81 research outputs found

    Tissue engineering: a challenge of today's medicine

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    During the last years, tissue engineering-based therapies have been introduced in clinical practice in the head and face area. The regeneration of complex tissue structures for all sites of the body is envisioned for the future. In the present situation, specialists of the different fields publish excellent research papers in specialised journals. As a result, the scientific community, seperated towards distinct sub-specialities, has difficulties in communication. To overcome this problem, the demanding, complex and interdisciplinary aspects of tissue engineering has to be approached from new ways. We have conceptualised Head & Face Medicine therefore as a thematically broad ranged journal, including all disciplines involved in the head and neck area. We hope this journal will attract basic researchers and clinicians who are involved in investigating and applying complex themes (examplified by tissue engineering) in the head and face region and will contribute to a gain in scientific information, communication, and collaboration in order to improve the outcome of patient treatments

    Arstiüliõpilaste stress, läbipõlemine ja tervis kolmel esimesel õppeaastal

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    Eesmärk. Kirjeldada arstiüliõpilaste hinnanguid oma stressitasemele, tervise-, meeleolu-, motivatsiooni- ja läbipõlemisnäitajatele esimesel, kolmandal ja viiendal semestril ning võrrelda tulemusi semestrite ja erialade kaupa. Metoodika. 2010. aasta sügisel korraldati esimest, kolmandat ja viiendat semestrit ülikoolis õppivate arstiüliõpilaste hulgas anonüümne ankeetküsitlus. Küsimustik oli koostatud rahvusvaheliselt valideeritud küsimustike põhjal. Vaatluse alla võeti seitse alavaldkonda: üldandmed, motivatsioon õpinguteks, eksamite soorituskindlus, meeleolu, stressitase, tervise ja läbipõlemise näitajad. Tulemuste analüüsimisel kasutati üldsagedustabeleid, c2-testi, mitteparameetrilist t-testi ja dispersioonanalüüsi. Tulemused. Valim koosnes 345 arstiüliõpilasest. Üldine keskmine vastamismäär oli 51,6% ning see oli suurim ravi- (60%) ja väikseim proviisoriüliõpilaste hulgas (25,5%). Vastajate keskmine vanus oli 20,8 ± 1,9 aastat. Vastanutest suurema osa moodustasid eestlased ja naisüliõpilased. Võrreldes esimese semestriga, oli viienda semestri üliõpilaste hulgas oluliselt rohkem neid, kes hindasid oma stressitaseme kõrgeks, terviseseisundi halvaks, õpimotivatsiooni ja eksamite soorituskindluse madalaks (p Keskmiste skooride võrdlus kinnitas, et võrreldes hinnangutega 1. ja 3. semestril, oli viiendal semestril oluliselt kõrgem stressi-, emotsionaalse kurnatuse ja küünilisuse tase ning madalam õpimotivatsioon, halvem üldine ja vaimne tervis ning rohkem haigussümptomeid ja meelolulangust (p Järeldused. Arstiüliõpilaste hinnangud stressitasemele, tervisele, läbipõlemisnäitajatele, meeleolule, õpimotivatsioonile ja eksamite soorituskindlusele sõltuvad õppesemestrist, erialast ja mõneti ka soost. Seetõttu tuleb rohkem tähelepanu pöörata arstiüliõpilaste tervisele ja seda eriti ravieriala tudengitele viiendal semestril ning naisüliõpilastele. Tudengite stressijuhtimise oskusi tuleks parandada alates õpingute algusest.Eesti Arst 2014; 93(10):561–56

    Integration of an Objective Structured Clinical Examination (OSCE) into the Dental Preliminary Exams

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    Introduction: In the pre-clinical phase of the study of dentistry at the University of Greifswald, the course “Early Patient Contact (EPC)” is conducted within the framework of Community Medicine/Dentistry. The course is based on three pillars: the patient visiting program, special problem-oriented seminars, and communication training for doctors. The essential goal consists of providing students with real patient contact right at the beginning of their study of dentistry, thus making the study of dentistry patient-based very early on. Students are trained in taking comprehensive anamneses and recording clinical findings

