Objective: To investigate implant stability using resonance frequency measurements of topographic... more Objective: To investigate implant stability using resonance frequency measurements of topographically changed and/or surface chemistry‐modified implants in rabbit bone.Material and methods: Six groups of microstructured, screw‐shaped titanium implants: two oxidized, cation‐incorporated experimental implants [Mg implants and MgMp implants with micropatterned thread flanges (80–150 μm wide and 60–70 μm deep)] and four commercially available clinical implants (TiUnite®, Osseotite®, SLA®, and TiOblast®) were installed in 10 rabbit tibia for 6 weeks. The surface properties of the implants were characterized in detail using several analytical techniques. Implant stability was measured using a resonance frequency analyzer (Osstell™).Results: Surface characterization of the implants revealed microstructured, moderately rough implant surfaces varying 0.7–1.4 μm in Sa (mean height deviation), but with clear differences in surface chemistry. After 6 weeks, all implants showed statistically significantly higher increases in implant stability. When compared with one another, MgMp implants showed the most significant mean implant stability quotient (ISQ) value relative to the others (P≤0.016). In terms of increment (ΔISQ) in implant stability, MgMp implants showed a significantly greater value as compared with Osseotite® (P≤0.005), TiOblast® (P≤0.005), TiUnite® (P≤0.005), SLA® (P≤0.007), and Mg implants (P≤0.012). In addition, transducer direction dependence of resonance frequency analysis (RFA) measurements was observed such that the differences in the mean ISQ values between longitudinal and perpendicular measurements were significant at implant placement (P≤0.004) and after 6 weeks (P≤0).Conclusion: The present study found that implant surface properties influence RFA measurements of implant stability. Surface chemistry‐modified titanium implants showed higher mean ISQ values than did topographically changed implants. In particular, cation (magnesium)‐incorporated micropatterns in MgMp implants may play a primary role in ΔISQ.
International Journal of Nanomedicine, Feb 1, 2010
TiO 2 nanotubes are fabricated on TiO 2 grit-blasted, screw-shaped rough titanium (ASTM grade 4) ... more TiO 2 nanotubes are fabricated on TiO 2 grit-blasted, screw-shaped rough titanium (ASTM grade 4) implants (3.75 × 7 mm) using potentiostatic anodization at 20 V in 1 M H 3 PO 4 + 0.4 wt.% HF. The growth behavior and surface properties of the nanotubes are investigated as a function of the reaction time. The results show that vertically aligned nanotubes of ≈700 nm in length, with highly ordered structures of ≈40 nm spacing and ≈15 nm wall thickness may be grown independent of reaction time. The geometrical properties of nanotubes increase with reaction time (mean pore size, pore size distribution [PSD], and porosity ≈90 nm, ≈40-127 nm and 45%, respectively for 30 minutes; ≈107 nm, ≈63-140 nm and 56% for one hour; ≈108 nm, ≈58-150 nm and 60% for three hours). It is found that the fluorinated chemistry of the nanotubes of F-TiO 2 , TiOF 2 , and F-Ti-O with F ion incorporation of ≈5 at.%, and their amorphous structure is the same regardless of the reaction time, while the average roughness (Sa) gradually decreases and the developed surface area (Sdr) slightly increases with reaction time. The results of studies on animals show that, despite their low roughness values, after six weeks the fluorinated TiO 2 nanotube implants in rabbit femurs demonstrate significantly increased osseointegration strengths (41 vs 29 Ncm; P = 0.008) and new bone formation (57.5% vs 65.5%; P = 0.008) (n = 8), and reveal more frequently direct bone/cell contact at the bone-implant interface by highresolution scanning electron microscope observations as compared with the blasted, moderately rough implants that have hitherto been widely used for clinically favorable performance. The results of the animal studies constitute significant evidence that the presence of the nanotubes and the resulting fluorinated surface chemistry determine the nature of the bone responses to the implants. The present in vivo results point to potential applications of the TiO 2 nanotubes in the field of bone implants and bone tissue engineering.
Surface oxide properties are regarded to be of great importance in establishing successful osseoi... more Surface oxide properties are regarded to be of great importance in establishing successful osseointegration of titanium implants. Despite a large number of theoretical questions on the precise role of oxide properties of titanium implants, current knowledge obtained from in vivo studies is lacking. The present study is designed to address two aspects. The ®rst is to verify whether oxide properties of titanium implants indeed in¯uence the in vivo bone tissue responses. The second, is to investigate what oxide properties underline such bone tissue responses. For these purposes, screw-shaped/turned implants have been prepared by electrochemical oxidation methods, resulting in a wide range of oxide properties in terms of: (i) oxide thickness ranging from 200 to 1000 nm, (ii) the surface morphology of barrier and porous oxide ®lm structures, (iii) micro pore con®guration ± pore sizes 5 8 mm by length, about 1:27 mm 2 to 2:1 mm 2 by area and porosity of about 12.7±24.4%, (iv) the crystal structures of amorphous, anatase and mixtures of anatase and rutile type, (v) the chemical compositions of TiO 2 and ®nally, (vi) surface roughness of 0.96±1.03 mm (Sa). These implant oxide properties were divided into test implant samples of Group II, III, IV and V. Control samples (Group I) were turned commercially pure titanium implants. Quantitative bone tissue responses were evaluated biomechanically by resonance frequency analysis (RFA) and removal torque (RT) test. Quantitative histomorphometric analyses and qualitative enzyme histochemical detection of alkaline (ALP) and acidic phosphatase (ACP) activities were investigated on cut and ground sections after six weeks of implant insertion in rabbit tibia. In essence, from the biomechanical and quantitative histomorphometric measurements we concluded that oxide properties of titanium implants, i.e. the oxide thickness, the microporous structure, and the crystallinity signi®cantly in¯uence the bone tissue response. At this stage, however, it is not clear whether oxide properties in¯uence the bone tissue response separately or synergistically.
International Journal of Periodontics & Restorative Dentistry, 2014
This assignment applies to all translations of the Work as well as to preliminary display/posting... more This assignment applies to all translations of the Work as well as to preliminary display/posting of the abstract of the accepted article in electronic form before publication. If any changes in authorship (order, deletions, or additions) occur after the manuscript is submitted, agreement by all authors for such changes must be on file with the Publisher. An author's name may be removed only at his/her written request. (Note: Material prepared by employees of the US government in the course of their official duties cannot be copyrighted.
