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SyfteSyftet med studien var att utvärdera det kliniska resultatet av implantatbehandlingar utförda på studentkliniken på Malmö Högskola, samt att utvärdera de patientrapporterade resultaten efter behandlingarna.Material och metodMellan 2008-2012 fick 144 patienter totalt 328 implantat, alla patienter som utvärderats enligt det Nationella kvalitetsregistret för dentala implantat (NQRDI) inkluderades i sammanställningen av data. Ytterligare, kompletterande data om patienterna och implantaten som installerats samlades in via journaler, även information om patientens hälsa och dentala historik samlades in.Totalt skickades 223 OHIP-14S enkäter ut till patienter som fått implantatbehandling på studentkliniken och haft konstruktionen i bruk i minst ett år. Data från utvärderingarna, journaler samt enkätsvar extraherades och sammanställdes i Excel-dokument.ResultatTotalt hade 71 av de 144 patienter genomgått sin 3-års utvärdering, sammanställningen visade på hög success (96,8%) och survival (100%) hos de 156 installerade implantaten.121 (54%) av de 223 enkäterna som skickades ut besvarades. Utfallet visar att majoriteten av patienterna inte har några problem med sina tänder, mun eller proteser.KonklusionUtvärderingen av implantatbehandlingar gjorda på studentkliniken på Malmö Högskola visar på acceptabla resultat som är jämförbara med liknande studier inom området. Överlevnaden för suprakonstruktionerna är jämförbart med studier som utvärderat efter 5 år. Majoriteten av patienterna som behandlats med dentala implantat på studentkliniken har även rapporterat att de är nöjda med sin implantatbehandling och att de har en god självskattad munhälsa. / AimThe study aims to evaluate the success and survival rates of the implants installed at the undergraduate clinic at Malmö University, and to assess the patient reported outcomes of the treatments performed.Material and MethodBetween 2008-2012, 144 patients at the undergraduate clinic received a total of 328 implants, and all patients that were evaluated according to the National Quality Register for Dental Implants (NQRDI) after three years were included in the compilation of data. Additional and complementary data regarding patient and implant variables were also extracted from dental journals, as well as medical and dental history.A total of 223 OHIP-14S questionnaires were sent to an extended group of patients that have received implant treatment at the undergraduate clinic and had their construction in use for at least one year. The data from the evaluations, dental journals and the responded questionnaires were extracted and compiled in Excel-documents.ResultsOut of the 144 patients, 71 had undergone their 3 year evaluation, the compilation revealed high success (96,8%) and survival (100%) rates among the 156 installed implants.Out of the 223 questionnaires, 121 (54%) responses were received. The compilation present that the majority of the patients have a good self-assessed oral health and does not have any problems with their teeth, mouth or dentures.ConclusionThe outcome of implant treatments performed at the undergraduate clinic at Malmö University shows acceptable results comparable to outcomes in similar studies. The survival of supraconstructions is comparable to studies with a follow-up of 5 years. Furthermore, the majority of patients who received implant treatment at the undergraduate clinic are satisfied with their implant treatment and experience a good self-assessed oral health.

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Yes / Polyetheretherketone (or PEEK) is a thermoplastic polymer known for its high plasticity and toughness and has been widely employed as a material for a variety of load-bearing medical devices ranging from trauma implants to interspinal spacers and femoral stems. While being inherently chemically inert and therefore biocompatible and having very short lived post-radiation free radicals, PEEK presents different mechanical properties depending on its degree of crystallinity. It can be processed via extrusion, injection or compression moulding. However, these techniques do not allow high precision control over the fine morphological structure that strongly influences mechanical properties. Microinjection moulding, in contrast, makes it possible to produce fine details of medical implants with high precision and accuracy. Another advantage of this method is the controlled production of the material with heterogeneous structure due to variations in crystallinity. Having stiffness in the middle of the sample different from that at the edges enables a structure that mimics the bone/cartilage parts of an implant. This paper reports on the manufacturing of PEEK components by microinjection moulding, and their characterisation by physico-chemical (XRD, SAXS, TEM, FTIR, POM) and mechanical (tensile testing) means, in order to assess the suitability of use for biomedical application, such as spinal implants. We discuss the influence of such parameters as mould temperatures, injection speeds and hold pressures on the crystallinity and mechanical properties of the material. / Science Bridges: Bradford-China Programme for Pharmaceutical Sciences and Medical Technology, EP/G042365/1

L'objectif de cette étude est d'établir un lien possible entre la physiopathologie de la péri-implantite et la présence de cellules immunitaires (lymphocytes T (CD3) et macrophages (CD68)) présents dans le tissu conjonctif de lésions de péri-implantite comparativement au tissu péridentaire sain. Une analyse morphologique des échantillons colorés à l'hématoxyline et l'éosine ainsi qu'un marquage immunohistochimique de ces cellules ont été réalisés sur des biopsies de tissus péri-implantaires prélevées autour d'implants affectés par une péri-implantite sévère, et de tissus contrôles sains provenant de gingivectomies. L'identification des cellules positives a été réalisée à l'aide de la technique de marquage en immunofluorescence. À l'analyse histologique, les coupes ne contiennent pas les structures d'attache. Les résultats montrent une augmentation non significative de la densité de CD3 et de CD68. La densité des lymphocytes T et des macrophages dans les lésions de péri-implantite serait similaire à celle du tissu gingival sain.

