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Applications of Thin Films in Metallic Implants
Published in Sam Zhang, Materials for Devices, 2023
Katayoon Kalantari, Bahram Saleh, Thomas J. Webster
Several reasons lead to the failure of implants. Infection, improper design, lack of enough tests before implantation, and poor surgical technique during insertion and/or removal are just some of the causes of implant failure [167]. One of the main reasons for failure, amputation, or even death of a patient is implant-associated infection [168]. Infection known as a complex process related to the adhesion of bacterial onto material surfaces, aggregation or dispersion of their colonies and subsequent biofilm formation. Nevertheless, biofilm elimination becomes very challenging once it is created, due to its strong resistance to antimicrobial agents. Commonly, two types of bacteria, Staphylococcus aureus and Staphylococcus epidermidis, are responsible for most infections of implants in which both exist as natural pathogens of tissue and in the human skin, respectively [169]. Implant rejection and/or loosening happens because of bacterial colonization. Even by applying bioactive materials as coatings on implants, the dissolution rate of such coatings may decrease implant lifetimes through the formation of particle debris, which one must be very careful to avoid [170].
Recent Advances in Biocompatibility
Published in Yaser Dahman, Biomaterials Science and Technology, 2019
Implants tend to lose functionality over time. For example, it is estimated that between 2005 and 2030 that the total number of knee revision surgeries is going to increase by 607% (Gepreel and Niinomi, 2013). Implant failure is characterized as the need to revise surgery due to different factors caused by either the patient, surgeon, or by the biomaterial used (Zinar and Schmalzried, 2015). For example, infections resulting in revised surgery can be caused by the surgeon, the surgical team, the surgical equipment, or by the operating/recovery site (Zinar and Schmalzried, 2015). Patient health conditions can influence biomaterial performance in the body. For example, depression and renal dysfunction have shown to influence the biomaterial-tissue response (Zinar and Schmalzried, 2015). High life expectancy of patients is another factor relating to an increased number of revised surgeries (Gepreel and Niinomi, 2013).
Biomedical Applications of Laser Texturing
Published in Savaş Kaya, Sasikumar Yesudass, Srinivasan Arthanari, Sivakumar Bose, Goncagül Serdaroğlu, Materials Development and Processing for Biomedical Applications, 2022
Bruno Gago, Antonio Riveiro Rodríguez, Pablo Pou, Mónica Fernández-Arias, Jesús del Val García, Rafael Comesaña Piñeiro, Aida Badaoui, Mohamed Boutinguiza Larosi, Juan Pou Saracho
Infections caused by the contamination of the surgical site and surrounding areas are the most common cause of implant failure. This is a major clinical problem aggravated by the increased resistance of some bacteria to antibiotics (Campoccia, Montanaro, and Arciola 2006).
Preventing stress singularities in peri-implant bone – a finite element analysis using a graded bone model
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Oliver Roffmann, Meike Stiesch, Andreas Greuling
Nowadays implants are commonly used to treat patients with one or more missing teeth. Although implant treatment has been practised for several years, complications after a successful surgery can still occur due to various biological or biomechanical effects. The main reasons for implant failure are a lack of osseointegration, peri-implantitis, overloading and implant fracture (Manor et al. 2009). While those issues may be a consequence of poor oral hygiene, some complications are associated with biomechanical issues, especially incorrect loading of the bone (Misch 2015a). During mastication, the resulting force is transferred directly from the implant to the bone. Compared to a natural tooth, an implant has a different contact surface with the bone and different material properties. In addition, it lacks the periodontal ligament. This results in altered forces and stresses in the bone (Misch 2015a). According to a bone remodelling theory (Frost 2003), loading outside the adapted window leads to bone loss and possibly an increased probability of implant failure over time. Consequently, finding an optimal biomechanical design is of great interest to dental researchers.
Powder mixed-EDM for potential biomedical applications: A critical review
Published in Materials and Manufacturing Processes, 2020
Md Al-Amin, Ahmad Majdi Abdul Rani, Abdul Azeez Abdu Aliyu, Muhammad Al’Hapis Abdul Razak, Sri Hastuty, Michael G Bryant
The bio-implants such as bio-screws, plates, pins, stems, and others fixation of malfunction of body made of metallic biomaterials depend on the application and properties.[165] The bio-implants are classified into two categories: (a) permanent implants and (b) temporary implants.[166] The permanent implants including knee, hip, stent, and other joints are inserted into the body for serving a long-time span (over 10 years) while the temporary implants are implanted for a short time (below 2 years) such as screws, plates, pins, and other prostheses. An implant is considered as perfect if it bears the following characteristics strictly[11,38]: (a) outstanding biocompatibility, (b) excellent corrosion and wear resistance, (c) bone-like mechanical properties, (d) excellent bioactivity for sufficient osteointegration, (e) surface porosity around 25–48%, (f) surface roughness of Rmax 8–12 µm, (g) Ca:P ~ 1.64. While metallic implants add greater strength than the natural bone, a reasonable amount of orthopedic and dental bio-implants was stated to be damaged before being matured after implantation. Figure 5 depicts the implants failure before being matured within the human body. Implant failure was associated with bacterial infection, stress shielding due to mismatch modulus of elasticity, poor corrosion and wear resistance, insufficient osteointegration, and poor surface finish.[164,167–174]Table 6 summarize the premature failure of orthopedic and dental implants.
Application of finite element analysis to evaluate optimal parameters for bone/tooth drilling to avoid thermal necrosis
Published in Cogent Engineering, 2021
Nayana Prabhu, Dasharathraj K Shetty, Nithesh Naik, Nagaraja Shetty, Yash Kalpesh Parmar, Vathsala Patil, Nilakshman Sooriyaperakasam
The atraumatic surgical procedure is important when placing the implants in the bone. The main cause of implant failure is heat generation and surgical trauma (Mediouni et al., 2017). Therefore, implant failure studies to prevent thermal necrosis seem to be specific to preventing implant surgical failure. Earlier studies were mostly associated with in vitro experimental studies (Augustin et al., 2008; Pearce et al., 2005) while the recent studies mostly depend on computational analysis and experiments (Mediouni et al., 2017). Computational Analysis provides greater scope for assessing the salient parameters that can be used to prevent thermal necrosis. Most studies have found that Drilling Speed, Drilling Feed, Drilling Diameter, and Drilling Forces are the main parameters for the operator to control thermal necrosis. Pearce et al. (2005) investigated thermal bone damage or necrosis associated with orthopedic surgical procedures. During their studies on pig bones, they found that thermal necrosis could lead to infection and the inadvertent loosening of the implant subjects. It has been reported that if the bone is subjected to 56°C temperature for over 10s, necrosis appears. However, they did not compare or validate the results with the human bone model where drilling is done using K-wires, following micro examination using the scanning electron microscope (SEM). In their research, they used the drill with 656, 1180 and 2000 rpm speed, and discovered that reduced drilling speeds caused the greatest temperature rise. The temperature rise for 656 rpm was approximately twice that of 2000 rpm. The drilling speed of 1180 rpm appears to be the optimum for keeping the temperature low at both insertion speeds. The study also found that larger the drilling diameter, the higher the peak temperature. However, the authors have not discussed the effect of the increase in density during the k-wire drilling (due to the absence of a screw thread).