Topical Simvastatin Improves the Pro-Angiogenic and Pro-Osteogenic Properties of Bioglass Putty in the Rat Calvaria Critical-Size Model

Objective was to describe the effect of bioactive glass putty with and without topical simvastatin on new bone formation in critical-sized defects of rat calvaria. A calvarial bone defect was created in 20 male Wistar rats and filled with bioactive glass alone (n = 10) or combined with simvastatin (n = 10). After 4 weeks, the defects were histomorphometrically evaluated for volume fraction (Vv) of woven bone, vessel density, bioglass quantity, and inflammation. Compared to the bioglass-only group, rats treated with simvastatin had greater Vv of blood vessels (3.3% ± 0.7 vs 1.6% ± 0.1, P = .0002) and new bone (2.3% ± 0.2 vs 1.8% ± 2.5, P = .003). The Vv of the bioglass remnants in the bioglass-only group was higher than in the group treated with simvastatin (2.4% ± 0.08 vs 1.7% ± 0.3, P < .0004). Chronic inflammation was noted in 1 rat from each group. Topical simvastatin seems to improve the pro-angiogenic and pro-osteogenic properties of bioglass putty in rat calvaria critical-size defects without significant inflammation.