898 research outputs found

    Change in Working Length at Different Stages of Instrumentation as a Function of Canal Curvature

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    The aim of this study was to determine the change in working length (∆WL) before and after coronal flaring and after complete rotary instrumentation as a function of canal curvature. One mesiobuccal or mesiolingual canal from each of 43 extracted molars had coronal standardization and access performed. Once the access was completed, canal preparation was accomplished using Gates Glidden drills for coronal flaring and EndoSequence files for rotary instrumentation. WLs were obtained at 3 time points: pre-instrumentation (unflared), mid-instrumentation (flared) and post-instrumentation (concluded). Measurements were made via direct visualization (DV) and the CanalPro apex locator (EM) in triplicate by a single operator with blinding within the time points. Root curvature was measured using Schneider’s technique. The change in working length was assessed using repeated-measures ANCOVA. The direct visualization measurements were statistically larger than the electronic measurements (paired t-test difference = 0.20 mm, SE = 0.037, P \u3c .0001), although a difference this large may not be clinically important. Overall, a greater change in working length was observed in straight canals than in curved canals, and this trend was more pronounced when measured electronically than via direct visualization, especially in the unflared-concluded time points compared with unflared-flared time points. A greater change in working length was also observed in longer canals than in shorter canals.https://scholarscompass.vcu.edu/gradposters/1032/thumbnail.jp

    Factors considered by new faculty in their decision to choose careers in academic dentistry

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    To determine the characteristics of new dental faculty and what factors influenced them to choose academic careers, a survey was sent to deans at all U.S. dental schools to be distributed to faculty with length of service of four years or less. Responses were received from 240 individuals. About half of the respondents had been in private practice for an average of eight years, and 20 percent had military experience averaging almost sixteen years. A majority had postgraduate training and 60 percent had specialty training. Nearly 32 percent of new faculty were female and 80 percent were U.S. citizens. Analyses of responses to survey items indicated that correlated factors in the survey fell into the following empirical categories: teaching and scholarship, income and indebtedness, research, work schedule, influence of mentors and role models, and long-term aspirations. In general, the respondents identified factors relating to teaching and scholarship to be the most important influences on their choice of academic careers, while concerns about income and indebtedness were the most important negative considerations in this regard. Other positive factors identified by the survey related to the influence of mentors and role models, long-term aspirations, and research. Age, private practice experience, and military experience were found to particularly influence the new faculty members\u27 responses to items concerning income and indebtedness, and citizenship influenced responses to factors relating to research. The data from this select group of dentists support the current view that inequities in income of dental faculty compared to private practitioners and student debt are important concerns in choosing academic careers. Importantly, the desire to teach and participate in scholarly activities are important attractions in academic careers. Mentoring activities and creation of opportunities for career development are crucial factors in developing interest in academics among graduate dentists

    Equivalence Study of a Dental Anatomy Computer-Assisted Learning Program

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    Tooth Morphology is a computer-assisted learning program designed to teach the anatomy of the adult dentition. The purpose of this study was to test whether Tooth Morphology could teach dental anatomy to first-year dental students as well as the traditional lecture. A randomized controlled trial was performed with forty-five first-year dental students. The students were randomly assigned to either the Tooth Morphology group (n=23), which used the computer-assisted learning program and did not attend lecture, or the lecture group (n=22), which attended the traditional lecture and did not useTooth Morphology. The Tooth Morphology group had a final exam average of 90.0 (standard deviation=5.2), and the lecture group had a final exam average of 90.9 (sd=5.3). Analysis showed that the two groups’ scores were statistically equivalent (p\u3c0.05), with a priori equivalence bounds around the difference between the groups set at +/−5 points. It was concluded that Tooth Morphology taught the anatomy of the adult dentition as well as traditional lecture, as measured by exams. Based on the results of this study and student feedback, Tooth Morphology, in combination with interactive class meetings, has replaced the traditional dental anatomy lectures

    Survival Analysis of Complete Veneer Crowns vs. Multisurface Restorations: A Dental School Patient Population

