| 1. |
- Kassapidou, Maria, et al.
(författare)
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Cobalt-chromium alloys fabricated with four different techniques: Ion release, toxicity of released elements and surface roughness
- 2020
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Ingår i: Dental Materials. - : Elsevier BV. - 0109-5641 .- 1879-0097. ; 36:11
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To investigate the metal ion release, surface roughness and cytoxicity for Co-Cr alloys produced by different manufacturing techniques before and after heat treatment. In addition, to evaluate if the combination of materials affects the ion release. Methods. Five Co-Cr alloys were included, based on four manufacturing techniques. Commercially pure titanium, CpTi grade 4 and a titanium alloy were included for comparison. The ion release tests involved both Inductive Coupled Plasma Optical Emission Spectrometry and Inductive Coupled Plasma Mass Spectrometry analyses. The surface analysis was conducted with optical interferometry. Cells were indirectly exposed to the materials and cell viability was evaluated with the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) method. Results. All alloys showed a decrease of the total ion release when CpTi grade 4 was present. The total ion release decreased over time for all specimens and the highest ion release was observed from the cast and milled Co-Cr alloy in acidic conditions. The cast and laser-melted Co-Cr alloy and the titanium alloy became rougher after heat treatment. All materials were within the limits of cell viability according to standards. Significance. The ion release from Co-Cr alloys is influenced by the combination of materials, pH and time. Surface roughness is influenced by heat treatment. Furthermore, both ion release and surface roughness are influenced by the manufacturing technique and the alloy type. The clinical implication needs to be further investigated. (C) 2020 The Academy of Dental Materials. Published by Elsevier Inc.
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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. |
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| 4. |
- Barkarmo, Sargon, et al.
(författare)
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Inflammatory cytokine release from human peripheral blood mononuclear cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium in vitro.
- 2018
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Ingår i: Journal of biomaterials applications. - : SAGE Publications. - 1530-8022 .- 0885-3282. ; 33:2, s. 245-258
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate the cytokine expression profiles of blood cells exposed to polyetheretherketone and titanium-6 aluminum-4 vanadium materials in vitro. Materials and methods Coin-shaped samples composed of titanium-6 aluminum-4 vanadium, polyetheretherketone, and blasted polyetheretherketone were manufactured. The surfaces of the coins were characterized using optical interferometry, scanning electron microscopy, and contact angle measurements. Peripheral blood mononuclear cells collected from 10 blood donors were cultured for one, three, and six days in the presence or absence of the coins, and then assayed for cytokine production. Quantification of the peripheral blood mononuclear cells attached to the coins was performed using confocal microscopy after immunofluorescence staining. Results The machined titanium-6 aluminum-4 vanadium coins had a smoother surface topography compared to the machined polyetheretherketone and blasted polyetheretherketone. The highest mean contact angle was noted for the blasted polyetheretherketone, followed by the machined polyetheretherketone and titanium-6 aluminum-4 vanadium. The peripheral blood mononuclear cells produced significantly more proinflammatory cytokines when exposed to the polyetheretherketone surface compared to the titanium-6 aluminum-4 vanadium surface, while the blasted polyetheretherketone induced the highest level of proinflammatory cytokine release from the peripheral blood mononuclear cells. Significantly more cells attached to both polyetheretherketone surfaces, as compared to the titanium-6 aluminum-4 vanadium surface. Conclusion Polyetheretherketone induces a stronger inflammatory response from peripheral blood mononuclear cells than does titanium-6 aluminum-4 vanadium. Surface topography has an impact on cytokine release from peripheral blood mononuclear cells.
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| 5. |
- Bolind, Pia, 1953, et al.
(författare)
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A descriptive study on retrieved non-threaded and threaded implant designs
- 2005
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Ingår i: Clinical oral implants research. - : Wiley. - 0905-7161 .- 1600-0501. ; 16:4, s. 447-55
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: In the light microscope compare the amount of bone saucerization for non-threaded cylindrical and threaded implant designs in retrieved samples from patients. MATERIAL AND METHOD: Consecutively received retrieved oral implants from 117 patients, whereof 85 non-threaded cylindrical and 85 Branemark implants, have been included in the study. For 75 non-threaded cylindrical and 46 Branemark implants was the entire implant length available for calculation. Undecalcified ground sections were investigated in the light microscope with calculation of percentage of implant length coronal to the first bone-implant contact and percentage of bone to implant contact. RESULTS: Mean value for implant length coronal to first bone-implant contact was 65%, standard error of the mean (SEM) 3 (range 0-100%), for non-threaded cylindrical implants and 43%, SEM 6 (range 0-100%) for Branemark implants. Mean values of bone contact along the entire implant length was 23%, SEM 2 (range 0-65%), for the non-threaded cylindrical implants and 33%, SEM 5 (range 0-93%) for the Branemark implants. CONCLUSION: Within the limitations of this retrospective, retrieval study non-threaded cylindrical implants demonstrated a greater bone saucerization when evaluated in the light microscope.
