Alloplastic

Alloplastic refers to artificial, synthetic, or non-biological materials used to replace, augment, or repair tissues or functions in the human body. The term contrasts with autografts (tissues harvested from the same patient) and allografts or xenografts (tissues from other individuals or species). Alloplastic implants and prostheses are widely used across medical fields, including orthopedics (joint replacements, spinal implants), plastic and reconstructive surgery (breast implants, craniofacial implants), dentistry (dental implants and bone substitutes), ophthalmology (intraocular lenses), and ENT or maxillofacial surgery (airway stents, reconstructive implants).

Materials used include ceramics, polymers, metals, and composites. Common examples are titanium and its alloys, cobalt-chromium alloys, stainless steel alloys, silicone elastomers, polymethyl methacrylate, hydroxyapatite and other calcium phosphate ceramics, bioglass, and polyetheretherketone (PEEK). Some implants are designed to be bioinert, resisting chemical interaction with body fluids, while others are bioactive to promote tissue integration. Porous coatings and surface treatments can enhance osseointegration or tissue ingrowth.

Advantages of alloplastic materials include wide availability, the ability to customize implants, avoidance of donor site morbidity, and the potential to restore form and function when tissue is insufficient. Limitations and risks include infection, implant loosening or wear debris, allergic or hypersensitivity reactions to metals, corrosion products, fatigue failure, and the need for revision surgery. Long-term outcomes depend on material properties, implant design, surgical technique, and patient factors.

Regulatory oversight and postmarket surveillance guide their use. Alloplastic materials continue to evolve with advances in biomaterials science, aiming to balance biocompatibility, mechanical requirements, and patient safety.