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  • 1.
    Berglund, Anders
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Branting-Ekenbäck, C
    Ohlson, M
    En översikt över chairside CAD/CAM-system i Sverige. Garanteras patientsäkerheten genom CE-märkningen av utrustning och material?2013Report (Other academic)
    Abstract [sv]

    Inom odontologin har Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) blivit allt vanligare, främst på tandtekniska laboratorier, men tekniken blir också vanligare på tandläkarklinikerna, s.k. chairside CAD/CAM. Chairside CAD/CAM innebär att tandläkaren efter preparationen av en tand framställer tandersättningen i tre steg. I första steget används en intraoral scanner istället för den traditionella avtryckstagningen (Mörmann et al., 2002; Beuer et al., 2008; Hehn, 2001). Man kan även scanna modeller och avtryck, vilket kan vara bra om patienten har svårt att gapa eller har hög salivproduktion, då scannrarna är känsliga för fuktiga miljöer (Kachalia et al., 2010). Det digitala avtrycket överförs till datorn, där uppgifterna bearbetas och en modell av tänderna skapas i 3D. I det andra steget designar tandläkaren tandersättningen på 3D-modellen. Här bestämmer tandläkaren kusphöjd, kontakter approximalt, utsträckning mot preparationsgränsen och utseende på tandersättningen. I det tredje steget fräses tandersättningen fram ur ett keramblock i en fräsmaskin. Ofta målas kronan här för att karaktärisera den och ge den ett mer tandlikt utseende innan den bränns i ugn. Med större möjligheter att själv kunna sköta hela processen fram till färdig tandkonstruktion måste tandläkaren fundera över hur kvaliteten och säkerheten hos de färdiga produkterna kan säkerställas. Färdiga tandtekniska arbeten räknas som specialanpassade medicintekniska produkter och ska inte CE-märkas men de material som ingår i arbetet är oftast CE-märkta. Lag (1993:584) om medicintekniska produkter och Läkemedelsverkets föreskrifter (LVFS 2003:11) om medicintekniska produkter innehåller krav på att medicintekniska produkter som släpps ut på marknaden ska vara lämpliga och säkra för sina användningsområden genom att krav ställs som ska leda till att allvarliga avvikelser, olyckor och tillbud på grund av produkterna så långt som möjligt ska kunna undvikas. Avvikelser inkluderar här både funktionsfel och misstänkta biverkningar. Innan ett tandtekniskt laboratorium får börja leverera tandtekniska arbeten till tandläkare måste ett antal krav vara uppfyllda för att bl.a. säkerställa säkerheten hos dessa produkter för patienterna. Laboratoriet ska vara registrerat hos Läkemedelsverket och vid registreringen måste man intyga att man har en tillverkningsverksamhet som uppfyller de krav för specialanpassade medicintekniska produkter som ställs i LVFS 2003:11. Medicintekniska produkter ska konstrueras och tillverkas på ett sådant sätt att de inte äventyrar patienternas kliniska tillstånd eller säkerhet, användarnas eller i förekommande fall andra personers hälsa och säkerhet, när de används under avsedda förhållanden och för sitt avsedda ändamål. Riskerna med att använda produkterna ska vara acceptabla med tanke på fördelarna för patienten och förenliga med en hög hälso-och säkerhetsnivå. Detta innefattar omfattande krav både på produkt och tillverkningsprocess. Det finns en del oklarheter rörande hur det regelverk som styr framställningen av tandtekniska arbeten tillämpas för arbeten tillverkade med chairside CAD/CAM.

