ABSTRACT
There has been a growing interest in the use of porous alloplastic implants for reconstructive orbital surgeries. Porous polyethylene (medpor) and hydroxyapatite are two of the more popular and successful orbital implants that revolutionized orbital reconstructive surgery, However, due to its prohibitive costs the authors in cooperation with the Department of Science and Technology have explored the use of a locally manufactured low cost (P25) synthetic Bioceramic Porous Biphasic Calcium Phosphate as a prospective orbital implant material for orbital floor fracture reconstruction. This study aims to establish and demonstrate biocompatibility and bone grafting characteristic of porous biphasic calcium phosphate orbital implant in cats as well as its capability to induce and support bone growth at 1 and 3 months. The implant composition of 77 percent tricalcium phosphate and 23 percent hydroxyapatite analyzed by means of an x-ray diffractometer clearly demonstrates its similarity to bone. 12 orbits of 6 cats underwent orbital plate implantation. Gross, radiographic, histological and histomorphometric examinations were done for the specimens at 1 & 3 months post-operatively. Evidence of lamellar bone deposition, vascularization without any signs of infection, inflammation, and resorption were observed in 6 out of 6 orbits in 1 month and 6 out of 6 at 3 months. Histomorphometric evidence shows bone-implant ratio of 30 percent deposition at 1 month and 50 percent deposition at 3 months. Porous biphasic calcium phosphate, an inexpensive orbital implant alternative has proven to have physiological bone induction as well as bone conduction properties. It is biocompatible, allows vascularization and is resistant to resorption. (Author)