Introduction
The materials that are compatible with the living tissues are known as Biomaterials. A nondrug substance that augment or replace the function of bodily tissue or organ is known as a biomaterial.1 In Modern dentistry, Dental implant is fabricated through blending of both science and technology based on various concepts like surface engineering, surface chemistry and physics and biomechanics from macro- scale to nanoscale manufacturing technologies.2
The physical properties of the materials, their ability for eliciting inflammation or rejection response, induction of tissues, their surface configuration and their potential to corrode in the tissue environment are all important factors; It is mandatory to understand, realize, and utilize the benefits of biotechnology in health care. Surgical implant design and material concepts are optimized with the advancement of biomechanical sciences.3
History
Ancient era (AD 1000)
Evidences for implant usage is found from ancient egyptian and south American civilization.An arabian surgeon Albucasis de condue was credited with a written paper on transplants. It was for replacement of missing teeth.4 The artificial tooth is carved with dark stone in pre Columbian era.
Foundational period (1800-1910)
Endosseous oral implantology had its start in this era only.
In 1809 - Tooth root shaped gold was used by Maggiolo.
In 1887 - Harris reported the use of lead coated platinum post fitted teeth made of porcelain.
In 1890 - Zamenski reported the teeth implantation; Rubber, porcelain and gutta-percha were used.
In 1898- R.E payne filled tooth socket with silver capsule.
In the early 1900’s - lambotte fabricated of aluminum, red copper, magnesium, silver, brass, gold and soft steel plated with nickel and gold. 4, 5
Premodern era (1901-1930)
In 1901- R.E Payne reported a new technique called capsule implantation; He introduced it at the third international dental congress clinics.
In 1903, a tooth made of porcelain was implanted by Scholl in Pennsylvania; It had a root that is made of porcelain and is corrugated.
In 1913, the alveoli was filled with 24 carat gold and iridium by Dr. Edward and greenfield. The ability of tissue to heal and immobility of dental implant in submerged implant 5 concept was also introduced by Greenfield.
Dawn of the modern era (1935-1978)
In this era, the naturally derived materials are replaced by synthetic polymers, ceramics and metal alloys; They were found to have predictable results and better performance than the natural ones. A vitalium screw was anchored within bone by strock; Immediately a porcelain crown was mounted on it. This implant had survival for 15 years. 5, 6
Modern Era
From the period of mid 1930’s to the present, the modern implant dentistry is delineated; The popularity of dental implants in current period is mainly because of the development and the research work in the biomaterial field; This has laid the foundation of this field.
Requirements of an ideal implant material
The two basic criteria that every dental implant material must meet are:
Certain basic criteria like ideal mechanical, chemical, physical and biological properties have to be fulfilled by the implant material; Few accepted guidelines for dental implants according to ADA specifications are:
Assessment of physical properties to measure the material strength.
Freedom from defects.
Evaluation of biocompatibility and safety with tissue interference & cytotoxicity testing characteristics.
Ease of fabrication.
Sterilization potential without causing any degradation of material.
Assessment of efficacy: It should be done with at least two independent longitudinal prospective clinical studies.
Classification
Based on composition
Table 2
ndosseous dental implant materials
Biological classification – According to tissue response
According to property of bio compatibility , biomaterials are broadly classified into three major categories: bioactive, bioresorbable and bioinert.
Bioactive- These materials react with hard and soft tissues when they are placed inside the oral cavity. Glass ceramic, bio glass and synthetic hydroxyapatite are few examples.
Bioresorbable – When these materials start resorbing bone replaces them. Examples are tricalcium phosphate, calcium carbonate, gypsum, polylactic–polyglycolic acid copolymers and calcium oxide.
Bioinert – These materials have less interaction with the surrounding tissue; It leads to osteogenesis. Few examples are alumina, stainless steel, zirconium and titanium and ultra-high-molecular-weight polyethylene.
The term “osteoconductive” refers to bioinert and bioactive materials; These materials can act as “scaffolds” for bone deposition on its surface. Bioinert materials allow close approximation of bone. Their surface leading to contact osteogenesis. These materials allow the formation of new bone on their surface and ion exchange with the tissues leads to the formation of a chemical bonding along the interface bonding osteogenesis. Biotolerant are those that are not necessarily rejected when implanted into living tissue. They are human bone morphogenetic protein-2 (rh BMP-2), which induces bone formation de novo Bioinert materials allow close approximation of bone on their surface leading to contact osteogenesis. These materials allow the formation of new bone on their surface and ion exchange with the tissues leads to the formation of a chemical Bioinert materials allow close approximation of bone on their surface leading to contact osteogenesis. These materials allow the formation of new bone on their surface and ion exchange with the tissues leads to the formation of a chemicalnert materials allow close approximation of bone on their surface leading to contact osteogenesis. These materials allow the formation of new bone on their surface and ion exchange with the tissues leads to the formation of a chemical bonding along the interface bonding osteogenesis.
