IRCT2014080618711N1 IRCT 2014-08-22 Mashhad University of Medical Sciences effect of dexamethasone on dental pulp Histologic response of human dental pulp to dexamethasone treatment following MTA-direct pulp capping and MTA-partial pulpotomy: A randomized clinical trial 2014-08-20 anticipated 40 Complete https://irct.ir/trial/16883 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Single, Purpose: Treatment. N/A pulpitis. Intervention 1: Forty intact premolar teeth will select from 10 healthy orthodontic patients that will candidates for extraction of four premolars; the teeth will randomiz for DPC (n=20) or PP (n=20). After anesthesia and isolation, a class I cavity was prepared and buccal pulp horn will expose using a high speed ½ round high speed bur under copious water coolant. The buccal pulp horn exposure will pinpoint in size for DPC group, while whole head of the bur will enter into the pulpal horn in PP group. The half of the DPC or PP groups, will receive dexamethasone in "solution" . Subsequently, exposure site was sealed using ProRoot MTA and cavities will restore with glass ionomer. After 60 days, the teeth were extracted and 4 micron sections prepared. Histologic evaluation will performe by an independent oral and maxillofacial pathologist. Intervention 2: for group 1: The buccal pulp horn exposure will pinpoint in size for DPC group. Intervention 3: for group 2: whole head of the bur will enter into the pulpal horn in PP group. Intervention 4: for goup 3:The half of the DPC group, will receive dexamethasone in "solution". Intervention 5: for group 4:The half PP group , will receive dexamethasone in "solution".