Effects of sulfur-based hemostatic agents and gingival retraction cords handled with latex gloves on the polymerization of polyvinyl siloxane impression materials

OBJECTIVES: This study investigated the possible interactions between three addition silicone materials (Express(®), Aquasil Ultra(®) and Adsil(®)), three hemostatic agents (ferric sulfate, StatGel FS(®); aluminum sulfate, GelCord(®); and aluminum chloride, Hemostop(®)) and gingival retraction cords previously handled with latex gloves to determine whether direct contact with medicaments or indirect contamination by latex in conditions similar to those found in clinical practice inhibit or affect the setting of the impression materials. MATERIAL AND METHODS: A portable device for the simultaneous test of several specimens was specifically developed for this study. Polymerization inhibition was analyzed by examination of the impressions and the molded surface. Ten trials were performed for each addition silicone material used in the study, at a total of 240 study samples. RESULTS: All the samples tested (N=240) were nonreactive regardless of the type of combination used. CONCLUSIONS: Aluminum sulfate, ferric sulfate and aluminum chloride hemostatic solutions did not show any inhibitory potential on the addition silicone samples under study, and there were no changes in polymerization as a result of contact between addition silicone and retraction cords handled with latex gloves

Advanced producer service firms as strategic networks, global cities as strategic places

Sassen’s identification of global cities as ‘strategic places’ is explored through world city network analysis. This involves searching out advanced producer service (APS) firms that constitute ‘strategic networks’, from whose activities strategic places can be defined. 25 out of 175 APS firms are found to be strategic and from their office networks, 45 cities out of 526 are designated as strategic places. A measure of ‘strategicness’ of cities is devised and individual findings from this are discussed by drawing on existing literature about how APS firms use specific cities. A key finding shows that New York and London have different levels of strategicness and this is related to the former’s innovation prowess and the latter’s role in global consumption of services. Other cases of strategicness discussed in terms of the balance between production and consumption of advanced producer services are: Beijing, Hong Kong and Shanghai; Palo Alto; Mexico City; Johannesburg; and Dubai and Frankfurt

Illuminating dental instrument, coupling and method of use

A dental instrument, or a coupling connectable to the dental instrument, comprises an illuminator having a plurality of light emitting diodes that are each capable of emitting light at a selected wavelength in a range 260 to 880 nm. White or near white light emitting diodes may also be included together with a switch. Fluorescence-based diagnosis can be assisted by the use of a single dye or mixture of dyes. Light of about 400-540 nm wavelength may be used to distinguish composite, porcelain or other tooth coloured filling materials from normal tooth structures. Light of about 260-450 nm wavelength may be used to identify dental caries, calculus and/or dental plaque. Light of about 350-500 nm wavelength may be used to cure dental composite. Typically, the dental instrument is, or comprises, a drill, de-scaler, or other instruments such as for cleaning, examination or diagnosis of dental conditions

In vitro performance of class I and II composite restorations : a literature review on nondestructive laboratory trials - Part II

ABSTRACT A literature review was conducted on adhesive Class I and II restorations and nondestructive in vitro tests using the PubMed/Medline database for the 1995-2010 period. The first part of this review has presented and critically appraised selected literature dealing with the quality and in vitro behavior of adhesive Class II restorations using photoelasticity, finite element analysis, and microleakage study protocols. This second part reviews additional parameters, which are deformation and fracture resistance to cyclic loading, shrinkage stress and tooth deformation following restoration placement, bond strength (microtensile, tensile, and shear tests), and marginal and internal adaptation. In addition, a “relevance score” has been proposed that aims to classify the different study protocols according, firstly, to the resulting quality, quantity, and consistency of the evidence and then, secondly, to their potential clinical relevance, as estimated by their ability to simulate oral and biomechanical strains. The highest clinical relevance was attributed to marginal and internal adaptation studies, following cyclic loading in a moist environement. However, a combination of in vitro protocols will have an even greater predictive potential and has to be considered as a crucial preclinical research approach with which to investigate the numerous restorative configurations that cannot be efficiently and rapidly tested in vivo.</jats:p