Background: Titanium implants have been widely used clinically for various types of bone-anchored... more Background: Titanium implants have been widely used clinically for various types of bone-anchored reconstructions. A thin native oxide film, naturally formed on titanium implants contacts with bone tissue and has been considered to be of great importance for successful osseointegration. However, the precise role of surface oxide properties in the osseointegration process is not known in detail. Aims and Hypothesis: The overall aims of this thesis were (i) to develop anodic oxidation methods of titanium implants (paper 1), (ii) to characterize the surface properties of native and anodic oxides (paper 2) and (iii) to investigate if and which surface oxide properties will influence the bone tissue response. In vivo animal studies (papers 3-6) in the present thesis hypothesized that osseointegration would be reinforced by mechanical interlocking and chemical bonding between bone and implant surface. Mechanical interlocking is assumed to be associated with the surface roughness/ pore configurations, while chemical bonding is dependent on surface chemistry. Materials and Methods: Machined-turned commercially pure (c.p) titanium implants were used for controls. Test implants were prepared by electrochemical anodic oxidation at the galvanostatic mode in various electrolytes. We tested implants with enhanced oxide films achieved by micro arc oxidation (MAO) process in acetic acid as electrolyte. Other investigated electrolytes were sulphuric acid (S implants), phosphoric acid (P implants) and a calcium containing mixed electrolyte system (Ca implants). The surface oxide properties were analyzed in terms of the oxide thickness, chemical composition, pore configurations (pore size, pore size distribution, porosity), crystal structure and surface roughness by using different analytical techniques including X-ray Photoelectron Spectroscopy (XPS), Auger Electron Spectroscopy (AES), Scanning Electron Microscopy (SEM), thin-film X-ray diffractometry (TF-XRD), Raman spectroscopy and TopScan 3D®. Implants (n = 176) were inserted in the femur and tibia of mature New Zealand white rabbits (n = 22). The follow up time was 6 weeks. Bone tissue responses were evaluated with resonance frequency analysis (RFA), removal torque test (RTQ), qualitative histology, histomorphometrical quantifications and enzyme histochemistry of alkaline (ALP) and acidic phosphatase (ACP). Results: The electrochemical oxide growth behaviour was greatly dependent on the nature of the electrolytes employed, the current density, the electrolyte concentration, the electrolyte temperature, the agitation speed and the chemical composition of the titanium electrode. The MAO method at galvanostatic mode demonstrated systemic changes of surface oxide properties of titanium implants by controlling the mentioned electrochemical parameters. This provides an opportunity to investigate the effects of such oxide properties on the bone tissue response.Oxidized, microporous implants having oxide thicknesses of about 600, 800 and 1000 nm demonstrated significantly stronger bone responses as compared to nonporous implants with oxide thicknesses of 17 and 200 nm. Chemically modified S and P implants demonstrated significantly improved bone responses compared to controls. Calcium deposited, oxidized titanium implants showed the strongest bone responses of all tested implantsConclusions: Our findings indicated that osseointegration occurred from a combination of mechanical interlocking and biochemical bonding at least with respect to two tested implants, namely S and P implants. The faster and stronger osseointegration, particularly found with Ca implants may have clinical applications too
Purpose: This study was undertaken to investigate surface properties of surface-modified titanium... more Purpose: This study was undertaken to investigate surface properties of surface-modified titanium implants in terms of surface chemistry, morphology, pore characteristics, oxide thickness, crystal structure, and roughness. Materials and methods: An oxidized, custom-made Mg implant, an oxidized commercially available implant (TiUnite), and a dual acid-etched surface (Osseotite) were investigated. Surface characteristics were evaluated with various surface analytic techniques. Results: Surface chemistry showed similar fingerprints of titanium oxide and carbon contaminant in common for all implants but also revealed essential differences of the elements such as about 9 at% Mg for the Mg implant, about 11 at% P for the TiUnite implant and about 12 at% Na for the Osseotite implant. Surface morphology of the Mg and TiUnite implants demonstrated a duplex oxide structure, ie, an inner barrier layer without pores and an outer porous layer with numerous pores, whereas the Osseotite implant revealed a crystallographically etched appearance with pits. The diameter and depth of pores/pits was < or = 2 microm and < or = 1.5 microm in the Mg implant, < or = 4 microm and < or = 10 microm in the TiUnite implant, and < or = 2 microm and < or = 1 microm in the Osseotite implant, respectively. Oxide layer revealed homogeneous thickness, about 3.4 microm of all threads in the Mg implants. On the contrary, TiUnite showed heterogeneous oxide thickness, about 1 to 11 microm, which gradually increased with thread numbers. Crystal structure showed a mixture of anatase and rutile phase for the Mg implants. With respect to roughness, Sa showed 0.69 microm in the Mg implant, 1.35 microm in the TiUnite implant, and 0.72 microm in the Osseotite implant. Conclusions: Well-defined surface characterization may provide a scientific basis for a better understanding of the effects of the implant surface on the biological response. The surface-engineered implants resulted in various surface characteristics, as a result of different manufacturing techniques.
Purpose: The aim was to answer a fundamental question: Do the chemical properties of titanium imp... more Purpose: The aim was to answer a fundamental question: Do the chemical properties of titanium implants influence osseointegration? Materials and methods: Screw-type implants produced of turned commercially pure (grade 1) titanium (controls) and electrochemically calcium-deposited titanium implants (Ca test implants) were placed in the tibiae and femora of a total of 10 mature New Zealand white rabbits. The macro arc oxidation method was applied for Ca implants. Surface oxides were characterized with different analytic techniques, including x-ray photoelectron spectroscopy, auger electron spectroscopy, scanning electron microscopy, thin-film x-ray diffractometry, and TopScan 3D. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. Results: After a follow-up period of 6 weeks, test Ca implants showed a significant increase in mean peak removal torque (P = .0001) and in the histomorphometric measurement of bone-to-metal contact around the implants (P = .028) in comparison to controls. In addition, more mature mineralized bone was observed adjacent to test Ca implants compared to controls, as evaluated on 10-microm undecalcified, toluidine blue-stained, cut, and ground sections. Discussion: The potential role of surface Ca chemistry to a superior bone response is discussed with specific reference to interaction with Ca(+)-binding proteins and function as binding sites of calcium phosphate mineral. Conclusion: The present results suggest that the surface chemical composition of titanium implants is of great importance for the bone response. Ca ion-deposited titanium implants showed fast and strong osseointegration in the rabbit bone model.
