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Titanium (Ti) and Ti alloys possess extensive applications in the medical field due to their non-toxic, biocompatible, and antibacterial properties. This study investigates the biocompatibility enhancement of a Ti-based alloy, Ti-6Al-4V, through a multi-step process involving cathodic arc ion plating of a TiZrTa thin film and subsequent laser-textured oxidation (LTO). LTO treatment produced a structured microtopography with regular groove patterns, including straight lines (L-s), circles (L-c), and checkboards (L-ch), resulting in surface oxidation and the formation of various oxides on the TiZrTa coating. Microstructure analyses revealed substantial alterations in surface topography induced by laser texturing. Antibacterial assessments against Staphylococcus aureus (S. aureus) showed that the films with LTO treatment did not exhibit significant advantages after 12 or 24 h of coculture because the laser-textured portions consisted of a combination of the film and the substrate, and the antibacterial effect was not obvious. Coatings with LTO treatment significantly improved L-929 mouse fibroblasts cell viability at 48 h, particularly for samples with a 50 μm spacing of straight and circular patterns (L-s and L-c). After two weeks of MG-63 human osteosarcoma cell culture, the viability of all samples reached similar levels. It suggested that the TiZrTa-coated Ti-6Al-4V exhibited good biocompatibility with both cells. This study contributed to the understanding of surface modification techniques for enhancing the biocompatibility of Ti-based alloys in biomedical applications. • A TiZrTa thin film with LTO treatment was applied onto Ti-6Al-4V alloys. • LTO produced regular groove patterns and resulted in superior hydrophilicity. • LTO-treated thin films did not have obvious antibacterial improvement of S. aureus. • LTO-treated thin films improved the cell viability of both L-929 and MG-63 cells. [ABSTRACT FROM AUTHOR]

Titanium and titanium alloy materials are often made as medical implants. Surface properties of titanium medical implants play decisive roles for antibacterial and biological response and tissue biocompatibility. In this study, cathode arc evaporation (CAE) technology was used to deposit TiNb–Zr–Ta and nitrogen-doped TiNb–Zr–Ta coatings with nanostructures on the Ti–6Al–4V dental abutment screws. The deposited coatings were then oxidized at high temperature to produce different oxides on the surface of the coatings. The mechanical properties, antibacterial properties and biocompatibilities of the coatings were analyzed. The effect of coatings on the abutment screw loosening and removal torque between the abutment screw and the pure titanium implant fixture was studied by removal torque measurement. In addition, Staphylococcus aureus (S. aureus) was used for evaluating the antibacterial properties of coatings, and mouse fibroblasts (L929) were used for ISO 10993-5 cytotoxicity analyses to determine whether it had good biocompatibility. Nanolayered structures and multiphases of polycrystalline TiNb–Zr–Ta were obtained by co-deposition of Ta, Zr and TiNb. When small content of N was introduced, the TiNb–Zr–Ta(N) showed a polycrystalline TiNb–Zr–Ta where N atoms entered the metallic lattice at interstitial sites. After oxidation, oxide phases of Ta 2 O 5 , TiO 2 , Nb 2 O 5 and ZrO 2 were formed on the surface of TiNb–Zr–Ta and TiNb–Zr–Ta(N). Ta 2 O 5 was obtained on the surface of the coating prior to other oxides such as TiO 2 , Nb 2 O 5 and ZrO 2. The deposited TiNb–Zr–Ta and TiNb–Zr–Ta(N) coatings had high contact angle and exhibited a hydrophobic feature, while the annealed TiNb–Zr–Ta–O and TiNb–Zr–Ta(N)–O showed hydrophilicity. The deposited TiNb–Zr–Ta had similar hardness and Young's modulus values to that of the uncoated Ti–6Al–4V. When N was doped, the TiNb–Zr–Ta(N) had the highest hardness and Young's modulus. The hardness of the annealed TiNb–Zr–Ta(N) coating only decreased slightly due to the small oxide layer of ∼140 nm. Compared with the uncoated Ti–6Al–4V, TiNb–Zr–Ta serial coatings deposited on abutment screws had higher removal torques, which prevented the abutment screw of dental implant from loosening after long-term use. The biocompatibility of TiNb–Zr–Ta serial coatings was similar to that of the uncoated Ti–6Al–4V. In addition, the oxidized TiNb–Zr–Ta and TiNb–Zr–Ta(N) coatings had excellent antibacterial properties. It is speculated that the resulting Ta 2 O 5 of both coatings may inhibit bacterial growth and improve the antibacterial effect. Based on the above advantages, the TiNb–Zr–Ta serial coatings are expected to have the potential to be applied to biomedical implants. • TiNb–Zr–Ta and nitrogen-doped TiNb–Zr–Ta coatings were obtained by co-deposition of Ta, Zr and TiNb targets. • After annealing, oxide phases were formed on the surface of TiNb–Zr–Ta and nitrogen-doped TiNb–Zr–Ta. • All coatings fabricated provided good biocompatibility similar to Ti–6Al–4V alloy. • Annealed coatings with Ta 2 O 5 on the surface possessed good antibacterial effect. • The highest removal torque was obtained for the abutment screw coated with TiNbZrTa. [ABSTRACT FROM AUTHOR]

