title: Nanotechnology in ligature-induced periodontitis: protective effect of a doxycycline gel with nanoparticules.
abstract: OBJECTIVE
  The aim of this study was to test the efficacy of a locally applied 8.5% nanostructured doxycycline (DOX) gel in preventing alveolar bone loss in experimental periodontal disease (EPD) in rats by using the tapping mode atomic force microscopy (AFM).
  
  
  METHODS
  EPD was induced in 24 Wistar rats. Animals were treated with the doxycycline gel topically, immediately after EPD induction, and 3 times a day during 11 days. Four groups (n=6) were formed as follows: Naïve group (animals not subjected to EPD nor treated); non-treated (NT) group (animals subjected to EPD, but not treated); vehicle gel (VG) group (animals subjected to EPD and treated with topical gel vehicle); and DOX group (test group): animals subjected to EPD and treated with the 8.5% DOX gel. In order to investigate topographical changes in histological sections, a novel simple method was used for sample preparation, by etching sections from paraffin-embedded specimens with xylol.
  
  
  RESULTS
  Comparing the AFM images, several grooves were observed on the surface of the alveolar bone and other periodontal structures in the NT and VG groups, with significantly greater depths when compared to the DOX group (p<0.05).
  
  
  CONCLUSIONS
  Periodontal structures were brought into high relief confirming to be a simple and cost-effective method for AFM imaging with ultrastructural resolution. The doxycycline gel was able to afford periodontal surface preservation, with flatter grooves.
authors.affiliation: Orthodontics, Federal University of Ceará, Fortaleza, CE, Brazil. marcobotelho@pesquisador.cnpq.br
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Botelho
authors.forename: Jose Galberto
authors.initials: JG
authors.lastname: Martins
authors.forename: Ronaldo Sousa
authors.initials: RS
authors.lastname: Ruela
authors.forename: Dinalva Brito
authors.initials: DB
authors.lastname: Queiroz
authors.forename: Wagner Sousa
authors.initials: WS
authors.lastname: Ruela
mesh_terms: D000287:Administration, Topical; D016301:Alveolar Bone Loss / Q000473:pathology / Q000517:prevention & control*; D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D003739:Dental Cementum / Q000473:pathology; D004318:Doxycycline / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D005782:Gels; D005881:Gingiva / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D008297:Male; D018625:Microscopy, Atomic Force; D054118:Nanospheres / Q000008:administration & dosage*; D036103:Nanotechnology; D009504:Neutrophils / Q000473:pathology; D010513:Periodontal Ligament / Q000473:pathology; D010518:Periodontitis / Q000209:etiology* / Q000473:pathology; D009195:Peroxidase / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014092:Tooth Root / Q000473:pathology
chemical_list: D000900:Anti-Bacterial Agents; D005782:Gels; D009195:Peroxidase; D004318:Doxycycline