Journal of Oral and Maxillofacial Research, Jul 25, 2010
Objectives: To observe the early adsorption of extracellular matrix and blood plasma proteins to ... more Objectives: To observe the early adsorption of extracellular matrix and blood plasma proteins to magnesium-incorporated titanium oxide surfaces, which has shown superior bone response in animal models. Material and Methods: Commercially pure titanium discs were blasted with titanium dioxide (TiO 2) particles (control), and for the test group, TiO 2 blasted discs were further processed with a micro-arc oxidation method (test). Surface morphology was investigated by scanning electron microscopy, surface topography by optic interferometry, characterization by X-ray photoelectron spectroscopy (XPS), and by X-ray diffraction (XRD) analysis. The adsorption of 3 different proteins (fibronectin, albumin, and collagen type I) was investigated by an immunoblotting technique. Results: The test surface showed a porous structure, whereas the control surface showed a typical TiO 2 blasted structure. XPS data revealed magnesium-incorporation to the anodic oxide film of the surface. There was no difference in surface roughness between the control and test surfaces. For the protein adsorption test, the amount of albumin was significantly higher on the control surface whereas the amount of fibronectin was significantly higher on the test surface. Although there was no significant difference, the test surface had a tendency to adsorb more collagen type I. Conclusions: The magnesium-incorporated anodized surface showed significantly higher fibronectin adsorption and lower albumin adsorption than the blasted surface. These results may be one of the reasons for the excellent bone response previously observed in animal studies.
Purpose: To investigate detailed surface characterization of oxidized implants in a newly invente... more Purpose: To investigate detailed surface characterization of oxidized implants in a newly invented electrolyte system and to determine optimal surface oxide properties to enhance the bone response in rabbits. Materials and methods: A total of 100 screw-type titanium implants were prepared and divided into 1 control group (machine-turned implants) and 4 test groups (magnesium ion-incorporated oxidized implants). Forty implants were used for surface analyses. A total of 60 implants, 12 implants from each group, were placed in the tibiae of 10 New Zealand white rabbits and measured with a removal torque test after a healing period of 6 weeks. Results: For the test groups, the oxide thicknesses ranged from about 1,000 to 5,800 nm; for the control group, mean oxide thickness was about 17 nm. The surface morphology showed porous structures for test groups and nonporous barrier film for the control group. Pore diameter ranged from < or = 0.5 microm to < or = 3.0 microm. In regard to surface roughness, arithmetic average height deviation (Sa) values varied from 0.68 to 0.98 microm for test implants and 0.55 microm for control implants; developed surface ratio (Sdr) values ranged from 10.6% to 46% for the test groups and were about 10.6% for the control group. A mixture of anatase and rutile-type crystals were observed in the test groups; amorphous-type crystals were observed in the control group. After a healing period of 6 weeks, removal torque measurements in all 4 test groups demonstrated significantly greater implant integration as compared to machine-turned control implants (P < or = .033). Discussion: Determinant oxide properties of oxidized implants are discussed in association with bone responses. Of all surface properties, RTVs were linearly increased as relative atomic concentrations of magnesium ion increase. Conclusions: Surface properties of the oxidized implants in the present study, especially surface chemistry, influenced bone responses. The surface chemistry of the optimal oxidized implant should be composed of approximately 9% magnesium at relative atomic concentration in titanium oxide matrix and have an oxide thickness of approximately 1,000 to 5,000 nm, a porosity of about 24%, and a surface roughness of about 0.8 microm in Sa and 27% to 46% in Sdr; its oxide crystal structure should be a mixture of anatase- and rutile-phase crystals.
Research projects focusing on biomaterials related factors; the bulk implant material, the macro-... more Research projects focusing on biomaterials related factors; the bulk implant material, the macro-design of the implant and the microsurface roughness are routinely being conducted at our laboratories. In this study, we have investigated the bone tissue reactions to turned commercially pure (c.p.) titanium implants with various thicknesses of the oxide films after 6 weeks of insertion in rabbit bone. The control c.p. titanium implants had an oxide thickness of 17-200 nm while the test implants revealed an oxide thickness between 600 and 1000 nm. Routine histological investigations of the tissue reactions around the implants and enzyme histochemical detections of alkaline and acid phosphatase activities demonstrated similar findings around both the control and test implants. In general, the histomorphometrical parameters (bone to implant contact and newly formed bone) revealed significant quantitative differences between the control and test implants. The test implants demonstrated a greater bone response histomorphometrically than control implants and the osteoconductivity was more pronounced around the test implant surfaces. The parameters that differed between the implant surfaces, i.e. the oxide thickness, the pore size distribution, the porosity and the crystallinity of the surface oxides may represent factors that have an influence on the histomorphometrical results indicated by a stronger bone tissue response to the test implant surfaces, with an oxide thickness of more than 600 nm.
To apply a new statistical method (principle component analysis; PCA) to evaluate osseointegratio... more To apply a new statistical method (principle component analysis; PCA) to evaluate osseointegration. Two different commercially available implants were selected for the study. Twenty implants, 10 of each type, were placed in the rabbit tibiae (n = 10). The fluorochromes (FLCs) alizarin complexone and calcein green were administered after 20 days and 4 days before sacrifice for labeling. On the day of implantation and retrieval (6 weeks), implant stability was measured with a resonance frequency analyzer (RFA). The retrieved samples were ground sectioned for histomorphometric and FLC quantification. The collected data were analyzed by a PCA software program (Qlucore Omics Explorer, Lund, Sweden) to explore and determine the correlation between different study variables and to analyze the differences between different implants. The RFA presented no significant differences at either time point. The bone-to-implant contact was significantly higher for the TiUnite (NobelBiocare, Gothenburg, Sweden); however, the bone area and FLC quantification showed higher values for the Osseotite (3i Implant Innovation, FL). Consistent with these results, the PCA indicated a strong correlation between TiUnite and high bone-to-implant contact values and between Osseotite and high bone area and FLC values. No correlation between RFA and the biological responses were found. The application of the PCA analysis may help interpret and correlate results obtained from numerous evaluations.
Journal of Materials Science: Materials in Medicine, Mar 17, 2015
To investigate in vitro cellular cytokine expression in relation to commercially pure titanium di... more To investigate in vitro cellular cytokine expression in relation to commercially pure titanium discs, comparing a native surface to a fluorinated oxide nanotube surface. Control samples pure titanium discs with a homogenous wave of the margins and grooves and an often smeared-out surface structure. Test samples pure titanium discs with a fluorinated titanium oxide chemistry and surface morphology with nanopore/tube geometry characterized by ordered structures of nanotubes with a diameter of &120 nm, a spacing of &30 nm, and a wall thickness of &10 nm. Cross-section view showed vertically aligned nanotubes with similar lengths of &700 nm. Peripheral blood mononuclear leucocytes were cultured for 1, 3, and 6 days according to standard procedures. BioPlex Pro TM assays were used for analysis and detection of cytokines. Selected inflammatory cytokines are reported. A pronounced difference in production of the inflammatogenic cytokines was observed. Leucocytes exposed to control coins produced significantly more TNF-a, IL-1ß, and IL-6 than the test nanotube coins. The effect on the T H 2 cytokine IL-4 was less pronounced at day 6 compared to days 1 and 3, and slightly higher expressed on the control coins. The morphology and surface chemistry of the titanium surface have a profound impact on basic cytokine production in vitro. Within the limitations of the present study, it seems that the fluorinated oxide nanotube surface results in a lower inflammatory response compared to a rather flat surface that seems to favour inflammation.
