Tooth is composed of three hard tissues enamel, dentin and cementum .The colour of the tooth is determined by reflectance of dentin and thickness of enamel[30].As cementum is in root portion of the tooth its influence on determining the color of the tooth is not much. Tooth color is different among the different people, different teeth in same person and different areas of the same tooth[31].Tooth color is not constant and it changes due to various reasons.According to the location of the stain the tooth discoloration can be intrinsic or extrinsic. Internalized stain or discoloration has also been described[32].
2.2.1 Intrinsic tooth discoloration
Intrinsic tooth discoloration occurs during odontogenesis and post eruption. It alters the light transmission properties of enamel and dentin.
Etiology of intrinsic tooth discoloration [2].
a.Pre eruptive causes
»Medications (Tetracycline)
»Metabolism (Fluorosis)
»Genetics (Hyperbilirubinaemia,Amelogenesis imperfecta,Cystic fibrosis of pancreas, Congenital erythropoietic porphyria, Enamel hypoplasia, Alkaptonuria, Dentinogenesis imperfecta)
»Dental trauma (Turner’s tooth)
b.Post eruptive causes
»Pulpal necrosis
»Intra-pulpal hemorrhage
»Residual pulp tissue after endodontic treatment
»Endodontic material (Medications/irrigants ,root canal sealer)
»Filling Materials
»Root resorption
»Aging
2.2.2 Extrinsic tooth discoloration
Extrinsic tooth discoloration lies outside the tooth substance on tooth surface. Extrinsic discoloration can be the result of incorporation of chromogenic compound into the tooth pellicle which is direct in origin or due to chemical interaction with another compound which is indirect in origin. So according to the origin extrinsic discoloration may be direct or ...
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...be applied directly, or produced in a chemical reaction from sodium perborate or carbamide peroxide (CH6N2O3, or CH4N2O.H2O2)[6]. Hydrogen peroxide (30-35%) and carbamide peroxide are mainly used for vital bleaching, while sodium perborate is used for non-vital bleaching.
Hydrogen peroxide oxidizes organic and inorganic compounds by free radicals (OH•, O•-2).O•-2 is produced in large no by ionization of weakly acidic aqueous hydrogen peroxide while OH• is produced by ionization of buffered hydrogen peroxide at ph 9.5-10.8.But OH• has better bleaching effect than O•-2 [35].
2.4. Bleaching agents
According to Federal Health Office of Switzerland and the Medications Institute Swissmedic as cosmetics patients can directly use maximum of 6% hydrogen peroxide or equivalent amount of other free radicals releasing agents. Higher concentration are only for professional use.
The purpose of this experiment was to examine how the stoichiometry, “the quantitative relationships between substances involved in a chemical reaction”, can be applied to determine the quantity of sodium hypochlorite found in a bleach product. This experiment allowed it to determine how much oxidizing agent is in a cleaner by using a redox reaction, which is a reaction involving the transfer of electrons from the compound being oxidized to the compound being reduced. To determine the amount of oxidizing agent, it is necessary to accurately measure out known amounts of redox reactants, know the stoichiometry
Teeth #1, 16, and 17 are unerupted. There is a PFM on tooth #22. There were two 3-unit bridges: teeth #19 through 21 with a gold abutment on tooth #19, the pontic on tooth #20 and a PFM abutment on tooth #21, as well as on teeth #23 through 25, with PFM abutments on teeth #23 and 25, and the pontic on tooth #24. The amalgam restorations are as follows: an MO on tooth #2 and an MOD on teeth #3 and 5. There are cervical composites on teeth #3 and 4. Tooth #15 was missing the crown. Tooth #13 was a root tip. There are class two furcations on the lingual surface of teeth #1, 18, and 19, and a class one furcation on the buccal surface of tooth #18. There is 2mm of recession on the facial surfaces of teeth #4, 5, 6, 7, 8, 15, 29, 25, 26, and 27, as well as the lingual surfaces of teeth #3, 5, 6, 7, 8, 15, 21, 22, 26, 27. There is 4mm of recession on the facial surfaces of teeth #3 and 23, as well as the lingual surfaces of teeth #12, 23, and 25. There is 6mm of recession on the facial surface of tooth #22. Teeth #3, 4, 18, 26, and 27 had attrition. There was erosion on the lingual and incisal surfaces of teeth #8 through
Humans only get one set of adult teeth after losing all of their primary teeth therefore, it is important to take care of them. “Dental caries: Strategies to control this preventable disease” is an article written by Rugg-Gunn, Andrew presents several reasons why dental decay is a widespread disease. Rugg-Gunn cites that the main cause of dental decay is lack of fluoride, poor diet, bacteria from plaque, and sugars. Based on this evidence, Rugg-Gunn concludes that “dental caries can be prevented” (Rugg-Gunn128), but there is no evidence of stopping the disease from happening. While Rugg-Gunn raises a revolving problem around the world with human oral decay he however, does not have a good approach on what decay really is.
