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Our understanding of the causes of periodontal disease have two major competing paradigms: one that focuses on ‘local’ etiologic factors and one that focuses on remote ‘host‐level’ factors. We provide a historical overview of local and remote cause hypotheses and discuss some key reasons why the local cause hypothesis has become dominant. 相似文献
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Marques DN da Mata AD Silveira JM Marques JR Amaral JP Guilherme NF 《Clinical oral investigations》2012,16(1):155-163
The objective of this study is to compare salivary hydrogen peroxide (HP) release kinetics and potential toxicity of systemic
exposure of four different whitening products. A double-blind, randomized controlled trial was conducted in a Portuguese dental
faculty clinic. Two hundred forty volunteers were randomized to eight intervention groups. Participants were randomly assigned
to receive active or placebo applications of one of four different products: Opalescence 10% PF™ (OPL), Vivastyle? 10%™ (VS10%),
Vivadent Paint On Plus™ (PO+), and Trés White Supreme™ (TWS). Saliva collection was obtained by established methods at different
times. The HP salivary content was determined by a photometric method. Salivary HP variations, total amount of salivary HP,
and counts of subjects above the safe daily HP dose were the main outcome measures. All whitening systems significantly released
HP to the saliva when compared to placebo, and all showed different release kinetics. The adaptable tray system (TWS) presented
a risk increase of 37% [20–54%, 95% confidence interval] when compared to the other systems. The use of an adaptable tray
whitening system with higher concentration of HP increases the toxicity potential. 相似文献
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Introduction
The aim of this study was to determine the root and canal morphology of the mandibular first molars in a Korean population of Mongolian origin by retrospective analysis of a large number of cone-beam computed tomography (CBCT) images.Methods
A total of 976 subjects with bilateral mandibular first molars were examined by using in vivo CBCT methods. The number and configuration of roots, the number of root canals, and the canal configuration based on Vertucci's classification were determined.Results
Overall, 25.82% of examined molars had 3 roots, 73.51% had 2 roots, and 0.67% had 1 root. The incidence of fourth canal was 50.36%. A right-sided predominance was noted for extra distal roots (P < .001), whereas a left-sided predominance was observed for extra distal canals (P < .001). No significant sex-related differences were shown for their prevalence. The bilateral prevalence rate was 69.13% for extra distal roots and 78.08% for extra distolingual (DL) canals. In the mesial roots, type IV canal was the most frequent (76.86% for 2-rooted molars and 72.96% for 3-rooted molars). In the distal roots, type l was the most common (66.62% for 2-rooted molars and 99.40%–100% for 3-rooted molars). The incidence of 2 canals in distobuccal roots, first reported in this study, was 0.15%.Conclusions
Among mandibular first molars, there is a high prevalence of a separate DL root and/or a separate DL canal, and such molars commonly have 4 canals in the Korean population. CBCT is a useful tool for determining root and canal morphology. 相似文献89.
Gomes V Brand?o V Mimoso J Gago P Trigo J Santos W Marques N Candeias R Pereira S Marques V Camacho A de Jesus I 《Revista portuguesa de cardiologia》2012,31(3):193-201
ObjectiveTo analyze the impact of reperfusion by either primary percutaneous coronary intervention (PPCI) or fibrinolysis, and mortality rates of a pre-hospital fast-track network for treating patients with ST-elevation myocardial infarction (STEMI).Methods and ResultsA pre-hospital network for STEMI patients, designated the Green Lane for Acute Myocardial Infarction (GL-AMI), has been implemented in the southern region of Portugal – the Algarve Project. We performed an observational study based on a prospective registry of 1338 patients admitted to Faro Hospital between 2004 and 2009, classified in two groups according to the method of admission: emergency department group (EDG) and GL-AMI group (GLG). More patients from GLG were reperfused (p < 0.0001). PPCI was the preferred method of reperfusion, 73.1% in GLG and 45.3% in EDG. Time delays were significantly shorter in GLG, except for pre-hospital delay: pre-hospital delay (p = 0.11); door-to-needle (p < 0.0001); door-to-balloon (p < 0.0001); and delay between symptoms and reperfusion (p < 0.0001). In-hospital mortality (4.3% vs 9.2%, p = 0.0007) and 6-month mortality (6.3% vs 13.8%, p < 0.0001) were significantly lower in GLG.ConclusionsThe Algarve Project significantly reduced the time delay between onset of symptoms and reperfusion, significantly increased the rate of reperfusion, and significantly reduced in-hospital and six-month mortality. 相似文献
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Tzu I Lee Joana Issac Shih-Hsien Lin Tzung Lieh Yeh I. Hui Lee Po See Chen Kao Chin Chen Yen Kuang Yang 《General hospital psychiatry》2013