| 1. |
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| 2. |
- Albrektsson, Tomas, 1945, et al.
(författare)
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Histologic investigations on 33 retrieved Nobelpharma implants.
- 1993
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Ingår i: Clinical materials. - 0267-6605. ; 12:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Thirty Nobelpharma implants were retrieved from 17 patients despite a remaining clinical stability, after between 1 and 16 years of clinical function. The reasons for implant removal were bone resorption in combination with soft tissue disorders, psychological causes, implant fracture and post mortem cases. When measured at the cortical passage, there was an average of 84.9% direct bone-to-implant contact and 81.8% average surface bone area in individual threads as evaluated in a computerized morphometric system at the light microscopic level.
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| 3. |
- Andersson, P., et al.
(författare)
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Factors Influencing Resonance Frequency Analysis (RFA) Measurements and 5-Year Survival of Neoss Dental Implants
- 2019
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Ingår i: International Journal of Dentistry. - : Hindawi Limited. - 1687-8728 .- 1687-8736. ; - 2019
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Tidskriftsartikel (refereegranskat)abstract
- - Background. Diagnostic instruments based on resonance frequency analysis (RFA) can be utilised to assess dental implant stability during treatment and follow-up. Aim. The aim of the present study was to investigate the influence of patient- and implant-related factors on implant stability and the 5-year implant survival. In addition, the influence of stability (ISQ value) at placement and abutment connection on implant survival was evaluated. Materials and Methods. RFA measurements from a total of 334 consecutive patients with 745 dental implants (Neoss Ltd., Harrogate, UK) were retrospectively analysed after at least 5 years in function. Statistics were used to evaluate the influence of the different variables on implant stability and implant survival. Odds ratio calculations were performed to compare the risk for implant failure using 60, 65, 70, and 75 ISQ as threshold levels at placement and loading. Results. A total of 20 implant failures in 14 patients were noted during the 5 years of follow-up, giving an overall cumulative survival rate (CSR) of 97.3% at the implant level and 95.8% at the patient level. Gender, jaw, position, bone quality, and implant diameter had an influence on implant stability at placement. Jaw, bone quality, and implant diameter had an influence on stability after 3-4 months of healing. More failures were observed in full than in partial rehabilitations. Age, gender, jaw, position, bone quantity, bone quality, implant diameter, and implant length had no influence on implant survival. Implants with ISQ values below the threshold levels showed lower survival rates compared to implants with values above these levels. Conclusions. The present study showed a significantly higher risk for implant failure, showing an ISQ value below 70 and 75 at placement or after 3-4 months of healing. The results indicate that RFA measurements can be used to identify implants with increased risk for failure. © 2019 Peter Andersson et al.
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| 4. |
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| 5. |
- Buranawat, B, et al.
(författare)
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Evaluation of a Beta-Calcium Metaphosphate Bone Graft Containing Bone Morphogenetic Protein- 7 (OP-1) in Rabbit Maxillary Defects.
- 2014
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Ingår i: Journal of periodontology. - : Wiley. - 1943-3670 .- 0022-3492. ; 85:2, s. 298-307
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Tidskriftsartikel (refereegranskat)abstract
- Background: Calcium phosphate based materials have been widely used as bone substitutes and more recently are being exploited together with growth factors as bone tissue engineering scaffolds regulating cell behavior. The aim of the study was to evaluate the in vitro and in vivo response to a newly developed calcium metaphosphate bone graft, with and without bone stimulating growth factor. Materials and methods: Porous scaffolds of β calcium metaphosphate (CMP) were developed and extensively tested in vitro. Subsequently, CMP grafts with osteogenic protein 1 (OP-1) (test) and, without (control) were implanted into experimental rabbit maxillary bone defects. Animals were sacrificed 2, 4, and 8 weeks and samples examined with micro-computed tomography (µCT) and processed for histomorphometric analysis. Results: At 8 weeks the scaffolds containing OP-1 induced greater bone formation (P=0.018) than CMP alone, based on histomorphometric evaluation, % Bone area [Test 57.1±5.6 and Control 49.4±7.7] and micro-CT analysis, % Bone volume density (BV/TV) [Test 63.46±5.61 and Control 51.20±6.71]. Thus, this data indicated that both test and control CMP grafts showed a good degree of bone formation. Furthermore, the CMP materials showed signs of resorption from 4 weeks and no graft materials were observed at 8 weeks. Conclusion: In vitro the OP-1 loaded graft demonstrated a release profile and bioactivity over a 28 day period. In vivo testing confirmed enhanced bone formation of the OP-1 loaded graft after 8 weeks of healing.
