INTRODUCTION

Synthetic particulate-based materials are notable for their ability to provide a robust and durable implant and have long been used as bulking agents in a variety of surgical and nonsurgical settings. Radiesse® (BioForm Medical, Inc., San Mateo, CA) is an injectable filler material composed of synthetic calcium hydroxylapatite (CaHA) microspheres suspended in an aqueous carrier gel. Seventy percent of the composition of Radiesse is sodium carboxymethylcellulose carrier gel; the remaining 30 percent of the composition is CaHA microspheres. These uniform microspheres (25–45 microns) are identical in composition to the mineral portion of human bone and teeth.

CaHA has been used for over twenty years in various forms in plastic and reconstructive surgery, otology, otolaryngology, neurosurgery, orthopedic surgery, maxillofacial surgery, and dentistry. The excipients that comprise the aqueous gel carrier (i.e., cellulose, glycerin, and sterile water) are classified as “Generally Recognized as Safe” (21 CFR 182) by the Food and Drug Administration and have an extensive record of use in intramuscular injectable products such as Cortone®, Decadron®, and Dalalone®.

The components of CaHA occur naturally in the body and therefore are inherently biocompatible. Results from extensive in vitro and in vivo safety studies, including toxicology assessments, standardized biocompatibility testing, and a three-year animal study, demonstrate that injectable CaHA is biocompatible, nontoxic, nonirritating, and nonantigenic. Because CaHA contains no animal or human tissue derivatives, patient sensitivity testing is not required before use.