Clinical Implant Dentistry and Related Research, Dec 1, 2006
Background: The current hard tissue implants research aims to accelerate bone healing by designin... more Background: The current hard tissue implants research aims to accelerate bone healing by designing surfaces that are bioactive. However, the role of the inflammatory response to these surfaces is so far incompletely described.
Clinical Implant Dentistry and Related Research, Jul 1, 2004
Background: In oral implantology there has been a general trend away from machine-turned minimall... more Background: In oral implantology there has been a general trend away from machine-turned minimally rough and acidetched and blasted implants toward intermediary roughened surfaces. Mechanical interlocking at micron resolution is claimed to be the dominant reason for the fixation of such implants in bone. However, clinical demands for stronger and faster bone bonding to the implant (eg, in immediately loaded and compromised bone cases) have motivated the development of novel surfaces capable of chemical bonding. Purpose: The purpose of the present study is to investigate bone tissue reactions to a newly developed calciumincorporated oxidized implant. The specific aim is to assess the effect of calcium surface chemistry on the bone response. Materials and Methods: Calcium (Ca) ion-incorporated implants were prepared by micro arc oxidation methods. Surface oxide properties were characterized by using various surface analytic techniques involving scanning electron microscopy, x-ray diffractometry, x-ray photoelectron spectroscopy, and optical interferometry. Twenty screw-shaped commercially pure (CP) titanium implants (10 turned implants [controls] and 10 Ca-incorporated implants [tests]) were inserted in the femoral condyles of 10 New Zealand White rabbits. Results: After a healing period of 6 weeks, resonance frequency analyses and removal torque measurements of the Caincorporated oxidized implants demonstrated statistically significant improvements of implant integration with bone in comparison to machine-turned control implants (p = 0.013 and p = 0.005, respectively). Conclusions: The Ca-reinforced surface chemistry of the oxidized implants significantly improved bone responses in a rabbit model. The present study suggests that biochemical bonding at the bone-implant interface, in combination with mechanical interlocking, may play a dominant role in the fixation of Ca-incorporated oxidized implants in bone. The observed rapid and strong integration of test Ca implants may have clinical implications for immediate or early loading and improved performance in compromised bone.
: The present experimental study was designed to address two issues. The first was to investigate... more : The present experimental study was designed to address two issues. The first was to investigate whether oxide properties of titanium implants influenced bone tissue responses after an in vivo implantation time of six weeks. If such a result was found, the second aim was to investigate which oxide properties are involved in such bone tissue responses. Screw‐shaped implants with a wide range of oxide properties were prepared by electrochemical oxidation methods, where the oxide thickness varied in the range of 200 nm to 1000 nm. The surface morphology was prepared in two substantially different ways, i.e. barrier and porous oxide film structures. The micropore structure revealed pore sizes of 8 μm in diameter, with a range in opening area from 1.27 μm2 to 2.1 μm2. Porosity ranged from 12.7% to 24.4%. The crystal structures of the titanium oxide were amorphous, anatase and a mixture of anatase and rutile type. The chemical compositions consisted mainly of TiO2. Surface roughness ranged from 0.96 μm to 1.03 μm (Sa). Each group of test samples showed its own, defined status with respect to these various parameters. The oxide properties of turned commercially pure titanium implants were used in the control group, which was characterized by an oxide thickness of 17.4 ± 6.2 nm, amorphous type in crystallinity, TiO2 in chemical composition, and a surface roughness of 0.83 μm (Sa). Bone tissue responses were evaluated by resonance frequency measurements and removal torque tests that were undertaken six weeks after implant insertion in rabbit tibia. Implants that had an oxide thickness of approximately 600, 800 and 1000 nm demonstrated significantly stronger bone responses in the evaluation of removal torque values than did implants that had an oxide thickness of approximately 17 and 200 nm (P &lt; 0.05). However, there were no difference between implants with oxide thicknesses of 17 and 200 nm (P = 0.99). It was concluded that oxide properties of titanium implants, which include oxide thickness, micropore configurations and crystal structures, greatly influence the bone tissue response in the evaluation of removal torque values. However, it is not fully understood whether these oxide properties influence the bone tissue response separately or synergistically.
Journal of the Royal Society Interface, Apr 15, 2009
Quantifying the in vivo interfacial biochemical bond strength of bone implants is a biological ch... more Quantifying the in vivo interfacial biochemical bond strength of bone implants is a biological challenge. We have developed a new and novel in vivo method to identify an interfacial biochemical bond in bone implants and to measure its bonding strength. This method, named biochemical bond measurement (BBM), involves a combination of the implant devices to measure true interfacial bond strength and surface property controls, and thus enables the contributions of mechanical interlocking and biochemical bonding to be distinguished from the measured strength values. We applied the BBM method to a rabbit model, and observed great differences in bone integration between the oxygen (control group) and magnesium (test group) plasma immersion ion-implanted titanium implants (0.046 versus 0.086 MPa, nZ10, pZ0.005). The biochemical bond in the test implants resulted in superior interfacial behaviour of the implants to bone: (i) close contact to approximately 2 mm thin amorphous interfacial tissue, (ii) pronounced mineralization of the interfacial tissue, (iii) rapid bone healing in contact, and (iv) strong integration to bone. The BBM method can be applied to in vivo experimental models not only to validate the presence of a biochemical bond at the bone-implant interface but also to measure the relative quantity of biochemical bond strength. The present study may provide new avenues for better understanding the role of a biochemical bond involved in the integration of bone implants.
Ten-year results for Branemark implants immediately loaded with fixed prostheses at implant place... more Ten-year results for Branemark implants immediately loaded with fixed prostheses at implant placement. Int J Oral Maxillofac Implants 1997;12:495-503. 19.Tselios N, Parel SM, Jones JD. Immediate placement and immediate provisional abutment modeling in anterior single-tooth implant restorations using a CAD/CAM application: a clinical report.