    A retrospective analysis of submissions, acceptance rate, open peer review operations, and prepublication bias of the multidisciplinary open access journal Head & Face Medicine

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    <p>Abstract</p> <p>Background</p> <p><it>Head & Face Medicine </it>(HFM) was launched in August 2005 to provide multidisciplinary science in the field of head and face disorders with an open access and open peer review publication platform. The objective of this study is to evaluate the characteristics of submissions, the effectiveness of open peer reviewing, and factors biasing the acceptance or rejection of submitted manuscripts.</p> <p>Methods</p> <p>A 1-year period of submissions and all concomitant journal operations were retrospectively analyzed. The analysis included submission rate, reviewer rate, acceptance rate, article type, and differences in duration for peer reviewing, final decision, publishing, and PubMed inclusion. Statistical analysis included Mann-Whitney U test, Chi-square test, regression analysis, and binary logistic regression.</p> <p>Results</p> <p><it>HFM </it>received 126 articles (10.5 articles/month) for consideration in the first year. Submissions have been increasing, but not significantly over time. Peer reviewing was completed for 82 articles and resulted in an acceptance rate of 48.8%. In total, 431 peer reviewers were invited (5.3/manuscript), of which 40.4% agreed to review. The mean peer review time was 37.8 days. The mean time between submission and acceptance (including time for revision) was 95.9 days. Accepted papers were published on average 99.3 days after submission. The mean time between manuscript submission and PubMed inclusion was 101.3 days. The main article types submitted to HFM were original research, reviews, and case reports. The article type had no influence on rejection or acceptance. The variable 'number of invited reviewers' was the only significant (p < 0.05) predictor for rejection of manuscripts.</p> <p>Conclusion</p> <p>The positive trend in submissions confirms the need for publication platforms for multidisciplinary science. <it>HFM's </it>peer review time comes in shorter than the 6-weeks turnaround time the Editors set themselves as the maximum. Rejection of manuscripts was associated with the number of invited reviewers. None of the other parameters tested had any effect on the final decision. Thus, <it>HFM's </it>ethical policy, which is based on Open Access, Open Peer, and transparency of journal operations, is free of 'editorial bias' in accepting manuscripts.</p> <p>Original data</p> <p>Provided as a downloadable tab-delimited text file (URL and variable code available under section 'additional files').</p

    Osseointegration of zirconia implants compared with titanium : an in vivo study

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    Background Titanium and titanium alloys are widely used for fabrication of dental implants. Since the material composition and the surface topography of a biomaterial play a fundamental role in osseointegration, various chemical and physical surface modifications have been developed to improve osseous healing. Zirconia-based implants were introduced into dental implantology as an altenative to titanium implants. Zirconia seems to be a suitable implant material because of its tooth-like colour, its mechanical properties and its biocompatibility. As the osseointegration of zirconia implants has not been extensively investigated, the aim of this study was to compare the osseous healing of zirconia implants with titanium implants which have a roughened surface but otherwise similar implant geometries. Methods Forty-eight zirconia and titanium implants were introduced into the tibia of 12 minipigs. After 1, 4 or 12 weeks, animals were sacrificed and specimens containing the implants were examined in terms of histological and ultrastructural techniques. Results Histological results showed direct bone contact on the zirconia and titanium surfaces. Bone implant contact as measured by histomorphometry was slightly better on titanium than on zirconia surfaces. However, a statistically significant difference between the two groups was not observed. Conclusion The results demonstrated that zirconia implants with modified surfaces result in an osseointegration which is comparable with that of titanium implants

    Analysis of Early Hard Tissue Formation in Dentine by Energy Dispersive X-Ray Microanalysis and Energy-Filtering Transmission Electron Microscopy