A cathodic-arc evaporation system with plasma-enhanced duct equipment was used to deposit TiZrN, TiZrCN, and TiZr/a-C coatings. Reactive gases (N 2 and C 2 H 2 ) activated by the Ti and Zr plasma in the evaporation process was used to deposit the TiZrCN and TiZr/a-C coatings with different C and nitrogen contents. The crystalline structures and bonding states of coatings were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. The microbial activity of the coatings was evaluated against Staphylococcus aureus (Gram-positive bacteria) and Actinobacillus actinomycetemcomitans (Gram-negative bacteria) by in vitro antibacterial analysis using a fluorescence staining method employing SYTO9 and a bacterial-viability test on an agar plate. The cell compatibility and morphology related to CCD-966SK cell-line human skin fibroblast cells on the coated samples were also determined using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, reverse-transcriptase-polymerase chain reaction, and scanning electron microscopy. The results suggest that the TiZrCN coatings not only possess better antibacterial performance than TiZrN and TiZr/a-C coatings but also maintain good compatibility with human skin fibroblast cells. [ABSTRACT FROM AUTHOR]

The surface characteristics of biomaterials play an important role in their interaction with biological systems. Tantalum (Ta) oxides and their coatings have been proved to increase their applications in the biomedical fields such as medical devices and dental implants by improving their osseointegration and corrosion resistance. In this study, Ta and amorphous tantalum oxide coatings were deposited by using magnetron sputtering. A hydrophilic crystalline β-Ta 2 O 5 coating was obtained by rapid thermal annealing of the deposited tantalum oxide coating at 700 °C. In this study, Staphylococcus aureus and Actinobacillus actinomycetemcomitans ( A. actinomycetemcomitans ) are Gram-positive and Gram-negative bacteria, respectively, that exhibit physiological commensalism on the human skin and oral areas. Both bacteria were chosen as the model for in vitro anti-bacterial analyses by a fluorescence staining method employing Syto9. The cytocompatibility of human skin fibroblast cells (CCD-966SK) on the coatings was also determined using an MTT assay. It showed that the amorphous tantalum oxide coatings possessed good antibacterial performance, while the hydrophilic crystalline tantalum oxide coatings exhibited outperformed human skin fibroblast cellular biocompatibility. [ABSTRACT FROM AUTHOR]

Abstract: This study used a twin-gun magnetron sputtering system to deposit ZrO2-silver (Ag) coatings on biograde pure-titanium implant materials, and the Ag content in the deposited coatings was controlled by the magnetron power. The films were then annealed using rapid thermal annealing at 350°C for 2min to induce the nucleation and growth of nanoparticles on the film surface. Staphylococcus aureus (S. aureus) and Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) were used for in vitro antibacterial analyses. The cytocompatibility, mRNA expression, and adhesive morphology of human gingival fibroblast (HGF) cells on the coatings were also determined. The obtained results suggest that ZrO2-Ag composite coatings containing less than 10.6at.% Ag show hydrophobicity, good viability and proliferation of HGF cells, and antibacterial effects on S. aureus and A. actinomycetemcomitans. Moreover, the antibacterial performance of ZrO2-Ag coatings is superior to that pure-titanium whilst maintaining biological compatibility. [Copyright &y& Elsevier]

