| 1. |
- Sul, Young-Taeg, 1960, et al.
(författare)
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Characteristics of the surface oxides on turned and electrochemically oxidized pure titanium implants up to dielectric breakdown: the oxide thickness, micropore configurations, surface roughness, crystal structure and chemical composition.
- 2002
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Ingår i: Biomaterials. - 0142-9612 .- 1878-5905. ; 23:2, s. 491-501
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Tidskriftsartikel (refereegranskat)abstract
- Titanium implants have been used widely and successfully for various types of bone-anchored reconstructions. It is believed that properties of oxide films covering titanium implant surfaces are of crucial importance for a successful osseointegration, in particular at compromized bone sites. The aim of the present study is to investigate the surface properties of anodic oxides formed on commercially pure (c.p.) titanium screw implants as well as to study 'native' oxides on turned c.p. titanium implants. Anodic oxides were prepared by galvanostatic mode in CH3COOH up to the high forming voltage of dielectric breakdown and spark formation. The oxide thicknesses, measured with Auger electron spectroscopy (AES), were in the range of about 200-1000 nm. Barrier and porous structures dominated the surface morphology of the anodic film. Quantitative morphometric analyses of the micropore structures were performed using an image analysis system on scanning electron microscopy (SEM) negatives. The pore sizes were
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| 2. |
- Sul, Young-Taeg, 1960, et al.
(författare)
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Optimum surface properties of oxidized implants for reinforcement of osseointegration: surface chemistry, oxide thickness, porosity, roughness, and crystal structure
- 2005
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Ingår i: International Journal of Oral & Maxillofacial Implants. - Chicago, Ill. : Quintessence Pub. Co.. - 0882-2786 .- 1942-4434. ; 20:3, s. 349-59
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Sul, Young-Taeg, 1960, et al.
(författare)
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Oxidized implants and their influence on the bone response.
- 2001
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Ingår i: Journal of Materials Science: Materials in Medicine. - 0957-4530. ; 12:10-12, s. 1025-31
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Tidskriftsartikel (refereegranskat)abstract
- 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 first is to verify whether oxide properties of titanium implants indeed influence 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 film structures, (iii) micro pore configuration - pore sizes<8 microm by length, about 1.27 microm2 to 2.1 microm2 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 TiO2 and finally, (vi) surface roughness of 0.96-1.03 microm (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 significantly influence the bone tissue response. At this stage, however, it is not clear whether oxide properties influence the bone tissue response separately or synergistically. Copyright 2001 Kluwer Academic Publishers
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| 4. |
- Sul, Young-Taeg, 1960, et al.
(författare)
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Resonance frequency and removal torque analysis of implants with turned and anodized surface oxides.
- 2002
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Ingår i: Clin Oral Implants Res. - 0905-7161. ; 13:3, s. 252-9
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Tidskriftsartikel (refereegranskat)abstract
- 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 microm in diameter, with a range in opening area from 1.27 microm 2 to 2.1 microm 2. 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 microm to 1.03 microm (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 microm (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 < 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.
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| 5. |
- Arvidsson, Anna, 1973, et al.
(författare)
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Formation of calcium phosphates on titanium implants with four different bioactive surface preparations. An in vitro study
- 2007
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Ingår i: Journal of Materials Science-Materials in Medicine. - : Springer Science and Business Media LLC. - 0957-4530 .- 1573-4838. ; 18:10, s. 1945-1954
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to compare the nucleating and growing behaviour on four types of bioactive surfaces by using the simulated body fluid (SBF) model. Titanium discs were blasted and then prepared by alkali and heat treatment, anodic oxidation, fluoridation, or hydroxyapatite coating. The discs were immersed in SBF for 1, 2, 4 and 6 weeks. Calcium phosphates were found on all specimens, as analysed with scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX). After 1 and 2 weeks of SBF immersion more titanium was accessible with SEM/EDX on the blasted surfaces than the four bioactive surface types, indicating a difference in coverage by calcium phosphates. The Ca/P mean ratio of the surfaces was approximately 1.5 after 1 week, in contrast to the fluoridated specimens which displayed a Ca/P mean ratio of approximately 2. Powder X-ray diffraction (P-XRD) analyses showed the presence of hydroxyapatite on all types of surfaces after 4 and 6 weeks of immersion. The samples immersed for 6 weeks showed a higher degree of crystallinity than the samples immersed for 4 weeks. In conclusion, differences appeared at the early SBF immersion times of 1 and 2 weeks between controls and bioactive surface types, as well as between different bioactive surface types.
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| 6. |
- Franke Stenport, Victoria, 1970, et al.
