**2.1. Examples of biomedical implants**

An orthopedic implant is a medical device built from metallic alloys such as Ti which is used to replace a missing joint or bone or to support a damaged bone. It may consist of a single type or comprise modular parts of biomaterial. For example, bone plates and bone screws used in spinal fusion surgery and fixation of fractured bone part. Meanwhile, the hip and knee replacements are medically termed as artificial joints or prostheses used to treat various type of arthritis affecting these joints, which are common health complaints in elderly patients. Besides, the bone implants are also used to treat the bone damaged from accident or cancer or musculoskeletal diseases [30].

Dental implant is an artificial tooth root made of Ti used to place into the jaw and hold a dental prosthesis as replacement for tooth or bridge. This technique was invented in 1952 by a Swedish orthopedic surgeon named Per-Ingvar Brånemark [45]. The implant is considered the standard in replacement of missing teeth due to periodontal diseases, injuries, or some other reasons [46]. Dental implants are divided into three types, namely, the osseointegrated, miniimplant for orthodontic anchorage, and zygomatic [47]. Besides, another important implant used in dental application is the titanium mesh membrane. This barrier implant membrane surface provides great mechanical properties for Guided Bone Regeneration (GBR) treatment to assist the new bone formation [48].

Cardiovascular implants use Ti metals for the replacement of heart valves (pacemaker cases and defibrillators), endovascular stents, and stent-graft combinations. These implants help to overcome cardiovascular diseases which physically damage the heart, resulting in loss of cardiac function. The types of implants are classified as temporary internal, temporary external and permanent internal devices. One of the demands is stents which include the bare metal stents, drug-eluting stent, and bioabsorbable stents [49]. Craniofacial implants are important in the application of craniofacial prostheses or also known as an epistheses. Epistheses may be used to repair or improve absence of facial structures due to malformation present at birth, operations that involve treatment for cancer, or trauma. The osseointegrated titanium implant is one of the common types of implants used in epistheses [45].

Further development and improvement on the implant is required for complete compatibility with the area of implantation, for shorter surgical duration and improved cosmesis [30, 50].
