title: Low-dose doxycycline inhibits bone resorption associated with apical periodontitis.
abstract: OBJECTIVE
  To test the effect of low-dose doxycycline on bone resorption associated with apical periodontitis.
  
  
  METHODS
  Apical periodontitis was induced by occlusal pulp exposure in the mandibular first molars of 36 rats. Animals were divided into three groups of 12: group A received doxycycline in drinking water at a dose of 5.85 mg day(-1); group B received a dose of 1.48 mg day(-1) (one-quarter of the original dose); and group C received no medicament and served as the control. A bioassay determined the doxycycline serum levels. After 21 days, the mandibles were removed, radiographed and the radiographs scanned to generate digital images. These images were analysed morphometrically and the total area of the periapical bone resorption of the mesial and distal roots of each tooth was determined and used to compare the groups. Statistical analysis was completed using anova with repeated measures.
  
  
  RESULTS
  The mean doxycycline serum level in group A was 0.22(+/-0.03) microg mL(-1) and in group B below the detection level of the assay (<0.062 microg mL(-1)). The mean area of the periapical bone resorption in the control group C was 2.91(+/-0.61) mm(2). In animals treated with a low-dose doxycycline, the mean size of the bone resorption was significantly smaller at 1.59(+/-0.59) mm(2) (group A) and 1.72(+/-0.85) mm(2) (group B) (P = 0.001). No significant difference was found in the area of the bone resorption between these two groups A and B.
  
  
  CONCLUSIONS
  Low-dose doxycycline reduced the area of bone resorption associated with apical periodontitis in the mandibular first molar teeth of rats.
authors.affiliation: Department of Oral Biology, Teh Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. metzger@post.tau.ac.il
authors.forename: Z
authors.initials: Z
authors.lastname: Metzger
authors.forename: D
authors.initials: D
authors.lastname: Belkin
authors.forename: N
authors.initials: N
authors.lastname: Kariv
authors.forename: M
authors.initials: M
authors.lastname: Dotan
authors.forename: A
authors.initials: A
authors.lastname: Kfir
mesh_terms: D000284:Administration, Oral; D016301:Alveolar Bone Loss / Q000209:etiology / Q000517:prevention & control*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000097:blood; D004318:Doxycycline / Q000008:administration & dosage* / Q000097:blood; D005240:Feasibility Studies; D005260:Female; D010485:Periapical Periodontitis / Q000150:complications*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000900:Anti-Bacterial Agents; D004318:Doxycycline