title: Effect of propolis on dentin regeneration and the potential role of dental pulp stem cell in Guinea pigs.
abstract: OBJECTIVE
  Evaluation of the effect of Propolis as a bioactive material on quality of dentin and presence of dental pulp stem cells.
  
  
  METHODS
  For conducting this experimental split-mouth study,a total of 48 maxillary and mandibular incisors of male guinea pigs were randomly divided into an experimental Propolis group and a control calcium hydroxide group. Cutting the crowns and using Propolis or calcium hydroxide to cap the pulp, all of the cavities were sealed. Sections of the teeth were obtained after sacrificing 4 guinea pigs from each group on the 10(th), 15(th) and 30(th) day. After they had been stained by hematoxylin and eosin (H&E), specimens underwent a histological evaluation under a light microscope for identification of the presence of odontoblast-like cells, pulp vitality, congestion, inflammation of the pulp and the presence of remnants of the material used. The immunohistochemistry (IHC) method using CD29 and CD146 was performed to evaluate the presence of stem cells and the results were statistically evaluated by Kruskal-Wallis, Chi Square and Fisher tests.
  
  
  RESULTS
  In H&E stained specimens, there was no difference between the two groups in the presence of odontoblast-like cells, pulp vitality, congestion, inflammation of the pulp and the presence of remnants of used material(p>0.05). There was a significant difference between the quality of regenerative dentin on the 15(th) and 30(th) days (p<0.05): all of the Propolis cases presented tubular dentin while 14% of the calcium hydroxide cases produced porous dentin. There was no significant difference between Propolis and calcium hydroxide in stimulation of dental pulp stem cells (DPSCs).
  
  
  CONCLUSIONS
  This study which is the first one that documented the stimulation of stem cells by Propolis, provides evidence that this material has advantages over calcium hydroxide as a capping agent in vital pulp therapy. In addition to producing no pulpal inflammation, infection or necrosis this material induces the production of high quality tubular dentin.
authors.affiliation: 1. Department of Endodontic, Dental Research Center of Shahid Beheshti University of Medical Science, Tehran, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Ahangari
authors.forename: Mandana
authors.initials: M
authors.lastname: Naseri
authors.forename: Maryam
authors.initials: M
authors.lastname: Jalili
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Mansouri
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Mashhadiabbas
authors.forename: Anahita
authors.initials: A
authors.lastname: Torkaman
keywords: Dental Pulp Stem Cell; Dentin; Guinea Pigs; Propolis; Regeneration