Objective: To investigate implant stability using resonance frequency measurements of topographic... more Objective: To investigate implant stability using resonance frequency measurements of topographically changed and/or surface chemistry‐modified implants in rabbit bone.Material and methods: Six groups of microstructured, screw‐shaped titanium implants: two oxidized, cation‐incorporated experimental implants [Mg implants and MgMp implants with micropatterned thread flanges (80–150 μm wide and 60–70 μm deep)] and four commercially available clinical implants (TiUnite®, Osseotite®, SLA®, and TiOblast®) were installed in 10 rabbit tibia for 6 weeks. The surface properties of the implants were characterized in detail using several analytical techniques. Implant stability was measured using a resonance frequency analyzer (Osstell™).Results: Surface characterization of the implants revealed microstructured, moderately rough implant surfaces varying 0.7–1.4 μm in Sa (mean height deviation), but with clear differences in surface chemistry. After 6 weeks, all implants showed statistically significantly higher increases in implant stability. When compared with one another, MgMp implants showed the most significant mean implant stability quotient (ISQ) value relative to the others (P≤0.016). In terms of increment (ΔISQ) in implant stability, MgMp implants showed a significantly greater value as compared with Osseotite® (P≤0.005), TiOblast® (P≤0.005), TiUnite® (P≤0.005), SLA® (P≤0.007), and Mg implants (P≤0.012). In addition, transducer direction dependence of resonance frequency analysis (RFA) measurements was observed such that the differences in the mean ISQ values between longitudinal and perpendicular measurements were significant at implant placement (P≤0.004) and after 6 weeks (P≤0).Conclusion: The present study found that implant surface properties influence RFA measurements of implant stability. Surface chemistry‐modified titanium implants showed higher mean ISQ values than did topographically changed implants. In particular, cation (magnesium)‐incorporated micropatterns in MgMp implants may play a primary role in ΔISQ.
International Journal of Nanomedicine, Feb 1, 2010
TiO 2 nanotubes are fabricated on TiO 2 grit-blasted, screw-shaped rough titanium (ASTM grade 4) ... more TiO 2 nanotubes are fabricated on TiO 2 grit-blasted, screw-shaped rough titanium (ASTM grade 4) implants (3.75 × 7 mm) using potentiostatic anodization at 20 V in 1 M H 3 PO 4 + 0.4 wt.% HF. The growth behavior and surface properties of the nanotubes are investigated as a function of the reaction time. The results show that vertically aligned nanotubes of ≈700 nm in length, with highly ordered structures of ≈40 nm spacing and ≈15 nm wall thickness may be grown independent of reaction time. The geometrical properties of nanotubes increase with reaction time (mean pore size, pore size distribution [PSD], and porosity ≈90 nm, ≈40-127 nm and 45%, respectively for 30 minutes; ≈107 nm, ≈63-140 nm and 56% for one hour; ≈108 nm, ≈58-150 nm and 60% for three hours). It is found that the fluorinated chemistry of the nanotubes of F-TiO 2 , TiOF 2 , and F-Ti-O with F ion incorporation of ≈5 at.%, and their amorphous structure is the same regardless of the reaction time, while the average roughness (Sa) gradually decreases and the developed surface area (Sdr) slightly increases with reaction time. The results of studies on animals show that, despite their low roughness values, after six weeks the fluorinated TiO 2 nanotube implants in rabbit femurs demonstrate significantly increased osseointegration strengths (41 vs 29 Ncm; P = 0.008) and new bone formation (57.5% vs 65.5%; P = 0.008) (n = 8), and reveal more frequently direct bone/cell contact at the bone-implant interface by highresolution scanning electron microscope observations as compared with the blasted, moderately rough implants that have hitherto been widely used for clinically favorable performance. The results of the animal studies constitute significant evidence that the presence of the nanotubes and the resulting fluorinated surface chemistry determine the nature of the bone responses to the implants. The present in vivo results point to potential applications of the TiO 2 nanotubes in the field of bone implants and bone tissue engineering.
Surface oxide properties are regarded to be of great importance in establishing successful osseoi... more Surface oxide properties are regarded to be of great importance in establishing successful osseointegration of titanium implants. Despite a large number of theoretical questions on the precise role of oxide properties of titanium implants, current knowledge obtained from in vivo studies is lacking. The present study is designed to address two aspects. The ®rst is to verify whether oxide properties of titanium implants indeed in¯uence the in vivo bone tissue responses. The second, is to investigate what oxide properties underline such bone tissue responses. For these purposes, screw-shaped/turned implants have been prepared by electrochemical oxidation methods, resulting in a wide range of oxide properties in terms of: (i) oxide thickness ranging from 200 to 1000 nm, (ii) the surface morphology of barrier and porous oxide ®lm structures, (iii) micro pore con®guration ± pore sizes 5 8 mm by length, about 1:27 mm 2 to 2:1 mm 2 by area and porosity of about 12.7±24.4%, (iv) the crystal structures of amorphous, anatase and mixtures of anatase and rutile type, (v) the chemical compositions of TiO 2 and ®nally, (vi) surface roughness of 0.96±1.03 mm (Sa). These implant oxide properties were divided into test implant samples of Group II, III, IV and V. Control samples (Group I) were turned commercially pure titanium implants. Quantitative bone tissue responses were evaluated biomechanically by resonance frequency analysis (RFA) and removal torque (RT) test. Quantitative histomorphometric analyses and qualitative enzyme histochemical detection of alkaline (ALP) and acidic phosphatase (ACP) activities were investigated on cut and ground sections after six weeks of implant insertion in rabbit tibia. In essence, from the biomechanical and quantitative histomorphometric measurements we concluded that oxide properties of titanium implants, i.e. the oxide thickness, the microporous structure, and the crystallinity signi®cantly in¯uence the bone tissue response. At this stage, however, it is not clear whether oxide properties in¯uence the bone tissue response separately or synergistically.
International Journal of Periodontics & Restorative Dentistry, 2014
This assignment applies to all translations of the Work as well as to preliminary display/posting... more This assignment applies to all translations of the Work as well as to preliminary display/posting of the abstract of the accepted article in electronic form before publication. If any changes in authorship (order, deletions, or additions) occur after the manuscript is submitted, agreement by all authors for such changes must be on file with the Publisher. An author's name may be removed only at his/her written request. (Note: Material prepared by employees of the US government in the course of their official duties cannot be copyrighted.
