Root surface changes following manual and ultrasonic instrumentation - a scanning electron microscopic study

OBJECTIVE

The aim of this study is to assess the efficacy of hand and ultrasonic scaling and to evaluate the surface roughness on the root surface of periodontally involved teeth using a scanning electron microscope.

PATIENTS AND METHODS

A sample of 90 single-rooted teeth with a hopeless prognosis was selected for the study and divided into three separate groups. Group I consist of no treatment. In Group II, hand scaling was done using Gracey curettes, and in Group III, ultrasonic scaling was done. The teeth were then extracted and fixed in 10% formaldehyde solution for 24-48 hours and subjected to scanning electron microscopic (SEM) evaluation.

RESULTS

The SEM analysis revealed that the remaining calculus index was found to be similar in the ultrasonic group and the hand scaling group, whereas the surface roughness was found to be the least in the ultrasonic group.

CONCLUSIONS

Hand instrumentation has resulted in more surface roughness as compared to ultrasonic instruments.

Evaluating consumer website logs: a case study of The Times/The Sunday Times website

Information professionals have featured strongly in the evaluation of the use of commercial online hosts and online public access catalogues, but not so strongly in the evaluation of the use of websites. This paper describes a piece of research that was conducted on The Times/The Sunday Times websites, to determine the most appropriate methods for evaluating use and to establish what forms of analysis could best be derived. A database of one million subscribers and three months’ worth of logs, constituting 65 million lines of data, were obtained and the data were analysed using parsing techniques and the Statistical Package for the Social Sciences. There were problems associated with the analysis, largely because of the difficulties in establishing the identity of Web users, determining what actually constitutes use and measuring the time spent online.

Men in their 30s were the sites’ most numerous subscribers. The majority of subscribers were foreign and came from commercial organisations. Use varied considerably from hour to hour and day to day and from country to country: in the UK, midweek lunchtimes proved very popular. On average, a user conducted 2.35 sessions over the survey period, spent 15 minutes on a search session and 0.5-2.1 minutes on reading a page. Commercial organisations and Americans were the heaviest users and news pages proved to be the most popular.

Implicit cognition is impaired and dissociable in a head-injured group with executive deficits

Implicit or non-conscious cognition is traditionally assumed to be robust to pathology but Gomez-Beldarrain et al. recently showed deficits on a single implicit task after head injury. Laboratory research suggests that implicit processes dissociate. This study therefore examined implicit cognition in 20 head-injured patients and age- and IQ-matched controls using a battery of four implicit cognition tasks: a serial reaction time task (SRT), mere exposure effect task, automatic stereotype activation and hidden co-variation detection. Patients were assessed on an extensive neuropsychological battery, and MRI scanned. Inclusion criteria included impairment on at least one measure of executive function. The patient group was impaired relative to the control group on all the implicit cognition tasks except automatic stereotype activation. Effect size analyses using the control mean and standard deviation for reference showed further dissociations across patients and across implicit tasks. Patients impaired on implicit tasks had more cognitive deficits overall than those unimpaired, and a larger dysexecutive self/other discrepancy (DEX) score suggesting greater behavioural problems. Performance on the SRT task correlated with a composite measure of executive function. Head injury thus produced heterogeneous impairments in the implicit acquisition of new information. Implicit activation of existing knowledge structures appeared intact. Impairments in implicit cognition and executive function may interact to produce dysfunctional behaviour after head injury. Future comparisons of implicit and explicit cognition should use several measures of each function, to ensure that they measure the latent variable of interest.

Direct erosion of lumbar spine by an abdominal aortic aneurysm, resulting in paraparesis: unusual presentation. Case report

Abdominal aortic aneurysm is a condition affecting nearly 4% of the elderly population. It has a potential for producing a wide range of symptoms, including abdominal pain and back pain. The latter is particularly difficult to interpret in patients with chronic rheumatological conditions, and delayed diagnosis may be associated with a poor outcome. We present a patient with rheumatoid arthritis and chronic low back pain, who developed bilateral leg weakness and hesitancy of micturition, due to an abdominal aortic aneurysm invading the spine.

The relationship of haemoglobin to serum erythropoietin concentrations in the anaemia of rheumatoid arthritis: the effect of oral prednisolone

Previous studies of the erythropoietin response to anaemia in RA have yielded conflicting findings. Some have found the response to be impaired and others have found a normal response. We have compared erythropoietin (EPO) levels measured by radioimmunoassay, in 54 anaemic rheumatoid patients and 55 patients with iron deficiency anaemia but no inflammatory disease. The erythropoietin response in the rheumatoid patients was impaired compared with the control group (P < 0.025) but only seven rheumatoid patients showed a response which fell below the 95% confidence intervals predicted for the control group. Rheumatoid patients who fell within the highest quartile for serum ferritin concentrations (i.e. those most likely to have anaemia of chronic disease) had significantly lower EPO levels compared with the control group (P < 0.01). EPO levels in rheumatoid patients within the lowest quartile for ferritin (i.e. those with iron deficiency anaemia) were not significantly different from the control group (P = 0.670). The difference in EPO response between the RA patients in the upper and lower quartile for ferritin approached but did not achieve significance (P = 0.056). In a second study 15 anaemic RA patients were given a 5-day course of oral prednisolone 1.5 mgkg-1. Hemoglobin did not rise significantly until day 4 but EPO levels fell by day 1 (P < 0.005) and remained lower than pretreatment values throughout the study. Thus, in RA patients, anaemia of chronic disease is associated with inappropriately low EPO concentrations but this does not appear to be the major cause of the anaemia and Hb response to prednisolone does not depend upon an increase in EPO concentration.