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| 6. |
- Grossi-Oliveira, G.A., et al.
(författare)
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Early Osseointegration Events on Neoss® ProActive and Bimodal Implants: A Comparison of Different Surfaces in an Animal Model
- 2015
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 17:6, s. 1060-1072
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Tidskriftsartikel (refereegranskat)abstract
- © 2015 Wiley Periodicals, Inc. Background: Cell interactions, adherence, and osseointegration at the bone-implant interface can be directly influenced by the surface properties of the titanium implant. Purpose: To characterize osseointegration of Neoss® implants with conventional (control group) and hydrophilic (test group) surface treatments. Materials and Methods: Six Labrador dogs received Neoss implants with conventional and hydrophilic surfaces. The bone-implant interfaces were evaluated 1 and 4 weeks after implantation, and osseointegration was evaluated using histological, histomorphometric, fluorescence, and resonance frequency analyses. The surfaces were also subjected to topographic and hydrophilicity analyses. Results: The topographic analyses revealed increased surface roughness in the test group compared with the control group (surface area roughness 0.42 and 0.78μm, respectively, for control and test group surfaces; p≤.05). The wettability values were higher in the test group (contact angles 67.2° and 27.2° for the control and test group surfaces, respectively; p≤.05). Implants in the test group also exhibited better stability, more bone-implant contact, and increased bone area compared with implants in the control group. Conclusion: Neoss implants in the test group improved bone formation in the early stages of osseointegration compared with implants in the control group.
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| 7. |
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| 8. |
- Hallman, M, et al.
(författare)
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Histologic analysis of clinical biopsies taken 6 months and 3 years after maxillary sinus floor augmentation with 80% bovine hydroxyapatite and 20% autogenous bone mixed with fibrin glue.
- 2001
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Ingår i: Clinical Implant Dentistry and Related Research. - 1523-0899 .- 1708-8208. ; 3:2, s. 87-96
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Bovine hydroxyapatite (Bio-Oss, Geistlich Pharmaceutical, Wollhausen, Switzerland) has been suggested to be used in maxillary sinus floor augmentation procedures prior to or in conjunction with implant placement. However, the long-term histologic fate of this material is not well understood. PURPOSE: The aim with this study was to histologically evaluate the tissue response in patients to a mixture of bovine hydroxyapatite (BH), autogenous bone, and fibrin glue 6 months and 3 years after a maxillary sinus floor augmentation procedure. MATERIALS AND METHOD: Biopsies were taken from a group of 20 consecutive patients 6 months (n = 16) and 3 years (n = 12) after maxillary sinus floor augmentation with a mixture of BH (80%), autogenous bone (20%), and fibrin glue and prepared for histologic analysis. RESULTS: Light microscopy and morphometry from biopsies taken after 6 months showed various amounts of mineralized bone tissue. The specimen area was occupied by 54.1 +/- 12.6% nonmineralized tissue, followed by 21.2 +/- 24.5% lamellar bone, 14.5 +/- 10.3% BH particles, and 10.2 +/- 13.4% woven bone. The nonmineralized tissue seen in bone-forming areas consisted of a loose connective tissue, rich with vessels and cells. There were no signs of resorption of the BH particles. The lamellar bone appeared to have originated from the recipient site and was seldom in contact with the BH particles. After 3 years, the nonmineralized tissue area had decreased to 36.0 +/- 19.0% (p < .05) and consisted mainly of bone marrow tissue. The surface area of lamellar bone had increased to 50.7 +/- 22.8% (p < .05), and there was almost no immature bone. The mean specimen area occupied by BH particles, was 12.4 +/- 8.7% and had not changed from 6 months (not significant). Moreover, the sizes of the particles were similar after 6 months and 3 years. The degree of BH particle-bone contact had increased from 28.8% +/- 19.9% after 6 months to 54.5 +/- 28.8% after 3 years (p < .05). CONCLUSION: Histology of specimens from maxillary sinuses augmented with 80% BH particles, 20% autogenous bone, and fibrin glue showed a positive bone tissue response after 6 months and 3 years after augmentation of the maxillary sinus floor prior to implant placement in a group fo 20 patients. The bone surrounding and in contact with the BH particles after 6 months was mainly immature woven bone, which with time was replaced by mature lamellar bone filling the interparticle space as observed in the 3-year specimens. Moreover, bone-integrated BH particles seem to be resistant to resorption. The results indicate that the procedure may be considered when only small amounts of intraoral autogenous bone graft are available.
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| 9. |
- Lundgren, Stefan, et al.
