71 research outputs found

    Implant failure and history of failed endodontic treatment : a retrospective case-control study

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    Residual bacterial biofilm and/or bacteria in planktonic form may be survived in the bone following an extraction of an infected tooth that was endodontically treated unsuccessfully Failed endodontic treatment may be associated with failure of implants to osseointegrate in the same sites. Therefore, the aim of this retrospective case-control study is to examine the risk of implant failure in previous failed endodontic sites. This retrospective case-control study is based on 94 dental records of implants placed at the University of Minnesota School of Dentistry. Dental records of patients who received an implant in sites with previously failed endodontic therapy in the dental school were identified from the electronic database, while control subjects were obtained from the same pool of patients with the requirement to have received an implant in a site that was not endodontically treated. The mean age of the population was 62.89±14.17 years with 57.4% of the sample being females and 42.6% of them being males. In regards to the socio-economic status and dental insurance, 84.0% of this population was classified as low socio-economic status and 68.1% had dental insurance. Tobacco use was self-reported by 9.6% and hypercholesterolemia was the most prevalent systemic medical condition. Dental implant failure was identified in two of the included records (2.1%), both of which were placed in sites with a history of failed endodontic treatment. Within the limitations of this retrospective case-control study, further investigation with a larger population group into implant failure of sites that previously had unsuccessful endodontic treatment would be warranted. Implant failure may be associated with a history of failed endodontic treatment

    Dental implant failure and bone augmentation : a retrospective study

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    To retrospectively assess the failure rate of implants placed in augmented and non-augmented sites and to investigate whether the time of implant and bone placement are associated with the risk of implant failure in a university setting. In this retros

    Patients’ Socio-Economic Status, Tobacco and Medical History Associated with Implant Failure

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    Svrha: Željela se istražiti moguća veza između pacijenata kod kojih se dogodilo odbacivanje implantata i onih s uspješnom implantoprotetičkom terapijom. Materijali i metode: Ovo retrospektivno istraživanje temelji se na 186 slučajeva s odbacivanjem implantata i 186 uspješnih slučajeva s usporedivom dobi i spolom, što je činilo ukupno 372 pacijenta. Zabilježeni su dob tijekom postupka, spol, povijest bolesti, pušenje, status zdravstvenog osiguranja, poštanski broj i ishod liječenja (odbacivanje implantata/uspješno liječenje implantatom). Rezultati: Sudjelovalo je 47,6 % žena, 48,9 % pojedinaca sa zdravstvenim osiguranjem i 9,7 % pušača. Pronađena je statistički značajna povezanost (p ≤ 0,05) između odbacivanja implantata i uspješne implantoprotetičke terapije s obzirom na pušenje, socijalno-ekonomski status i povijest bolesti. Status zdravstvenog osiguranja i područje implantacije (regija, zubni luk) nisu statistički značajno utjecali (p > 0,05) na rezultat implantoprotetičke terapije. Zaključci: Uzimajući u obzir ograničenja ove retrospektivne studije slučaja, pojedinci s visokim socijalno-ekonomskim statusom, a pritom nepušači i s preboljelim srčanim udarom, imali su veću vjerojatnost za uspješno liječenje implantatima od onih s niskim socijalno-ekonomskim statusom i bez srčanog udara u povijesti bolesti.Objective: To examine the potential association between patients’ characteristics that experienced implant failure and those who had successful implant treatment. Materials and methods: This retrospective case-control study is based on 186 dental records of implant failure and 186 age and gender matched successful treatments for a total of 372 patients. Age at the time of the procedure, gender, medical history, tobacco use, dental insurance status, ZIP code and type of treatment provided (implant failure/successful implant treatment) were recorded. Results: The population consisted of 47.6% females, 48.9% individuals with dental insurance and 9.7% self-reported tobacco users. A statistically significant association (p≤0.05) was found between implant failure and successful implant treatment in regards to tobacco use, socio-economic status and medical history. Insurance status and implant location (region, arch) did not affect significantly (p>0.05) the outcome of implant therapy. Conclusions: Within the limitation of this retrospective case-control study, individuals with high socio-economic status, no history of tobacco use and history of heart attack were more likely to have a successful implant treatment than those with a low socio-economic status, tobacco users and without history of heart attack

    The Precipitation Imaging Package : Assessment of Microphysical and Bulk Characteristics of Snow