Background: Titanium implants have been widely used clinically for various types of bone-anchored... more Background: Titanium implants have been widely used clinically for various types of bone-anchored reconstructions. A thin native oxide film, naturally formed on titanium implants contacts with bone tissue and has been considered to be of great importance for successful osseointegration. However, the precise role of surface oxide properties in the osseointegration process is not known in detail. Aims and Hypothesis: The overall aims of this thesis were (i) to develop anodic oxidation methods of titanium implants (paper 1), (ii) to characterize the surface properties of native and anodic oxides (paper 2) and (iii) to investigate if and which surface oxide properties will influence the bone tissue response. In vivo animal studies (papers 3-6) in the present thesis hypothesized that osseointegration would be reinforced by mechanical interlocking and chemical bonding between bone and implant surface. Mechanical interlocking is assumed to be associated with the surface roughness/ pore configurations, while chemical bonding is dependent on surface chemistry. Materials and Methods: Machined-turned commercially pure (c.p) titanium implants were used for controls. Test implants were prepared by electrochemical anodic oxidation at the galvanostatic mode in various electrolytes. We tested implants with enhanced oxide films achieved by micro arc oxidation (MAO) process in acetic acid as electrolyte. Other investigated electrolytes were sulphuric acid (S implants), phosphoric acid (P implants) and a calcium containing mixed electrolyte system (Ca implants). The surface oxide properties were analyzed in terms of the oxide thickness, chemical composition, pore configurations (pore size, pore size distribution, porosity), crystal structure and surface roughness by using different analytical techniques including X-ray Photoelectron Spectroscopy (XPS), Auger Electron Spectroscopy (AES), Scanning Electron Microscopy (SEM), thin-film X-ray diffractometry (TF-XRD), Raman spectroscopy and TopScan 3D®. Implants (n = 176) were inserted in the femur and tibia of mature New Zealand white rabbits (n = 22). The follow up time was 6 weeks. Bone tissue responses were evaluated with resonance frequency analysis (RFA), removal torque test (RTQ), qualitative histology, histomorphometrical quantifications and enzyme histochemistry of alkaline (ALP) and acidic phosphatase (ACP). Results: The electrochemical oxide growth behaviour was greatly dependent on the nature of the electrolytes employed, the current density, the electrolyte concentration, the electrolyte temperature, the agitation speed and the chemical composition of the titanium electrode. The MAO method at galvanostatic mode demonstrated systemic changes of surface oxide properties of titanium implants by controlling the mentioned electrochemical parameters. This provides an opportunity to investigate the effects of such oxide properties on the bone tissue response.Oxidized, microporous implants having oxide thicknesses of about 600, 800 and 1000 nm demonstrated significantly stronger bone responses as compared to nonporous implants with oxide thicknesses of 17 and 200 nm. Chemically modified S and P implants demonstrated significantly improved bone responses compared to controls. Calcium deposited, oxidized titanium implants showed the strongest bone responses of all tested implantsConclusions: Our findings indicated that osseointegration occurred from a combination of mechanical interlocking and biochemical bonding at least with respect to two tested implants, namely S and P implants. The faster and stronger osseointegration, particularly found with Ca implants may have clinical applications too
Purpose: This study was undertaken to investigate surface properties of surface-modified titanium... more Purpose: This study was undertaken to investigate surface properties of surface-modified titanium implants in terms of surface chemistry, morphology, pore characteristics, oxide thickness, crystal structure, and roughness. Materials and methods: An oxidized, custom-made Mg implant, an oxidized commercially available implant (TiUnite), and a dual acid-etched surface (Osseotite) were investigated. Surface characteristics were evaluated with various surface analytic techniques. Results: Surface chemistry showed similar fingerprints of titanium oxide and carbon contaminant in common for all implants but also revealed essential differences of the elements such as about 9 at% Mg for the Mg implant, about 11 at% P for the TiUnite implant and about 12 at% Na for the Osseotite implant. Surface morphology of the Mg and TiUnite implants demonstrated a duplex oxide structure, ie, an inner barrier layer without pores and an outer porous layer with numerous pores, whereas the Osseotite implant revealed a crystallographically etched appearance with pits. The diameter and depth of pores/pits was < or = 2 microm and < or = 1.5 microm in the Mg implant, < or = 4 microm and < or = 10 microm in the TiUnite implant, and < or = 2 microm and < or = 1 microm in the Osseotite implant, respectively. Oxide layer revealed homogeneous thickness, about 3.4 microm of all threads in the Mg implants. On the contrary, TiUnite showed heterogeneous oxide thickness, about 1 to 11 microm, which gradually increased with thread numbers. Crystal structure showed a mixture of anatase and rutile phase for the Mg implants. With respect to roughness, Sa showed 0.69 microm in the Mg implant, 1.35 microm in the TiUnite implant, and 0.72 microm in the Osseotite implant. Conclusions: Well-defined surface characterization may provide a scientific basis for a better understanding of the effects of the implant surface on the biological response. The surface-engineered implants resulted in various surface characteristics, as a result of different manufacturing techniques.
Purpose: The aim was to answer a fundamental question: Do the chemical properties of titanium imp... more Purpose: The aim was to answer a fundamental question: Do the chemical properties of titanium implants influence osseointegration? Materials and methods: Screw-type implants produced of turned commercially pure (grade 1) titanium (controls) and electrochemically calcium-deposited titanium implants (Ca test implants) were placed in the tibiae and femora of a total of 10 mature New Zealand white rabbits. The macro arc oxidation method was applied for Ca implants. Surface oxides were characterized with different analytic techniques, including x-ray photoelectron spectroscopy, auger electron spectroscopy, scanning electron microscopy, thin-film x-ray diffractometry, and TopScan 3D. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. Results: After a follow-up period of 6 weeks, test Ca implants showed a significant increase in mean peak removal torque (P = .0001) and in the histomorphometric measurement of bone-to-metal contact around the implants (P = .028) in comparison to controls. In addition, more mature mineralized bone was observed adjacent to test Ca implants compared to controls, as evaluated on 10-microm undecalcified, toluidine blue-stained, cut, and ground sections. Discussion: The potential role of surface Ca chemistry to a superior bone response is discussed with specific reference to interaction with Ca(+)-binding proteins and function as binding sites of calcium phosphate mineral. Conclusion: The present results suggest that the surface chemical composition of titanium implants is of great importance for the bone response. Ca ion-deposited titanium implants showed fast and strong osseointegration in the rabbit bone model.