(författare)
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Spontaneous bone formation in the maxillary sinus after removal of a cyst: coincidence or consequence?
- 2003
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Ingår i: Clinical Implant Dentistry and Related Research. ; 5:2, s. 78-81
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Maxillary sinus floor-augmentation techniques are frequently used to increase the bone volume in the posterior edentulous maxilla to enable placement and integration of titanium implants. PURPOSE: The purpose of this report is to document an unexpected healing pattern after maxillary sinus surgery and to discuss the implications for future bone-augmentation techniques. MATERIALS AND METHODS: In a patient referred for sinus augmentation, an intrasinus mucosal cyst was removed 3 months prior to the planned augmentation procedure. A replaceable bone window was prepared in the lateral aspect of the sinus wall. The cyst was removed, the ruptured mucosa was sutured, and the bone window was replaced, resulting in a secluded space in the sinus. RESULTS: After 3 months of healing, the space between the replaced bony window and the lifted sinus membrane was filled with newly formed bone. The surgical technique was repeated in a second patient and resulted in a similar bone reformation pattern. CONCLUSION: Surgical trauma and the creation of a secluded space between the bone surfaces and the sinus mucosa result in spontaneous bone formation in the maxillary sinus. The surgical approach described may be used to achieve bone reformation to enable placement of dental implants without the addition of any grafting material.
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| 10. |
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| 11. |
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| 12. |
- Pagliani, L, et al.
(författare)
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The relationship between resonance frequency analysis (RFA) and lateral displacement of dental implants: an in vitro study.
- 2013
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Ingår i: Journal of oral rehabilitation. - : Wiley. - 1365-2842 .- 0305-182X. ; 40:3, s. 221-227
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Tidskriftsartikel (refereegranskat)abstract
- This in vitro investigation was conducted to study the relationship between resonance frequency analysis (RFA) and lateral displacement measurements of dental implants. A total of 30 implant sites were prepared in nine fresh bovine bone specimens. The bone density around each preparation was determined by using cone beam computerized tomography (CBCT) and imaging software. Dental implants were then inserted during continuous registration of insertion torque. RFA measurements were performed in perpendicular and parallel to the long axis of the specimens. The bone blocks were embedded in plaster and fixated in a specially designed rig for displacement measurements. A lateral force of 25N was applied via an abutment perpendicular and parallel to each implant and the displacement measured in μm. In addition, a flex constant (Nμm(-1) ) was calculated for each measurement. There was a significant inverse correlation between RFA and lateral implant displacement (μm) measurements and between RFA measurements and the flex constant in both perpendicular and parallel directions in bone (P≤0·001). Moreover, both RFA and displacement measurements correlated with bone density (P≤0·001). It is concluded that RFA measurements reflect the micromobility of dental implants, which in turn is determined by the bone density at the implant site.
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| 13. |
- Palma, VC, et al.
(författare)
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Bone reformation and implant integration following maxillary sinus membrane elevation: an experimental study in primates.
- 2006
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Ingår i: Clinical Implant Dental Related Research. ; 8:1, s. 11-24
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent clinical studies have described maxillary sinus floor augmentation by simply elevating the maxillary sinus membrane without the use of adjunctive grafting materials. PURPOSE: This experimental study aimed at comparing the histologic outcomes of sinus membrane elevation and simultaneous placement of implants with and without adjunctive autogenous bone grafts. The purpose was also to investigate the role played by the implant surface in osseointegration under such circumstances. MATERIALS AND METHODS: Four tufted capuchin primates had all upper premolars and the first molar extracted bilaterally. Four months later, the animals underwent maxillary sinus membrane elevation surgery using a replaceable bone window technique. The schneiderian membrane was kept elevated by insertion of two implants (turned and oxidized, Branemark System, Nobel Biocare AB, Goteborg, Sweden) in both sinuses. The right sinus was left with no additional treatment, whereas the left sinus was filled with autogenous bone graft. Implant stability was assessed through resonance frequency analysis (Osstell, Integration Diagnostics AB, Goteborg, Sweden) at installation and at sacrifice. The pattern of bone formation in the experimental sites and related to the different implant surfaces was investigated using fluorochromes. The animals were sacrificed 6 months after the maxillary sinus floor augmentation procedure for histology and histomorphometry (bone-implant contact, bone area in threads, and bone area in rectangle). RESULTS: The results showed no differences between membrane-elevated and grafted sites regarding implant stability, bone-implant contacts, and bone area within and outside implant threads. The oxidized implants exhibited improved integration compared with turned ones as higher values of bone-implant contact and bone area within threads were observed. CONCLUSIONS: The amount of augmented bone tissue in the maxillary sinus after sinus membrane elevation with or without adjunctive autogenous bone grafts does not differ after 6 months of healing. New bone is frequently deposited in contact with the schneiderian membrane in coagulum-alone sites, indicating the osteoinductive potential of the membrane. Oxidized implants show a stronger bone tissue response than turned implants in sinus floor augmentation procedures.
