Effect of systemic doxycycline on alveolar bone loss after periradicular surgery

Studies in the periodontic literature have shown an average of 0.5 mm to > 1.0 mm of bone loss after full thickness flap reflection. Similar literature has revealed that the tetracycline family of antibiotics can prevent bone loss. The purpose of this study was to observe the effect of systemic Doxycycline on crestal alveolar bone loss after periradicular surgery in beagle dogs. Five beagle dogs were used in two phases of this study. In the first phase (control sides), after reflecting full thickness flaps in one mandibular quadrant, notches were placed in the enamel of the third and fourth premolar teeth using a one-quarter round bur. Using magnification, measurements were taken from the reference notches to the height of the alveolar crest. After 8 wk, flaps were reflected in the same quadrant and measurements retaken, and the amount of bone loss was then measured. In the second phase (experimental sides), the same procedure was performed on the contralateral mandibular quadrant, but the dogs were placed on 4.4 mg/kg/day of Doxycycline for 10 days after reflections of full thickness flaps. After another 8 wk, the area was reflapped and measured. There was significantly (p < 0.01) less bone loss on the Doxycycline-treated side.