Implant dentistry provides a predictable method of tooth replacement. Many prospective implant sites, however, are deficient in bone and require some form of bone regeneration prior to implant placement. Various regenerative therapies have been developed to facilitate implant placement in such sites.
To regenerate bone, it is necessary to provide sufficient space or “regeneration chamber” in which bone growth may occur. Creating a protected sanctuary may facilitate bone regeneration by protecting the developing bone tissue from excessive pressure from the overlying soft tissue. It is also necessary to block the ingress of cells which may proliferate and migrate faster than bone and may fill the space with tissues other than bone (e.g., epithelium or fibrous connective tissue).
Calcium sulfate (CS) has been used in bone regeneration for more than fifty years. It is exhibits significant biocompatibility and is completely resorbed in a relatively short time. The micro-environment surrounding degrading CS is known to be rich in calcium while eliciting a minimal inflammatory response. Calcium sulfate can be cast into various forms and can serve as a delivery vehicle for other biologic materials, such as antibiotics and growth factors.
Although CS is often mixed and placed into bone defects prior to setting, the use of preformed CS shapes has been reported by our group and others. Since it is impossible to create a rigid space-making device in situ it is necessary that such devices be fabricated beforehand. This also facilitates “loading” the prefabricated devices with biologically active agents such as antibiotics or osteotropic agents.
To this end, our research group has been investigating preformed CS space-makers that deliver bioactive agents. Ongoing efforts measure degradation and release kinetics, mechanical properties, and bioactivity both in vitro and in vivo.