Journal of Oral and Maxillofacial Research, Jul 25, 2010
Objectives: To observe the early adsorption of extracellular matrix and blood plasma proteins to ... more Objectives: To observe the early adsorption of extracellular matrix and blood plasma proteins to magnesium-incorporated titanium oxide surfaces, which has shown superior bone response in animal models. Material and Methods: Commercially pure titanium discs were blasted with titanium dioxide (TiO 2) particles (control), and for the test group, TiO 2 blasted discs were further processed with a micro-arc oxidation method (test). Surface morphology was investigated by scanning electron microscopy, surface topography by optic interferometry, characterization by X-ray photoelectron spectroscopy (XPS), and by X-ray diffraction (XRD) analysis. The adsorption of 3 different proteins (fibronectin, albumin, and collagen type I) was investigated by an immunoblotting technique. Results: The test surface showed a porous structure, whereas the control surface showed a typical TiO 2 blasted structure. XPS data revealed magnesium-incorporation to the anodic oxide film of the surface. There was no difference in surface roughness between the control and test surfaces. For the protein adsorption test, the amount of albumin was significantly higher on the control surface whereas the amount of fibronectin was significantly higher on the test surface. Although there was no significant difference, the test surface had a tendency to adsorb more collagen type I. Conclusions: The magnesium-incorporated anodized surface showed significantly higher fibronectin adsorption and lower albumin adsorption than the blasted surface. These results may be one of the reasons for the excellent bone response previously observed in animal studies.
Purpose: To investigate detailed surface characterization of oxidized implants in a newly invente... more Purpose: To investigate detailed surface characterization of oxidized implants in a newly invented electrolyte system and to determine optimal surface oxide properties to enhance the bone response in rabbits. Materials and methods: A total of 100 screw-type titanium implants were prepared and divided into 1 control group (machine-turned implants) and 4 test groups (magnesium ion-incorporated oxidized implants). Forty implants were used for surface analyses. A total of 60 implants, 12 implants from each group, were placed in the tibiae of 10 New Zealand white rabbits and measured with a removal torque test after a healing period of 6 weeks. Results: For the test groups, the oxide thicknesses ranged from about 1,000 to 5,800 nm; for the control group, mean oxide thickness was about 17 nm. The surface morphology showed porous structures for test groups and nonporous barrier film for the control group. Pore diameter ranged from < or = 0.5 microm to < or = 3.0 microm. In regard to surface roughness, arithmetic average height deviation (Sa) values varied from 0.68 to 0.98 microm for test implants and 0.55 microm for control implants; developed surface ratio (Sdr) values ranged from 10.6% to 46% for the test groups and were about 10.6% for the control group. A mixture of anatase and rutile-type crystals were observed in the test groups; amorphous-type crystals were observed in the control group. After a healing period of 6 weeks, removal torque measurements in all 4 test groups demonstrated significantly greater implant integration as compared to machine-turned control implants (P < or = .033). Discussion: Determinant oxide properties of oxidized implants are discussed in association with bone responses. Of all surface properties, RTVs were linearly increased as relative atomic concentrations of magnesium ion increase. Conclusions: Surface properties of the oxidized implants in the present study, especially surface chemistry, influenced bone responses. The surface chemistry of the optimal oxidized implant should be composed of approximately 9% magnesium at relative atomic concentration in titanium oxide matrix and have an oxide thickness of approximately 1,000 to 5,000 nm, a porosity of about 24%, and a surface roughness of about 0.8 microm in Sa and 27% to 46% in Sdr; its oxide crystal structure should be a mixture of anatase- and rutile-phase crystals.
Research projects focusing on biomaterials related factors; the bulk implant material, the macro-... more Research projects focusing on biomaterials related factors; the bulk implant material, the macro-design of the implant and the microsurface roughness are routinely being conducted at our laboratories. In this study, we have investigated the bone tissue reactions to turned commercially pure (c.p.) titanium implants with various thicknesses of the oxide films after 6 weeks of insertion in rabbit bone. The control c.p. titanium implants had an oxide thickness of 17-200 nm while the test implants revealed an oxide thickness between 600 and 1000 nm. Routine histological investigations of the tissue reactions around the implants and enzyme histochemical detections of alkaline and acid phosphatase activities demonstrated similar findings around both the control and test implants. In general, the histomorphometrical parameters (bone to implant contact and newly formed bone) revealed significant quantitative differences between the control and test implants. The test implants demonstrated a greater bone response histomorphometrically than control implants and the osteoconductivity was more pronounced around the test implant surfaces. The parameters that differed between the implant surfaces, i.e. the oxide thickness, the pore size distribution, the porosity and the crystallinity of the surface oxides may represent factors that have an influence on the histomorphometrical results indicated by a stronger bone tissue response to the test implant surfaces, with an oxide thickness of more than 600 nm.
To apply a new statistical method (principle component analysis; PCA) to evaluate osseointegratio... more To apply a new statistical method (principle component analysis; PCA) to evaluate osseointegration. Two different commercially available implants were selected for the study. Twenty implants, 10 of each type, were placed in the rabbit tibiae (n = 10). The fluorochromes (FLCs) alizarin complexone and calcein green were administered after 20 days and 4 days before sacrifice for labeling. On the day of implantation and retrieval (6 weeks), implant stability was measured with a resonance frequency analyzer (RFA). The retrieved samples were ground sectioned for histomorphometric and FLC quantification. The collected data were analyzed by a PCA software program (Qlucore Omics Explorer, Lund, Sweden) to explore and determine the correlation between different study variables and to analyze the differences between different implants. The RFA presented no significant differences at either time point. The bone-to-implant contact was significantly higher for the TiUnite (NobelBiocare, Gothenburg, Sweden); however, the bone area and FLC quantification showed higher values for the Osseotite (3i Implant Innovation, FL). Consistent with these results, the PCA indicated a strong correlation between TiUnite and high bone-to-implant contact values and between Osseotite and high bone area and FLC values. No correlation between RFA and the biological responses were found. The application of the PCA analysis may help interpret and correlate results obtained from numerous evaluations.
Journal of Materials Science: Materials in Medicine, Mar 17, 2015
To investigate in vitro cellular cytokine expression in relation to commercially pure titanium di... more To investigate in vitro cellular cytokine expression in relation to commercially pure titanium discs, comparing a native surface to a fluorinated oxide nanotube surface. Control samples pure titanium discs with a homogenous wave of the margins and grooves and an often smeared-out surface structure. Test samples pure titanium discs with a fluorinated titanium oxide chemistry and surface morphology with nanopore/tube geometry characterized by ordered structures of nanotubes with a diameter of &120 nm, a spacing of &30 nm, and a wall thickness of &10 nm. Cross-section view showed vertically aligned nanotubes with similar lengths of &700 nm. Peripheral blood mononuclear leucocytes were cultured for 1, 3, and 6 days according to standard procedures. BioPlex Pro TM assays were used for analysis and detection of cytokines. Selected inflammatory cytokines are reported. A pronounced difference in production of the inflammatogenic cytokines was observed. Leucocytes exposed to control coins produced significantly more TNF-a, IL-1ß, and IL-6 than the test nanotube coins. The effect on the T H 2 cytokine IL-4 was less pronounced at day 6 compared to days 1 and 3, and slightly higher expressed on the control coins. The morphology and surface chemistry of the titanium surface have a profound impact on basic cytokine production in vitro. Within the limitations of the present study, it seems that the fluorinated oxide nanotube surface results in a lower inflammatory response compared to a rather flat surface that seems to favour inflammation.
