| 1. |
- Bougas, Kostas, 1980, et al.
(författare)
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In vitro Evaluation of Calcium Phosphate Precipitation on Possibly Bioactive Titanium Surfaces in the Presence of Laminin.
- 2011
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Ingår i: Journal of Oral & Maxillofacial Research. - : Stilus Optimus. - 2029-283X. ; 2:3, s. e3-
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of the present study was to evaluate calcium phosphate precipitation and the amount of precipitated protein on three potentially bioactive surfaces when adding laminin in simulated body fluid.Material and Methods: Blasted titanium discs were prepared by three different techniques claimed to provide bioactivity: alkali and heat treatment (AH), anodic oxidation (AO) or hydroxyapatite coating (HA). A blasted surface incubated in laminin-containing simulated body fuid served as a positive control (B) while a blasted surface incubated in non laminin-containing simulated body fuid served as a negative control (B-). The immersion time was 1 hour, 24 hours, 72 hours and 1 week. Surface topography was investigated by interferometry and morphology by Scanning Electron Microscopy (SEM). Analysis of the precipitated calcium and phosphorous was performed by Energy Dispersive X-ray Spectroscopy (EDX) and the adsorbed laminin was quantified by iodine (125I) labeling.Results: SEM demonstrated that all specimens except for the negative control were totally covered with calcium phosphate (CaP) after 1 week. EDX revealed that B- demonstrated lower sum of Ca and P levels compared to the other groups after 1 week. Iodine labeling demonstrated that laminin precipitated in a similar manner on the possibly bioactive surfaces as on the positive control surface.Conclusions: Our results indicate that laminin precipitates equally on all tested titanium surfaces and may function as a nucleation center thus locally elevating the calcium concentration. Nevertheless further studies are required to clarify the role of laminin in the interaction of biomaterials with the host bone tissue.
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| 2. |
- Bougas, Kostas, 1980, et al.
(författare)
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Laminin Coating Promotes Calcium Phosphate Precipitation on Titanium Discs in vitro.
- 2011
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Ingår i: Journal of Oral & Maxillofacial Research. - : Stilus Optimus. - 2029-283X. ; 2:4, s. e5-
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The objective of this study was to investigate the effect of a laminin coating on calcium phosphate precipitation on three potentially bioactive titanium surfaces in simulated body fluid.Material and Methods: Blasted titanium discs were prepared by alkali and heat treatment (AH), anodic oxidation (AO) or hydroxyapatite coating (HA) and subsequently coated with laminin. A laminin coated blasted surface (B) served as a positive control while a blasted non coated (B-) served as a negative control. Surface morphology was examined by Scanning Electron Microscopy (SEM). The analysis of the precipitated calcium and phosphorous was performed by Energy Dispersive X-ray Spectroscopy (EDX).Results: The thickness of the laminin coating was estimated at 26 Å by ellipsometry. Interferometry revealed that the coating process did not affect any of the tested topographical parameters on µm level when comparing B to B-. After 2 weeks of incubation in SBF, the alkali-heat treated discs displayed the highest calcium phosphate deposition and the B group showed higher levels of calcium phosphate than the B- group.Conclusions: Our results suggest that laminin may have the potential to be used as a coating agent in order to enhance the osseoinductive performance of biomaterial surfaces, with the protein molecules possibly functioning as nucleation centres for apatite formation. Nevertheless, in vivo studies are required in order to clarify the longevity of the coating and its performance in the complex biological environment.
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| 3. |
- Edén Strindberg, Jerker, et al.
(författare)
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Comparison of Swedish and Norwegian Use of Cone-Beam Computed Tomography : a Questionnaire Study
- 2015
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Ingår i: Journal of Oral & Maxillofacial Research. - : Kaunas University of Medicine. - 2029-283X. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Cone-beam computed tomography in dentistry can be used in some countries by other dentists than specialists in radiology. The frequency of buying cone-beam computed tomography to examine patients is rapidly growing, thus knowledge of how to use it is very important. The aim was to compare the outcome of an investigation on the use of cone-beam computed tomography in Sweden with a previous Norwegian study, regarding specifically technical aspects. Material and Methods: The questionnaire contained 45 questions, including 35 comparable questions to Norwegian clinics one year previous. Results were based on inter-comparison of the outcome from each of the two questionnaire studies. Results: Responses rate was 71% in Sweden. There, most of cone-beam computed tomography (CBCT) examinations performed by dental nurses, while in Norway by specialists. More than two-thirds of the CBCT units had a scout image function, regularly used in both Sweden (79%) and Norway (75%). In Sweden 4% and in Norway 41% of the respondents did not wait for the report from the radiographic specialist before initiating treatment. Conclusions: The bilateral comparison showed an overall similarity between the two countries. The survey gave explicit and important knowledge of the need for education and training of the whole team, since radiation dose to the patient could vary a lot for the same kind of radiographic examination. It is essential to establish quality assurance protocols with defined responsibilities in the team in order to maintain high diagnostic accuracy for all examinations when using cone-beam computed tomography for patient examinations.
