1,721,149 research outputs found
Oral Health of Children and Adolescents with Diabetes Mellitus
Get PDFAim: To examine the oral health of children and adolescents with and without diabetes mellitus. Background: Diabetes mellitus is the most common metabolic disease in childhood and demonstrates an increasing incidence. Many children live with gingivitis as a precursor to periodontitis. If left untreated, it can cause the development of periodontitis. The links between periodontitis and diabetes mellitus are known but have been little studied in the age group of children and adolescents. Materials and Methods: Clinical examination and collection of sulcus fluid from participants aged 5 to 21 years was performed. The following data were collected: demographic variables, caries prevalence, DMF-T, VPI, PUFA, salivary flow rate, HbA1c, PSI, and the concentration of IL-1β, IL-6, MMP-8, and TNF-α. Results: Patients with diabetes mellitus showed a significantly lower salivary flow rate with higher concentrations of MMP-8 and IL-1β. The data indicate that at this age, regular visits to the dentist are of great importance for the promotion of oral health in children and adolescents regardless of diabetes and that patients with diabetes mellitus in particular benefit from prevention, as they belong to the periodontitis risk group. Conclusions: Patients with low salivary flow rates and increased inflammatory mediators are high-risk patients for whom dental preventive measures play a major role
On failure of oral implants
No full textIntroduktion: Behandling med orala implantat är idag en effektiv och fungerande metod att ersätta bettfunktion vid partiell eller hel tandlöshet. Trots höga överlevnads- och lyckandesiffror finns ändå riskfaktorer som för vissa patienter kan resultera i implantatförlust. Man behöver noggrant utreda olika faktorer som kan påverka benförankringen, osseointegrationen, av implantaten för att ytterligare förbättra lyckandesiffrorna. Om faktorer som leder till ökad implantatförlust kan identifieras, skulle det underlätta för såväl tandläkare som för patienten genom att man då får möjlighet att undvika eller kompensera för individuella risker. Den här avhandlingen har haft som syfte att presentera kända riskfaktorer bakom implantatförluster.
Material och metodik: Artiklarna som ingår i denna avhandling kan indelas i tre olika sorters studier. Först gjordes en allmän översikt om kända faktorer bakom implantatproblem (arbete I). Därefter utfördes en meta-analys innebärande en genomgång av relevant litteratur för att mer djupgående kunna analysera en selekterad riskfaktor, nämligen att patienter som röker kan påverka såväl benförlust runt implantatet som postoperativ infektionsrisk och implantatförlust.(Arbete II). Därefter utfördes sju retrospektiva (tillbakablickande) studier(Arbeten III-IX) baserat på 10.096 implantat, konsekutivt insatta på tillsammans 2670 patienter på en klinik – folktandvården i Skåne, specialisttandvården Malmö under tiden 1980 till 2014. Efter godkännande från etisk nämnd har det blivit möjligt att datorbehandla tandläkarjournaler från detta patientmaterial. Data införs på en SPSS fil (SPSS software, version 23, SPSS Inc, Chicago, USA). Anatomiska-, patient-, hälso- och implantatrelaterade faktorer registrerades. De kliniska studier som ingår i avhandlingen har fokuserats kring frågeställningar som implantatförlust och bruxism(tandgnissling), medikamentell behandling med protonpumpsinhibitorer(magsårsmedicin) eller serotonin(antidepressivt medel), lyckandedata för implantat insatta av olika kirurger, tidiga förluster och s k clusterbeteende. Klusterbeteende avser att implantatförluster inte är jämnt fördelade bland patienterna, utan att det rör sig främst om ett fåtal patienter som har många misslyckanden. Därtill utfördes röntgenologiska beräkningar av benförlust runt implantat som varit insatta under mer än 20 års tid. Olika statistiska modeller användes för att testa om erhållna data var signifikant skilda åt i jämförelse med relevanta kontroller.
Resultat och Diskussion: Den systematiskta genomgången av litteraturen antydde att det fanns en serie faktorer som kunde påverka implantatutgången; t ex lågt vridmoment vid implantatinsättningen om man samtidigt avsåg belasta implantaten snabbt; att oerfarna eller dåligt skolade kirurger har sämre kliniskt resultat än mer skolade kollegor; implantatinsättning i överkäken; implantatinsättning i bakre delen av käkarna eller i ben av dålig kvalitet/kvantitet; rökande patienter; användning av korta implantat eller för många implantat; insättning av icke gängade implantat eller användande av s k täckprotes. Därtill fanns antydningar om andra faktorer som möjligen skulle kunna påverka implantatframgången negativt, som att låta implantaten ha direkt genomgång i slemhinnan utan tidigare vilofas, som direktbelastning av implantaten, som insättning av implantat direkt efter tandutdragning, som implantat med liten diameter. En del senare studier antydde att moderna moderat råa implantatytor kunde kompensera för risker med en del faktorer som insättning i överkäken, användande av korta implantat eller vid direktbelastning (Studie I). Den mer systematiska analysen av rökande patienter fann en ökning av implantatförlusterna hos rökare och därtill påverkades infektionsrisken efter implantatinsättningen och man fick ökad benförlust runt implantaten när patienten rökte (Studie II).
