Long-term clinical and experimental/surface analytical studies of carbon/carbon maxillofacial implants

Szabo, Gyorgy,Barabas, Jozsef,Bogdan, Sandor,Nemeth, Zsolt,Sebok, Bela,Kiss, Gabor Korean Association of Maxillofacial Plastic and Re 2015 Maxillofacial Plastic Reconstructive Surgery Vol.37 No.-

Background: Over the past 30-40 years, various carbon implant materials have become more interesting, because they are well accepted by the biological environment. The traditional carbon-based polymers give rise to many complications. The polymer complication may be eliminated through carbon fibres bound by pyrocarbon (carbon/carbon). The aim of this study is to present the long-term clinical results of carbon/carbon implants, and the results of the scanning electron microscope and energy dispersive spectrometer investigation of an implant retrieved from the human body after 8 years. Methods: Mandibular reconstruction (8-10 years ago) was performed with pure (99.99 %) carbon implants in 16 patients (10 malignant tumours, 4 large cystic lesions and 2 augmentative processes). The long-term effect of the human body on the carbon/carbon implant was investigated by comparing the structure, the surface morphology and the composition of an implant retrieved after 8 years to a sterilized, but not implanted one. Results: Of the 16 patients, the implants had to be removed earlier in 5 patients because of the defect that arose on the oral mucosa above the carbon plates. During the long-term follow-up, plate fracture, loosening of the screws, infection or inflammations around the carbon/carbon implants were not observed. The thickness of the carbon fibres constituting the implants did not change during the 8-year period, the surface of the implant retrieved was covered with a thin surface layer not present on the unimplanted implant. The composition of this layer is identical to the composition of the underlying carbon fibres. Residual soft tissue penetrating the bulk material between the carbon fibre bunches was found on the retrieved implant indicating the importance of the surface morphology in tissue growth and adhering implants. Conclusions: The surface morphology and the structure were not changed after 8 years. The two main components of the implant retrieved from the human body are still carbon and oxygen, but the amount of oxygen is 3-4 times higher than on the surface of the reference implant, which can be attributed to the oxidative effect of the human body, consequently in the integration and biocompatibility of the implant. The clinical conclusion is that if the soft part cover is appropriate, the carbon implants are cosmetically and functionally more suitable than titanium plates.

Characterization of SiC Nanostructures in Crystalline and Porous Silicon Formed by Ion Beam Synthesis

우형주,김기동,최한우,김준곤 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.61

We have investigated the optical properties of 3C-SiC nanocrystals formed by implanting high-fluence carbon ions into a crystalline silicon (c-Si) substrate. Si (100) samples were implanted by 200-keV carbon ions for a fixed fluence of 1.6 × 1017 cm−2 at different temperatures of room temperature (RT), 500 ℃ and 800 ℃ followed by post-implantation annealing at 1050 ℃ for 2 h in a pure nitrogen ambient. A photoluminescence (PL) spectrum with a peak at 525 nm (2.36 eV)could be observed only in the case of implantation at the elevated temperature (800 ℃, followed by high-temperature thermal annealing. The formation of precursors to 3C-SiC nano-crystals seems to be allowed only in the case of high-temperature implantation. X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (XTEM) measurements showed that the 3C-SiC nano-crystals of 5 - 8 nm in diameter were mostly aligned with the (100) silicon substrate, with the SiC (111) planes parallel to the sample surface. We have also investigated the room-temperature PL characteristics of porous silicon (PS) implanted with carbon. PS samples made by anodizing were implanted with 200-keV carbon ions at a fluence of 1.6 × 1017 cm−2 at room temperature and 800℃ and were subsequently annealed at temperatures of 300 - 1050 ℃ in a nitrogen ambient. The typical intense red-orange light (~650 nm) from the porous Si surface disappeared markedly after implantation, and a considerable blue light appeared after thermal annealing. The formation of 3C-SiC could be confirmed by X-ray photoelectron spectroscopy (XPS) and XTEM measurements,and the effects of different implantation and annealing temperatures on the light-emission properties of the implanted porous silicon could be described.

The Tissue Response to Titanium and Carbon-coated Blade-vent Implants in the Mandibles of Dong

Bae, Chang,Choie, Mok-Kyun,Kim, Hong-Ki,Park, Keum-Soo,Kim, Kwang-Hyun CATHOLIC MEDICAL CENTER 1987 Bulletin of the Clinical Research Institute Vol.15 No.1

In order to investigate the influence of implant materials, functional stress and width of channel on the tissue reaction around implants, the tissues around the endosseous implants were observed histopathologically. Fibrous capsules existed around the almost functional implants and around the implants embedded into the wide channels, while they were not observed around the non-functional implants embedded into the narrow channels. And there was little difference between the tissue reaction to the pure titanium implants and that to the carbon-coated implants.

