Effect of diphosphonate on the prevention of X-radiation-induced inhibition of bone formation in rats.

A histologic and histometric study of the effect of EHDP (ethane-1-hydroxy-1,1-diphosphonate) on the alveolar wound healing of irradiated animals is presented. This drug was selected based on its osteosclerotic effect when applied at low doses. The three left mandibular molars of 80 male Wistar rats were extracted. The rats were grouped into 4 sets of 20 rats each. Group I received no further treatment; Group II received daily intraperitoneal injections of EHDP (7.5 mg/Kg of body weight during 10 days); Group III: 15 Gy of X-radiation were applied to the head; and Group IV were irradiated and injected with EHDP as were animals of Groups III and II. Half of the animals were killed after 14 days and the other half 30 days post-extraction. Sections were made at the level of the mesial socket of the first molar in a bucco-lingual orientation, on which histometric determinations of bone activity were made. The results showed the attenuation of the inhibitory effect of radiation on bone formation when the animals were treated with EHDP.