  • 2. Clemente, Francesco
    et al.
    D'Alonzo, Marco
    Controzzi, Marco
    Edin, Benoni B.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Physiology.
    Cipriani, Christian
    Non-Invasive, Temporally Discrete Feedback of Object Contact and Release Improves Grasp Control of Closed-Loop Myoelectric Transradial Prostheses2016In: IEEE transactions on neural systems and rehabilitation engineering, ISSN 1534-4320, E-ISSN 1558-0210, Vol. 24, no 12, p. 1314-1322Article in journal (Refereed)
    Abstract [en]

    Human grasping and manipulation control critically depends on tactile feedback. Without this feedback, the ability for fine control of a prosthesis is limited in upper limb amputees. Although various approaches have been investigated in the past, at present there is no commercially available device able to restore tactile feedback in upper limb amputees. Based on the Discrete Event-driven Sensory feedback Control (DESC) policy we present a device able to deliver short-lasting vibrotactile feedback to transradial amputees using commercially available myoelectric hands. The device (DESC-glove) comprises sensorized thimbles to be placed on the prosthesis digits, a battery-powered electronic board, and vibrating units embedded in an arm-cuff being transiently activated when the prosthesis makes and breaks contact with objects. The consequences of using the DESC-glove were evaluated in a longitudinal study. Five transradial amputees were equipped with the device for onemonth at home. Through a simple test proposed here for the first time-the virtual eggs test-we demonstrate the effectiveness of the device for prosthetic control in daily life conditions. In the future the device could be easily exploited as an add-on to complement myoelectric prostheses or even embedded in prosthetic sockets to enhance their control by upper limb amputees.

  • 3.
    Myllymaa, Katja
    et al.
    Microsensor Laboratory, School of Engineering and Technology, Savonia University of Applied Sciences, Kuopio, Finland; Department of Physics, University of Kuopio, Kuopio, Finland.
    Myllymaa, Sami
    Department of Physics, University of Kuopio, Kuopio, Finland.
    Korhonen, Hannu
    Department of Physics, University of Kuopio, Kuopio, Finland.
    Lammi, Mikko
    Departmentof Applied Biotechnology, University of Kuopio, Kuopio; Biocenter Kuopio, University of Kuopio, Kuopio, Finland.
    Saarenpää, Hanna
    Department of Chemistry, University of Joensuu, Joensuu, Finland.
    Suvanto, Mika
    Department of Chemistry, University of Joensuu, Joensuu, Finland.
    Pakkanen, Tapani
    Department of Chemistry, University of Joensuu, Joensuu, Finland.
    Tiitu, Virpi
    Department of Biomedicine, Anatomy, University of Kuopio, Kuopio, Finland.
    Lappalainen, Reijo
    Department of Physics, University of Kuopio, Kuopio, Finland.
    Improved adherence and spreading of Saos-2 cells on polypropylene surfaces achieved by surface texturing and carbon nitride coating.2009In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 20, no 11, p. 2337-2347, article id 19507005Article in journal (Refereed)
    Abstract [en]

    The adhesion and contact guidance of human primary osteogenic sarcoma cells (Saos-2) were characterized on smooth, microstructured (MST) and micro- and nano-structured (MNST) polypropylene (PP) and on the same samples with a silicon-doped carbon nitride (C(3)N(4)-Si) coating. Injection molding was used to pattern the PP surfaces and the coating was obtained by using ultra-short pulsed laser deposition (USPLD). Surfaces were characterized using atomic force microscopy and surface energy components were calculated according to the Owens-Wendt model. The results showed C(3)N(4)-Si coated surfaces to be significantly more hydrophilic than uncoated ones. In addition, there were 86% more cells in the smooth C(3)N(4)-Si coated PP compared to smooth uncoated PP and 551%/476% more cells with MST/MNST C(3)N(4)-Si coated PP than could be obtained with MST/MNST uncoated PP. Thus the adhesion, spreading and contact guidance of osteoblast-like cells was effectively improved by combining surface texturing and deposition of osteocompatible C(3)N(4)-Si coating.

  • 4. Raina, Deepak Bushan
    et al.
    Larsson, David
    Umeå University, Faculty of Medicine. Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Orthopedics, Lund 221 85, Sweden.
    Mrkonjic, Filip
    Isaksson, Hanna
    Kumar, Ashok
    Lidgren, Lars
    Tagil, Magnus
    Gelatin- hydroxyapatite- calcium sulphate based biomaterial for long term sustained delivery of bone morphogenic protein-2 and zoledronic acid for increased bone formation: In-vitro and in-vivo carrier properties2018In: Journal of Controlled Release, ISSN 0168-3659, E-ISSN 1873-4995, Vol. 272, p. 83-96Article in journal (Refereed)
    Abstract [en]

