title: Analysis of the dentin-pulp complex in teeth submitted to orthodontic movement in rats.
abstract: In order to microscopically analyze the pulpal effects of orthodontic movement, 49 maxillary first molars of rats were submitted to orthodontic appliance composed of a closed coil spring anchored to the maxillary incisors, placed for the achievement of mesial movement.
  
  
  METHODS
  Ten animals were used as the control group and were not submitted to orthodontic force; the other animals were divided into groups according to the study period of tooth movement, namely 1, 2, 3, 4, 5, 6 and 7 days. The investigation of pulp and periodontal changes included hyalinization, fibrosis, reactive dentin and vascular congestion. Statistical evaluation was performed between control and experimental groups and between periods of observation using non-parametric chi-square, Kruskal-Wallis and Dunn tests.
  
  
  RESULTS
  There was no statistically significant difference concerning pulpal changes between control and experimental groups nor between periods of observation. The control group, at 3 and 5 days, revealed greater hyalinization of the periodontal ligament (p<0.05), whereas root resorption was significantly greater at 5 and 7 days (p<0.05).
  
  
  CONCLUSIONS
  No morphological change from the effect of induced tooth movement could be found in the dentin-pulp complex. In addition, no inflammatory or pulp degeneration, detectable in optical microscopy, was found in experimental groups.
authors.affiliation: Bauru School of Dentistry, University of São Paulo, SP, Brazil. camilamassaro@usp.br
authors.forename: Camila da Siveira
authors.initials: Cda S
authors.lastname: Massaro
authors.forename: Renata Bianco
authors.initials: RB
authors.lastname: Consolaro
authors.forename: Milton
authors.initials: M
authors.lastname: Santamaria
authors.forename: Maria Fernanda Martins-Ortiz
authors.initials: MF
authors.lastname: Consolaro
authors.forename: Alberto
authors.initials: A
authors.lastname: Consolaro
mesh_terms: D000818:Animals; D003782:Dental Pulp / Q000033:anatomy & histology*; D003804:Dentin / Q000033:anatomy & histology*; D023421:Models, Animal; D009967:Orthodontic Appliances; D010513:Periodontal Ligament / Q000033:anatomy & histology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012391:Root Resorption / Q000209:etiology; D013997:Time Factors; D014087:Tooth Movement Techniques / Q000295:instrumentation*