Abstract: Composite metal nitride–metal (MeN–Me) physical vapor deposited (PVD) films (e.g. TaN–Cu, TiN–Cu, ZrN–Ag, etc.) are often considered for applications such as tribological and antibacterial coatings. In this study, ZrN, ZrO2–Ag and ZrNO–Ag coatings with different Ag contents were deposited by reactive magnetron sputtering. Monoclinic ZrO2 and fcc Ag composite structures were obtained when Zr and Ag were cosputtered to react with oxygen. ZrNO–Ag showed a porous structure containing monoclinic ZrO2, fcc Ag and Zr2ON2. Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) and Staphylococcus aureus (S. aureus), major pathogens frequently found in the implant-associated infections, were cultured on the coated samples. The antibacterial effects were determined using in vitro anti-bacterial analyses by a fluorescence staining method employing Syto9 and bacterial viability agar tests. In addition, the biocompatibility of human gingival fibroblast (HGF) cells on coatings was also evaluated by a MTT test assay. It showed that the nanostructure and Ag content of the ZrO2–Ag and ZrNO–Ag coatings were correlated with the biocidal property. The ZrN coating deposited by magnetron sputtering did not improve the bacterial reduction of A. actinomycetemcomitans and S. aureus. The ZrO2–Ag and ZrNO–Ag coated samples had lower bacterial retention, and the ZrNO–Ag coatings with silver content of 11.8at.% possessed the best antibacterial performance with excellent HGF cell compatibility as well. [Copyright &y& Elsevier]

Abstract: Bacterial adhesion and colonization are considered to play key roles in the pathogenesis of peri-implant disease, which is an inflammatory process leading the destruction of both soft and hard tissue around a Titanium (Ti) implant. The osseointegration of Ti implants is influenced by their composition and surface treatment. Zirconia (ZrO2) coatings have been shown to improve implant osseointegration in various biomedical fields, including orthopedic devices and dental implants. This study used a twin-gun magnetron sputtering system to deposit ZrO2–Sliver (Ag) and ZrO2–Copper (Cu) coatings on biograde pure-Ti implant materials. The effects of Ag and Cu on the antibacterial properties of the coated Ti samples were investigated using Staphylococcus aureus (S. aureus) and Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), which are found frequently in implant-associated infections. The in vitro antibacterial analyses employed a fluorescence staining method using SYTO9 and bacterial-viability tests on agar plates. Incorporating Ag and Cu into ZrO2 changed the structure of crystalline ZrO2, and the nanostructures of the resulting ZrO2–Ag and ZrO2–Cu coatings were found to be correlated with the antibacterial performance. The adherence of S. aureus and A. actinomycetemcomitans was less for ZrO2 samples with a small doping of Cu than for uncoated Ti. The ZrO2–Ag coating with an Ag content of 10.6at.%, which showed hydrophobicity, exhibited the lowest bacterial retention and viability of S. aureus and A. actinomycetemcomitans. The results suggest that ZrO2–Ag and ZrO2–Cu coatings improve the antibacterial performance relative to pure-Ti implant materials. [Copyright &y& Elsevier]

Abstract: Titanium-based materials have been used for dental implants due to their excellent biological compatibility, superior mechanical strength and high corrosion resistance. The osseointegration of titanium dental implants is related to their composition and surface treatment. A better anti-bacterial performance of the abutment seated in the prosthetic crown is beneficial for the osseointegration and for avoiding the infection after implantation surgery. In this study, TaN-Ag coatings with different Ag contents were deposited on a bio-grade pure Ti dental implant material. A twin-gun magnetron sputtering system was used for the deposition of TaN-Ag coatings. The Ag content in the deposited coatings was controlled by the magnetron power ratio of Ag/(Ta+Ag) targets. To verify the susceptibility of implant surface to bacterial adhesion, Staphylococcus aureus, one of the major pathogen frequently found in the implant-associated infections, was chosen for in vitro anti-bacterial analyses. In addition, the biocompatibility of human gingival fibroblast (HGF) cells on coatings was also evaluated. A composite structure of crystalline TaN and Ag nanoparticles was identified. The TaN-Ag coating with the highest Ag content of 21.4at.% possessed the lowest bacterial retention and viability of S. aureus. From the MTT assay test, the mean optical density values for the TaN and TaN-Ag coated samples after 72h of HGF adhesion were greater than the value obtained from the uncoated Ti. The results suggested that the TaN-Ag coatings improve antibacterial performance with compatible biological response. [ABSTRACT FROM AUTHOR]

