Calcium sulfate (CS) (CaSO4) occupies a unique position among bone regenerative materials. It is used in clinical practice for long time than most currently available biomaterials and is widely recognized as a biocompatible material with applications in bone regeneration. It has the advantage that it is available and inexpensive (Thomas & Puleo, 2009). The ‘‘gypsum’’ or CS is a mineral consisting of calcium sulfate dehydrate (CaSO4.2H2O). It must be screened before use in medical practice for impurities such as silicates, lead, strontium, and other naturally occurring materials (Ricci, Alexander, Nadkarni, Hawkins, Turner, Rosenblum, Brezenoff, De Leonardis & Pecora, 2000). Calcium sulfate hemihydrate (CSH) or Plaster of Paris (POP) is resulted from heating gypsum to 110ºC in a process known as calcination for water loss (Anusavice, 2003). The hemihydrate form of CS exists in two forms, α and β, which differ in crystal size, surface area, and lattice imperfections. The α -hemihydrate form is quite hard and relatively insoluble when compared with the β -hemihydrate. When the hemihydrate is mixed with water, the dihydrate is formed in a mild exothermic reaction (Anusavice, 2003). As …show more content…
This allows direct, seamless host bone to calcium-cement contact, which may not only allow easier osteoconduction but also reduce the risk of filling defects and stress concentration (Clayer, 2008). The use of aqueous CS has a theoretical advantage in that it fills the cystic cavity completely, becomes solid and therefore prevents refilling of the cavity, and provides immediate structural support with resistance to compressive forces (Clayer, 2008 and Jepegnanam & Schroeder, 2012). Patients would, therefore, have the advantage of early functional use of the involved bone and the avoidance of splintage during the healing phase (Johnson & Clayer,