(författare)
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Precipitation of calcium phosphate in the presence of albumin on titanium implants with four different possibly bioactive surface preparations. An in vitro study
- 2008
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Ingår i: Journal of Materials Science: Materials in Medicine. - : Springer Science and Business Media LLC. - 0957-4530 .- 1573-4838. ; 19:12, s. 3497-3505
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to compare the nucleating behaviour on four types of bioactive surfaces by using the simulated body fluid (SBF) model with the presence albumin. Titanium discs were blasted (B) and then prepared by alkali and heat treatment (AH), anodic oxidation (AO), fluoridation (F), or hydroxyapatite coating (HA). The discs were immersed in SBF with 4.5 mg/ml albumin for 3 days, 1, 2, 3 and 4 weeks and analysed with scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX) and X-ray photoelectron spectroscopy (XPS). Topographic surface characterisation was performed with a contact stylus profilometer. The results demonstrated that the bioactive surfaces initiated an enhanced calcium phosphate (CaP) formation and a more rapid increase of protein content was present on the bioactive surfaces compared to the blasted control surface. The observation was present on all bioactive surfaces. The fact that there was a difference between the bioactive surfaces and the blasted control surface with respect to precipitation of CaP and protein content on the surfaces support the fact that there may be biochemical advantages in vivo by using a bioactive surface.
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| 7. |
- Göransson, Anna, 1970, et al.
(författare)
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An in vitro comparison of possibly bioactive titanium implant surfaces.
- 2009
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Ingår i: Journal of Biomedical Materials Research Part A. - : Wiley. - 1552-4965 .- 1549-3296. ; 88:4, s. 1037-1047
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to compare Ca and P formation (CaP) and subsequent bone cell response of a blasted and four different possibly bioactive commercially pure (cp) titanium surfaces; 1. Fluoride etched (Fluoride), 2. Alkali-heat treated (AH), 3. Magnesium ion incorporated anodized (TiMgO), and 4. Nano HA coated and heat treated (nano HA) in vitro. Furthermore, to evaluate the significance of the SBF formed CaP coat on bone cell response. The surfaces were characterized by Optical Interferometry, Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). CaP formation was evaluated after 12, 24 and 72 h in simulated body fluid (SBF). Primary human mandibular osteoblast-like cells were cultured on the various surfaces subjected to SBF for 72 h. Cellular attachment, differentiation (osteocalcin) and protein production (TGF-beta(1)) was evaluated after 3 h and 10 days respectively. Despite different morphological appearances, the roughness of the differently modified surfaces was similar. The possibly bioactive surfaces gave rise to an earlier CaP formation than the blasted surface, however, after 72 h the blasted surface demonstrated increased CaP formation compared to the possibly bioactive surfaces. Subsequent bone cell attachment was correlated to neither surface roughness nor the amount of formed CaP after SBF treatment. In contrast, osteocalcin and TGF-beta(1) production were largely correlated to the amount of CaP formed on the surfaces. However, bone response (cell attachment, osteocalcin and TGF-F production) on the blasted controls were similar or increased compared to the SBF treated fluoridated, AH and TiMgO surface. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.
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| 8. |
- Göransson, Anna, 1970, et al.
(författare)
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Inflammatory response to oxidised surface with Mg 2+ -ions incorporated in vitro
- 2004
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Ingår i: 7th World Biomaterials Congress, Sidney, 17 -21 May 2004.
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Konferensbidrag (refereegranskat)abstract
- Introduction Oxide films that grow spontaneously on titanium surfaces in contact with air may explain the bio-passivity of the material. Various procedures have been carried out to modify the properties of titanium oxide films to further improve the biocompatibility. Anodic oxidation is one technique to increase the thickness of the oxide layer that demonstrates significant stronger bone response in vivo. The concomitant increase in surface roughness and size and presence of pores of the thicker oxide layer seems to work as a potential contributor to the results (1). Attempts to implant ion in the oxide layers to overcome the drawbacks of calcium phosphate coatings (hydroxylapatite) such as i.e. delaminating and biodegradation during function seem promising (2). However the reasons why a thicker oxide layer with and without incorporated ions is favourable compared to conventionally turned and blasted surfaces are not fully understood. The aim of this study was to compare the early inflammatory response to the turned, blasted and electrochemically oxidised surface with Mg 2+ ions incorporated. Materials and Methods A total of 108 pure titanium discs were prepared with a turned surface. Thirty-six were kept as turned controls while 36 were blasted with 75 μm Al2O3 particles and 36 underwent electrochemically oxidation and Mg 2+ ion incorporation. MicroXam™, (Phase-Shift, Tucson, Arizona, USA) was used to for topographical characterisation. The