title: Combined local application of tetracycline and bisphosphonate reduces alveolar bone resorption in rats.
abstract: BACKGROUND
  Recent animal studies have shown that a combination of chemically-modified tetracyclines together with bisphosphonates, when delivered systemically, are synergistically effective in suppressing periodontal bone loss. In the present study, we explored the combined efficacy of local delivery of alendronate and tetracyclines in reducing alveolar bone loss.
  
  
  METHODS
  Eighty-six (86) male Wistar rats were used in these experiments. The flap was elevated using a special periosteal elevator, on both sides of the mandible, as described previously. A gelfoam pellet containing the drugs was applied between the alveolar bone and the mucoperiosteal flap, according to the experimental protocol. The rats were divided into 5 treatment groups: 1) alendronate; 2) doxycycline hyclate 10% (DOXY); 3) tetracycline hydrochloride 1% (TET); 4) alendronate + DOXY; and 5) alendronate + TET. In the operated control sites (C), saline was applied. The rats were sacrificed 21 days following the flap procedure. Sections of the mandibles (1.5 mm), in a buccal-lingual direction, underwent microradiography and were analyzed for bone loss.
  
  
  RESULTS
  DOXY alone was most effective in reducing bone loss. Alendronate was also effective in reducing bone loss as shown in previous reports. TET did not reduce bone loss significantly when used alone. In combination with alendronate TET was synergistically effective. The combined local treatment of alendronate + DOXY showed no additive effect.
  
  
  CONCLUSIONS
  In the present study, we found that tetracyclines can be most effective in reducing alveolar bone loss when applied locally. The combined local treatment of alendronate and tetracycline may have a synergistic effect.
authors.affiliation: Department of Prosthodontics, Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel. yaffeavi@netvision.net.il
authors.forename: A
authors.initials: A
authors.lastname: Yaffe
authors.forename: A
authors.initials: A
authors.lastname: Herman
authors.forename: H
authors.initials: H
authors.lastname: Bahar
authors.forename: I
authors.initials: I
authors.lastname: Binderman
mesh_terms: D000287:Administration, Topical; D019386:Alendronate / Q000008:administration & dosage / Q000627:therapeutic use*; D016301:Alveolar Bone Loss / Q000517:prevention & control*; D000539:Alveolar Process / Q000187:drug effects; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001862:Bone Resorption / Q000517:prevention & control; D004318:Doxycycline / Q000008:administration & dosage / Q000627:therapeutic use*; D004337:Drug Carriers; D004338:Drug Combinations; D004357:Drug Synergism; D005781:Gelatin Sponge, Absorbable; D008297:Male; D008334:Mandible / Q000187:drug effects; D008852:Microradiography; D051381:Rats; D017208:Rats, Wistar; D013524:Surgical Flaps; D013752:Tetracycline / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D004337:Drug Carriers; D004338:Drug Combinations; D013752:Tetracycline; D004318:Doxycycline; D019386:Alendronate