Abstract: Experiment with rapid prototyping technique and validation finite element model was performed to evaluate the biomechanical behavior of an immediately loaded mandibular implant. Also, 18 finite element models of six implant designs and three surface roughnesses with anisotropic bone material properties were analyzed to compare the bone stresses and the sliding at the bone–implant interface under a vertical or lateral force of 130N. The results show that bone stress (strain) of an immediately loaded implant is heavily dependent on the implant design and surface roughness. Improving the initial interfacial interlocking using a threaded implant has a higher priority than using cylindrical or step designs with a rough surface for an immediately loaded implant. [Copyright &y& Elsevier]

Abstract: This study attempted to estimate the elastic modulus of cortical specimens directly from the computed tomography (CT) number (CT). Cubic specimens of fresh bovine femora were tested under compressive loading. The corresponding three-dimensional mesh models of these specimens were established with the aid of CT images. The elastic modulus of each element was determined using the following transfer formula: E=A×(CT)B. The A and B were determined by matching the simulation results with the experimental force–displacement curves. An optimization approach was used to match the entire specimen sets between simulations and experiments. The results indicated that the elastic modulus of cortical bone can be effectively estimated using a power relationship (E=1.26×10−3×(CT)1.93) directly from the CT number. This procedure eliminates the need to determine the bone density, and therefore reduces the computational time required to define mechanical properties in finite element methods. [Copyright &y& Elsevier]

Abstract: Objectives: This study investigated the surrounding bone stress and the implant–bone interfacial sliding of implant designs and implant sizes of immediately loaded implant with maxillary sinus augmentation by using three-dimensional (3D) non-linear finite element (FE) analysis. Methods: Twenty-four FE models including four implant designs (cylindrical, threaded, stepped and step-thread implants) and three implant dimensions (standard, long and wide threaded implants) with a bonded and three levels of frictional contact of implant–bone interfaces were analyzed. The maxillary model was constructed from computer tomography (CT) images of a human skull and all 3D implant models were created via the computer-aided design (CAD) software. Results: The use of threaded implants decreased the bone stress and sliding distance obviously about 30% as compared with non-threaded (cylindrical and stepped) implants. Increasing the implant''s length or diameter reduced the bone stress by 13–26%. Employing a immediately loaded implant with smooth machine surface (μ =0.3, μ represents frictional coefficient) increased the bone stress by 28–63% as compared with the osseointegrated (bonded interfaces) implants. Roughening the implant surface (μ >0.3) did not reduced the bone stress, however it did decrease the interfacial sliding between implant and bone. Conclusions: For an immediately loaded implant placed with sinus augmentation, using threaded implant could decrease both the bone stress and implant–bone sliding distance which may improve the implant initial stability and long-term survival. Rough surface of implants shows no benefit to reduce the bone stress but they could lower the interfacial sliding. On the contrary, employing long or wide implants decrease the bone stress but they cannot diminish the interfacial sliding. [Copyright &y& Elsevier]

In this study, amorphous tantalum oxide coatings were deposited onto the Ti substrate with and without plasma electrolytic oxidation (PEO)-pretreatment by using a high-powered impulse magnetron sputtering system. The antibacterial tests were conducted using Syto9 fluorescent dyes to study the antibacterial performance of Gram-positive (Staphylococcus aureus) and Gram-negative (Actinobacillus actinomycetemcomitans) bacteria. In vitro studies, the cell cytotoxicity and cell viability were evaluated with soft-tissue derived human skin fibroblasts and hard-tissue derived human osteosarcoma cells. The results of the antibacterial experiments revealed that both the Ta 2 O 5 and PEO-pretreated Ta 2 O 5 samples had superior antibacterial properties compared to the uncoated Ti samples. Cell viability analyses showed that the Ta 2 O 5 films with and without PEO pretreatment exhibited better cell growth compared to the Ti specimens in human skin fibroblasts and human osteosarcoma cells. The cell viability of PEO-pretreated Ta 2 O 5 films even two-fold higher than the Ti specimens in human osteosarcoma cells. In addition, no cytotoxicity was detected in both the Ta 2 O 5 and PEO-pretreated Ta 2 O 5 films. It concluded that porous Ta 2 O 5 film pretreated with PEO procedure possessed both great biocompatibility and antibacterial abilities. It might have highly potential to be a candidate for the surface materials of dental or orthopedic implants. • Amorphous Ta 2 O 5 are deposited by high-powered impulse magnetron sputtering. • The plasma electrolytic oxidation-pretreated Ta 2 O 5 has the highest hydrophilicity. • The Ta 2 O 5 coatings showed good antibacterial properties. • The cell viability of human skin fibroblasts is the highest for the Ta 2 O 5 coatings. • The MG-63 cell viability is the highest for the porous PEO-pretreated Ta 2 O 5 coatings. [ABSTRACT FROM AUTHOR]