Rökning kunde verifieras som riskfaktor i den kliniska analysen och även om patienten åt antidepressiva tabletter av serotonin-typ, så ökade i vart fall de tidiga implantatförlusterna (Studie III). Patienter som gnisslade tänder hade signifikant ökning av implantatförluster och fick därtill ökning av implantatfrakturer och brott på tandbroar (Studie IV). Resultaten visade också att en vanlig typ av magsårsmedicin; s k proton pumphämmare, resulterade i ökning av antalet implantatförluster (Studie V). Man fann däremot inga säkra tecken på ökad implantatförlust vad gällde sena resultat för de som åt antidepressiva mediciner av serotonintyp (Studie VI). Vidare fanns klara antydningar att vissa kirurger hade fler implantatförluster än andra, något som kan ha att göra med vald kirurgisk teknik, kirurgisk förmåga, kirurgiskt omdöme(vissa tänkta implantatpatienter skall kanske inte operas utan få annan behandling) (Studie VII). Vissa patienter med specifika karaktäristika som pekats på i studie I förlorade klart fler implantat än medelpatienten (Studie VIII). Slutligen noterades en mycket klar övervikt för tidiga implantatförluster under de första två åren efter implantatinsättningen, varefter ytterliga implantatförluster förekom men var långt mer ovanliga. En särskild faktor som antytts ställa till stora kliniska problem, som benförlust runt implantaten, visade sig i verkligheten sällan leda till implantatförlust. De flesta implantat som uppvisade benförlust fungerade trots detta utmärkt kliniskt (Studie IX).
Den övergripande målsättningen med denna avhandling har varit att öka kunskapen om olika faktorer bakom implantatförlust för att på så sätt kunna bidra till ytterligare förbättring av kliniska resultat i framtiden.Introduction: Nowadays oral implant placement is an effective and predictable treatment modality for replacing missing teeth in both fully and partially edentulous patients. Despite the high implant survival and success rates, there is a general appreciation that some risk factors predispose individuals to more complications and implant failures and may result in lower implant survival and success rates. Determining the exact elements that are critical for osseointegration would be extremely useful. A better understanding of the factors associated with implant failure provide data for the planning of future studies, facilitate clinical decision-making, and may enhance implant success. Once identified, the risks can then be avoided, or an alternative intervention can be applied, implying in the least cost to produce a given level of effectiveness in oral rehabilitation. The general aim of the present thesis was to assess the impact of several factors on the failure of oral implants.
Materials and Methods: The articles included in the present thesis consist of three types of studies. First, a general overview was performed in order to identify risk factors associated with the failure of oral implants (Study I). Then, a systematic review of the literature with meta-analyses was performed to analyze the influence of one risk factor (smoking) on the failure of oral implants, marginal bone loss (MBL), and postoperative infection around implants (Study II). The seven retrospective studies (Study III-IX) were based on all 2,670 patients provided with 10,096 implants, consecutively treated on a routine basis at one specialist clinic (Clinic for Prosthodontics, Centre of Dental Specialist Care, Malmö, Sweden - Folktandvården Skåne AB, Specialisttandvård Malmö) during the period from 1980 to 2014. The dental records of all patients ever treated with implants in this clinic were read in order to collect the data. The data were directly entered into a SPSS file (SPSS software, version 23, SPSS Inc., Chicago, USA) as the files were being read. Several anatomical-, patient-, health-, and implant-related factors were collected. The clinical studies included in the thesis focused on the association between implant failure and bruxism, the intake of proton pump inhibitors and of selective serotonin reuptake inhibitors and their relation to failure, the impact of different surgeons, and the number of early failures, cluster behavior of failures, and clinical and radiological outcomes of implants followed up for a minimum of 20 years.
Besides descriptive statistics and tests for the comparison of 2 or of 3 or more independent and dependent groups of continuous and categorical data, survival analyses, logistic regression models, generalized estimating equation method, and multilevel mixed effects parametric survival analysis were performed, depending on the study.
