Effects of Alpha-Tricalcium Phosphate Containing Simvastatin on Alveolar Ridge Augmentation

Abstract

Augmentation of alveolar bone after tooth extraction is beneficial for subsequent prosthetic treatment. Simvastatin, a therapeutic drug for hypercholestemia, stimulates BMP-2 expression in osteoblasts and local application of simvastatin augments bone. The purpose of the present study is to examine whether local application of alpha-tricalcium phosphate containing simvastatin augments the bone of the tooth-extracted site. Porous α-TCP rods containing different doses of simvastatin (0, 0.25, 0.50, 1.0mg) were prepared. The right mandibular incisors of rats were extracted. The tooth sockets were filled with one of the rods in the experimental groups and were not filled with the material in the control group. Animals were sacrificed at 4 and 8 weeks and the tooth-extracted sites were analyzed with soft X-ray photography, dual-energy bone absorptiometry and micro CT, and histologically examined. Bone mineral content and bone width of the tooth extracted site were significantly higher in 0.5mg and 1.0mg groups at 4 weeks and in 1.0mg group at 8 weeks than those of the control and 0mg groups. Histologically, extensive new bone formation was observed outside of the socket walls in simvastatin-applied experimental groups. The present results indicate that local application of simvastatin with α-TCP would be potential to preserve alveolar ridge after tooth extraction although further studies are required.