disks were incubated with human mononuclear cells isolated from buffy coats of healthy blood donors (C-lab, Blood Supply Unit Sahlgrenska University hospital, Sweden) and cultured at a concentration of 106 cells/ml in 24 well cell culture plates. Half of the discs with the different treated surfaces were immediately treated with LPS while half were left without any stimuli. The incubation times were 24 and 72h. After each incubation period the incubation medium was collected and centrifuged. The supernatant was analysed with respect to cell viability and cytokine levels. Cell viability was estimated by analysing the content of lactatdehydrogenas (LDH)(Sahlgrenska University hospital, C-lab) and a commercially available ELISA assay (Biotrak system™, Amersham Bioscience, UK) was used to quantify TNF-α and IL -10 levels. The cells adherent to the material was stained with 2,6- diamidino-2-phenyindole (DAPI) (Sigma, USA) to evaluate the total cell number. In order to characterize differentiation of the adherent cells expression of 27E10 and RM3/1 (Biogenisis, UK) was used. The marker 27E10 and RM3/1 define acute and chronic inflammatory phenotypes respectively. Differentiated cells were evaluated as the percentage of positively stained cells from the total cell numbers. Results Surface evaluation revealed similar roughness for the turned control and the anodised surface with Mg 2+ ions incorporated while the blasted surface demonstrated a rougher surface profile (fig 1, 2). Fig 1 Fig 2 Sa-average height deviation (ym) SURFACE CTR Blasted Anodised+Mg Mean SA 1,2 1,0 ,8 ,6 ,4 ,2 0,0 Sdr-developed surface area (%) SURFACE CTR Blasted Anodised+Mg Mean SDR 40 30 20 10 0 LDH values were generally low for all surfaces (within the range of 0.8-1.6 μkat/l) but were slightly increased after LPS stimulation and after 72h. TNF-α was transient higher day one and after LPS stimulation especially on the turned control surface (fig 3, 4) Fig 3 Fig 4 TNF-a 24h (pg/ml) SURFACE CTR Blasted Anodised+Mg Mean C 3000 2000 1000 0 LPS LPSLPS+ TNF-a 72h (pg/ml) SURFACE CTR Blasted Anodised+Mg Mean C 400 300 200 100 0 LPS LPSLPS+ IL-10 levels were generally low irrespective of time. Increased IL-10 amounts after LPS stimulation and after 24 h were observed for all surfaces. The total cell numbers decreased on all surfaces from 24h to 72h but there were no major difference between stimulated and un-stimulated wells. Acute monocytic phenotype 27E10 marker dominated on all surfaces while the expression of the chronic RM3/1 marker was almost absent on all surfaces both at 24 and 72h. Conclusion The present study indicates a surface topography- and chemistry related difference in the acute inflammatory response with a stronger acute inflammatory response to the turned control compared to the blasted and anodised surface with Mg 2+ ions incorporated. References 1.Göransson, A, Jansson, E, Tengvall, P, Wennerberg, A. Bone formation after 4 weeks …topography : an in vivo study. Biomaterials 2002; 24: 197-205 2.Sul YT. PhD Thesis 2002, Göteborg University, Sweden
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| 9. |
- Göransson, Anna, 1970, et al.
(författare)
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Inflammatory response to titanium surfaces with with Potential Bioactive Properties: An In Vitro Study
- 2006
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Ingår i: Clinical Implant Dentistry and Related Research. ; 8:4, s. 210-217
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Tidskriftsartikel (refereegranskat)abstract
- 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. Purpose: The aim of the study was to evaluate early inflammatory response in vitro to a potentially bioactive surface—an anodized surface with Mg ions incorporated (anodized/Mg)—and to compare it to a turned, a blasted, and an anodized surface. Materials and Methods: An interferometer was used for topographical characterizations. The disks were incubated with human mononuclear cells. Adherent cells were investigated with respect to number of cells, viability, differentiation, and cytokine production with and without lipopolysaccharide stimulation after 24 and 72 hours. Results: The number of adhered mononuclear cells differed significantly between the different modified surfaces, with the highest number on the anodized surface. However, there were no significant differences in cytokine production and differentiation between the different modified surfaces. The amount of anti-inflammatory mediator interleukin-10 remained over time, while the number of cells and pro-inflammatory cytokine tumor necrosis factor-α decreased. The cells were viable on all surfaces, respectively. Conclusion: The anodized surfaces with and without Mg ions showed an increased cell adherence, however, otherwise an inflammatory response similar to the turned and blasted surfaces. Furthermore, the potentially bioactive anodized/Mg surface showed a similar response to the TiUnite-like anodized surface despite the former having a surface roughness of a smoother character.
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| 10. |
- Sul, Young-Taeg, 1960, et al.
(författare)
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Surface characteristics of electrochemically oxidized implants and acid-etched implants: surface chemistry, morphology, pore configurations, oxide thickness, crystal structure, and roughness.
- 2008
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Ingår i: International Journal of Oral & Maxillofacial Implants. - 0882-2786 .- 1942-4434. ; 23:4
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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