Prevention of the surface resorption of bone grafts by topical application of bisphosphonate on different carrier materials.

objectiveThe hypothesis of the present study was that topically applied bisphosphonate (BP) on a collagen membrane or alternatively bovine bone mineral prevents surface resorption of onlay bone grafts. MATERIAL AND

methodsIn eight adult pigs, bone blocks were harvested bilaterally from the mandible and fixed to the lateral cortex of the horizontal ramus to simulate a ridge augmentation. In a split-mouth study design, we used alendronate in aqueous solution (1 mg/ml) on the test-side in three different ways: on a collagen membrane (Bio-Gide®), soaked in bovine bone mineral granules (Bio-Oss®), or applied to the bone graft directly. The same materials without BP were used as controls on the contralateral side. After 3 months, the animals were sacrificed. The evaluation included sequential fluorochromic labeling and measurement of bone height in microradiography and toluidine blue staining.

resultsIn five cases, necrosis of the overlying periosteal tissues with BP was observed macroscopically. A statistically significantly lower loss in graft height was seen on the test-side for Bio-Gide® + alendronate (0.65 %) versus Bio-Gide® (1.52 %), p = 0.002; Bio-Oss® + alendronate (1.16 %) versus Bio-Oss® (4.20 %), p = 0.001; and bone graft + alendronate (1.25 %) versus bone graft alone (6.01 %), p = 0.006. An inhibitory effect on bone remodeling was observed by a statistically significantly lower number of resorption lacunae.

conclusionThe hypothesis was accepted that a bisphosphonate-treated membrane reduced bone graft resorption; however, periosteal necrosis requires better adaptation of the dosage. CLINICAL RELEVANCE: A bisphosphonate membrane could be a helpful tool to preserve augmentation height of onlay bone grafts.