    In this study, a novel macroporous composite biomaterial consisting of gelatin-hydroxyapatite-calcium sulphate for delivery of bone morphogenic protein-2 (rhBMP-2) and zoledronic acid (ZA) has been developed. The biomaterial scaffold has a porous structure and functionalization of the scaffold with rhBMP-2 induces osteogenic differentiation of MC3T3-e1 cells seen by a significant increase in biochemical and genetic markers of osteoblastic differentiation. In-vivo muscle pouch experiments showed higher mineralization using scaffold + rhBMP-2 when compared to an approved absorbable collagen sponge (ACS) + rhBMP-2 as verified by micro-CT. Co-delivery of rhBMP-2 + ZA via the novel scaffold enabled a reduction in the effective rhBMP-2 doses. The presence of tartrate resistant acid phosphatase staining in the rhBMP-2 group indicates osteoclastic resorption, which could be stalled by adding ZA, which by speculation could explain the net increase in mineralization. The new scaffold allowed for slow release of rhBMP-2 in-vitro (3.3 +/- 0.1%) after 4 weeks. Using single photon emission computed tomography (SPECT), the release kinetics of I-125-rhBMP-2 in-vivo was followed for 4 weeks and a total of 65.3 +/- 15.2% I-125-rhBMP-2 was released from the scaffolds. In-vitro C-14-ZA release curve shows an initial burst release on day 1 (8.8 +/- 0.7%) followed by a slow release during the following 4 weeks (13 +/- 0.1%). In-vivo, an initial release of 43.2 +/- 7.6% of C-14-ZA was detected after 1 day, after which the scaffold retained the remaining ZA during 4-weeks. Taken together, our results show that the developed biomaterial is an efficient carrier for spatio-temporal delivery of rhBMP-2 and ZA leading to increased bone formation compared to commercially available carrier for rhBMP-2.

  • 5. Raina, Deepak Bushan
    et al.
    Larsson, David
    Umeå University, Faculty of Medicine, Department of Clinical Sciences. Lund University, Faculty of Medicine, Department of Clinical Sciences Lund, Orthopedics, Lund, Sweden.
    Sezgin, Erdem Aras
    Isaksson, Hanna
    Tägil, Magnus
    Lidgren, Lars
    Biomodulation of an implant for enhanced bone-implant anchorage2019In: Acta Biomaterialia, ISSN 1742-7061, E-ISSN 1878-7568, Vol. 96, p. 619-630Article in journal (Refereed)
    Abstract [en]

    Aseptic loosening of implants is the major cause for revision surgery. By modulating the bone-implant interface, early bone-implant anchorage could be improved. Implant surface manipulation by the addition of osteopromotive molecules locally and systemically to promote implant integration has been described with limited success. This study describes a novel approach by making the implant capable of biologically modulating its surroundings. It was hypothesized that the early implant fixation would improve by filling the interior of the implant with a carrier providing spatio-temporal release of bone active drugs with known osteogenic effect. The implant consisted of a threaded polyether ether ketone (PEEK) hollow chamber with holes at the bottom. The implant was filled with a calcium sulphate (CaS)/hydroxyapatite (HA) carrier, delivering two bone active molecules; zoledronic acid (ZA) and bone morphogenic protein-2 (BMP-2). At first, a rat abdominal muscle pouch model indicated a sustained in-vivo release of both I-125-rhBMP-2 (57%) and C-14-ZA (22%) from the CaS/HA carrier over a period of 4-weeks. The biomodulated implant was then inserted in the proximal tibia in rats with the following experimental groups: G1) Empty implant, G2) Implant + CaS/HA, G3) Implant + CaS/HA + ZA and G4) Implant + CaS/HA + ZA + rhBMP-2. Significantly higher bone volume (BV) was seen around the implant in groups G3 (3.3 +/- 0.7 mm(3)) and G4 (3.1 +/- 0.7 mm(3)) compared to the control (1.3 +/- 0.4 mm(3)) using micro-computed tomography and qualitative histology. Group G3, also exhibited significantly higher pull-out force and absorbed energy when compared to the control group G1. These findings indicate that a low dose of ZA alone, released in a controlled manner from within a fenestrated implant is enough to improve implant anchorage without the need of adding rhBMP-2. This simple method of using a fenestrated implant containing a ceramic carrier releasing bone active molecules improved bone anchorage and could clinically reduce prosthetic failure. Statement of Significance Aseptic loosening remains as a major cause for implant revisions and early reaction of surrounding bone to the prosthesis is important for longevity. A novel approach to enhance early bone-implant anchorage is presented. The implant is filled with a carrier providing controlled release of bone active molecules. In an animal model, a calcium sulphate (CaS)/hydroxyapatite (HA) carrier was used to provide a spatio-temporal release of bone morphogenic protein-2 (BMP-2) and zoledronic acid (ZA). Significantly better bone-implant integration was achieved using ZA alone, thereby eliminating the need for adding BMP-2. The developed method of implant biomodulation holds potential to prevent implant loosening and is an alternative to prosthetic coatings or systemic drug treatment. Importantly, all constituents are approved for clinical use.