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| 14. |
- Roxvall, L, et al.
(författare)
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Anti-inflammatory agents inhibit leukocyte accumulation and vascular leakage induced by trypsin and trypsin-digested serum in hamster cheek pouch.
- 1993
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Ingår i: The Journal of surgical research. - : Elsevier BV. - 0022-4804. ; 54:3, s. 207-11
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Tidskriftsartikel (refereegranskat)abstract
- In the present study we investigated the effect of nordihydroguaiaretic acid (NDGA), indomethacin, and cortisone on trypsin-induced acute inflammation in the hamster cheek pouch. Permeability changes, evaluated by fluorescence microscopy after injection of FITC-dextran (MW 150,000), induced by trypsin (2.5 microM) and trypsinated serum (2.5 microM) were significantly suppressed by pretreatment with NDGA (20 mg/kg) and indomethacin (20 mg/kg). Pretreatment with cortisone (40 mg/kg) reduced the permeability changes induced by trypsinated serum but had no significant effect on trypsin-induced leakages. Accumulation of polymorphonuclear leukocytes, as calculated by a whole tissue histological technique, induced by trypsin or trypsinated serum, was significantly reduced by pretreatment with cortisone, NDGA, or indomethacin. These results indicate a role of both cyclooxygenase and lipoxygenase products in trypsin-induced acute inflammation in the hamster cheek pouch.
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| 15. |
- Salata, L.A., et al.
(författare)
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Osseointegration of oxidized and turned implants in circumferential bone defects with and without adjunctive therapies: an experimental study on BMP-2 and autogenous bone graft in the dog mandible
- 2007
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Ingår i: INTERNATIONAL JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY. - : Elsevier BV. - 0901-5027. ; 36:1, s. 62-71
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to compare the integration and implant stability of turned and oxidized titanium implants when placed in experimental bone defects with autogenous bone graft, BMP-2 or without adjunctive therapy. Four defects were prepared on each side of the mandible of 12 mongrel dogs five months after tooth extractions. Implants with turned and oxidized surfaces were placed in the defects. The circumferential gaps were filled with either autogenous bone grafts, a BMP-allogeneic dog mixture in a thermoplastic carrier, carrier alone or left without any treatment (control). There were no statistically significant differences between control and treated sites, neither for turned nor for oxidized implants with regard to histomorphometric measurements in ground sections and to implant stability as measured with resonance frequency analysis (RFA) after 4 and 12 weeks of healing. However, oxidized implants showed a significantly higher stability after 4 weeks and a tendency (p < 0.1) of that after 12 weeks. Histomorphometry showed more bone contacts for oxidized than for turned implants. It is concluded that oxidized implants gain stability more rapidly and integrate with more bone contacts than implants with a turned surface when placed in bone defects.
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| 16. |
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| 17. |
- Sennerby, Lars, 1960, et al.
(författare)
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Soft-tissue response to clinically retrieved titanium cover screws reimplanted in the rat abdominal wall.
- 1989
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Ingår i: The International journal of oral & maxillofacial implants. - 0882-2786. ; 4:3, s. 233-9
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Tidskriftsartikel (refereegranskat)abstract
- Clinically retrieved titanium implant cover screws (Brånemark implant system), rinsed in saline or subjected to ultrasonic cleaning and sterilization, as well as unused sterile screws were studied by scanning electron microscopy and implanted in the rat abdominal wall for 6 weeks. Irrespective of cleaning procedure, the heads of the clinically retrieved screws were covered by numerous contaminants not present on the unused screws. The reimplanted screws elicited a different tissue response than the unused screws. The tissue response to the contaminated screws was characterized by a significantly thicker fibrous capsule and by a significantly larger number of macrophages located close to the implant. Moreover, judging from their ultrastructure, studied with transmission electron microscopy, the macrophages appeared to be in a more active state when compared to those located adjacent to unused screws.
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| 18. |
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| 19. |
- Sennerby, Ulf, et al.
