Characterization of dentine to assess bond strength of dental composites

This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. Furthermore, micro gap formation after restoration of 3 mm diameter cavities in dentine was assessed by SEM. Initial hydroxyapatite level in ivory was half that in human dentine. Surface hydroxyapatites decreased by approximately half with every 23 s of acid etch. The human dentine strength (56 MPa) was approximately double that of ivory, while the modulus was almost comparable to that of ivory. With adhesive use, average shear bond strengths were 30 and 26 MPa with and without acid etching. With no adhesive, average bond strength was 6 MPa for conventional composites. This, however, increased to 14 MPa with a commercial flowable "self-bonding" composite or upon addition of low levels of an acidic monomer to the experimental composite. The acidic monomer additionally reduced micro-gap formation with the experimental composite. Improved bonding and mechanical properties should reduce composite failures due to recurrent caries or fracture respectively

Assessment of the quality of reporting of randomized clinical trials in paediatric dentistry: A comparative systematic review

OBJECTIVES This systematic review aimed to determine the improvement in quality of the reporting of randomized clinical trials (RCTs) in paediatric dentistry. The quality of reporting during the period 2014–2015 was compared with the quality of reporting during 1985–2006. METHODS This systematic review compared the scientific quality of RCTs in paediatric dentistry published in five paediatric dentistry journals during the defined periods. The Consolidated Standards for Reporting Trials (CONSORT) checklist of 2010 was used to evaluate the quality of reporting. The inter-reviewers’ agreement was assessed by calculating the kappa score, and disagreements between reviewers were resolved by consequent discussion. The p values and percentages were used to test for significant differences between the two reviews (1985–2006 and 2014–2015). RESULTS A total of 40 articles were included. Although the quality of reporting showed considerable heterogeneity, the overall quality of reporting by RCTs was satisfactory and had improved over the years. CONCLUSIONS Using CONSORT checklist, this study showed general improvement in the quality of reporting of RCTs published in pediatric dentistry journals in all article's sections

ERISA Subrogation and the Controversy over Sereboff: Silencing the Critics, the Divided Bench Is a Legitimate Standard

ERISA protects employees in the administration ofemployer-sponsored benefit plans. When a party is injuredby third parties and a health and welfare benefit plangoverned by ERISA pays benefits, conflicts have arisenbetween insurers seeking subrogation and individualsseeking full recovery. Injured parties claim they shouldnot have to reimburse insurers while insurers denyresponsibility for damage caused by third parties. TheSupreme Court set the standard for plan fiduciary rightsto ERISA subrogation in Sereboff v. Mid Atlantic MedicalServices, Inc. Sereboff held that the plain wording of 29U.S.C. § 1132(a)(3) means equitable relief available underthe historically divided courts of law and equity. TheCourt reasoned that the statute specifies only equitablerelief\u27 rather than specific categories of equitable relief,such as constructive trusts and equitable liens.Controversy continues as scholars criticize the standard asunsupported by ERISA and contrary to ERISA\u27s purposes.This Note asserts that the standard is supported by statuteand precedent: Mertens v. Hewitt Associates and Great-West Life & Annuity Insurance Co. v. Knudson. ThisNote concludes that the Court established a workablestandard, the ultimate legitimacy of which lies in theequitable balance it achieves between fiduciary rights to enforce ERISA plan subrogation provisions and theprotection of beneficiaries. The critics should accept theCourt\u27s equitable solution: equitable relief under thedivided bench

Can lay-led walking programmes increase physical activity in middle aged adults? : a randomised controlled trial

Study objective: To compare health walks, a community based lay-led walking scheme versus advice only on physical activity and cardiovascular health status in middle aged adults. Design: Randomised controlled trial with one year follow up. Physical activity was measured by questionnaire. Other measures included attitudes to exercise, body mass index, cholesterol, aerobic capacity, and blood pressure. Setting: Primary care and community. Participants: 260 men and women aged 40–70 years, taking less than 120 minutes of moderate intensity activity per week. Main results: Seventy three per cent of people completed the trial. Of these, the proportion increasing their activity above 120 minutes of moderate intensity activity per week was 22.6% in the advice only and 35.7% in the health walks group at 12 months (between group difference =13% (95% CI 0.003% to 25.9%) p=0.05). Intention to treat analysis, using the last known value for missing cases, demonstrated smaller differences between the groups (between group difference =6% (95% CI -5% to 16.4%)) with the trend in favour of health walks. There were improvements in the total time spent and number of occasions of moderate intensity activity, and aerobic capacity, but no statistically significant differences between the groups. Other cardiovascular risk factors remained unchanged. Conclusions: There were no significant between group differences in self reported physical activity at 12 month follow up when the analysis was by intention to treat. In people who completed the trial, health walks was more effective than giving advice only in increasing moderate intensity activity above 120 minutes per week

Detection and mapping of hydrothermally altered rocks in the vicinity of the comstock lode, Virginia Range, Nevada, using enhanced LANDSAT images

The author has identified the following significant results. LANDSAT images enhanced by the band-ratioing method can be used for reconnaissance alteration mapping in moderately heavily vegetated semiarid terrain as well as in sparsely vegetated to semiarid terrain where the technique was originally developed. Significant vegetation cover in a scene, however, requires the use of MSS ratios 4/5, 4/6, and 6/7 rather than 4/5, 5/6, and 6/7, and requires careful interpretation of the results. Supplemental information suitable to vegetation identification and cover estimates, such as standard LANDSAT false-color composites and low altitude aerial photographs of selected areas is desirable

High field magneto-transport in high mobility gated InSb/InAlSb quantum well heterostructures

We present high field magneto-transport data from a range of 30nm wide InSb/InAlSb quantum wells. The low temperature carrier mobility of the samples studied ranged from 18.4 to 39.5 m2V-1s-1 with carrier densities between 1.5x1015 and 3.28x1015 m-2. Room temperature mobilities are reported in excess of 6 m2V-1s-1. It is found that the Landau level broadening decreases with carrier density and beating patterns are observed in the magnetoresistance with non-zero node amplitudes in samples with the narrowest broadening despite the presence of a large g-factor. The beating is attributed to Rashba splitting phenomenon and Rashba coupling parameters are extracted from the difference in spin populations for a range of samples and gate biases. The influence of Landau level broadening and spin-dependent scattering rates on the observation of beating in the Shubnikov-de Haas oscillations is investigated by simulations of the magnetoconductance. Data with non-zero beat node amplitudes are accompanied by asymmetric peaks in the Fourier transform, which are successfully reproduced by introducing a spin-dependent broadening in the simulations. It is found that the low-energy (majority) spin up state suffers more scattering than the high-energy (minority) spin down state and that the absence of beating patterns in the majority of (lower density) samples can be attributed to the same effect when the magnitude of the level broadening is large