We measured black bear (Ursus americanus) reproduction and cub survival during 1994 - 1998, and 1995 - 1999, respectively, in the George Washington and Jefferson National Forests in Virginia to determine age-specific and overall cub production and cub survival. We observed females in estrus between 6 June and 22 August; the mean date of estrus was 17 July. Ages of primiparity ranged between 3 and 5 years with an average of 3.36 years (n=11, SE=0.15). Average litter size for 1995 - 1998 was 2.32 cubs/litter (SE=0.11, n=53) and 85.7% of available females ≥ age 4 (those not accompanied by cubs) reproduced in a given den season. We monitored 98 (48M:50F) black bear cubs equipped with expandable radio-collars (Higgins 1997) or radio transmitters implanted subcutaneously between 1995 and 1999 to estimate cub survival. Kaplan-Meier staggered entry analysis provided 306-day survival rates for 82 cubs. The survival estimates for males and females were 73% (0.49, 0.96) and 91% (0.80, 1.00), respectively. The overall 306-day survival rate for all cubs was 81% (0.67,0.94) using Kaplan-Meier and 76% (0.63, 0.92) using Heisey-Fuller (Mayfield) methods. We also evaluated the utility of radio transmitters implanted subcutaneously in 42 (21M:21F) wild black bear (Ursus americanus) cubs from 2 study areas in Virginia between 1996 and 1999 to monitor first year cub survival. More than 64% (27 of 42) of the implants fell out prematurely (2-198 days), and 16.6% (7 of 42) failed for unknown reasons. Less than 5% (2 of 42) of these cubs denned wearing failed implants, and 9.5% (4 of 42) experienced mortality less than 1 month after implant surgery. About 9.5% (4 of 42) of implanted black bear cubs wore working transmitters through to the following den season. / Master of Science

Electrolytic charging of hydrogen, at room temperature and in the absence of externally applied stress, induced surface cracking in 316 stainless steel and cobalt based ZIMALOY. Hot Isostatic Pressed (H.I.P.) ZIMALOY showed less susceptibility to surface cracking than 316 stainless steel samples. The susceptibility of 316 stainless steel to surface cracking was determined with samples in the High Energy Rate Forged (HERF), the sensitized, the annealed, and the annealed and sensitized conditions. Investigations showed that surface cracking typically occurred at specific microstructural features. Hence, the relative susceptibilities of twin boundaries, slip bands, grain boundaries, and heavily sensitized regions was established. It was observed that twin boundaries crack most readily in non-sensitized samples, and that both grain boundaries and twin boundaries crack easily in sensitized structures. These observations, coupled with the similarity between hydrogen embrittlement and failure of orthopedic implants, suggest that orthopedic applications should use H.I.P. ZIMALOY in preference to 316 stainless steel whenever possible, and that when the use of 316 stainless steel is unavoidable, HERFed parts should be used. Further investigations are recommended to better assess the hydrogen compatibility of sensitized 316 stainless steel, and to determine the influence of sensitization on the suitability of 316 stainless steel for orthopedic application. / Master of Science

Postlingually deafened cochlear implant (CI) adults have large variability in speech perception abilities. While CIs are one of the most successful neural prosthetic devices, they are not able to adequately provide fine structure cues which results in a degraded signal for the listener to interpret. While behavioral measures remain the gold standard for determining speech perception abilities, an objective measure is needed for patients who are unable to provide reliable behavioral responses. Behavioral, cognitive, and neural measures were collected in this study to identify potential neural biomarkers that correlate with speech perception performance. Behavioral experiments evaluated participants' abilities to identify, discriminate, and recognize words as well as sentences in quiet and in noise. Cognitive measures were assessed to determine the roles of attention, impulse control, memory, and cognitive flexibility on speech recognition. Auditory event-related potentials (ERP) were obtained with a double oddball paradigm to produce the mismatch negativity (MMN) response, which has been shown to have associations with phonetic categorical perception at the group level. The results indicated that executive function is highly predictive of speech performance and that the MMN is associated with categorical perception at the individual level. These findings are clinically relevant to determining appropriate follow-up care post-implantation.

