides tested at this time period. At 8 weeks more reparative dentin was noted with slight to moderate pulpal responses. At all time periods ZOE produced the least pulpal response while
silicate produced the most severe response at 5 and 8 weeks. This study reports the
biological responses of four
calcium hydroxide compounds used as cavity liners in non-exposures in a series of primary and permanent teeth of monkeys using ZOE and
silicate as controls. Responses to the four Ca(
OH)2 compounds were moderate for all the experimental compounds except
Pulpdent which was more severe at the early time period tested. ZOE produced a milder and
silicate a severe response at all periods. All of these compounds were placed by random selection in anterior and posterior teeth of both arches and five teeth were evaluated in both primary and permanent teeth at 3 days, 5 and 8 weeks.