title: Effect of experimentally induced occlusal trauma on substance p expression in human dental pulp and periodontal ligament.
abstract: BACKGROUND
  The purpose of this study was to quantify the effect of occlusal trauma experimentally induced with occlusal interferences on substance P (SP) expression in healthy human dental pulp and periodontal ligament.
  
  
  METHODS
  Twenty-eight human dental pulp and periodontal ligament samples were obtained from healthy premolars in which extraction was indicated for orthodontic reasons. Before extraction, occlusal trauma was induced with experimental occlusal interferences in half of these premolars by placing a resin block over their occlusal surface and submitting patients to chew gum for 30 minutes. The remaining healthy premolars were extracted without occlusal trauma and served as a control group. All dental pulp and periodontal ligament samples were processed, and SP was measured by radioimmunoassay.
  
  
  RESULTS
  There was 45% and 120% greater SP expression in dental pulp and periodontal ligament, respectively, of teeth with experimentally induced occlusal trauma. Paired t test showed statistically significant differences for both human dental pulp and periodontal ligament (P = .02 and P < .001, respectively) of teeth submitted to occlusal trauma when compared with control group values.
  
  
  CONCLUSIONS
  SP expression in human dental pulp and periodontal ligament increases when teeth are submitted to occlusal trauma experimentally induced with occlusal interferences.
authors.affiliation: Postgraduate Endodontics Department, School of Dentistry, Pontificia Universidad Javeriana, Bogotá, Colombia. javiercaviedes@gmail.com
authors.forename: Javier
authors.initials: J
authors.lastname: Caviedes-Bucheli
authors.forename: Maria Mercedes
authors.initials: MM
authors.lastname: Azuero-Holguin
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Correa-Ortiz
authors.forename: Marco Vinicio
authors.initials: MV
authors.lastname: Aguilar-Mora
authors.forename: James Dario
authors.initials: JD
authors.lastname: Pedroza-Flores
authors.forename: Esteban
authors.initials: E
authors.lastname: Ulate
authors.forename: Nelson
authors.initials: N
authors.lastname: Lombana
authors.forename: Hugo Roberto
authors.initials: HR
authors.lastname: Munoz
mesh_terms: D000293:Adolescent; D000328:Adult; D001641:Bicuspid / Q000378:metabolism; D002638:Chewing Gum; D003769:Dental Occlusion, Traumatic / Q000378:metabolism*; D003782:Dental Pulp / Q000378:metabolism*; D006801:Humans; D008409:Mastication / Q000502:physiology; D018377:Neurotransmitter Agents / Q000032:analysis / Q000378:metabolism*; D010513:Periodontal Ligament / Q000378:metabolism*; D013373:Substance P / Q000032:analysis / Q000378:metabolism*; D013997:Time Factors; D055815:Young Adult
chemical_list: D002638:Chewing Gum; D018377:Neurotransmitter Agents; D013373:Substance P