title: [An experimental study of expression changes of inducible nitric oxide synthase in rat dental pulp during direct pulp capping with two capping agents].
abstract: OBJECTIVE
  To observe the expression of inducible nitric oxide synthase (iNOS) in rat dental pulp after direct pulp capping with calcium hydroxide (CH) and mineral trioxide aggregate (MTA).
  
  
  METHODS
  Samples from 42 Wistar rats were immediately collected at 1, 3, 7, 14, 21 and 28 days after direct pulp capping with CH and MTA. Pulp tissues were studided with immunohistochemical stain. Software for image analysis was used to test the optical density of each specimen. The data were analyzed by paired t-test and Dunnett-t test with SPSS 11.5.
  
  
  RESULTS
  In normal pulp, the stain of iNOS was negative. After direct pulp capping with CH or MTA, iNOS expression demonstrated weakly positive, positive, weakly positive, negative at different time, the expression was low immediately after capping but became strong after 3 days. Until 7 days the stain became less positive gradually and at 21 days the stain approached normal. The expression was mainly at the fibroblasts, odontoblasts, vascular endothelial cells, neutrophils, etc near the bottom of the pulp capping agent. The diffence of iNOS expression was significant 3 days after direct pulp capping with this two capping agents.
  
  
  CONCLUSIONS
  After direct pulp capping, iNOS expression increasd at first and then decreased, the diffence of capping agents will have an impact on the expression of iNOS 3 days after direct pulp capping.
authors.affiliation: Dept. of Cadres, School of Stomatology, China Medical University, Shenyang 110002, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Zhang
authors.forename: Yanju
authors.initials: Y
authors.lastname: Lin
authors.forename: Ya
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D017607:Aluminum Compounds; D000818:Animals; D017610:Calcium Compounds; D002126:Calcium Hydroxide; D003782:Dental Pulp; D003785:Dental Pulp Capping; D004338:Drug Combinations; D052247:Nitric Oxide Synthase Type II; D010087:Oxides; D057872:Pulp Capping and Pulpectomy Agents; D051381:Rats; D017208:Rats, Wistar; D012390:Root Canal Therapy; D017640:Silicates
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D057872:Pulp Capping and Pulpectomy Agents; D017640:Silicates; C086631:mineral trioxide aggregate; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D002126:Calcium Hydroxide