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    The purpose of this study was to compare the longevity of crowns versus large multisurface restorations in posterior teeth. The investigation used the treatment database at Virginia Commonwealth University School of Dentistry. The inclusion criteria for the final data set used for analysis were: only one restored tooth per patient, premolars with three or more restored surfaces, molars with four or more restored surfaces, molars and premolars restored with complete veneer metal crowns, or crowns veneered with metal and porcelain. The Kaplan-Meier approach was used to visualize the survival curves, and the Cox proportional hazards model was used for analysis of predictor variables. The investigation indicates crowns survive longer than large restorations and premolar restorations survive longer than molar restorations. The median survival for crowns exceeded 16.6 years, with the median survival of premolar restorations being 4.4 years and molar restorations 1.3 years. An interaction between age and treatment was discovered, with overall survival decreasing as patient age increases. The doctor supervising the treatment also affected survival with treatment supervised by specialists lasting longer than treatment supervised by nonspecialists

    Restoring Lateral Incisors and Orthodontic Treatment: Perceptions among General Dentists and Othodontists

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    The purpose of this study was to identify and compare preferences and perceptions of orthodontists and general dentists when restoring peg-shaped lateral incisors. The investigation sought to summarize these preferences with regard to treatment planning, tooth preparation and interdisciplinary communication. A pair of mailed and electronic surveys was distributed to 1,500 general dentists and orthodontists, respectively. The results indicated that general dentists perceived that general dentists held the primary decision-making responsibility, while orthodontists disagreed (P\u3c0.0001). Orthodontists prioritized the treatment goals of Class I canine relationship and overbite/overjet more significantly than general dentists, whom valued tooth proportions more highly (P\u3c0.0001). General dentists reported receiving significantly less input than orthodontists report seeking (P\u3c0.0001).The consensus of both groups showed that the tooth should be positioned centered mesiodistally and guided by the gingival margins incisogingivally. Both groups agree that orthodontists must improve communication to improve treatment results

    Passive immunization during pregnancy for congenital cytomegalovirus infection

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    BACKGROUND Currently, there is no effective intervention for a primary cytomegalovirus (CMV) infection during pregnancy. METHODS We studied pregnant women with a primary CMV infection. The therapy group comprised women whose amniotic fluid contained either CMV or CMV DNA and who were offered intravenous CMV hyperimmune globulin at a dose of 200 U per kilogram of maternal weight. A prevention group, consisting of women with a recent primary infection before 21 weeks\u27 gestation or who declined amniocentesis, was offered monthly hyperimmune globulin (100 U per kilogram intravenously). RESULTS In the therapy group, 31 women received hyperimmune globulin, only 1 (3 percent) of whom gave birth to an infant with CMV disease (symptomatic at birth and handicapped at two or more years of age), as compared with 7 of 14 women who did not receive hyperimmune globulin (50 percent). Thus, hyperimmune globulin therapy was associated with a significantly lower risk of congenital CMV disease (adjusted odds ratio, 0.02; 95 percent confidence interval, ¡∞ to 0.15; P\u3c0.001). In the prevention group, 37 women received hyperimmune globulin, 6 (16 percent) of whom had infants with congenital CMV infection, as compared with 19 of 47 women (40 percent) who did not receive hyperimmune globulin. Thus, hyperimmune globulin therapy was associated with a significantly lower risk of congenital CMV infection (adjusted odds ratio, 0.32; 95 percent confidence interval, 0.10 to 0.94; P=0.04). Hyperimmune globulin therapy significantly (P\u3c0.001) increased CMV-specific IgG concentrations and avidity and decreased natural killer cells and HLA-DR+ cells and had no adverse effects. CONCLUSIONS Treatment of pregnant women with CMV-specific hyperimmune globulin is safe, and the findings of this nonrandomized study suggest that it may be effective in the treatment and prevention of congenital CMV infection. A controlled trial of this agent may now be appropriate

    Placental enlargement in women with primary maternal cytomegalovirus infection is associated with fetal and neonatal disease