Results and Conclusions: After a systematic review of the literature, it may be suggested that the following situations may increase the implant failure rate: a low insertion torque of implants that are planned to be immediately or early loaded, inexperienced surgeons inserting the implants, implant insertion in the maxilla, implant insertion in the posterior region of the jaws, implants in heavy smokers, implant insertion in bone qualities type III and IV, implant insertion in places with small bone volumes, use of shorter length implants, greater number of implants placed per patient, lack of initial implant stability, use of cylindrical (non-threaded) implants and prosthetic rehabilitation with implant-supported overdentures. Moreover, it may be suggested that the following situations may be correlated with an increase in the implant failure rate but with a weaker association than the factors listed above: use of the non-submerged technique, immediate loading, implant insertion in fresh extraction sockets, smaller diameter implants. Some recently published studies suggest that modern, moderately rough implants may present with similar results irrespective if placed in maxillae, in smoking patients or using only short implants (Study I). The systematic review of the literature with meta-analyses suggested that the insertion of oral implants in smokers affects the implant failure rates, the incidence of postoperative infections, as well as the marginal bone loss (Study II).
Smoking and the intake of antidepressants are suggested to be potentially influencing factors with respect to the occurrence of implant failures up to the second-stage surgery - abutment connection (Study III). Bruxism may significantly increase both the implant failure rate and the rate of mechanical and technical complications of implant-supported restorations (Study IV). The intake of proton pump inhibitors may be associated with an increased risk of oral implant failure (Study V), but not so the intake of selective serotonin reuptake inhibitors (Study VI). Different levels of failure incidence of oral implants could be observed depending on the individual surgeons, occasionally reaching significant levels. Although a direct causal relationship could not be ascertained, it is suggested that the surgeons’ technique, skills, and/or judgment may influence the oral implant survival rates (Study VII). A cluster pattern among patients with implant failure is highly probable. Shorter implants, turned implants, poor bone quality, younger patients, the intake of antidepressants and of proton pump inhibitors, smoking, and bruxism were identified as suggested potential factors exerting a statistically significant influence on the cluster behavior of dental implant failures (Study VIII). Most of the implant failures occur at the first years after implantation, regardless of a very long follow-up. Implants in different jaw locations, irradiation, and bruxism were the factors suggested to affect the survival of implants. Marginal bone loss can be insignificant in long term observations, but it may, nevertheless, be the cause of secondary failure of oral implants in some cases (Study IX)
Locking versus non-locking plate fixation in the management of mandibular fractures : a meta-analysis
No full textThe aim of the present study was to test whether there is a significant difference in the clinical outcomes between locking and non-locking plate fixation in the management of mandibular fractures. An electronic search without time or language restrictions was undertaken in December 2013. Eligible studies were clinical human studies, either randomized or not. The search strategy identified 10 publications. The I(2) statistic was used to express the percentage of the total variation across studies due to heterogeneity. The inverse variance method was used for the random-effects model in the case of heterogeneity being detected, or the fixed-effects model in the case of heterogeneity not being detected. The estimates of an intervention were expressed as the risk ratio (RR) with 95% confidence interval. Eight studies were judged to be at high risk of bias, whereas two studies were considered at moderate risk of bias. There was no statistically significant effect on the outcome of postoperative infection (P=0.17), malocclusion (P=0.15), hardware failure (P=0.77), hardware removal (P=0.95), wound dehiscence (P=0.98), or paraesthesia (P=0.20) in favour of locking plate fixation. The test for overall effect showed that the difference between the procedures did not significantly affect the incidence of postoperative complications (P=0.21), with RR 0.79 (95% CI 0.54-1.14)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Occlusal acuity and bite force in young adults
No full textOcclusal tactile acuity (OTA) and bite force are essential components of the sensorimotor control of oral behaviors. While these variables have been studied independently, it has not yet been revealed whethercompressive force impacts the occlusal perception mediated by the mechanoreceptive afferents in the periodontal ligament. The present study examined the effect of repetition and maximum bite force on OTA by testingnine aluminum foils of different thicknesses together with a sham test with no foil, three times each, in randomized order in 36 healthy individuals. In addition, the 40 μm foil was tested three more times at the start ofeach session to evaluate possible short-term effects. This test session was repeated with and without an interspersed maximum bite force task in between. The results demonstrated that repeated measurements increasedOTA significantly (p = 0.033); a change mainly driven by the 40 μm thickness, whereas maximum bite force testsdid not affect OTA (p = 0.097). Collectively, the results suggest that the enhanced OTA may be attributed torepetition-mediated learning and neuroplasticity within the pathways related to OTA. Furthermore, thecompressive bite force may have induced a short-term change that lasted seconds and was not detected by thesubsequent OTA measurements or may have altogether inhibited the facilitatory effect of repeated OTA. Thisunderscores the potential for future research to explore the implications of compressive force and pain on OTA inpatient populations, which could provide valuable insights into the adaptive mechanisms of the sensorimotorsystem in pathological conditions
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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