Fabrication and characterization of porous glass-ceramics as novel orbital implant materials

Reference Presenter Authors
02-017 Francesco Baino Baino, F.(Politecnico di Torino); Gautier di Confiengo, G.(National Research Council); Faga, M.G.(National Research Council);

The management of intraocular cancer, severe orbital traumas or life-threatening ocular infections may often require the surgical removal of the patient’s diseased eye. An orbital implant, coupled with an ocular prosthesis, is then inserted in the orbital socket to provide volume replacement and proper aesthetics. Porous hydroxyapatite and alumina gained prominence since their highly-interconnected porous structure allows them to act as a passive framework for fibrovascular ingrowth, offering low complication rates while enhancing motility of the overlying aesthetic prosthesis. However, there are still drawbacks to these materials, including the high cost and the risk of postoperative extrusion. In the attempt to overcome these limitations, two types of porous glass-ceramic (GC) orbital implants were fabricated in this work by sponge replication. Both materials exhibited a 3D network of interconnected macropores (total porosity above 50 vol.%, mean pore size above 0.2 mm) that are potentially available for fibrovascular tissue ingrowth. Compressive strength (5-15 MPa) is adequate for allowing surgical manipulation and support to host orbital tissues. The surface roughness of these GC implants (Ra around 300 nm) is significantly lower than that of “gold standard” commercial alumina implants (Ra around 750 nm). This is a key achievement to limit the risk of postoperative conjunctival abrasion and to achieve clinical success. As a whole, these results support the suitability of the produced GC porous materials for use as orbital implants and motivate future investigation about experimenting new biocompatible ceramics and glasses in ocular surgery.