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Fluoride
Question | Answer |
---|---|
Fluoride | |
• An anion (F-) of the element florine | |
• Tightly bonds with CA+ and phosphate (in teeth) | |
• This bond decreases the ability of acid to demineralize tooth enamel. | |
• When the mouth is acidic (state of dimineralization) and fluoride is around, fluorine will grab hold of calcium and phosphate and bond. Next time the mouth is acidic, the bond with fluoride will not break as easily. | |
• It takes a constant low dose of fluoride to make these bonds with the enamel since there are so many bonds. | |
Water Fluoridation: | |
One of the most successful public health disease prevention measures ever etablished. Why? | |
One of the seven most remarkable achievements of the 20th century (1900s) and helpful things to humans why? because you don't have to change any habit, just drink water. | |
1. Safe when monitored by public agencies | |
2. Low cost | |
3. Coverage of all socioeconomic strata, available to everyone | |
4. No behavior change | |
Time Line | |
• Early 1900's – A group of Dentists noticed that a community in Colorado where they all drank water from wells had brown stains on their teeth and low caries rate | |
• 1933 -they believed there may be something in the water and began studying the relationship between naturally occuring levels of fluoride in the drinking water and dental fluorosis and dental caries. | |
1. In 1950s, 60s, &70 the reduction of dental caries was 50% from fluoridated water programs | |
2. The 80's and 90's show a 30% reduction. What happened? Dilution. Still effective but the statistics were not as striking because the sample group was not pure and received fluoride from other sources. | |
Dilution | |
• The apparent reduction in measurable water fluoridation benefits resulting from the ubiquitous availability of fluoride from other sources in both the fluoridated community and fluoride deficient comparison community. | |
• Direct relationship between the amount of fluoride in the water and dental fluorosis. | |
fluoride= color change | |
• Inverse relationship between the amount fluoride in the water and dental caries. | |
fluoride = cavities | |
Through observation of fluoridated communites and amount of dental fluorosis, it was acknowledged the optimal level for dental purposes, is 0.7-1.2 ppm of fluoride in the drinking water. | |
Jan, 1945 was the first time fluoride was deliberately added to the public water supply in Grand Rapids, Michigan. The eventual results were a 55% reduction in DMFT(decayed missing filled teeth) in children 12-14yrs. | |
The opportunity to ingest fluoride has increased due to toothpastes, commercially processed food and beverages located in a fluoridated community. | |
Most recent idea to come to light is the topical benefit of fluoridated water to adults and kids age and above. Previously people believed fluoride needed to be taken systemically to be effective | |
• By age 45-54 amount of root caries doubles | |
• by age 35-44 root caries becomes a dental problem | |
• by age 55-66 amount of root caries redoubles | |
• by age 65-84, 67% of adults will have root caries. | |
• 5 studies done showed less coronal and root surface lesions in adult teeth in fluoridated communites. | |
• Is this a systemic or topical effect? Topical effect because once the enamel is formed, there is no way from inside the tooth for fluoride to get into the enamel | |
Change in Effectiveness | |
• in the 50s, data showed fantastic effectiveness. | |
• In the 90s, the abundance of readily available fluoride toothpaste, rinses, food, beverages lowered the percentage difference, between newly fluoridated communities and communities that didn't have fluoride. Due to diffusion. | |
Diffusion | |
the extension of the benefits of community water fluoridation to residents of fluoride-deficient communities. | |
• Consuming products made in a fluoridated community benefits person living in a nonfluoridated community. | |
• Diffusion has a leveling effect when comparing fluoridated and nonfluoridated communities. | |
• Diffusion also occurs when children and adults lives in nonfluoridated community travel to fluoride child care, school | |
• Dilution- due to diffusion, the dilution is greater | |
• Diffusion- means you can get fluoride from many sources, food, water, other communities | |
Cost | |
• the cost of water fluoridation is usually expressed as the annual cost per person of the population being served. | |
• The cost per person is dependent upon population. Inversely related to the size of the population community. The more people, the lower the cost. | |