Surface modification and induced ultra high surface hardness by nitrogen ion implantation of low alloy steel

A.O. OLOFINJANA,Z. CHEN,J.M. BELL 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10

A surface hardenable low alloy carbon steel was implanted with medium energy (20 - 50KeV) N₂? ions to produced a modified hardened surface. The implantation conditions were varied and are given in several doses. The surface hardness of treated and untreated steels were measured using depth sensing ultra micro indentation system (UMIS). It is shown that the hardness of nitrogen ion implanted steels varied from 20 to 50㎬ depending on the implantation conditions and the doses of implantation. The structure of the modified surfaces was examined by X-ray photoelectron spectroscopy (XPS). It was found that the high hardness on the implanted surfaces was as a result of formation of non-equilibrium nitrides. High-resolution XPS studies indicated that the nitride formers were essentially C and Si from the alloy steel. The result suggests that the ion implantation provided the conditions for a preferential formation of C and Si nitrides. The combination of evidences from nano-indentation and XPS, provided a strong evidence for the existence of sp³ type of bonding in a suspected (C,si)xNy stoichiometry. The formation of ultra hard surface from relatively cheap low alloy steel has significant implication for wear resistance implanted low alloy steels.

Recent developments in the application of carbon-based nanomaterials in implantable and wearable enzyme-biofuel cells

Serag Eman,El-Maghraby Azza,El Nemr Ahmed 한국탄소학회 2022 Carbon Letters Vol.32 No.2

The implanted electronic devices require a stable, continuous, and long-lasting energy source to function correctly. These devices are powered by alkaline batteries and lithium ions. When used in implantable or wearable devices, these batteries can pose a threat to human health and the environment. Because of these factors, implantable and wearable devices using enzyme biofuel cells (EBFCs) are receiving a lot of attention. These EBFCs use human physiological fluid to provide long-term control for these devices. Carbon nanomaterials have successfully been demonstrated in enzymatic biofuel cells to improve applications by increasing current and power density; they have the potential to enhance EBFC efficiency. This review summarizes the fundamental process of EBFC compounds based on carbon nanomaterials before delving into the most recent advancements that have been tested and used as implantable and wearable self-power sources.

Nanostructured Biointerfacing of Metals with Carbon Nanotube/Chitosan Hybrids by Electrodeposition for Cell Stimulation and Therapeutics Delivery

Patel, Kapil D.,Kim, Tae-Hyun,Lee, Eun-Jung,Han, Cheol-Min,Lee, Ja-Yeon,Singh, Rajendra K.,Kim, Hae-Won American Chemical Society 2014 ACS APPLIED MATERIALS & INTERFACES Vol.6 No.22

<P>Exploring the biological interfaces of metallic implants has been an important issue in achieving biofunctional success. Here we develop a biointerface with nanotopological features and bioactive composition, comprising a carbon nanotube (CNT) and chitosan (Chi) hybrid, via an electrophoretic deposition (EPD). The physicochemical properties, in vitro biocompatibility, and protein delivering capacity of the decorated nanohybrid layer were investigated, to address its potential usefulness as bone regenerating implants. Over a wide compositional range, the nanostructured hybrid interfaces were successfully formed with varying thicknesses, depending on the electrodeposition parameters. CNT-Chi hybrid interfaces showed a time-sequenced degradation in saline water, and a rapid induction of hydroxyapatite mineral in a simulated body fluid. The nanostructured hybrid substrates stimulated the initial adhesion events of the osteoblastic cells, including cell adhesion rate, spreading behaviors, and expression of adhesive proteins. The nanostructured hybrid interfaces significantly improved the adsorption of protein molecules, which was enabled by the surface charge interaction, and increased surface area of the nanotopology. Furthermore, the incorporated protein was released at a highly sustained rate, profiling a diffusion-controlled pattern over a couple of weeks, suggesting the possible usefulness as a protein delivery device. Collectively, the nanostructured hybrid CNT-Chi layer, implemented by an electrodeposition, is considered a biocompatible, cell-stimulating, and protein-delivering biointerface of metallic implants.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2014/aamick.2014.6.issue-22/am505759p/production/images/medium/am-2014-05759p_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am505759p'>ACS Electronic Supporting Info</A></P>