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    Thin cryosections and sections of embedded tissue were prepared from dentine of cryofixed rat incisors. Energy dispersive X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS) have been applied to study the calcium and phosphorus distribution in predentine of these incisors. A small enrichment of calcium and phosphorus was found in the predentine zone near the dentine border. Element distributions were correlated with analyses of the early crystal formation in dentine. These investigations were carried out by parallel applications of electron spectroscopic diffraction (ESD) and electron spectroscopic imaging (ESI) using zero-loss filtering. It was found that the earliest crystal formations already showed the lattice of the hexagonal mineral apatite. They form parallelly arranged chains of dots which coalesce rapidly to form needle-like crystallites along the collagen microfibrils

    Behavior of osteoblastic cells cultured on titanium and structured zirconia surfaces

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    Background Osseointegration is crucial for the long-term success of dental implants and depends on the tissue reaction at the tissue-implant interface. Mechanical properties and biocompatibility make zirconia a suitable material for dental implants, although surface processings are still problematic. The aim of the present study was to compare osteoblast behavior on structured zirconia and titanium surfaces under standardized conditions. Methods The surface characteristics were determined by scanning electron microscopy (SEM). In primary bovine osteoblasts attachment kinetics, proliferation rate and synthesis of bone-associated proteins were tested on different surfaces. Results The results demonstrated that the proliferation rate of cells was significantly higher on zirconia surfaces than on titanium surfaces (p < 0.05; Student's t-test). In contrast, attachment and adhesion strength of the primary cells was significant higher on titanium surfaces (p < 0.05; U test). No significant differences were found in the synthesis of bone-specific proteins. Ultrastructural analysis revealed phenotypic features of osteoblast-like cells on both zirconia and titanium surfaces. Conclusion The study demonstrates distinct effects of the surface composition on osteoblasts in culture. Zirconia improves cell proliferation significantly during the first days of culture, but it does not improve attachment and adhesion strength. Both materials do not differ with respect to protein synthesis or ultrastructural appearance of osteoblasts. Zirconium oxide may therefore be a suitable material for dental implants

    Strain driven fast osseointegration of implants

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    BACKGROUND: Although the bone's capability of dental implant osseointegration has clinically been utilised as early as in the Gallo-Roman population, the specific mechanisms for the emergence and maintenance of peri-implant bone under functional load have not been identified. Here we show that under immediate loading of specially designed dental implants with masticatory loads, osseointegration is rapidly achieved. METHODS: We examined the bone reaction around non- and immediately loaded dental implants inserted in the mandible of mature minipigs during the presently assumed time for osseointegration. We used threaded conical titanium implants containing a titanium2+ oxide surface, allowing direct bone contact after insertion. The external geometry was designed according to finite element analysis: the calculation showed that physiological amplitudes of strain (500–3,000 ustrain) generated through mastication were homogenously distributed in peri-implant bone. The strain-energy density (SED) rate under assessment of a 1 Hz loading cycle was 150 Jm-3 s-1, peak dislocations were lower then nm. RESULTS: Bone was in direct contact to the implant surface (bone/implant contact rate 90%) from day one of implant insertion, as quantified by undecalcified histological sections. This effect was substantiated by ultrastructural analysis of intimate osteoblast attachment and mature collagen mineralisation at the titanium surface. We detected no loss in the intimate bone/implant bond during the experimental period of either control or experimental animals, indicating that immediate load had no adverse effect on bone structure in peri-implant bone. CONCLUSION: In terms of clinical relevance, the load related bone reaction at the implant interface may in combination with substrate effects be responsible for an immediate osseointegration state

    Trick or treat?

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    The purpose of this article is to draw attention to current transgressions in scientific writing and to promote commitment to ethical standards and good science. All participants of any research project, particularly under interdiciplinary team approach, should not only play an active role on the management and carrying out of their study but also ensure that their study is not fraudulent. Manuscript fabrication, data and/or figure manupilation, piracy (plagiarism), sloppy research, and transgressions in authorship are reasons for loss of scientific value and records, retraction of articles, and application of a variety of sanctions
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