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"Thèse en cotutelle : Doctorat en génie des matériaux et de la métallurgie, Université Laval, Québec, Canada, Philosophiæ doctor (Ph. D.) et Politecnico di Milano, Milano, Italie." / Récemment, le Fe et ses alliages ont montré leur potentiel en tant que matériaux dégradables pour des applications biomédicales. Néanmoins, la vitesse de corrosion lente limite leurs performances dans certaines situations. Les matériaux composites à matrice de fer représentent une approche possible, non seulement pour améliorer leurs propriétés mécaniques, mais aussi pour accélérer et ajuster la vitesse de corrosion dans un environnement physiologique. Dans ce travail, des composites à base de Fe renforcés par des particules Mg2Si ont été proposés. Les poudres initiales ont été préparées par différentes combinaisons de procédés de mélange et de broyage, et finalement consolidées par laminage à chaud. L'influence de la microstructure sur les propriétés mécaniques et le comportement à la corrosion de Fe/Mg2Si a été étudiée. Les échantillons contenant des particules Mg2Si plus petites présentaient une distribution plus homogène du renforcement. Le rendement et l’état limite ultime à la traction ont augmenté par rapport à ceux du Fe pur. La présence des particules de renforcement a joué un rôle crucial dans la susceptibilité à l'attaque de corrosion localisée dans les composites à base de Fe. L'initiation de la corrosion et son développement ont été systématiquement suivis pour étudier le mécanisme de corrosion. L'importance des particules de Mg2Si dans le déclenchement des processus de corrosion a été expliquée. Des mesures électrochimiques et des tests d'immersion statique ont indiqué que l'ajout de Mg2Si pourrait augmenter le taux de corrosion du Fe. Il a été constaté que la taille et la distribution des particules de renfort jouaient un rôle crucial à l'uniformité de l'attaque de corrosion. Après, une série de tests d'immersion à différents intervalles d'exposition (20, 50 et 100 jours) à la solution modifiée de Hanks a été réalisée à fin d’évaluer le comportement de dégradation des composites Fe/Mg2Si et Fe pur préparés par différentes techniques de métallurgie des poudres. Les résultats ont révélé l’importance du Mg2Si dans la composition et la stabilité des films protecteurs formés lors des expériences de corrosion statique. Les composites Fe/Mg2Si présentaient des taux de dégradation plus élevés que le Fe pur à toutes les étapes du test d'immersion. Les taux de dégradation à des intervalles d'exposition distincts dépendaient fortement de la composition et de la stabilité des films protecteurs d'oxyde, d'hydroxyde, de carbonate et de phosphate formés sur les surfaces dégradées. La libération d'ions Fe dans la solution aux stades ultérieurs de l'expérience était limitée en raison de l'effet de barrière dû au dépôt insoluble. Cette étude fondamentale a servi de base aux processus de formation de film protecteur dans la solution de Hanks modifiée, permettant une identification détaillée de leurs caractéristiques. / Fe-based alloys have shown a potential as a degradable material for biomedical applications. Nevertheless, the slow corrosion rate limits their performance as a biodegradable implant. One approach to control and modify their corrosion properties is the reinforcement addition, to create metal matrix composites in which the second phase is aimed at tuning not only the mechanical properties but also the corrosion mode and rate in a physiological environment. This thesis presents an original and thorough contribution on a very pertinent topic, the design, development, and validation of a new Fe/Mg2Si composites prepared powder metallurgy. The initial powders were prepared by different combinations of mixing and high energy ball milling processes and finally consolidated by hot rolling. Mechanical properties, microstructural features, as well as the corrosion performance, were extensively investigated in relation to the reinforcement size and distribution. The composites made of small size reinforcement particles showed a general increase in tensile strength. For instance, high energy ball milled samples exhibited better tensile performances (YS = 523 MPa, UTS = 630 MPa) while having the lower ductility (around 4%). A fundamental understanding