Kinetic Monte Carlo (kMC) Study of the Effect of Carbon Co-implantation on the Pre-amorphization Process

Soon-Yeol Park,Bum-Goo Cho,Seung-Su Yang,Taeyoung Won 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.1

We report our kinetic Monte Carlo (kMC) study of the effect of carbon co-implantation on the pre-amorphization implant (PAI) process. We employed the BCA (binary collision approximation) approach for the acquisition of the initial as-implanted dopant profile and the kMC method for the simulation of the diffusion process during the annealing. The simulation results implied that carbon co-implantation suppress boron diffusion due to recombination with interstitials. Also, we could compare boron diffusion with carbon diffusion by calculating the reaction of carbon atoms with interstitials, and we found that boron diffusion was affected by the carbon co-implantation energy by enhancing the trapping of interstitials between boron atoms and interstitials. We report our kinetic Monte Carlo (kMC) study of the effect of carbon co-implantation on the pre-amorphization implant (PAI) process. We employed the BCA (binary collision approximation) approach for the acquisition of the initial as-implanted dopant profile and the kMC method for the simulation of the diffusion process during the annealing. The simulation results implied that carbon co-implantation suppress boron diffusion due to recombination with interstitials. Also, we could compare boron diffusion with carbon diffusion by calculating the reaction of carbon atoms with interstitials, and we found that boron diffusion was affected by the carbon co-implantation energy by enhancing the trapping of interstitials between boron atoms and interstitials.

Device Characteristics and Hot Carrier Lifetime Characteristics Shift Analysis by Carbon Implant used for V_th Adjustment

Mun, Seong-Yeol,Kang, Seong-Jun,Joung, Yang-Hee The Korea Institute of Information and Commucation 2013 Journal of information and communication convergen Vol.11 No.4

In this paper, a carbon implant is investigated in detail from the perspectives of performance advantages and side effects for the thick n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET). Threshold voltage ($V_{th}$) adjustment using a carbon implant significantly improves the $V_{th}$ mismatch performance in a thick (3.3-V) n-MOS transistor. It has been reported that a bad mismatch occurs particularly in the case of 0.11-${\mu}m$ $V_{th}$ node technology. This paper investigates a carbon implant process as a promising candidate for the optimal $V_{th}$ roll-off curve. The carbon implant makes the $V_{th}$ roll-off curve perfectly flat, which is explained in detail. Further, the mechanism of hot carrier injection lifetime degradation by the carbon implant is investigated, and new process integration involving the addition of a nitrogen implant in the lightly doped drain process is offered as its solution. This paper presents the critical side effects, such as Isub increases and device performance shifts caused by the carbon implant and suggests an efficient method to avoid these issues.

Kinetic Monte Carlo Study on Boron Diffusion with Carbon Pre-implantation after a Pre-amorphization Process

박순열,성건식,원태영 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.51

We report our kinetic Monte Carlo (kMC) study on the effect of carbon co-implant during the pre-amorphization implant (PAI) process. We employed BCA (Binary Collision Approximation) approach for the acquisition of the initial as-implant dopant profile and kMC method for the simulation of diffusion process during the annealing process. The simulation results implied that carbon co-implant effectively suppresses the boron diffusion due to the recombination with interstitials. Also, we could compare the boron diffusion with carbon diffusion by calculating carbon reaction with interstitial. We could find that boron diffusion is affected by the energy level of the carbon co-implant due to the enhancement of the trapping of interstitial between boron and interstitials.

Selective cell adhesion on an ion implanted poly(bisphenol A carbonate) film

Ho-Je Kwon,Chan-Hee Jung,In-Tae Hwang,Young-Chang Nho,최재학 한국공업화학회 2009 Journal of Industrial and Engineering Chemistry Vol.15 No.5

Conventional ion implantation has been shown to modify the surface properties of polymers such as their hardness, conductivity, and biocompatibility. In this study, poly(bisphenol A carbonate) (PC) films were implanted by Ar+ ions with an energy level of 100 keV in order to improve their biocompatibility. The results of the surface analyses revealed an increasing intensity of the functional groups on the ion implanted PC surfaces such as OH, C55O, and C–O after implantation, which contributed to an improvement of their hydrophilicity. The in vitro cell culture test revealed that the HaCaT cells were selectively adhered to the ion implanted regions of the PC.