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| 4. |
- Ekberg, Ewacarin, et al.
(författare)
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Can MRI Observations Predict Treatment Outcome of Lavage in Patients with Painful TMJ Disc Displacement without Reduction?
- 2015
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Ingår i: Journal of Oral & Maxillofacial Research. - : Kaunas University of Medicine. - 2029-283X. ; 30:1
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The purpose of this study was to examine magnetic resonance imaging findings in patients with painful disc displacement without reduction of the temporomandibular joint to determine whether the findings were able to predict treatment outcome of lavage and a control group treated with local anaesthesia without lavage in a short-term: 3-month perspective. MATERIAL AND METHODS: Bilateral magnetic resonance images were taken of 37 patients with the clinical diagnosis of painful disc displacement without reduction. Twenty-three patients received unilateral extra-articular local anaesthetics and 14 unilateral lavage and extra-articular local anaesthetics. The primary treatment outcome defining success was reduction in pain intensity of at least 30% during jaw movement at the 3-month follow-up. RESULTS: Bilateral disc displacement was found in 30 patients. In 31 patients the disc on the treated side was deformed, and bilaterally in 19 patients. Osteoarthritis was observed in 28 patients, and 13 patients had bilateral changes. Thirty patients responded to treatment and 7 did not, with no difference between the two treated groups. In neither the treated nor the contralateral temporomandibular joint did treatment outcome depend on disc diagnosis, disc shape, joint effusion, or osseous diagnoses. Magnetic resonance imaging findings of disc position, disc shape, joint effusion or osseous diagnosis on the treated or contralateral side did not give information of treatment outcome. CONCLUSIONS: Magnetic resonance imaging findings could not predict treatment outcome in patients treated with either local anaesthetics or local anaesthetics and lavage.
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| 5. |
- Franke Stenport, Victoria, 1970, et al.
(författare)
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Precipitation of Calcium Phosphates in the Presence of Collagen Type I on Four Different Bioactive Titanium Surfaces: an in Vitro Study.
- 2015
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Ingår i: Journal of oral & maxillofacial research. - : Stilus Optimus. - 2029-283X. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- To compare the properties of calcium phosphate precipitation on four different bioactive surface preparations and one control surface in the simulated body fluid model with added collagen type I.Blasted titanium discs were treated with four different surface modifications, alkali and heat, sodium fluoride, anodic oxidation and hydroxyapatite coating. The discs were divided into five groups where one group, the blasted, served as control. The discs were immersed in simulated body fluid and collagen for 24 h, 3 days, 1 week and 2 weeks and then analysed by optical interferometry, scanning electron microscopy/energy dispersive X-ray analysis and X-ray photoelectron spectroscopy.All surfaces show small precipitates after 3 days which with longer immersion times increase. After 2 weeks the surfaces were completely covered with precipitates, and Ca/P ratios were approximately 1.3, independently on surface preparation. The fluoridated discs showed significantly (P ≤ 0.05) higher degree of CaP after one week of immersion as compared to the other surface preparations. The collagen type I content increased with time, as reflected by increased nitrogen content.The results from this study indicate that a fluoridated titanium surface may favour precipitation of calcium phosphate in the presence of collagen type I, as compared to the other surface treatments of the present study.
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| 6. |
- Gudac, Jelena, et al.
(författare)
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Comparison of Selected Anatomical and Treatment-related Diagnostic Parameters Estimated by Cone-Beam Computed Tomography and Digital Periapical Radiography in Teeth with Apical Periodontitis
- 2020
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Ingår i: Journal of Oral & Maxillofacial Research. - : Lithuanian University of Health Sciences, Faculty of Odontology Baltic Osseointegration Academy (BOA). - 2029-283X. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To compare selected anatomical and treatment-related diagnostic parameters estimated by cone-beam computed tomography and by digital periapical radiography in teeth with apical periodontitis, and to evaluate reliability of different examiners in interpretation of images obtained by both methods.Material and Methods: Teeth with apical periodontitis were evaluated independently by 2 endodontists and 1 radiologist based on 128 cone-beam computed tomography (CBCT) and 162 digital periapical radiography (DPR) images. Anatomical (size, relation with root, location of periapical radiolucency) and treatment-related (canal obturation length, homogeneity, coronal seal) parameters were assessed. Fleiss kappa reflected inter-observer agreement while intra-examiner agreement was estimated by Cohen's kappa. McNemar and McNemar-Bowker tests served for evaluation of differences between CBCT- and DPR-based estimates.Results: Cohen's kappa ranged from 0.62 to 1 for all examiners. Fleiss kappa values were nearly perfect for majority of parameters. Diagnostic discrepancy between methods was found for size of radiolucency that in 15 - 17% cases was larger, and in 25 - 28% smaller in DPR than in CBCT images. DPR revealed 20% of root canals scored as non-obturated while in CBCT - obturation present. Canal obturation was rated as homogenous by CBCT, while absent or non-homogenous by DPR, in 17 - 23%, and 11 - 14% of cases, respectively. Radiologist detected more root perforations in CBCT than in DPR images.Conclusions: Good intra- and inter-examiner agreement for anatomical and treatment-related diagnostic parameters was achieved using cone-beam computed tomography and digital periapical radiography methods and demonstrated similar diagnostic capability, although variation regarding root perforations and canal obturation quality was observed.
