Publications by authors named "Krejci I"

The advent of adhesive dentistry has had a dramatic effect on the practice of aesthetic dentistry, significantly expanding the range of treatment alternatives that clinicians can provide for their patients. Although adhesion is generally associated with the total bonding technique, adhesive systems can be applied in several different manners that include selective, separate, and secure bonding. It is the goal of this article to present the different bonding procedures, to explain the rationales behind each, and to formulate their indications.

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Purpose: Quality standards for restorations recently have been defined in Switzerland. Amalgam substitutes must meet restoration Grade 2 requirements (i.e.

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New condensed derivatives of anpirtoline, in which the pyridine ring is replaced with quinoline, quinazoline, 7-chloroquinoline, and 7-chloroquinazoline nuclei, have been synthesized. Their receptor binding profiles (5-HT1A, 5-HT1B) and analgesic activity (hot plate, acetic acid induced writhing) have been studied. The analgesic activity of compounds 4e-4g, and 4l are at least comparable to that of clinically used drugs flupirtine and tramadol under the same conditions.

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We investigated the effect of the nootropic substance oxiracetam on the impairment of memory induced in mice by the non-competitive NMDA antagonist MK-801. Memory capacities of animals having different experience were evaluated using the elevated plus-maze test. Oxiracetam was injected immediately after the acquisition session(s), MK-801 was given 30 min before the retention session which followed 24 h after the acquisition session(s).

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A series of epibatidine analogs and their positional isomers bearing an 8-azabicyclo[3.2.1]octane moiety is described.

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New derivatives of anpirtoline and deazaanpirtoline modified in the side chain have been synthesized. The series includes compounds 3 with side-chains containing piperidine or pyrrolidine rings, compounds 4 containing 8-azabicyclo[3.2.

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Objectives: The purpose of this study was to investigate whether the composite resin in a syringe showed a consistent shrinkage through its content. Additionally, the amount of linear shrinkage was compared between materials.

Methods: Five brands of syringe-type and one brand of carpule-type composite resins were used in this study.

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Objectives: To visualise the ultrastructure of the interface of SCA compomer adhesive and of Optibond composite adhesive in enamel and dentin, and to relate the findings to the marginal adaptation of these two products in mixed class V restorations.

Methods: The ultrastructure was investigated using a scanning electron microscope (SEM) with and without prior argon ion etching, an environmental SEM, a field emission SEM, a confocal laser scanning microscope, and a transmission electron microscope. The marginal adaptation was quantified in mixed class V restorations by using the replica technique and a SEM under simulated dentinal fluid before and after simultaneous mechanical and thermal loading.

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Resin composites in the post-amalgam age.

Compend Contin Educ Dent

December 1999

Resin-based composites are now being used as either amalgam substitutes or amalgam alternatives for the direct placement of box-shaped, stress-bearing restorations in posterior teeth. The expected longevity of these restorations is 8 years. With amalgam substitutes, preservation of enamel and dentin and restoration of tooth form and function must be warranted for the full length of the envisaged service life.

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Statement Of Problem: An in-vitro study revealed that a celluloid strip-finished composite surface discolored more than the polished composite surface. Thus, the celluloid strip-finished composite surface may not cure enough compared with the polished composite surface.

Purpose: This study tested the hypothesis that the celluloid strip-finished composite surface did not cure enough compared with the polished composite surface.

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Objective: The search for the ideal polishing agent for resin composite materials is still ongoing. A new polishing brush with abrasive bristles for polishing resin-based restorations was tested to determine if it polishes restorations, including those with concave surfaces, macrostructured occlusal surfaces, and textured surfaces, without destroying their delicate texture or microstructure.

Method And Materials: The polishing effectiveness and the ultimate destructive potential of these brushes were assessed quantitatively and subjectively in vitro.

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New condensed derivatives of anpirtoline, in which the pyridine ring is replaced with quinoline, isoquinoline, quinazoline, and phthalazine nuclei, have been synthesized. Their receptor binding profiles (5-HT1A, 5-HT1B) and analgesic activity (hot plate, acetic acid induced writhing) have been studied. The analgesic activity of compounds 7d, 8b, 8c, and 8e are at least comparable to that of the clinically used drugs flupirtine and tramadol under the same conditions.

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New deaza derivatives of anpirtoline have been synthesized by three different methods. Their receptor binding profiles (5-HT1A, 5-HT1B) and analgesic activity (hot plate, acetic acid induced writhing) have been studied.

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For differences among materials to be easily detected, low variation in in vitro wear tests is desirable. The working hypothesis of this paper was that antagonists standardized for shape and size and according to materials would show mean values similar to those found in natural, non-standardized cusps, and that standardization would lead to a reduction in mean variation. First, the shapes and sizes of palatal cusps of non-erupted human upper third molars were measured.

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Conventional treatment of proximal cavities can result in significant damage to the adjacent dentition. This paper describes a recently developed technique of proximal cavity preparation and finishing by use of selectively diamond-coated, ultrasonically driven instruments. By using these instruments for composite, compomer, ceramic, amalgam, and even gold restorations, the inadvertent damage to neighboring teeth is completely avoided.

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Ceramic optimized polymer and fiber-reinforced composite materials represent a significant development in prosthetic dentistry. When utilized in conjunction with adhesive luting techniques, exceptionally conservative crown and bridge restorations may be achieved. This article discusses utilization of these materials in inlay and onlay restorations, as well as clinical and laboratory procedures for fabrication, preparation, and seating of adhesive crown and bridge restorations.

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Amnesic properties of scopolamine, a muscarinic receptor antagonist, and MK-801, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, were evaluated in mice by means of the elevated plus-maze test. In this test, transfer latency, the time mice took to move from the open arm to the enclosed arm, was used as an index of learning and memory. The 3-day pretreatment training dramatically decreased transfer latencies.

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A mechanical computerized three-dimensional scanner with a resolution of 1 micron was used to assess loss of enamel caused by orthodontic bonding and debonding. A total of 2646 measurements was performed on six human premolars. The results showed an average loss of enamel of 7.

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