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    Background. Serological testing for primary maternal cytomegalovirus (CMV) infection during pregnancy is not routine, but ultrasound studies are routine. Therefore, we evaluated placental thickening in women with primary CMV infection during pregnancy. Methods. The study included 92 women with primary CMV infection during pregnancy and 73 CMV-seropositive pregnant women without primary CMV infection. Neonatal CMV transmission was determined by CMV culture of urine samples. Thirty-two women were treated with CMV hyperimmune globulin to either prevent or treat intrauterine CMV infection. Maximal placental thickness was measured by longitudinal (nonoblique) scanning with the ultrasound beam perpendicular to the chorial dish. Programmed placental ultrasound evaluations were performed from 16 to 36 weeks of gestation. Results. At each measurement between 16 and 36 weeks of gestation, women with primary CMV infection who had a fetus or newborn with CMV disease had placentas that were significantly thicker than those of women with primary CMV infection who did not have a diseased fetus or newborn (P <.0001); the latter group, in turn, P <.0001 had placentas that were significantly thicker than those of seropositive control subjects (P <.0001). For both women P <.0001 with and women without diseased fetuses or newborns, receipt of hyperimmune globulin after primary CMV infection was associated with statistically significant reductions in placental thickness (P <.001). Placental vertical P <.001 thickness values, which are predictive of primary maternal infection, were observed at each measurement from 16 to 36 weeks of gestation, and cutoff values ranged from 22 mm to 35 mm, with the best sensitivity and specificity at 28 and 32 weeks of gestation. Conclusions. Primary maternal CMV infection and fetal or neonatal disease are associated with sonographically thickened placentas, which respond to administration of hyperimmune globulin. These observations suggest that many of the manifestations of fetal and neonatal disease are caused by placental insufficiency

    Serum Vitamin D, PTH, and Calcium Levels in Patients with and without Early Childhood Caries

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    Purpose: The purpose was to determine differences in serum vitamin D, parathyroid hormone (PTH), and calcium levels between patients with early childhood caries (ECC) and patients without dental decay. Materials and Methods: Serum vitamin D, PTH, and calcium levels were obtained from 30 children without dental decay who acted as controls and 60 children with ECC. A questionnaire was filled out by the parent/guardian of each participant consisting of questions regarding medical and dental history, exposure to sources of vitamin D and demographic information. Results: The difference in the vitamin D levels of the participants was most strongly associated with race. African American participants demonstrated lower levels of vitamin D than non-African Americans. After adjusting for race- related differences there was no significant difference in the Vitamin D levels in the ECC cases and the healthy controls. Conclusions: The results of this study suggest that vitamin D levels, at least among non-African Americans, are unrelated to caries development. Future research in this area must control for important confounding factors such as skin pigmentation, season of measurement of serum vitamin D, sun exposure, fluoride exposure, water fluoridation status and tooth brushing in order to allow for vitamin D levels to be better tested against caries experience

    The OpenPMU Platform for Open Source Phasor Measurements

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    Levosimendan for the prevention of acute organ dysfunction in sepsis

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    BACKGROUND Levosimendan is a calcium-sensitizing drug with inotropic and other properties that may improve outcomes in patients with sepsis. METHODS We conducted a double-blind, randomized clinical trial to investigate whether levosimendan reduces the severity of organ dysfunction in adults with sepsis. Patients were randomly assigned to receive a blinded infusion of levosimendan (at a dose of 0.05 to 0.2 μg per kilogram of body weight per minute) for 24 hours or placebo in addition to standard care. The primary outcome was the mean daily Sequential Organ Failure Assessment (SOFA) score in the intensive care unit up to day 28 (scores for each of five systems range from 0 to 4, with higher scores indicating more severe dysfunction; maximum score, 20). Secondary outcomes included 28-day mortality, time to weaning from mechanical ventilation, and adverse events. RESULTS The trial recruited 516 patients; 259 were assigned to receive levosimendan and 257 to receive placebo. There was no significant difference in the mean (±SD) SOFA score between the levosimendan group and the placebo group (6.68±3.96 vs. 6.06±3.89; mean difference, 0.61; 95% confidence interval [CI], −0.07 to 1.29; P=0.053). Mortality at 28 days was 34.5% in the levosimendan group and 30.9% in the placebo group (absolute difference, 3.6 percentage points; 95% CI, −4.5 to 11.7; P=0.43). Among patients requiring ventilation at baseline, those in the levosimendan group were less likely than those in the placebo group to be successfully weaned from mechanical ventilation over the period of 28 days (hazard ratio, 0.77; 95% CI, 0.60 to 0.97; P=0.03). More patients in the levosimendan group than in the placebo group had supraventricular tachyarrhythmia (3.1% vs. 0.4%; absolute difference, 2.7 percentage points; 95% CI, 0.1 to 5.3; P=0.04). CONCLUSIONS The addition of levosimendan to standard treatment in adults with sepsis was not associated with less severe organ dysfunction or lower mortality. Levosimendan was associated with a lower likelihood of successful weaning from mechanical ventilation and a higher risk of supraventricular tachyarrhythmia. (Funded by the NIHR Efficacy and Mechanism Evaluation Programme and others; LeoPARDS Current Controlled Trials number, ISRCTN12776039.
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