title: Hierarchy of variables correlated to odontoblast-like cell numbers following pulp capping.
abstract: OBJECTIVE
  Following tooth pulp exposure, pulpal repair is accomplished by dentine bridge secretion by odontoblast-like cells. However, little information is available about the hierarchy of variables, which influence odontoblast-like cell numbers. The purpose of this study was to examine correlations between pulp capping events and odontoblast-like cell numbers.
  
  
  METHODS
  Two hundred and fifty standardised pulp exposed cavities were prepared in non-human primate teeth according to ISO usage guidelines. Exposed pulps were capped with Calcium hydroxide [Ca(OH)(2)], and multi-step and self-etching primer composite resins. Teeth were collected from 3 to 60-days to observe pulp reactions. Statistical analysis was evaluated using analysis of variance.
  
  
  RESULTS
  The hierarchy of variables correlated to odontoblast-like cells were the dentine bridge area (P = 0.0001), time since pulp exposure (P = 0.0001), odontoblast numbers opposite the exposure site (P = 0.0002), and pulp capping materials (P = 0.0313). Other pulp capping variables were found to be less likely to be correlated with odontoblast-like cell numbers.
  
  
  CONCLUSIONS
  The area of dentine bridge formation is directly related to the numbers of odontoblast-like cells, cell activity is time dependent, and the cell numbers are much lower than original odontoblast cells. The time-lag between the appearance of odontoblast-like cells at the site of pulp exposure, and the limited numbers of these cells, explain why pulpal repair is difficult to achieve successfully following pulp exposure.
authors.affiliation: Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, IN, USA. petmurra@iupui.edu
authors.forename: P E
authors.initials: PE
authors.lastname: Murray
authors.forename: Y
authors.initials: Y
authors.lastname: Kitasako
authors.forename: J
authors.initials: J
authors.lastname: Tagami
authors.forename: L J
authors.initials: LJ
authors.lastname: Windsor
authors.forename: A J
authors.initials: AJ
authors.lastname: Smith
mesh_terms: D000818:Animals; D002126:Calcium Hydroxide / Q000627:therapeutic use; D003782:Dental Pulp / Q000166:cytology* / Q000187:drug effects; D003785:Dental Pulp Capping / Q000145:classification / Q000379:methods*; D003789:Dental Pulp Exposure / Q000628:therapy; D003809:Dentin, Secondary / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D017220:Dentin-Bonding Agents / Q000627:therapeutic use; D008251:Macaca; D008689:Methacrylates / Q000627:therapeutic use; D008903:Minerals / Q000627:therapeutic use; D009804:Odontoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
chemical_list: C116064:Bond Well LC; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D008903:Minerals; C100742:All-Bond 2; C025702:Dycal; D002126:Calcium Hydroxide