Biotolerant are those that are not necessarily rejected when implanted into living tissue. They are human bone morphogenetic protein-2 (rh BMP-2), which induces bone formation de novo Bioinert materials allow close approximation of bone on their surface leading to contact osteogenesis. These materials allow the formation of new bone on their surface and ion exchange with the tissues leads to the formation of a chemical bonding along the interface bonding osteogenesis.
Biotolerant are those that are not necessarily rejected when implanted into living tissue. They are human bone morphogenetic protein-2 (rh BMP-2), which induces bone formation de novoioinert materials allow close approximation of bone on their surface leading to contact osteogenesis. These materials allow the formation of new bone on their surface and ion exchange with the tissues leads to the formation of a chemical bonding along the interface bonding osteogenesis.
Biotolerant are those that are not necessarily rejected when implanted into living tissue. They are human bone morphogenetic protein-2 (rh BMP-2), which induces bone formation de novo Bioinert materials allow close approximation of bone on their surface leading to contact osteogenesis. These materials allow the formation of new bone on their surface and ion exchange with the tissues leads to the formation of a chemical bonding along the interface bonding osteogenesis. Biotolerant are those that are not necessarily rejected when implanted into living tissue. They are human bone morphogenetic protein-2 (rh BMP-2), which induces bone formation de novo.
Table 3
Based on the type of material used and the biologic response they elicit when implanted:
Table 4
Coating of dental implant ceramic materials
[i] According to Lace field, 1998 9
Discussion
In patients with edentulism the QOL (Quality Of Life) is improved by rehabilitation with oral implants. 10 Brane mark, introduced pure titanium in 1960s and it remained the material of choice for oral end osseous implants. 11 Different materials such as metals, alloys, glasses, carbon, ceramics and polymer-based materials have been used as oral implants from ancient era to modern era of dental implant history. 12, 13, 14, 15
These different oral implant materials interact with the human body at different degrees. 15, 16 The mechanical, chemical and biological properties of a bio material together with the ability to Osseo integrate are the ideal requirements of an oral implant bio material.
Although hypersensitivity is one of the most common problem reported with titanium implant,17, 18, 19, 20, 21 they have excellent mechanical properties like good fracture strength; The second common problem reported with these titanium implant is mainly due to the difference in the elastic moduli gradient of surrounding bone and the titanium implant. Stress concentrations occur at the bone-implant interface during load transfer. 22, 23 The result is bone loss around the implant. 24, 25
Titanium implants may cause aesthetic problems due to their lack of light transmission.26 In cases of thin mucosal biotype and/or mucosal regression, the peri-implant soft tissue around titanium implants may appear dark. If the smile line is high, more aesthetic problems occur.27, 28 Patient demand for metal-free oral biomaterials is also increasing.
All implant biomaterials have their own advantages and disadvantages; PEEK is considered as a good biomaterial for dental implants due to its good properties such as low plaque affinity, high biocompatibility and good aesthetics.29 The main advantage of PEEK as an implant material is that its Young's modulus is close to that of human bones, thus increasing stress and deformation, reducing stress resistance and bone resorption. Unfilled PEEK has an elastic modulus of 3-4GPa. The addition of additional materials such as carbon fibers increases PEEK's modulus of elasticity to 18Gpa compared to bone (14Gpa). Thus, PEEK can substitute titanium.30, 31
PEEK is an alternative to ceramic in terms of mechanical properties. Although unmodified PEEK is considered a bioinert material, there is no conclusive evidence of osteoconductive effects. Therefore, the survival of unmodified Peek implant is questionable. Inadequate osteo conductivity and bioactivity of dental implants can lead to severe implantitis and implant rejection. These are some of the current strategies to improve PEEK bioactivity.32 PEEK can be viable alternative to titanium abutments.33 How ever, because of its lower fracture resistance PEEK is not used as a definitive abutment material.34
Compared to all thermoplastic composites, PEEK biomaterials are with excellent shock absorption and fracture resistance. Further improvements in material properties and surface modifications allow for wide applications in the field of dental implants. A limited number of studies on PEEK implants have been published and long-term follow-up studies are needed due to the recent use of the material in dentistry.
Conclusion
There is an ongoing research process for the "perfect" dental implant biomaterial. In future, the dental implant biomaterial research will be focused on the cutting-edge interface of material science.
With continued research and development in the field of new metal and polymer materials, the future will see many innovations in new metal-polymer binary materials formulations with excellent properties.
Biomaterials can represent a combination of performance, strength, predictability and integrity. Three-dimensional (3-D) printing/molding techniques using elements of nanotechnology will advance these innovations.
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