of corrosion initiation, protective film formation, and growth on Fe-based materials and leads to a design of smarter and surface responsive biomaterials with modulable degradation rates, at distinct stages of the corrosion process. Here, the corrosion performance of Fe/Mg2Si composites varied with the reinforcement size and distribution. The predominant localized pitting corrosion in Fe/Mg2Si prepared by mixing was replaced by a more uniform pattern found in samples produced by mechanical milling. Further, it was found that Mg2Si plays a significant role in the composition and stability of the protective films formed during the static corrosion experiments. Fe/Mg2Si showed a higher corrosion rate compared to that of pure Fe at all stages of the corrosion experiment (1, 10, 20, 50 and 100 days). Moreover, the final degradation products varied with the substrate chemical composition and microstructure. In case of pure Fe, low solubility (Fe3(PO4)2) covered the entire surface, while Fe/Mg2Si exhibited the presence of carbonates at the latest stages of the test. The details about the degradation behaviour during long-term exposure times to the physiological environment highlighted in this work add a new knowledge on corrosion mechanism of degradable implant materials. In particular, the ability to tune mechanical and corrosion behavior of the composites as a function of reinforcement properties and manufacturing method was experimentally verified, highlighting the microstructure-corrosion property relationship. / I biomateriali in ferro puro e in leghe a base di ferro presentano una combinazione interessante di proprietà meccaniche, elettrochimiche e biologiche; per questo motivo, questa classe di materiali metallici possono trovare utilizzo in applicazioni di tipo impiantistico biomedicale. Malgrado ciò, nonostante le sue soddisfacenti proprietà meccaniche, questo elemento impiegato allo stato puro mostra un inconveniente rilevante - un basso tasso di degradazione. L’oggetto di questa tesi è lo studio di un nuovo gruppo di materiali biodegradabili compositi a matrice ferrosa (Fe/Mg2Si), in cui il Fe costituisce la matrice e il Mg2Si è impiegato come rinforzo; questi materiali sono stati sviluppati con tecniche di metallurgia delle polveri, e presentano un, alta resistenza meccanica come caratteristica principale. Le polveri che costituiscono i materiali di partenza sono stati preparati con diverse combinazioni di procedure oltre al semplice mescolamento e/o high energy ball milling (macinatura in mulino a sfere a alta energia). Tutte le formulazioni preparate sono state compattate attraverso laminazione a caldo. Le proprietà meccaniche, le caratteristiche microstrutturali, la composizione delle fasi e le prestazioni in termini di corrosione sono state studiate dettagliatamente, in relazione alla dimensione delle particelle di rinforzo e della loro distribuzione. Lavori precedenti hanno confermato l’efficacia dell’aggiunta di una seconda fase, soprattutto se finemente dispersa, per aumentare il tasso di degradazione di materiali metallici per applicazioni biomedicali a base Fe: gli esperimenti condotti in questo lavoro hanno confermato che i compositi Fe/Mg2Si hanno mostrato, rispetto al Fe puro che compone la matrice, non solo una resistenza meccanica più elevata, ma anche un tasso di degradazione più alto negli esperimenti di laboratorio in vitro. Infine, i materiali ottenuti tramite high energy ball milling, presentano una resistenza alla trazione migliore (carico di snervamento= 523 MPa, resistenza alla trazione = 630 MPa), ma contemporaneamente una ridotta duttilità (circa 4%). Una attenzione particolare è stata posta nello studio degli effetti della presenza di Mg2Si sui meccanismi di corrosione.Tutti i compositi studiati hanno mostrato un tasso di degradazione più elevato rispetto alla matrice fabbricata con la stessa procedura; inoltre, la formazione del film di prodotti di degradazione sulla superficie del materiale cambiava in maniera rilevante in funzione della composizione chimica del substrato e della sua microstruttura. Nel caso del Fe puro, cristalli isolati di vivianite (Fe3(PO4)2) erano presenti su tutta la superficie, mentre carbonati di Fe si formavano principalmente sulla superficie dei compositi, specialmente negli ultimi stadi del processo di degradazione.