1) The average cost is 0.17 cents (really big city) -7.62 (smaller community) per person. compared to a filling $250 each. | |
Optimal Levels | |
• A relationship exists between the amount of water a person drinks and the temperature. | |
• The US public health service established a range for optimal levels of fluoride in the drinking water based upon the annual average daily air temperature. This is 0.7-1.2ppm. | |
• In the Mojave desert, people drink more water so there should be less fluoride in the water. Should be closer to 0.7 ppm | |
• In Alaska, residents drink less water so they increase the amount of fluoride in the water. Should be closer to 1.2 ppm | |
Changes Today | |
• This rather simple calculation has been upset in recent years by: | |
1) The use of home purification systems, tap water is filtered. in price of purification = fluoride | |
2) Consumption of other beverages or water not from the tap. Soft drink consumption has increased. More people drink fruit juice and bottled water than tap water. American Pediatric Association recommends that a child does not get more than 4oz of fruit j | |
Distribution and Metabolism of Ingested Fluoride | |
• Fluoride is absorbed from the gastrointestinal tract and the remainder is excreted from the feces (won't do anything for erupted teeth) | |
• The absorbed fluoride goes into the systemic circulation and about half is bound to hard tissues such as bones and unerupted teeth. The rest is excreted into the urine. | |
• Almost no fluoride is absorbed into soft tissue. | |
• Fluoride can be deposited into bone. | |
Metabolism continued | |
• Up to 50% of the fluoride can be eliminated by extensive sweating. | |
• Approx 0.1 ppm is found in breast milk. | |
• 0.01-0.04 ppm is found in saliva | |
• Concentration of fluoride in the plaque is 50-100 times higher than in the whole saliva. | |
• Fluoride loves to hang out in plaque, when mouth is acidic fluoride in plaque will get into the enamel. Don't need a cleaning for a fluoride application. | |
• National board question: In what bodily fluids can fluoride be found? breast milk, perspiration, urine and saliva | |
Dental Fluorosis | |
• A developmental defect of the enamel that occurs when an excessive amount of fluoride is ingested during the period of enamel formation. | |
• Once enamel has undergone mineralization, enamel fluorosis cannot occur. 6 months to enamel maturation | |
• Mildest form of dental fluorosis is a matte white color often seen on the incisal edges of anterior teeth or cusps of posterior teeth (snowcapping). Enamel doesn't form and is pitted and it may get stained from food, but it will not form cavities. | |
Fluorosis | |
• In its most severe form the stains are chocolate brown to black. The stains are not evident at the time of eruption. They are caused by posteruptive uptake of exogenous stains from the diet. Pits and fractured enamel are caused by posteruptive breakdown | |
• What age would you notice staining? 7 or 8 years old | |
• There is no indication that infrequent topical fluoride applications by a professional in the dental office causes fluorosis or from the use of fluoride mouth rinses or self applied gels. | |
• Key factor for dental fluorosis appears to be improper use of dietary supplements and the ingestion of fluoride toothpastes by preschooler. | |
• Children can swallow from 35-50% of the fluoride while brushing. For children between 3-6 years that means ingestion of fluoride in the range of 0.1-0.4 per brushing so that twice daily brushing would be optimum intake. | |
• optimum range between ages of 3-6 because of enamel | |
• Generally before age 3 we don't use toothpaste | |
• The susceptible period for the entire permanent dentition has been reported to be between 11mos and 7yrs of age. | |
1) The most critical period for fluorosis of the permanent mx central incisors is between 15 and 30 mos. | |
2) 24mos seems to be the focal pt of fluorosis succeptibility for these teeth. | |
• Treatment includes removal of the stain (bleaching) and then if neeeded covering the veneer. In severe cases, crowning the entire tooth may be necessary. | |
Other systemic effects | |
• Skeletal deformities. an area in Mt. Kilimanjaro, bones are brittle because the dirt where they grow food has a high level of fluoride, including in the air and water | |
• | of osteoblasts increases in the presence of fluoride |
• the rate of bone formation increases and causes bone deformities | |
• Serum activity of skeletal alkaline phosphotase raises | |
• has been found to be carcinogenic in rodents in high doses | |
Opponents to Fluoridation | |
