An Overview of Biomedical Implants (eBook)

Biomaterials for the Human Body

Tolou Shokuhfar (Autor)

eBook Download: EPUB

2025
440 Seiten
Wiley (Verlag)
9781119850991 (ISBN)

Infos

Understand the core materials that create biomedical innovation

Some of the greatest medical advances in recent decades have come in the form of biomedical implants. Whether in the form of traditional orthopedic implants, medical devices for the cardiovascular system, or polymer-based ocular implants, biomedical implants can be lifesaving or life-transforming interventions. The biomaterials which comprise these implants are a vital area of ongoing research, but no prior volume has ever taken comprehensive stock of this subject and its growing applications.

An Overview of Biomedical Implants fills this gap with a thorough overview of all major biomaterials and their role in biomedical implants. Composed for an interdisciplinary audience, the book addresses all scales and areas of application. The result is an essential resource in this critical ongoing area of biomedical research.

An Overview of Biomedical Implants readers will also find:

• Description of the relationship between every specific biomaterial and its role in each major implant category
• Detailed discussion of nanoscale to molecular-scale to industrial-scale biomaterials
• Concrete examples in every chapter, along with a list of pertinent references

An Overview of Biomedical Implants is ideal for physicians, scientists, and engineers-those working in the area of biomaterials, medical, biological and chemical and applied physics, pharmaceutical science and as a reference for professors and students in these areas.

Tolou Shokuhfar, PhD, is an Associate Professor of Bioengineering at University of Illinois at Chicago. She is a recipient of an NSF CAREER Award that pioneers the visualization of biomineralization, biological materials, nanomaterial/protein interactions and microorganisms in nanoenclosures. She has also received the SFB Ortho SIG Faculty Abstract award, TMS Young Leaders Award, DSL Young Scientist Award, and 'INSIGHT Diversity Award for Inspiring Women in STEM'. Dr. Shokuhfar has been the Chair for Orthopedic Biomaterials SIG and Vice Chair of Nanomaterials SIG at the Society for Biomaterials since 2019.

Textauszug

1
Biomaterials for Dental Implants

CHAPTER MENU

1.1 Introduction: Dental Implants and Current Materials, 1

1.2 Ceramic Dental Implants, 8

1.3 Polyetheretherketone (PEEK), 15

1.4 Peptide Coatings for Dental Implants, 20

1.5 Functionally Graded Dental Implants, 22

1.6 Looking to the Future: State‐of‐the‐Art Biomaterials for Dental Implants, 26

1.7 Conclusion, 28

References, 29

1.1 Introduction: Dental Implants and Current Materials

1.1.1 The Need for Better Dental Implants

An interdisciplinary approach including surface chemistry, physics, and engineering as well as biomechanics is required to develop successful dental implants [1]. Dental implants have been prevalent throughout the past century; however, evidence of dental implants within ancient Mayan and Egyptian civilizations has been found [2]. This brings us to the first prototype of the modern dental implant, which was created by Greenfield in 1913 and was first described as an implant/prosthetic combination made of an iridium–platinum alloy [2]. In the 1970s, Brånemark’s experimentation led to the general acceptance of oral implants and highlighted the importance of osseointegration [3]. We now understand that the success of a dental implant depends on the chemical, physical, mechanical, and topographic characteristics of its surface [4]. As a result of continuous modifications to implant design and surface topography, dental implant placement is a fairly common treatment procedure with high implant survival rates and limited peri‐implant bone loss [5]. In fact, the survival rate of dental implants has been reported to be above 90% [6]. Nowadays, implant surface modifications focus on stronger and faster bone healing to further limit dental implant failure [5]. Even with great advancements in the field of dental implantology, there is still a relatively significant number of dental implant failures, many of which are caused by compromised bone conditions that promote implant failure. For example, diabetes, osteoporosis, obesity, and the use of drugs can decrease bone healing around dental implants [6]. Furthermore, complications involving osseointegrated dental implants can arise from inflammatory conditions associated with bacteria, more specifically, peri‐implantitis [7].

Peri‐implantitis is a pathological condition that occurs in tissues surrounding dental implants [7]. It is characterized by inflammation of the peri‐implant connective tissues as well as loss of supporting bone [7]. In other words, plaque and its byproducts lead to hard and soft tissue breakdown and eventually implant failure, which is a prevalent issue [8]. Factors such as smoking or a history of periodontal disease increase the prevalence of peri‐implantitis [8]. However, even with the lack of the aforementioned factors, features such as implant placement, material biocompatibility, and material degradation also play important roles in the development of peri‐implantitis or osseointegration breakdown [8]. Osseointegration is the formation of bone tissue around the implant without fibrous tissue growth at the bone–implant interface, resulting in direct anchorage of the implant [1]. The osseointegration process can be visualized in Figure 1.1. In fact, the structural and functional union of the implant and living bone is significantly influenced by the surface characteristics of the dental implant [4]. Thus, proper osseointegration is crucial for the success of the implant and is a research topic of great importance. Presently, researchers are finding ways to optimize implant surfaces by studying specific features such as roughness of the implant surface as well as various materials for dental implants in order to promote proper osseointegration and combat peri‐implantitis [10].

