Bacteria tooth decay

Anticariogenicity. Sugar alcohols are not fermented to release acids that may cause tooth decay by the oral bacteria which metabolize sugars and starches (208). As a result, use of sugar alcohols in sugar-free chewing gum, pressed mints, confections, and toothpaste has been widely accepted. 

The principal agents of tooth decay are the carboxylic acids produced when bacteria act on the remains of food. A more resistant coating forms when the OH ions in the apatite are replaced by F ions. The resulting mineral is called fluorapatite ... 

Bacteria on the surface of our teeth metabolize sugars to produce lactic acid, which lowers the pH enough to slowly dissolve tooth enamel. Fluoride inhibits tooth decay because it forms fluorapatite, Cal0(PO4)6F2, which is more acid resistant than hydroxyapatite. 

A freshly cleaned tooth surface quickly becomes coated with a thin pellicle of salivary proteins. This provides a surface for growth of dental plaque, which contains many bacteria and adhesive polysaccharides such as dextrans.1 The latter are generated from dietary sucrose by such bacteria as Streptococcus mutans. (Chapter 20) and others.131 Many factors affect the probability of tooth decay. 

A high sucrose diet promotes decay.11 While most people have some trouble with tooth decay, 1 or 2 per thousand remain totally free of caries and seem to be immune. Many factors must affect resistance to caries. For example, individuals vary in the kinds and numbers of bacteria present on teeth and in the structure of tooth enamel.0 Addition of fluoride ion to water supplies at a level of lppm (0.05 mM) is generally believed to reduce the incidence of tooth decay. However, caries has been declining in many developed countries at rates that are the same for water with or without fluoride.p q If teeth escape caries periodental disease, caused by bacteria, is often a major problem for older people.1... 

Due to its viscosity, polydextiose gives good mouthfeel in soft drinks, but does not provide any sweetness (RS = 0). The caloric level is 1 cal/g. It is partially metabolised in the large intestine (and, therefore, independently of insulin) and so is suitable for diabetic and low glycaemic index products. It does not promote tooth decay, as it is not metabolised by oral bacteria. 

Finally, a little chlorine gas is added, which sterilises the water and kills any remaining bacteria. Excess chlorine can be removed by the addition of sulfur dioxide gas. The addition of chlorine gas makes the water more acidic and so appropriate amounts of sodium hydroxide solution are added. Fluoride is sometimes added to water if there is insufficient occurring naturally, as it helps to prevent tooth decay. 

Xylitol, another polyhydroxy compound, is used as a sweetener in sugarless gum. It has approximately the same number of calories per gram as does sucrose and is not a low-calorie sweetener. However, because it does not have a carbonyl group, it is not fermented by bacteria in the mouth and does not promote tooth decay. 

Xylose is reduced to the meso alcohol xylitol. This alcohol is more or less as sweet as sugar and, as xylose (which is not sweet) can be extracted in large quantities from waste products such as sawdust or corncobs, xylitol is used as a sweetener in foods. There is an advantage in this. Though we can digest xylitol (so it is fattening), the bacteria on teeth cannot so that xylitol does not cause tooth decay. plane of symmetry... 

This chapter describes dental caries (tooth decay) and its causes. Sucrose and other mono- and disaccharides are metabolized to acid (lactate) by bacteria that remain in stagnation areas of the teeth. Rats and hamsters fed a 50% sucrose diet developed a caries-sensitive, predominantly gram-positive microbiota that became caries resistant when the rodents were fed penicillin (Sect. 1). Further studies identified Streptococcus mutans (S. mutans) as the etiological agent. This organism synthesizes an insoluble polysaccharide capsule that is stable and retains lactate at the enamel surface (Sect. 2). The key enzyme, glucosyl transferase, is related to salivary amylase which adheres to oral bacteria and enhances bacterial acid production. The chapter concludes with a discussion of salivary and other factors responsible for the marked variation observed in individual caries experience (Sect. 3). 

Bacteria and cavities Bacteria use sugar for energy and produce lactic acid. The acid causes the pH of saliva, which is normally 6.8, to drop below 6.0. When that happens, the rate of demineralization increases and tooth decay occurs. 

Water s great versahlity stems, in part, from a tendency TO form aqueous SOLUHONS by DISSOLVING A LARGE VARIETY OF SOLIDS AND OTHER LIQUIDS THE FACT THAT IT EXISTS AT NORMAL AIR TEMPERATURE AS A LIQUID IS DUE TO THE UNIQUE PROPERTY OF ITS MOLECULES. Even though water covers 70 percent of Earth s surface, IT IS RARE TO FIND PURE WATER IN NATURE. SeAWATER AND FRESHWATER SOURCES ALIKE CONTAIN DISSOLVED MINERALS AND CONTAMINANTS SUCH AS FERHLIZERS AND INDUSTRIAL POLLUTANTS. AS FOR THE WATER THAT COMES FROM THE TAP, IT GENERALLY CONTAINS FLUORIDES (ADDED TO REDUCE TOOTH DECAY) IN ADDIHON TO MINERALS (PRINCIPALLY CHLORIDES, SULFATES, BICARBONATES OF SODIUM, POTASSIUM, CALCIUM, AND MAGNESIUM), AND POSSIBLY ADDIHONAL CHLORINE (TO KILL BACTERIA) AND LEAD (IF THE PIPES CARRYING IT ARE MORE THAN 80 YEARS OLD). 