Development of oxide films on metallic implants with a desirable combination of mechanical properties and biocompatibility can greatly improve its functionality and application to the medical implant field. The present work is aimed to fabricate titanium (Ti) or zirconium (Zr) oxide films with porous structures onto Ti substrates by micro-arc oxidation (MAO) procedure. Before the MAO treatment, a series of Ti Zr alloy films were deposited on polished pure Ti substrates using a cathodic arc deposition system with different deposition cathode current ratios of Zr/Ti. The post-MAO-treated surface layers were characterized for its composition, crystalline structure, bonding states, surface morphology, and wettability. The results showed that porous crystalline titanium and zirconium oxides were formed using the MAO treatment for the Ti Zr films. To evaluate the bioactivity, cell viability and gene expression of human osteosarcoma cell line (MG-63) and human skin fibroblast cell line (SKF) cultured on different Ti Zr oxide films were determined. The results of MTT tests showed that the higher cell viability of MG-63 and SKF cells was found in MAO-treated Ti Zr films with higher Zr content. Gene expression data by RT-PCR and agarose gel electrophoresis showed that MG-63 cells and SKF cells exhibited notable osteogenic gene expression, such as Runx2, ALP, Dlx-5, OCN, BMP-2 and BMPR1A. The cell adhesion-related genes, such as fibronectin, collagen types I and III, and laminin were also remarkably expressed in the gel imaging. It suggested that the MAO-treated Ti Zr films were suitable for bone tissue- or soft tissue-derived cell growth and differentiation. The design and fabrication of Ti Zr oxide films with specific composition and porous surface layer with MAO treatment may provide a better material environment for cell bonding, living, and differentiation in dental and orthopedic implants. [ABSTRACT FROM AUTHOR]

Abstract: Tantalum is considered a highly biocompatible metal with high corrosion resistance. Metal-doped amorphous carbon films are gaining interest as an effective surface modifier for medical devices. In this study, tantalum (Ta), TaC/amorphous carbon (a-C), and Ta-containing amorphous hydrogenated carbon films (Ta-C:H) were synthesized using a twin-gun magnetron sputtering system to improve biological properties and explore potential applications for surgical implants or devices. Reactive C2H2, activated by the tantalum plasma in the magnetron sputtering process, was used to deposit the Ta-C:H coatings. The deposited TaC/a-C coatings, in which TaC was embedded in the amorphous carbon matrix as a nanocomposite film, exhibited favorable cell viability of the human osteosarcoma cell line (MG-63), similar to uncoated titanium. Among the examined materials, Ta-C:H coatings exhibited the highest biocompatibility for WS1 human fetal skin fibroblast cells derived from soft tissues and demonstrated the highest biological performance. [Copyright &y& Elsevier]

Abstract: Titanium (Ti)-based materials have been used for dental and orthopedic implants because of their excellent biological compatibility, superior mechanical strength, and high corrosion resistance. The hypothesis of this present study was to manufacture the Zn-doped TiO2 layer possessing the biocompatibility and antibacterial ability on the surface of Ti specimens. TiO2, ZnO, and Ti(Zn)O2 coatings were deposited on polished pure Ti substrates using a cathodic arc deposition system. Murine osteoblasts (MC3T3-E1) and human Staphylococcus aureus (S. aureus) were cultured onto the surface with different deposited coatings, respectively. The biocompatibility was examined by cell viability and osteogenic gene expression. The antibacterial ability was determined by SYTO9 nucleic acid staining. A porous Zn-doped TiO2 coating was successfully produced. The ZnO exhibited a fibrous structure with nanorods showing a hydrophobic feature (contact angle approximately 89°). These material properties affected the following biological performance. The antibacterial testing found no apparent difference between the uncoated Ti plate and the TiO2 coating. However, significantly lower numbers of S. aureus were observed on ZnO and Ti(Zn)O2 coatings compared to that on the uncoated Ti. The biocompatible testing exhibited that TiO2 and Ti(Zn)O2 coatings enhanced greater cell viability and proliferation than the uncoated Ti plate and ZnO coating. The osteogenic gene expression of Dlx-5 and osterix also improved for the TiO2 and Ti(Zn)O2 coatings. However, a significant inhibition of cell viability was found for the ZnO coating. These findings suggested that the composite Ti(Zn)O2 coating with a lower content of Zn (7.6±1.3at.%) not only improved antibacterial activity, but also maintained the biocompatibility to bone cells. [Copyright &y& Elsevier]