(författare)
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Cardiovascular diseases and risk of hip fracture
- 2009
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Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association (AMA). - 0098-7484 .- 1538-3598. ; 302:15, s. 1666-1673
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Recent studies indicate common etiologies for cardiovascular disease (CVD) and osteoporotic fractures. OBJECTIVES: To examine the relation between CVD and risk of hip fracture in twins and evaluate the relative importance of genetics and lifestyle factors in this association. DESIGN, SETTING, AND PARTICIPANTS: A cohort of all 31,936 Swedish twins born from 1914-1944 was followed up from the age of 50 years. The National Patient Registry identified twins with CVDs and fractures from 1964 through 2005. Time-dependent exposures using Cox proportional hazard regression models were evaluated. MAIN OUTCOME MEASURE: Time to hip fracture after diagnosis of CVD. RESULTS: The crude absolute rate of hip fractures was 12.6 per 1000 person-years after a diagnosis of heart failure, 12.6 per 1000 person-years after a stroke, 6.6 per 1000 person-years after a diagnosis of peripheral atherosclerosis, and 5.2 per 1000 person-years after a diagnosis of ischemic heart disease compared with 1.2 per 1000 person-years for those without a CVD diagnosis. The multivariable-adjusted hazard ratio (HR) of hip fracture after a diagnosis of heart failure was 4.40 (95% confidence interval [CI], 3.43-5.63); after a stroke, the HR was 5.09 (95% CI, 4.18-6.20); after a diagnosis of peripheral atherosclerosis, the HR was 3.20 (95% CI, 2.28-4.50); and after an ischemic heart disease event, the HR was 2.32 (95% CI, 1.91-2.84). Identical twins without heart failure and stroke also had, after their co-twins had been exposed to these respective diseases, an increased rate of hip fracture. These sibling twins pseudoexposed for heart failure had a multivariable-adjusted HR of 3.74 (95% CI, 1.97-7.10) for hip fracture, whereas pseudoexposure for stroke had an HR of 2.29 (95% CI, 1.20-4.35). CONCLUSIONS: A diagnosis of CVD was significantly associated with risk of subsequent hip fracture. Increased risks in co-twins without an index diagnosis suggest genetic factors in the association between CVD and osteoporotic fractures.
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| 20. |
- Thomsen, Peter, 1953, et al.
(författare)
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Structure of the interface between rabbit cortical bone and implants of gold, zirconium and titanium.
- 1997
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Ingår i: Journal of materials science. Materials in medicine. - 0957-4530. ; 8:11, s. 653-65
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Tidskriftsartikel (refereegranskat)abstract
- The role of surface properties (chemical and structural) for the interaction between biomaterials and tissue is not yet understood. In the present study, implants made of titanium, zirconium (transition metals with surface oxides) and gold (metallic surface) were inserted into the rabbit tibia. Light microscopic (LM) morphometry showed that after 1 and 6 mo the gold implants had less amount of bone within the threads and a lower degree of bone-implant contact than the titanium and zirconium implants, which did not differ from each other. These quantitative differences were supported by LM and ultrastructural observations of the interface. The ultrastructural observations in addition demonstrated that the layer of non-collagenous amorphous material located between the implant and the calcified bone was appreciably thicker around zirconium than around titanium implants. The factors potentially responsible for the observed morphological differences in the bone around the different material surfaces are discussed.
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| 21. |
- Vanden Bogaerde, L., et al.
(författare)
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A randomized case-series study comparing the stability of implant with two different surfaces placed in fresh extraction sockets and immediately loaded
- 2016
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Ingår i: International Journal of Dentistry. - : Hindawi Limited. - 1687-8728 .- 1687-8736. ; 2016
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Tidskriftsartikel (refereegranskat)abstract
- Background. Hydrophilic and moderately rough implant surfaces have been proposed to enhance the osseointegration response. Aim. The aim of this study was to compare early changes of stability for two implants with identical macrodesign but with different surface topographies. Materials and Methods. In 11 patients, a total of 22 implants (11 bimodal (minimally rough, control) and 11 proactive (moderately rough and hydrophilic, test), Neoss Ltd., Harrogate, UK) were immediately placed into fresh extraction sockets and immediately loaded. The peak insertion torque (IT) was measured in Ncm at placement. Resonance Frequency Analysis (RFA) measurements were made at baseline and 2, 4, 6, and 12 weeks after surgery. Results. The two implant types showed similar IT and RFA values at placement (NS). A dip of RFA values after 2 weeks followed by an increase was observed, where the test implant showed a less pronounced decrease and a more rapid recovery than the control implant. The test implants were significantly more stable than the control ones after 12 weeks. Conclusions. The results from the present study indicated that the hydrophilic and rougher test implant was more resistant to immediate loading and showed a significantly higher stability than the smoother control implant after 12 weeks. © 2016 Leonardo Vanden Bogaerde and Lars Sennerby.
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