Clinical Implant Dentistry and Related Research, Dec 1, 2006
Background: The current hard tissue implants research aims to accelerate bone healing by designin... more Background: The current hard tissue implants research aims to accelerate bone healing by designing surfaces that are bioactive. However, the role of the inflammatory response to these surfaces is so far incompletely described.
Clinical Implant Dentistry and Related Research, Jul 1, 2004
Background: In oral implantology there has been a general trend away from machine-turned minimall... more Background: In oral implantology there has been a general trend away from machine-turned minimally rough and acidetched and blasted implants toward intermediary roughened surfaces. Mechanical interlocking at micron resolution is claimed to be the dominant reason for the fixation of such implants in bone. However, clinical demands for stronger and faster bone bonding to the implant (eg, in immediately loaded and compromised bone cases) have motivated the development of novel surfaces capable of chemical bonding. Purpose: The purpose of the present study is to investigate bone tissue reactions to a newly developed calciumincorporated oxidized implant. The specific aim is to assess the effect of calcium surface chemistry on the bone response. Materials and Methods: Calcium (Ca) ion-incorporated implants were prepared by micro arc oxidation methods. Surface oxide properties were characterized by using various surface analytic techniques involving scanning electron microscopy, x-ray diffractometry, x-ray photoelectron spectroscopy, and optical interferometry. Twenty screw-shaped commercially pure (CP) titanium implants (10 turned implants [controls] and 10 Ca-incorporated implants [tests]) were inserted in the femoral condyles of 10 New Zealand White rabbits. Results: After a healing period of 6 weeks, resonance frequency analyses and removal torque measurements of the Caincorporated oxidized implants demonstrated statistically significant improvements of implant integration with bone in comparison to machine-turned control implants (p = 0.013 and p = 0.005, respectively). Conclusions: The Ca-reinforced surface chemistry of the oxidized implants significantly improved bone responses in a rabbit model. The present study suggests that biochemical bonding at the bone-implant interface, in combination with mechanical interlocking, may play a dominant role in the fixation of Ca-incorporated oxidized implants in bone. The observed rapid and strong integration of test Ca implants may have clinical implications for immediate or early loading and improved performance in compromised bone.
: The present experimental study was designed to address two issues. The first was to investigate... more : The present experimental study was designed to address two issues. The first was to investigate whether oxide properties of titanium implants influenced bone tissue responses after an in vivo implantation time of six weeks. If such a result was found, the second aim was to investigate which oxide properties are involved in such bone tissue responses. Screw‐shaped implants with a wide range of oxide properties were prepared by electrochemical oxidation methods, where the oxide thickness varied in the range of 200 nm to 1000 nm. The surface morphology was prepared in two substantially different ways, i.e. barrier and porous oxide film structures. The micropore structure revealed pore sizes of 8 μm in diameter, with a range in opening area from 1.27 μm2 to 2.1 μm2. Porosity ranged from 12.7% to 24.4%. The crystal structures of the titanium oxide were amorphous, anatase and a mixture of anatase and rutile type. The chemical compositions consisted mainly of TiO2. Surface roughness ranged from 0.96 μm to 1.03 μm (Sa). Each group of test samples showed its own, defined status with respect to these various parameters. The oxide properties of turned commercially pure titanium implants were used in the control group, which was characterized by an oxide thickness of 17.4 ± 6.2 nm, amorphous type in crystallinity, TiO2 in chemical composition, and a surface roughness of 0.83 μm (Sa). Bone tissue responses were evaluated by resonance frequency measurements and removal torque tests that were undertaken six weeks after implant insertion in rabbit tibia. Implants that had an oxide thickness of approximately 600, 800 and 1000 nm demonstrated significantly stronger bone responses in the evaluation of removal torque values than did implants that had an oxide thickness of approximately 17 and 200 nm (P &lt; 0.05). However, there were no difference between implants with oxide thicknesses of 17 and 200 nm (P = 0.99). It was concluded that oxide properties of titanium implants, which include oxide thickness, micropore configurations and crystal structures, greatly influence the bone tissue response in the evaluation of removal torque values. However, it is not fully understood whether these oxide properties influence the bone tissue response separately or synergistically.
Journal of the Royal Society Interface, Apr 15, 2009
Quantifying the in vivo interfacial biochemical bond strength of bone implants is a biological ch... more Quantifying the in vivo interfacial biochemical bond strength of bone implants is a biological challenge. We have developed a new and novel in vivo method to identify an interfacial biochemical bond in bone implants and to measure its bonding strength. This method, named biochemical bond measurement (BBM), involves a combination of the implant devices to measure true interfacial bond strength and surface property controls, and thus enables the contributions of mechanical interlocking and biochemical bonding to be distinguished from the measured strength values. We applied the BBM method to a rabbit model, and observed great differences in bone integration between the oxygen (control group) and magnesium (test group) plasma immersion ion-implanted titanium implants (0.046 versus 0.086 MPa, nZ10, pZ0.005). The biochemical bond in the test implants resulted in superior interfacial behaviour of the implants to bone: (i) close contact to approximately 2 mm thin amorphous interfacial tissue, (ii) pronounced mineralization of the interfacial tissue, (iii) rapid bone healing in contact, and (iv) strong integration to bone. The BBM method can be applied to in vivo experimental models not only to validate the presence of a biochemical bond at the bone-implant interface but also to measure the relative quantity of biochemical bond strength. The present study may provide new avenues for better understanding the role of a biochemical bond involved in the integration of bone implants.
Ten-year results for Branemark implants immediately loaded with fixed prostheses at implant place... more Ten-year results for Branemark implants immediately loaded with fixed prostheses at implant placement. Int J Oral Maxillofac Implants 1997;12:495-503. 19.Tselios N, Parel SM, Jones JD. Immediate placement and immediate provisional abutment modeling in anterior single-tooth implant restorations using a CAD/CAM application: a clinical report.
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