• main arguments | |
1) biologically harmful to the public-rats got bone cancer, high doses can be fatal, used in rat and insect poison (most persuasive argument) | |
2) unreasonable amount of government involvement in our health and govt is trying to control our minds | |
3) violates religous freedom and personal liberties | |
4) Dr. John Wilson most famous anti-fluoride proponent | |
Topical Fluoride | |
• A concentration of fluoride that is applied topically to erupted tooth surfaces to prevent the formation of dental caries. Includes the use of gels, foams, rinses, dentifrices, varnishes and water. 6 forms of topical fluoride | |
• History 1940- 1st office topical fluoride | |
• 1st type sodium fluoride NaF (still used) | |
• 2nd SnF- stanis fluoride | |
• 3rd- APF aciduated phosphoric fluoride (used today) | |
Chemical Reaction | |
• Reaction between enamel and Fluoride is influenced by: | |
1) pH (makes mouth acidic, demineralizes enamel and breaks it apart, fluoride runs in to make bonds with the enamel) | |
2) time (needs 4 minutes) | |
CaF- Calcium Fluoride | |
• Researchers originally hoped to create fluorhydroxyapatite a main crystal in enamel formation. The major reaction is calcium fluoride on the enamel when using NaF, SnF and APF. CaF lives in reservoirs in saliva and plaque. 6-8 weeks after an in office | |
NaF- Sodium Fluoride | |
• Powder, liquid, gel, foam (most in office products are foam) foam-ideal application, light and airy gets to a lot of places on the teeth. For daily home use prescription gel or liquid in ACT | |
• Ideal application | |
1) series of 4 applications, 1 week apart for high caries risk clients | |
2) Given when primary and permanent teeth erupt ages (3, 7, 10, 13) | |
3) Substitute for APF | |
4) Can be used as a varnish (painted on) is 5% (4 months is ideal, but usually given every 6 months when clients come in for cleanings) | |
NaF- Advantages/ Disadvantages | |
• Stable, long expiration date | |
• No taste, less sweeteners-flavors needed | |
• No stain or gingival irritation | |
• Safe for porcelain crowns and composites | |
• Varnish is easy to apply and quick | |
• No disadvantages to NaF | |
• | 1 product used |
SnF- Gel kam (use like a toothpaste but don't rinse) | |
• Originally comes as a powder that makes an 8% aqueous solution | |
• One application every 6 months, begin at 3yrs old | |
• Advantage: application correlates with dental visits | |
• Side note: No scientific basis for 6 mth visits. When fluoride was first put into toothpaste, Crest marketing team decided that they needed dentists to recommend their product. Ad campaign: Use Crest and visit your dentist twice a year. Insurance com | |
Disadvantage | |
• Very unstable, doesn't last long on shelf | |
• Bitter taste-need a lot of other ingredients | |
• it will stain teeth, but can be polished off | |
APF | |
• Thixotropic- comes out as a foam or gel, once a person bites down (subjected to pressure) it turns to liquid. Thixotropic: foam or gel + pressure= liquid | |
• Great Flavors | |
• Trays, swab, paint | |
• For maximum benefit teeth need to be exposed to Fl for 4 mins. | |
• APF is made up of 1.23% NaF and acidic solution 3.5 ph | |
• Applied every 6 months | |
• Regardless of age, if high caries risk(2 or more cavities within the last year), 4 applications within a 2-4 week are needed to stop the caries risk | |
• Advantages | |
• stable, clients like it, no stains, highest level of efficacy | |
• Disadvantages | |
• will leave etching or scratches on porcelains or veneers, or porcelain composite | |
Toxicity | |
• can be lethal when taken in large doses | |
• children most at risk, should be given a pea size amount of toothpaste, toxicity is less than an ounce for young kids and toddlers | |
• Adult lethal dose = 5 grams of F | |
• 1 swipe of toothpaste = 1gr | |
• 1 gr = 1mg of Fl | |
• 1000 grams of toothpaste=1 gram of fluoride | |
• 5000 grams of toothpaste =5 gram of fluoride | |
• 5000 grams =176 ounces | |
• 176 ounces = 22 tubes of 8oz toothpaste | |
• For kids who don't like toothpaste, brush with water or dip toothbrush into a little bit of Kids ACT to get a little bit of fluoride | |
Lethal & safe doses | |
Age Weight Lethal dose Standard | |
2 22 320mg 80mg | |
4 29 422 106 | |
6 37 538 135 | |
12 64 931 233 | |
Treatment for toxicity | |
• based on mg/kg | |
• 1kg= 2.2lbs | |
• <5mg/kg = give milk | |
• >5mg/kg = induce vomiting, give milk, go to emergency room | |
• >15mg/kg = call 911, induce vomiting, give milk | |
Signs of Toxicity | |
• cramping, vomiting, respiratory distress | |
• convulsions, coma, death-- usually occurs within 4 hrs. |