Calcium sulfate, also referenced as calcium sulphate or CaSO4, is an inorganic compound often used as a dessicant in its anhydrous form. A common example of calcium sulfate is Plaster of Paris, and the readily available compound is used in many other applications, particularly in the field of implant dentistry. It has a history of being used during bone regeneration procedures as a grafting material or a graft extender. It has also been utilized as a barrier for guided tissue regeneration. The compound is extremely biocompatible and the body is able to completely absorb the material over time. The body does not react significantly to calcium sulfate and the area of implantation becomes calcium-rich and primed for dental implant hardware. Studies show that tissue migrates over the material if primary closure is not obtained. While inexpensive and abundant, calcium sulfate is not used as often in dentistry as other biomaterials.