Dental decay

Fluorides ia small (1 ppm ia water, 0.1% ia dentifrices) quantities have been shown to provide dramatic reduction ia dental decay. Fluorides also show promise for bone treatment and ia pharmaceuticals (qv) (see also Chemotherapeutics, anticancer Steroids). However, larger quantities of fluorides can lead to dental fluorosis, bone fracture, and even death. The oral LD q for free fluoride ion ia rats appears to be 50 to 100 mg/kg body weight based on LD q values for several fluorides. 

Sodium monofluorophosphate is used ia most dentifrices at a concentration of 0.76 wt % which produces the desired fluoride level of 1000 ppm although one extra strength dentifrice has 1.14 wt % and 1500 ppm F. Although the mechanism of its efficacy ia reducing dental decay is not completely understood (75), it almost certainly reacts with the apatite of the tooth converting it to fluoroapatite which is less soluble ia mouth acids (see Dentifrices). 

Fluorides. Most woddwide reductions in dental decay can be ascribed to fluoride incorporation into drinking water, dentifrices, and mouth rinses. Numerous mechanisms have been described by which fluoride exerts a beneficial effect. Fluoride either reacts with tooth enamel to reduce its susceptibihty to dissolution in bacterial acids or interferes with the production of acid by bacterial within dental plaque. The multiple modes of action with fluoride may account for its remarkable effectiveness at concentrations far below those necessary with most therapeutic materials. Fluoride release from restorative dental materials foUow the same basic pattern. Fluoride is released in an initial short burst after placement of the material, and decreases rapidly to a low level of constant release. The constant low level release has been postulated to provide tooth protection by incorporation into tooth mineral. 

Fluoride F Few major industrial water problems Reduces dental decay Alum coagulation Magnesium Hydroxide reaction Anion exchange Membrane separation... 

The glass polyalkenoate cement uniquely combines translucency with the ability to bond to untreated tooth material and bone. Indeed, the only other cement to possess translucency is the dental silicate cement, while the zinc polycarboxylate cement is the only other adhesive cement. It is also an agent for the sustained release of fluoride. For these reasons the glass polyalkenoate cement has many applications in dentistry as well as being a candidate bone cement. Its translucency makes it a favoured material both for the restoration of front teeth and to cement translucent porcelain teeth and veneers. Its adhesive quality reduces and sometimes eliminates the need for the use of the dental drill. The release of fluoride from this cement protects neighbouring tooth material from the ravages of dental decay. New clinical techniques have been devised to exploit the unique characteristics of the material (McLean Wilson, 1977a,b,c Wilson McLean, 1988 Mount, 1990). 

Aluminium ions released from the dental silicate cement are also absorbed by hydroxyapatite and have a similar beneficial effect to that of fluoride (Halse Hals, 1976 Putt Kleber, 1985). Thus, the dental silicate cement confers protection against caries (dental decay) on surrounding tooth material. 

Syringate cements possess similar advantages to the vanillate cements. In addition, syringic acid possesses cariostatic properties, so syringates may inhibit the development of caries (dental decay). Again these advantages need to be confirmed. 

The simplest interpretation of these results is that a rat which was to exhibit no dental decay had genetically determined nutritional requirements such that, from the time the original egg was fertilized to the end of the experiment, it was supplied with enough of all the elements required to promote growth, development, and maintenance of healthy teeth. On the other hand, the rat that was to show extensive dental decay probably had genetically determined nutritional requirements such that deficiencies did develop, particularly on the caries-inducing diet. 

Of course, the basic reason for experiments on dental decay in rats is to throw light on dental decay in humans. One can hardly escape the observation that given access to the same food, different children... 

Opdyke DLJ (1962) The histochemistry of dental decay. Arch Oral Biol 7, 207-219. 

Poisonous fluoride salts are not toxic to the human body at the very low concentration levels used in drinking water and toothpaste to prevent dental decay. 

The most common oral condition and dental emergency is dental caries, which is a destructive disease of the hard tissues of the teeth due to bacterial infection with Streptococcus mutans and other bacteria. It is characterized by destruction of enamel and dentine. Dental decay presents as opaque white areas of enamel with grey undertones and in more advanced cases, brownish discoloured cavitations. Dental caries is initially asymptomatic and pain does not occur until the decay impinges on the pulp, and an inflammation develops. Treatment of caries involves removal of the softened and infected hard tissues, sealing of exposed dentines and restoration of the lost tooth structure with porcelain, silver, amalgam, composite plastic, gold etc. 

In terms nf humans, some research in New Zealand and the United Kingdom indicates that diets containing moderately high levels of molybdenum help to prevent dental decay. The high-molybdcnum soils in the United States are seldom used for production of food crops and thus the effects of molybdenum toxicity from food substances arc nol well known. 

Figure 9.15 The halogens have many varied uses - fluoride in toothpaste to help reduce dental decay, chlorine in household bleach to kill bacteria, bromine as a fire retardant, and iodine in photographic reproduction.

Fluoride poisoning results in dental decay, bone decay and deformity. 

Tea contains tannins that may provide protection against dental decay. 

The fluoride ion is added to most public drinking water supplies in order to reduce dental decay. This ion carries a -1 charge. Write the proton/electron numbers for both the fluoride ion and the fluorine neutral atom. 

Fluoride (Fl) is the most widely used of the pharmacologically beneficial trace elements in the area of public health. Dental caries has been described as the last major epidemic of preventable bacterial disease and dental decay leads to tooth loss, nutritional problems, and systemic infections. ... 

Mouatt B. Health and fitness series-2. Dental decay and the case for fluoride. J Fam Health Care 2003 13 34-6. 

Because it has no caloric value, when it became commercially available in 1885, saccharin became an important substitute for sucrose. The chief nutritional problem in the West was—and still is—the overconsumption of sugar and its consequences obesity, heart disease, and dental decay. Saccharin is also important to diabetics, who must limit their consumption of sucrose and glucose. Although the toxicity of saccharin was not studied carefully when the compound first became available to the public (our current concern with toxicity is a fairly recent development), extensive studies done since... 

Anticholinergic side-effects are particularly troublesome to elderly patients. Dry mouth promotes dental decay and denture problems ... 

The EPA has set a maximum amount of fluoride allowable in drinking water of 4.0 milligrams per liter of water (4.0 mg/L). For the prevention of dental decay, the Public Health Service (PHS) has, since 1962, recommended that public water supplies contain between 0.7 and 1.2 milligrams of fluoride per liter of drinking water. 

W.J. Loesche, Role of Streptococcus mutans in human dental decay, Microbiol. Rev. 50 (1986)353-380. 

The problem of dental decay is certainly a formidable one and can only be mentioned in passing here. Local factors may be of primary importance, but the role of the resistance of the tooth should not be minimized. May Mellanby saw some decrease in the incidence of caries... 

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