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| 7. |
- Hellén-Halme, Kristina, et al.
(författare)
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The Effects on Absorbed Dose Distribution in Intraoral X-ray Imaging When Using Tube Voltages of 60 and 70 kV for Bitewing Imaging.
- 2013
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Ingår i: eJournal of Oral and Maxillofacial Research. - : Stilus Optimus. - 2029-283X. ; 4:3, s. 2-2
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Tidskriftsartikel (refereegranskat)abstract
- Efforts are made in radiographic examinations to obtain the best image quality with the lowest possible absorbed dose to the patient. In dental radiography, the absorbed dose to patients is very low, but exposures are relatively frequent. It has been suggested that frequent low-dose exposures can pose a risk for development of future cancer. It has previously been reported that there was no significant difference in the diagnostic accuracy of approximal carious lesions in radiographs obtained using tube voltages of 60 and 70 kV. The aim of this study was, therefore, to evaluate the patient dose resulting from exposures at these tube voltages to obtain intraoral bitewing radiographs.
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| 8. |
- Henmi, Yoko, et al.
(författare)
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Bone Ingrowth to Ti Fibre Knit Block with High Deformability
- 2016
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Ingår i: Journal of Oral & Maxillofacial Research. - : Stilus Optimus. - 2029-283X. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The objective of this study is to develop a Ti fibre knit block without sintering, and to evaluate its deformability and new bone formation in vivo. Material and Methods A Ti fibre with a diameter of 150 μm was knitted to fabricate a Ti mesh tube. The mesh tube was compressed in a metal mould to fabricate porous Ti fibre knit blocks with three different porosities of 88%, 69%, and 50%. The elastic modulus and deformability were evaluated using a compression test. The knit block was implanted into bone defects of a rabbit’s hind limb, and new bone formation was evaluated using micro computed tomography (micro-CT) analysis and histological analysis. Results The knit blocks with 88% porosity showed excellent deformability, indicating potential appropriateness for bone defect filling. Although the porosities of the knit block were different, they indicated similar elastic modulus smaller than 1 GPa. The elastic modulus after deformation increased linearly as the applied compression stress increased. The micro-CT analysis indicated that in the block with 50% porosity new bone filled nearly all of the pore volume four weeks after implantation. In contrast, in the block with 88% porosity, new bone filled less than half of the pore volume even 12 weeks after implantation. The histological analysis also indicated new bone formation in the block. Conclusions The titanium fibre knit block with high porosity is potentially appropriate for bone defect filling, indicating good bone ingrowth after porosity reduction with applied compression.
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| 9. |
- Jimbo, Ryo, 1979, et al.
(författare)
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Protein adsorption to surface chemistry and crystal structure modification of titanium surfaces
- 2010
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Ingår i: Journal of Oral & Maxillofacial Research. - : Stilus Optimus. - 2029-283X. ; 1:3, s. e3-
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Tidskriftsartikel (refereegranskat)abstract
- 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 (TiO2) particles (control), and for the test group, TiO2 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 TiO2 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.
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| 10. |
- Johansson, Krister, et al.
(författare)
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Estimation of Blood Loss in Oral and Maxillofacial Surgery by Measurements of Low Haemoglobin Levels in Mixtures of Blood, Saliva and Saline : a Laboratory Study
- 2021
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Ingår i: Journal of Oral & Maxillofacial Research. - : Stilus Optimus. - 2029-283X. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Estimating blood loss is an important factor in several surgical procedures. The accuracy of blood loss measurements in situations where blood is mixed with saliva and saline is however uncertain. The purpose of this laboratory study was to ascertain if blood loss measurements in mixtures of blood, saline, and saliva are reliable and could be applicable in a clinical setting.Material and Methods: Venous blood and resting saliva were collected from six volunteers. Saliva, saline, and combinations thereof were mixed with blood to obtain different concentrations. A portable spectrophotometer was first used to measure the haemoglobin concentration in undiluted venous blood followed by measurements of the haemoglobin concentration after each dilution. To examine the strength of linear relationships, linear regression and Pearson correlations were used.Results: The measurements of haemoglobin concentrations in mixtures of blood, saline, and saliva were proven to be accurate for haemoglobin measurements > 0.3 g/dl (correlation = 0.986 to 1). For haemoglobin measurements < 0.3 g/dl, a small increase in haemoglobin values were reported, which was directly associated to the saliva concentration in the solution (correlation = 0.983 to 1). This interference of saliva was significantly eliminated by diluting the samples with saline, mimicking the clinical situation.Conclusions: The results suggest that a portable spectrophotometer can be used clinically to preoperatively measure the haemoglobin value of a venous blood sample and postoperatively measure the haemoglobin value of the collected liquids, including shed blood, thereby achieving a highly accurate method of measuring blood loss during oral and maxillofacial surgery.
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