Figure 1.1 Osseointegration of dental implants over time.

(From Ref. [9], 2021, Springer Nature, CC BY 4.0).

Currently, titanium or titanium alloys are the gold standard in dental applications [10]. Most dental implants marketed in the United States are made from either commercially pure titanium (cpTi) or titanium alloys [e.g. Ti6Al4V (TAV)] [4]. Seconds after titanium (Ti) is machined, adsorbed oxygen molecules form a thin oxide layer, which is what body tissues interact with [11]. This oxide layer allows for biocompatibility, while the rest of the implant material plays a role in the implant’s mechanical properties [11]. Chemical processes that occur at the tissue–implant interface include corrosion, adsorption of some biomolecules, denaturing of proteins, and catalytic activity [11]. For instance, TAV implants degrade and result in peri‐implant bone loss [12]. The origins of this degradation were revealed by Chen et al. [12] whose results suggest that the observed bone loss is caused by crevice corrosion and the release of consequential by‐products. These types of issues are driving scientists to find materials and methods to improve dental implants, specifically, the surface of dental implants.

1.1.2 Various Approaches and Biomaterials to Improve Dental Implants

The material composition and surface topography of implants greatly influence the wound healing processes that follow implantation and thus also influence subsequent osseointegration [13]. It has been found that implants with a rough surface allow for better osseointegration; however, excessive roughness can increase the risk of peri‐implantitis and ionic leakage [14]. Thus several methods have been proposed to produce a moderate roughness of 1–2 μm including titanium plasma spraying, particle blasting and acid etching, anodization of the implant surface, and coatings [14]. Examples of these methods are highlighted in Figure 1.2. One method, anodization or anodic oxidation on Ti‐based implants, creates an adherent oxide coating that can have a wide range of stoichiometries as well as microporosities and nanoporosities depending on electrolyte selection and condition manipulation [15].

Figure 1.2 Various aspects of dental implant surfaces viewed by scanning electron microscopy. (a) Original machined implant from Nobel Biocare with a smooth surface. (b) Rough surface of a dental implant system developed by the French company ETK implant that was sandblasted, and acid etched. (c) Surface of a Ti UniteTM implant from Nobel Biocare with a thick layer of titanium creating smooth asperities. (d) High magnification of an implant surface after sandblasting and HF acid etching. (e) Surface of a TA6V implant whose surface was sandblasted with corundum particles. (f) Surface of titanium implant, which was sprayed with titanium beads with a plasma torch.

(From Ref. [14], 2016, Elsevier).

Biomaterials of interest that could be used as a coating or as a Ti implant replacement include hydroxyapatite (HA), ceramic materials [e.g. alumina, calcium phosphate (CP), and zirconia], nanoparticulate zinc oxide (nZnO), and polyetheretherketone (PEEK). Each of these materials has their own promising aspects. Some studies have reported benefits of using HA‐coated dental implants as well as risks including dissolution of the coating (although they have not shown that dissolution leads to implant loss) [16]. Furthermore, HA coatings may be more susceptible to bacteria as compared to titanium implants [16]. Nevertheless, coating dental implants with HA has helped metallic materials to osseointegrate with the local tissue environment and distribute load stress [17]. Zirconia is a possible alternative to the traditional Ti‐based implant systems as it has superior biological, aesthetic, mechanical, and optical properties [18]. However, more long‐term and comparative clinical trials are necessary in order to validate zirconia as a viable alternative to titanium implants [18].

There are many other dental implant biomaterials that clinicians may not be familiar with. For example, bioactive dental glass‐ceramics (BDGCs) have shown bone–tooth bonding capabilities as well as positive biological reactions at the material–tissue interface [19]. This makes them an attractive implant coating biomaterial. Nanoparticulate zinc oxide is of great interest because of its integration with antimicrobial nanoparticles (NPs) resulting in a coating material that is antibacterial and promotes osteoblast growth, which would help prevent implant failure from aseptic loosening and infection [20]. PEEK possesses excellent mechanical characteristics and may be used in dentistry with surface modification to enhance its osseointegrative characteristics [10]. Another interesting approach to modifying dental implants is using functionally graded materials (FGMs). FGMs are heterogeneous composite materials that have a compositional gradient with continuously varying properties in the thickness direction [21]. Ultimately, these more “novel” biomaterials must be researched in more depth if they are to be used more frequently in the clinic.

An important...

Produkt-Details

• Erscheint lt. Verlag: 29.1.2025
• Sprache: englisch
• Themenwelt: Medizin / Pharmazie ► Gesundheitsfachberufe
• Themenwelt: Medizin / Pharmazie ► Medizinische Fachgebiete
• Themenwelt: Technik
• Schlagworte: biomaterials • dental implant • drug delivery implants • Heart valve • intraocular lens • Nanobiomaterials • nanomaterials • ocular implants • Orthopedic implants • pacemaker • polymer-based implants • Regenerative medicine • Stent • tissue regeneration
• ISBN-13: 9781119850991 / 9781119850991