The development prospects of medical detal titanium materials.

Many implant materials have been used in various dental applications depending on their efficacy and availability. A dental implant must possess the required characteristics, such as biocompatibility, corrosion & wear resistance, adequate mechanical properties, osseointegration, etc., to ensure its safe and optimum use. This review analyzes various aspects of titanium (Ti) and Ti alloys, including properties, manufacturing processes, surface modifications, applications as dental implants, and limitations. In addition, it also presents a perception of recent advances in Ti-based implant materials and the futuristic development of innovative dental implants.

Keywords: Dental implant, Titanium alloy, Surface modification, Corrosion resistance, Osseointegration, Biocompatibility, Antibacterial activity

Titanium (Ti) and Ti alloys have increased extensively since the early 1980s. It has become the more accepted metallic biomaterial for its distinct properties and numerous biomedical uses (Özcan et al., 2012; Vizureanu et al., 2020; Takeuchi et al., 2020). Most of the time, metallic biomaterials are utilized for their high load-bearing capacity and fatigue strength to sustain the regular movements’ loads applied to them (Gegner et al., 2014). Titanium has been presented as one of the more encouraging designing biomaterials for its low modulus of elasticity, low specific weight, extraordinary resistance to corrosion, outstanding strength-to-weight ratio, good tribological properties, and exceptional biocompatibility (Hatamleh et al., 2018; Mutombo, 2018). Titanium alloys have the more higher biocompatibility for biomedical applications than any metallic contents. However, because of the trend of osteogenesis, they are graded as bioinert materials compared to bioceramics like zirconia, alumina, hydroxyapatite, and combinations (Niinomi et al., 2008; Hoque et al., 2013, 2014; Ragurajan et al., 2018; Golieskardi et al., 2019). Current dentistry aims to reinstate the patient to usual purpose, health, aesthetics, and speech irrespective of the stomatognathic system's injury, atrophy, or disease. As a result, prosthetics in dentistry are one of the good options for persons who usually have inappropriate oral health but have lost their teeth because of periodontal illness, an injury, or some other reasons (Oshida et al., 2010; Golieskardi et al., 2020). Many implants of many designs are now made from pure titanium and its alloys.

Until now, more metallic implants have been manufactured using traditional methods like hot rolling, investment casting, forging, and machining. However, numerous advanced manufacturing approaches are also utilized as all the implant alloys cannot be efficiently handled into the ultimate form in a similar method (Trevisan et al., 2017). Compared to traditional dental casting, titanium prostheses can be better made up utilizing CAD/CAM (computer-aided design and computer-aided manufacturing) (Ohkubo et al., 2008). Nowadays, an innovative technique, 3D printing/Additive Manufacturing (AM), is customized to manufacture dental implants rapidly utilizing computer-aided design (Mohd and Abid, 2019). 3D printing/AM has demonstrated microscale resolution for the fabrication of implants through unclear efficiency of this process, but a potential approach for manufacturing dental implants (Thaisa and Andréa, 2019).

The metal ion release causes corrosion-related biological problems, such as toxicity, carcinogenicity, and hypersensitivity. The discharge of metal elements from the implant material to different body organs and peri-implant tissues was caused by biocorrosion, tribocorrosion, and their combination, which is a natural occurrence in the oral setting (Barão et al., 2021). While biofilms or high fluoride concentrations exist, this effect is amplified. The presence of metallic particles activates T-lymphocytes, neutrophils, and macrophages, increasing the production of cytokines and metallic proteases. Furthermore, vanadium, aluminum, and Ti–6Al–4V particles are toxic and mutagenic, causing Alzheimer's disease, osteomalacia, and neurological issues (Kirmanidou et al., 2016). Ti and Ti alloys have noteworthy applications in orthopedics and dentistry. Hence, many implants are being introduced into the market daily. This review aims to determine why and how this material has progressed significantly, especially CAD/CAM. It is essential to study the interaction of Ti with the biological environment to decide what characteristics make this material and its alloys attractive as an orthodontic treatment material.

3D printing (3DP) is an emerging technology for dental implants, overcoming numerous dental difficulties, including diastema, crown damage, and tooth loss, because it plays a vital role in preventive/restorative dentistry. 3DP can attain close control of (i) multiple compositions, (ii) microstructure, (iii) mechanical attributes, and (iv) biological methods of attached tissues and organs with the implants. Indeed, it focuses on an exceptional attribution in dentistry for implant and restoration applications because of the significance of 3DP via CAD/CAM for manufacturing and implantation. It is plausible that Ti material with desired features for curing dental distortions increases the speed with lesser effort (Gagg et al., 2013; Unnikrushnan et al., 2021).

This study aims to describe the different uses of titanium and its alloys in Dentistry, along with its historical development, manufacturing procedures, and surface modification techniques. Various mechanical and physiological properties of Ti alloys are abridged in this review. It also discusses good and future perspectives about its utilization which will provide an overview for future manufacturers, researchers, and academicians.