Do you crave sweets, but worry about the empty calories in sugary treats If so, you are not alone. Research tells us that, even as babies, we demonstrate preference for sweet tastes over all others. But there are many reasons to reduce our intake of refined sugars, in particular sucrose or table sugar. Too many people eat high-calorie, low-nutrition snacks rather than more nutritious foods. This can lead to obesity, a problem that is very common in our society. In addition, sucrose is responsible for tooth decay. Lactic acid, one of the products of the metabolism of sucrose by bacteria on our teeth, dissolves the tooth enamel, which results in a cavity. For those with diabetes, glucose intolerance, or hypoglycemia, sucrose in the diet makes it difficult to maintain a constant blood sugar level. 

As we saw in A Human Perspective Tooth Decay and Simple Sugars (Chapter 17), the lactate produced by oral bacteria is responsible for the gradual removal of calcium from tooth enamel and the resulting dental cavities. 

Hypofluoric status, fluorine deficiency in humans, is characterized, along with tooth decay, by the development of osteoporosis (Gabovich and Ovrutskiy 1969). In the first case, acid environment is created by osteo-cytes in the second case, by bacteria populating the surface of tooth enamel. Attention should be paid to the role of bacteria in the development of caries, as disturbed microflora of the mouth cavity seems to be one of its prerequisites. Up-to-date methods of tooth decay prevention (toothpastes, pills) combine the eflfects on the enamel structure and tooth tissue in general, and on the microflora that causes acidity at the points of its location. In this respect, the adaptation of microorganisms to particular fluorine levels is most likely the phenomenon of most significance. 

The primary use of stannous fluoride is in toothpastes, dental rinses, and fluoride treatments for teeth. Fluorides prevent tooth decay in two ways. First, fluorides kill bacteria that cause tooth decay. Second, fluorides react with other chemicals in the mouth to make new enamel to replace enamel destroyed by bacteria or worn away by mechanical processes. Studies suggest that stannous fluoride also has other beneficial effects, including preventing gingivitis (inflammation of the gums) and bad breath. 

Consumed in moderate amounts, sucrose poses no health hazards to humans or other animals. Eating excessive amounts of sucrose, however, is related to a number of health problems, most important, dental caries (tooth decay) and obesity. Sucrose is an important factor in the development of tooth decay because it provides the primary nutrient needed by bacteria living in the mouth. Cleaning one s teeth regularly is the best single way of preventing dental caries caused by the consumption of sucrose. Obesity is a problem that develops when a person consumes more foods than needed for normal healthy body function. When those foods are not utilized by the body, they are stored as fatty deposits, resulting in obesity and a number of health problems related to it, such as diabetes and heart disease. 

If dental chemistry continues to progress at the present rate, tooth decay may soon be a thing of the past. Cavities are holes that develop in tooth enamel, which is composed of the mineral hydroxyapatite, Ca5(P04)30H. Recent research has shown that there is constant dissolving and re-forming of the tooth mineral in the saliva at the tooth s surface. Demineralization (dissolving of tooth enamel) is mainly caused by weak acids in the saliva created by bacteria as they metabolize carbohydrates in food. (The solubility of Ca6(P04)30H in acidic saliva should come as no surprise to you if you understand how pH affects the solubility of a salt with basic anions.)... 

Precautions Polyphenol substances in tea are believed to inhibit the action of carcinogens in food and tobacco, and may protect against heart disease. Other elements of tea may prevent tooth decay. Tannins in tea help fight bacteria and viruses. 

Fluorine can replace Ca when in the form of hydrofluoric acid (HF), which is a weak acid with a tenacious capacity for destruction. On the other hand, fluorine fills gaps made by tooth decaying bacteria, and for this reason has been added as fluoride (F ) to public drinking water in the United States in an effort to improve oral hygiene. It s also used in nonstick cooking pans in the form of poly(tetrafluoroethene), also known as PTFE or Teflon. 

Tooth decay (dental caries) is one of the most common diseases in humans [8]. It has been defined as a chronic, dietomiaobial, site-specific disease caused by a shift from protective factors favouring tooth remineralization to destructive factors leading to demineralization [9]. The specific factors leading to destruction of the mineral phase of the tooth are the presence of oral bacteria, mainly Streptococcus mutans [10], and the availability of fermentable carbohydrates from the diet. This combination leads to the production of organic acids as a result of the metabolic process of the bacteria, of which the main one is lactic acid, though other weak acids, such as ethanoic and propanoic can also occur [11]. These acids dissolve the mineral component of the tooth, leading to loss of structure. 

A toothpaste may contain (a) A detergent, (b) An abrasive, (c) A fluoride, (d) Sodium pyrophosphate. Match each of these ingredients with the condition it helps to prevent, (i) Tooth decay (cavities), (ii) Tartar buildup, (iii) Accumulation of food debris and bacteria. 

Then the water is filtered again to remove the solid mass of fine particles (called a flocculate or floe ) leftover from the initial filtering treatment. Chlorine is added to kill any bacteria in the water. Then it s run through an activated charcoal filter that absorbs (collects on its surface) and removes substances responsible for taste, odor, and color. Fluoride may be added at this time to help prevent tooth decay. Finally, the purified water is collected in a holding tank, ready for your use. 

Bacteria on your teeth metabolize sugar into lactic acid—lowering the pH below 5 at the surface of a tooth. Acid causes tooth decay by dissolving enamel. 

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