Abstract: Titanium (Ti)-based materials have been used for dental/orthopedic implants due to their excellent biological compatibility, superior mechanical strength and high corrosion resistance. The osseointegration of Ti implants is related to their composition and surface treatment. Better biocompatibility and anti-bacterial performances of Ti implant are beneficial for the osseointegration and for avoiding the infection after implantation surgery. In this study, nanocomposite ZrCN/amorphous carbon (a-C) coatings with different carbon contents were deposited on a bio-grade pure Ti implant material. A cathodic-arc evaporation system with plasma enhanced duct equipment was used for the deposition of ZrCN/a-C coatings. Reactive gas (N2) and C2H2 activated by the zirconium plasma in the evaporation process were used to deposit the ZrCN/a-C coatings. To verify the susceptibility of implant surface to bacterial adhesion, Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), one of the major pathogen frequently found in the dental implant-associated infections, was chosen for in vitro anti-bacterial analyses. In addition, the biocompatibility of human gingival fibroblast (HGF) cells on coatings was also evaluated by a cell proliferation assay. The results suggested that the ZrCN/a-C coatings with carbon content higher than 12.7at.% can improve antibacterial performance with excellent HGF cell compatibility as well. [Copyright &y& Elsevier]

Abstract: One of the major causes of loosening of cementless acetabular cup implants is insufficient initial stability. This study used three-dimensional finite element models of the pelvis and acetabular components to investigate the effects of the number of screws, bone quality, and friction coefficient of the acetabular cup on the initial stability under normal walking. A commercially available hemispherical acetabular cup with five screw holes was used as the default model. The stiffness of the pelvis and the friction coefficient of the cup were systematically varied, within a realistic range, to assess the initial stability of the acetabular cup. The simulations showed that the inserted screws provide only a localized reduction in the relative micromotion between the cup and pelvis therefore inserting several screw closed together might not be useful. Changes in the pelvic stiffness have a non-linear effect on the initial stability of acetabular cup and the subchondral bone provides good support for fixation of the cementless cup. The friction coefficient of the acetabular cup plays a limited role, comparing with the factor of bone quality, in resisting relative micromotion in the cup–pelvis interface. [Copyright &y& Elsevier]

Abstract: One of the major causes inducing loosening in the cementless acetabular cup implanting is its insufficient initial stability. In this study, three-dimensional finite element models of the pelvis and acetabular components were developed to investigate the relationship between relative micromotion, initial stability, and screw fixation under six daily activity loadings. A commercial available hemispheric cup with five screw holes was used as the target acetabular cup. The simulation results showed that if screws were placed closed together, when the screw number increased from 1 to 5, the peak micromotion decreased less than 14%, from 126.5 to 108.8μm, while the stable region, micromotion less than 28μm, enlarged only by 40%, from 46.1% to 64.7%. However, if the screw could be placed near the cup rim, a single rim screw, 202.1μm micromotion, could provide better stability than that of four dome screws, 209.6μm micromotion, placed closed together. To conclude, multiple cup screws should be placed near cup rim and as separate as possible to enlarge the stable region and reduce the peak micromotion between cup and acetabulum. [Copyright &y& Elsevier]

This study reports a method for controlling loads on an in vivo dental implant and its application for the investigation of early loading versus delayed loading of dental implants. The method was developed for the purpose of studying an ongoing hypothesis that amounts to bone loss around dental implants are related to mechanical-mediated adaptation of the alveolar bone. Using a customized intra-oral hydraulic system, the daily loading over a dental implant has been completed and recorded for six Sinclair swine. Each pig had a 5-month duration implant loading. During the experiments (loading), no analgesic treatment was supplied. The mean of the in vivo daily loadings was confirmed through an in vitro bench test after each animal was euthanized. Variations of the averaged loading input among the six animals were smaller than 10%. Preliminary data produced by the model suggests that cervical bone loss is less for early loading than for delayed loading. The current system is expected to provide a useful load control model for the study of alveolar bone adaptation around dental implants in relation to various loadings. [Copyright &y& Elsevier]