ABSTRACT
Objective: To evaluate the effect of scaling procedures using different ultrasonic tips on the surface roughness, color stability and bacterial accumulation of lithium disilicate ceramic. Material and Methods: Scaling procedure was carried out using ultrasonic scaler (Satalec, Acteon, North America) with stainless-steel tip (US), titanium tip (UT) and plastic tip (UP), on disc shaped lithium disilicate samples cemented into a cavity prepared onto the labial surface of freshly extracted bovine teeth (10 samples per group). The samples were stored in coffee solution in an incubator at 37°C for 12 days, which is equivalent to 1 year of coffee consumption. The surface roughness was measured before and after the scaling procedure using a profilometer and atomic force microscopy. The color parameters were measured before and after scaling and staining procedures using VITA Easyshade Advance 4.0 according to the CIE L*a*b* color order system. The samples were then incubated with Streptococcus mutans (S. mutans) suspension. After incubation, the plates with 30 to 300 typical colonies of S. mutans were counted in a colony counter and mean values of colony forming units were obtained (CFU/mL). Results:The titanium scaling tip showed a statistically significant higher mean values of change in surface roughness ΔRa and bacterial count than the plastic scaling tip. Color changes (ΔE) were not a statistically significant among the groups. The results showed a statistically significant positive (direct) correlation between surface roughness and color change (p = 0.012) and also between surface roughness and bacterial count (p = 0.00). Conclusion: Within the limitations of this study, titanium scaling instruments cause irreversible surface alterations of lithium disilcate ceramics which was in direct correlation to the color changes and bacterial accumulation; therefore, dentists should proceed with caution when scaling lithium disilicate surfaces. The findings of the current study may indicate the need for instruments or equipment that can remove plaque and calculus without causing surface damage (AU)
Introdução: Avaliar o efeito de procedimentos de raspagem com diferentes pontas de ultrassom na rugosidade superficial, estabilidade de cor e acúmulo bacteriano em cerâmica de dissilicato de lítio. Material e Métodos: O procedimento de raspagem foi realizado usando um aparelho de ultrassom (Satalec, Acteon, América do Norte) com ponta de aço inoxidável (US), ponta de titânio (UT) e ponta de plástico (UP), em amostras de dissilicato de lítio em forma de disco cimentadas em uma cavidade preparada na superfície vestibular de dentes bovinos recém-extraídos (10 amostras por grupo). As amostras foram armazenadas em solução de café em incubadora a 37 ° C por 12 dias, o que equivale a 1 ano de consumo de café. A rugosidade da superfície foi medida antes e após o procedimento de raspagem usando um perfilômetro e um microscópio de força atômica. Os parâmetros de cor foram medidos antes e depois dos procedimentos de raspagem e armazenagem no café usando VITA Easyshade Advance 4.0 de acordo com o sistema de ordem de cores CIE L*a*b*. As amostras foram incubadas com suspensão de Streptococcus mutans (S. mutans). Após a incubação, as placas com 30 a 300 colônias típicas de S. mutans foram contadas em contador de colônias e obtidos os valores médios das unidades formadoras de colônias (UFC / mL). Resultados: A ponta de titânio mostrou valores estatisticamente maiores de mudança na rugosidade da superfície ΔRa e contagem de bactérias do que a ponta de raspagem de plástico. A mudança de cor (ΔE) não foi estatisticamente significativa entre os grupos. Os resultados mostraram uma correlação positiva (direta) estatisticamente significativa entre rugosidade superficial e alteração de cor (p = 0,012) e também entre rugosidade superficial e contagem bacteriana (p = 0,00). Conclusão: Dentro das limitações deste estudo, os instrumentos de raspagem de titânio causam alterações irreversíveis na superfície das cerâmicas de dissilicato de lítio que estão em correlação direta com as mudanças de cor e o acúmulo de bactérias. Portanto, os dentistas devem proceder com cautela ao realizar raspagem em superfícies de dissilicato de lítio. Os resultados deste estudo podem indicar a necessidade de instrumentos ou equipamentos que possam remover a placa e cálculo sem causar danos à superfície. (AU)
Subject(s)
Surface Properties , Ultrasonics , Bacterial Adhesion , Dental Scaling , ColorABSTRACT
A major challenge to the healthcare executive is to put together an organization that maximizes productivity, quality and market share while not losing sight of the organization's mission to serve the health needs of the community. Assess the organizational performance of ICUs in terms of shared cultural values, managerial practices and individual well-being dimensions, and determine the interrelations between the different dimensions of organizational performance of ICUs. It is a descriptive, cross- sectional study. This study was conducted in 19 Intensive Care Units [ICUs] at Alexandria University Hospital. The study subjects included 30% of the nurses [N= 135], and physicians [59] who were working in the previously mentioned ICUs and were available at the time of data collection. The study subjects were selected randomly The study used the Arabic translation of Multidimensional Organizational Performance Questionnaire. This tool geared towards assessment of dimensions of organizational performance of ICUs. Statistical significant difference between total mean score of the physicians' and the nurses' perception towards organizational culture, the four elements of the performance unit effectiveness and individual wellbeing dimensions of the organizational performance. Nurses and physicians differed in their perception toward the four dimensions of the organizational performance. Nurses were more "lacking task-security orientation" element of organizational culture dimension than the physician. Also, they show less skill in their relation with patients and caregivers but they are more likely to stay at their work than physicians
Subject(s)
Humans , Male , Female , Efficiency, Organizational , Cross-Sectional Studies , Surveys and Questionnaires , Quality of Health Care , Perception , Physicians , Nurses , Job Satisfaction , Hospitals, UniversityABSTRACT
The aim of this work was to assess cardiac status and pulmonary blood pressure in Egyptian sickle cell disease [SCD] pediatric patients. Possible role of L-carnitine in the amelioration of heart complications was also studied. This study was conducted on 37 pediatric patients with sickle cell disease, their mean age was 9.4 +/- 3.6 years. They were subjected to complete history taking, general examination, laboratory investigations [complete blood count and serum ferritin] and echocardiographic examination including measurement of cardiac chamber dimensions, systolic and diastolic functions of left ventricle and estimation of pulmonary artery systolic pressure [PASP]. The echocardiographic findings showed a significant increase in left atrial dimensions in SCD patients compared with the normal controls, which decreased after L-carnitine therapy but did not reach a significant difference. Other cardiac dimensions revealed no significant difference between the patients and control group. Systolic functions of left ventricle did not show any significant difference between patients and controls. Diastolic dysfunction was found in all patients. Diastolic parameters revealed a significant improvement by a decrease in E-wave peak velocity and E/A ratio after L-carnitine therapy. Pulmonary hypertension was found in 17 cases and showed a significant decrease after L-carnitine therapy. The clinical and laboratory re-evaluation of the patients after the period of therapy revealed a significant increase in weight and height of the patients together with a significant decrease in the frequency of blood transfusion and serum ferritin levels