Fremdsprachige Bücher

Sweet Tooth PDF

This article may sweet Tooth PDF cleanup to meet Wikipedia’s quality standards. Restoration of the underlying natural tooth shade is possible by simply removing surface stains caused by extrinsic factors, stainers such as tea, coffee, red wine and tobacco. The buildup of calculus and tartar can also influence the staining of teeth.

Författare: Jeff Lemire.

1911 kämpft sich ein Suchtrupp durch verschneite Einöden, um einen verschollenen Missionar aufzuspüren. In der Gegenwart sind Jepperd und Gus kurz davor, ein finsteres Geheimnis zu entdecken. Zwar trennen tausend Meilen und hundert Jahre die Schauplätze, doch die Entscheidungen, die dort getroffen werden, beeinflussen das Schicksal unserer Art.

To whiten the natural tooth shade, bleaching is suggested. It is a common procedure in cosmetic dentistry, and a number of different techniques are used by dental professionals. There is a plethora of products marketed for home use to do this also. Techniques include bleaching strips, bleaching pens, bleaching gels and laser tooth whitening. The perception of tooth color is the result of a complex interaction of factors such as: lighting conditions, translucency, opacity, light scattering, gloss, the human eye and brain. Females generally have slightly whiter teeth than males, partly because females‘ teeth are smaller, and therefore there is less bulk of dentin, partially visible through the enamel layer.

Extrinsic stains can become internalised through enamel defects or cracks or as a result of dentine becoming exposed but most extrinsic stains appear to be deposited on or in the dental pellicle. Dental plaque: although usually virtually invisible on the tooth surface, plaque may become stained by chromogenic bacteria such as Actinomyces species. Calculus: neglected plaque will eventually calcify, and lead to the formation of a hard deposit on the teeth, especially around the gumline. Ingesting colored liquids like sports drinks, cola, coffee, tea, and red wine can discolor teeth. Exposure to such metallic compounds may be in the form of medication or other environmental exposure. Changes in the thickness of the dental hard tissues would result in intrinsic discolouration. There are a few causal factors that may act locally or systematically, affecting only a single tooth or all teeth and cause discolouration as a result.

Several diseases that are known to affect the developing dentition especially during enamel and dentine formation can lead to discolouration. Dental trauma which may cause staining either as a result of pulp necrosis or internal resorption. Tetracycline is a broad spectrum antibiotic, and its derivative minocycline is common in the treatment of acne. Alkaptonuria: Metabolic disorder which promotes the accumulation of homogentisic acid in the body and may cause brown colour pigmentation in the teeth, gums and buccal mucosa. Age: the tooth enamel becomes thinner over time, which allows the dentine to shine through. Extrinsic stains may settle more readily into these cracks, and a thin layer of enamel can be left.

This thin enamel layer is partially transparent, allowing the dark background of the mouth to shine through, affording a darker appearance of the incisal edge. Whitening methods can usually be divided into two types. The first type includes methods that removes surface stains from teeth and includes toothpastes, air polishing and micro abrasion. The second type removes stains that have penetrated the enamel and therefore cannot be removed by the first type. Bleaching solutions generally contain hydrogen peroxide or carbamide peroxide, which bleaches the enamel dentine junction to change its color.

The peroxide penetrates the porosities in the rod-like crystal structure of enamel and breaks down stain deposits in the dentin. The whitening shade guides are used to measure tooth color. These shades determine the effectiveness of the whitening procedure, which may vary from two to seven shades. The effects of bleaching can last for several months, but may vary depending on the lifestyle of the patient. Consuming tooth staining foods or drinks that have a strong colour may compromise effectiveness of the treatment. Bleaching is least effective when the original tooth color is grayish and may require custom bleaching trays.

Bleaching is most effective with yellow discolored teeth. The advantages of this technique are that the results happen at one sitting at the dentist, it does not take a longer time for results to show like it does when the home bleaching technique is used. This is good if fast, effective results are required. However the disadvantages of this technique is that this is a one off treatment and if further whitening is needed the treatment will need to be carried out all over again. However, with at home bleaching, more bleaching gel can be purchased from the dentist and the same trays can be used, as long as they are intact and have no holes in them.