  • 6.
    Shchukarev, Andrey
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Malekzadeh, Behnosh Öhrnell
    Ransjö, Maria
    Tengvall, Pentti
    Westerlund, Anna
    Surface characterization of insulin-coated Ti6Al4V medical implants conditioned in cell culture medium: an XPS study2017In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 216, p. 33-38Article in journal (Refereed)
    Abstract [en]

    Surface characterization of insulin-coated Ti6Al4V medical implants, after incubation in α-minimum essential medium (α-MEM), was done by X-ray photoelectron spectroscopy (XPS), in order to analyze the insulin behavior at the implant – α-MEM interface. In the absence of serum proteins in cell culture medium, the coated insulin layer remained intact, but experienced a time-dependent structural transformation exposing hydrophobic parts of the protein toward the solution. The presence of fetal bovine serum (FBS) in the medium resulted in partial substitution of insulin by serum proteins. In spite of some insulin release, the remaining coated layer demonstrated a direct surface effect by stabilizing the structure of protein competitors, and by supporting the accumulation of calcium and phosphate ions at the interface. A structurally stable protein layer with incorporated calcium and phosphate ions at the implant–tissue interface could be an important prerequisite for enhanced bone formation.

  • 7.
    Stensdotter, Ann-Katrin
    et al.
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy. Sør-Trøndelag University College, Trondheim, Norway.
    Bjerke, Joakim
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy. Sør-Trøndelag University College, Trondheim, Norway.
    Djupsjobacka, Mats
    Postural sway in single-limb and bilateral quiet standing after unilateral total knee arthroplasty2015In: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 41, no 3, p. 769-773Article in journal (Refereed)
    Abstract [en]

    Aim: To investigate whether total knee arthroplasty (TKA) was associated with stability in single-limb stance and whether reduced stability in single-limb stance was associated with increased postural sway in bilateral quiet standing.

    Methods: 3D kinematics for center of mass was used to assess postural sway in 23 subjects with TKA and 23 controls. Tests included bilateral quiet standing with and without vision and on a compliant surface, and single-limb stance.

    Results: 30% of the subjects in the TKA group were unable to maintain single-limb stance for 20 s on any leg. Of the 70% in the TKA group able to stand on one leg, mean sway velocity in the medio-lateral direction was marginally higher for the prosthetic side (p = .02), but no differences were found between the TKA and the control group in single-limb stance. Performance in bilateral quiet standing was similar in TKA-subjects, able as well as unable to stand on one leg, and controls. Reduced quadriceps strength in the contralateral leg, higher BMI, and older age predicted failure to maintain single-limb stance.

    Conclusion: In subjects able to stand on one leg, performance was considered comparable between the prosthetic and contralateral side and between groups. Inability to stand on one leg did not affect postural sway in bilateral quiet standing. The results suggest that inability to maintain single-limb stance is explained by reduced physical capacity rather than the knee condition in itself. The present study emphasizes the importance of physical activity to improve strength and functional capacity.

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