The article Poor Teeth was written by Sarah Smarsh with the goal in mind being to shed light on the issue between upper and lower class society in a particularly concrete way. Teeth and dental health are an easy thing for people to imagine in their head because everyone has a set whether they’re white and shiny or black and rotted. This makes it easy to draw a comparison between people that care for their teeth and those who don’t. However, access to dental knowledge and services which the lower class often times doesn’t have is very different between the poor and the rich. While the rich stroll through life showing off their perfect glossy white rows of teeth, there are less privileged people out there with barren mouths whose weak pale gums
A techinque used to builded up a tooth by using a malleable filling material that will harden in the tooth quickly.
2H2O(aq) à 2H2O(l) + O2 (g) It is able to speed up the decomposition of hydrogen peroxide because the shape of its active site matches the shape of the hydrogen peroxide molecule. This type of reaction were a molecule is broken down into smaller pieces is called an anabolic reaction. I will be studying the effect of concentration of the catalase in this reaction. Hypothesis Hydrogen peroxide will breakdown to oxygen in water in the presence of catalase.
The Skin of Our Teeth by Thornton Wilder illustrates a family dodging one catastrophe after another. By the skin of their teeth, they will defeat ice, flood, and war. The main characters of this play are George and Maggie Antrobus, their two children, Henry and Gladys, and Sabina, who appears as the family's maid in the first and third acts, as well as a beauty queen seductress in the second act. The Skin of Our Teeth takes place at the Antrobus home in Excelsior, New Jersey; and the Atlantic City boardwalk.
The people who undergo blue light acne treatment also have to apply the topical solutions like Levulan to their skin for 15-60 minutes before they are exposed to light. When this solution is used bef...
In White Teeth, Zadie Smith warns against the dangers of purism and letting cultural background completely shape one’s identity while simultaneously paying tribute to the rich heritage and beliefs of her characters. It is a cautionary tale for immigrants but is never dismissive of their past. Smith is merely advising against tunnel vision and stressing the need to adapt to one’s environment. She shows the beauty that can stem from adaptation while warning that an inability to do so will lead to one’s downfall. London plays an especially important role as the battleground where the past and the present clash; a melting pot with a large immigrant population and inevitable moral struggle.
By analyzing my very own personal investment in the idea that heterosexuality is normal, I have realized that I am currently and that I used to deliberately present myself in a heterosexual persona to the world at large. Personally, when I was young, I used to be uncomfortable with women who broke the social norms of heteronormativity in public. I remember feeling anxious, and believing that one day soon society would perceive me as a divergent towards the norms because I hang out with women who didn’t present a heterosexual persona. I feared unspeakable things that would happen to me once I lost my privileges of being perceived as the ‘good’ heterosexual female. The lost of my social standing in society scared me; I was already a minority,
8. Chapman Kenneth W., Crim Gary A. Reducing microleakage in Class II restorations: An in vitro study. Oper Dent 1994; 25(11): 781-785.
Dental plaque is broadly classified as supragingival or subgingival based on its position on the tooth surface toward the gingival margin. Supragingival plaque is found at or above the gingival margin. Therefore, it can be further differentiated into coronal plaque, whi...
SILVER CONTENT which may results in discoloration of tooth structure if not removed meticulously from the crown and pulp chamber with xylol
Investigating the Effect of the Enzyme Catalyse On Hydrogen Peroxide Introduction The aim of this experiment is to determine the effects of varying enzyme (catalyse) on Hydrogen Peroxide. Hydrogen Peroxide + Catalyse à Water + Oxygen 2H2O2 à H2O + O2 + Heat Apparatus & Diagram [IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE][IMAGE] Bung Potato Hydrogen Peroxide Water Collected Oxygen Delivery Tube Measuring Cylinder [IMAGE] Using the Equipment Safely It is important that we use the apparatus carefully, as safety will be an issue throughout the whole experiment. We will wear goggles and an apron or lab coat to protect our eyes and clothes. As we are using enzymes and Hydrogen Peroxide we need to be extra careful, ensuring they don't come into contact with our eyes, skin or clothes. Catalyse is an enzyme found in all living cells.
Cosmetic dentistry is a specialized field that deals with improving the aesthetics of teeth and the human face. The teeth are an important part of human beauty. Even minor damage to the teeth, such as breakage or loss can drastically alter the overall appearance of the face. This is where cosmetic dentistry comes in to restore beauty. Cosmetic dentistry has become a highly specialized branch due to various advancements in surgical procedures and diagnostic techniques. Several new materials have also been discovered. These materials are very close to the natural enamel and bone from which teeth are made and are virtually indistinguishable. Cosmetic dentistry is an option in conditions such as teeth loss, gaps between teeth, cracked or chipped teeth, cavities and dental