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| 6. |
- Bolind, Pia, 1953, et al.
(författare)
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A study of 275 retrieved Branemark oral implants
- 2005
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Ingår i: The International journal of periodontics & restorative dentistry. - Chicago, Ill. : Quintessence Pub. Co.. - 0198-7569 .- 1945-3388. ; 25:5, s. 425-37
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this report was to describe the bone tissue response to Branemark oral implants retrieved from patients. The material consisted of consecutively received Branemark threaded oral implants and related patient data provided by clinicians. The implant samples were processed into undecalcified sections for evaluation under the light microscope. The analysis demonstrated a lower percentage of bone-to-implant contact for the unloaded implants as compared to the loaded implants. When the threads were divided into four different regions, the loaded implants had a lower percentage of bone-contacting length at the thread top as compared to the other three regions.
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| 7. |
- Bolind, Pia, 1953, et al.
(författare)
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Histologic evaluation of Branemark clinic oral implants retrieved from grafted sites
- 2006
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Ingår i: Clinical implant dentistry and related research. - Hamilton, Ont. : Wiley. - 1523-0899 .- 1708-8208. ; 8:1, s. 44-53
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this report is to quantitatively and qualitatively describe the bone tissue response to Branemark implants retrieved from grafted sites in patients. MATERIALS AND METHOD: The material consists of consecutively received Branemark implants retrieved from grafted sites. Thirty-five of these implants, retrieved from 16 patients, were suitable for the histologic evaluation of undecalcified sections in the light microscope. RESULTS: The unloaded implants were mainly lined with soft tissue, and sparse bone-implant contact was observed only in some sections. The loaded implants, with the exception of one implant removed due to mobility, had mature and new bone-implant contact. Resorption of graft through cutting cone structures was detected. Cement lines were found separating bone-like tissue albeit no cellular content and bone tissue with detectable osteocytes. CONCLUSION: In this heterogeneous group of implants from grafted sites, the unloaded implants showed limited bone-implant contact. The autografts showed seemingly mixed viability as judged by the cell content in the osteocyte lacunae and cement lines separating areas with filled and empty lacunae.
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| 8. |
- Bolind, Pia, 1953, et al.
(författare)
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Retrieved implants from irradiated sites in humans: a histologic/histomorphometric investigation of oral and craniofacial implants
- 2006
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Ingår i: Clinical implant dentistry and related research. - Hamilton, Ont. : Wiley. - 1523-0899 .- 1708-8208. ; 8:3, s. 142-50
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this report was to quantitatively and qualitatively evaluate the tissue response to bone-anchored implants retrieved from irradiated sites in patients. MATERIALS AND METHODS: The material consists of 23 consecutively received Branemark implants (Nobel Biocare AB, Goteborg, Sweden) placed in pre- or postoperatively irradiated sites. Twenty-two of the 23 implants were suitable for histologic evaluation of undecalcified sections in the light microscope. RESULTS: The oral implants with shorter time in situ demonstrated sparse bone to implant contact with mainly dense connective tissue in the interface. However, for implants with longer time in situ, high amounts of bone-implant contact and bone fill of threads were noted. The mean values of bone-implant contact and bone area within the thread were calculated to 40% (16-94) and 70% (13-96), respectively. The craniofacial implants, with the exception of two implants lined with a capsular formation, demonstrated mature and newly formed bone at the bone-implant interface. The mean value for bone-metal contact was calculated to 45 and 53% for two specimens. The mean value for bone area within the thread ranged from 65 to 88% for three specimens. CONCLUSION; The possibility to achieve bone anchorage of implants in irradiated tissue was supported by the findings in this study. However, due to limited material, conclusions with regard to radiation dose and bone tissue response to implants cannot be stated.
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