In this paper we introduce a new graph composition, called 2-amalgam, and we prove that the 2-amalgam of perfect graphs is perfect. This composition generalizes many of the operations known to preserve perfection, such as the clique identification, substitution, join and amalgam operations. We give polynominal-time algorithms to determined whether a general graph is decomposable with respect to...

STATEMENT OF PROBLEM The in vitro effectiveness of a uniform circumferential ferrule has been established in the literature; however, the effect of a nonuniform circumferential ferrule height on fracture resistance is unknown. PURPOSE This in vitro study investigated the resistance to static loading of endodontically treated teeth with uniform and nonuniform ferrule configurations. MATERIAL...

Fatigue of a composite girder according to Eurocode 4 is carried out on the decisive shear connector. It not taken into account that an internally highly statically indeterminate system in which failure dowel does necessarily lead girder. This applies particular dowels are characterised by crack propagation phase with high residual load-bearing capacity damaged dowel. In own small part and test...

statement of problem: amalgam is the most widely used dental restorative material. however, because of continuous low-level release of mercury from amalgam fillings, its safety has been questionable. purpose: the aim of this study was the evaluation of concentration of mercury in saliva before and after amalgam fillings and its relation with numbers and surfaces of amalgam fillings. materials a...

Under visual guidance, subjects reached for and manipulated an object that varied in weight and surface texture (slipperiness). The manipulatory action was either grasping, lifting, or posting in a slot. The task was constrained or unconstrained with respect to speed, grasp pattern, and contact force. Initiation time (pre-reach), movement time (reach), and post-contact errors were measured, to ...

Understanding the dispersion processes within marshes is important to assess their filtering abilities and their ecological limits. A laboratory experiment was designed to study the influence of marsh vegetation on longitudinal dispersion. The flow through vegetation was modeled by a recirculating current going through an array of wooden dowels in a 24 m long flume. The longitudinal dispersion ...

Dental amalgam has been maligned as a filling material, both because of its clinical properties and its alleged effects on systemic health, but reports of its demise have been premature. As of 2008, 57 percent of dentists were placing amalgam (March 2008 Dental Products Report Survey). A large 2011 survey showed that dentists in the United States place more dental amalgam than composite for fir...

Worldwide publicity of the amalgam controversy has intensified the growing concerns on its utilization and safety. This controversy has grown beyond the confines of the dental profession itself and has become an emotional public health issue. Amalgam has been the material of choice for restoring posterior teeth for more than 100 years. Presently, there has been a shift toward resin composite an...

adhesive (green). _Besides the physical and mechanical properties of dental amalgam, one of the main reasons for its success is its clinical simplicity and forgiving technique. The derisory “drill and fill” slogan associated with dental treatment pertinently describes the provision of an amalgam restoration. The usual protocol for amalgam restorations is a single-stage procedure. Following deca...

The aim of this in vitro study was to evaluate four different approaches to the decision of changing or not defective amalgam restorations in first primary molar teeth concerning the loss of dental structure. Ditched amalgam restorations (n = 11) were submitted to four different treatments, as follows: Control group - polishing and finishing of the restorations were carried out; Amalgam group -...