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    Remote-sensing observations are needed to estimate the regional and global impacts of snow. However, to retrieve accurate estimates of snow mass and rate, these observations require augmentation through additional information and assumptions about hydrometeor properties. The Precipitation Imaging Package (PIP) provides information about precipitation characteristics and can be utilized to improve estimates of snowfall rate and accumulation. Here, the goal is to demonstrate the quality and utility of two higher-order PIP-derived products: liquid water equivalent snow rate and an approximation of volume-weighted density called equivalent density. Accuracy of the PIP snow rate and equivalent density is obtained through intercomparison with established retrieval methods and through evaluation with colocated ground-based observations. The results confirm the ability of the PIP-derived products to quantify properties of snow rate and equivalent density, and demonstrate that the PIP produces physically realistic snow characteristics. When compared to the National Weather Service (NWS) snow field measurements of six-hourly accumulation, the PIP-derived accumulations were biased only +2.48% higher. Additionally, this work illustrates fundamentally different microphysical and bulk features of low and high snow-to-liquid ratio events, through assessment of observed particle size distributions, retrieved mass coefficients, and bulk properties. Importantly, this research establishes the role that PIP observations and higher-order products can serve for constraining microphysical assumptions in ground-based and spaceborne remotely sensed snowfall retrievals.Peer reviewe

    FANCD1/BRCA2 Plays Predominant Role in the Repair of DNA Damage Induced by ACNU or TMZ

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    Nimustine (ACNU) and temozolomide (TMZ) are DNA alkylating agents which are commonly used in chemotherapy for glioblastomas. ACNU is a DNA cross-linking agent and TMZ is a methylating agent. The therapeutic efficacy of these agents is limited by the development of resistance. In this work, the role of the Fanconi anemia (FA) repair pathway for DNA damage induced by ACNU or TMZ was examined. Cultured mouse embryonic fibroblasts were used: FANCA−/−, FANCC−/−, FANCA−/−C−/−, FANCD2−/− cells and their parental cells, and Chinese hamster ovary and lung fibroblast cells were used: FANCD1/BRCA2mt, FANCG−/− and their parental cells. Cell survival was examined after a 3 h ACNU or TMZ treatment by using colony formation assays. All FA repair pathways were involved in ACNU-induced DNA damage. However, FANCG and FANCD1/BRCA2 played notably important roles in the repair of TMZ-induced DNA damage. The most effective molecular target correlating with cellular sensitivity to both ACNU and TMZ was FANCD1/BRCA2. In addition, it was found that FANCD1/BRCA2 small interference RNA efficiently enhanced cellular sensitivity toward ACNU and TMZ in human glioblastoma A172 cells. These findings suggest that the down-regulation of FANCD1/BRCA2 might be an effective strategy to increase cellular chemo-sensitization towards ACNU and TMZ

    Predicting Academic Performance: A Systematic Literature Review

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    The ability to predict student performance in a course or program creates opportunities to improve educational outcomes. With effective performance prediction approaches, instructors can allocate resources and instruction more accurately. Research in this area seeks to identify features that can be used to make predictions, to identify algorithms that can improve predictions, and to quantify aspects of student performance. Moreover, research in predicting student performance seeks to determine interrelated features and to identify the underlying reasons why certain features work better than others. This working group report presents a systematic literature review of work in the area of predicting student performance. Our analysis shows a clearly increasing amount of research in this area, as well as an increasing variety of techniques used. At the same time, the review uncovered a number of issues with research quality that drives a need for the community to provide more detailed reporting of methods and results and to increase efforts to validate and replicate work.Peer reviewe

    A connectome and analysis of the adult Drosophila central brain.

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    The neural circuits responsible for animal behavior remain largely unknown. We summarize new methods and present the circuitry of a large fraction of the brain of the fruit fly Drosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses in, and proofread such large data sets. We define cell types, refine computational compartments, and provide an exhaustive atlas of cell examples and types, many of them novel. We provide detailed circuits consisting of neurons and their chemical synapses for most of the central brain. We make the data public and simplify access, reducing the effort needed to answer circuit questions, and provide procedures linking the neurons defined by our analysis with genetic reagents. Biologically, we examine distributions of connection strengths, neural motifs on different scales, electrical consequences of compartmentalization, and evidence that maximizing packing density is an important criterion in the evolution of the fly's brain

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure
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