Community Water Fluoridation PDF

Community Water Fluoridation A Public Health Initiative for Caries Control Prof. Glushchenko Objectives – Background After attending lecture and reading the assigned material, students will be able to: Define community water fluoridation Describe the history and phases of...

Community Water Fluoridation A Public Health Initiative for Caries Control Prof. Glushchenko Objectives – Background After attending lecture and reading the assigned material, students will be able to: Define community water fluoridation Describe the history and phases of water fluoridation Describe the mechanism of action of fluoride and how it works to protect dentition Explain the rationale for using water systems to provide primary prevention of dental caries Objectives – As a Health Promotion Program Identify the features of why water fluoridation is considered one of the top ten health promotion programs of the 20th century State the optimal amount of fluoride in PPM for near maximum caries reduction and near minimum fluorosis List the different classifications and characteristics of fluorosis (Dean’s Fluorosis Index) Objectives - Currently Describe fluorosis and how to monitor levels of fluoride exposure Identify fluoride supplements and their indications Identify different forms of fluoride application Fluoride F (Fluorine) is the 13th most abundant naturally occurring element on earth Naturally occurring in water sources, soil, plants, air, food (tea/fish) F - (Fluoride) is the bonded form of fluorine; - e.g. NaF (sodium fluoride) NF3 (Nitrogen trifluoride) F2 (Fluoride) Unit of measure: ppm = mg/L interchangeable WHO (World Health Organization) considers water fluoridation a “nutrient” (or “nutritional supplement”) important to health Other Common Other examples of added nutrients to foods? Supplements Other Vitamin C to orange juice and other juices - Prevents scurvy Nutritional - Scurvy symptoms: bruising, bleeding gums, weakness, fatigue, and rash Vitamin D to milk and grains -Prevents rickets Suppleme - Symptoms include delayed growth, bowlegs, weakness, and pain in the spine, pelvis, and legs Folic acid to cereals nts - Prevents birth defects including spina bifida - Spina bifida: a birth defect in which a developing baby's spinal cord fails to develop properly Iodine to table salt - Prevents goiter formation - Goiter: abnormal enlargement of the thyroid Ideal Public Health Initiative - Ideal Public Health Initiative -Ability to prevent/minimize disease - Ease of implementation - High benefit-to-cost ratio - Safety - Socially equitable: benefits all ages, equally fair and available to everybody – - Community-based prevention that has benefits without regard to socioeconomic status  Fluoridation is a prime example that meets all factors - Has been described as most cost effective, practical, and safe means for reducing and controlling the occurrence of tooth decay in a community - Essential form of primary prevention for childhood caries – one of the most prevalent childhood diseases Cost savings of community water fluoridation Water Reduce the health disparities that persist between various populations – through primary prevention of caries Fluoridation as a It is safe, and easy to implement. - Continuous protection with no Public Health compliance or effort No daily doses or schedules Initiative Does not affect taste, odor, or color at optimal levels Community Water Fluoridation 73.9% of US population live in communities served by community water fluoridation (CDC, 2011) CDC (Center for Disease Control and Prevention) - Considers water fluoridation to be one of the top 10 public health achievements in the 20th century -vAlong with chlorination, pasteurization and immunization History of Water Fluoridation Four Phases in early 20th century 1. Clinical Discovery Phase 2. Epidemiological Phase 3. Demonstration Phase 4. Technology Transfer Phase  1901-1933: pursuit of knowledge to determine enamel defects in people exposed to high levels of naturally occurring fluoride of the western U.S -1- Dr. Frederick McKay, dentist in Colorado Springs, CO Clinical Observed “Colorado Brown Stain” or mottled enamel Discover - Specific geographic area: pts born in CO or moved at a young age y Phase - Intrinsic: incorporated into enamel structure, could not be polished away Hypothesized direct relation to something in the drinking water due to intrinsic stain -1- Drs. McKay and G.V. Black observed corollary finding - People who had mottled enamel (later called fluorosis) Clinical also experienced less dental decay H.V. Churchill, chemist: Discovery water testing in AR by spectrographic analysis (1930s) - McKay sent water samples Phase from where high mottled enamel observed - Association between high levels of F in drinking water and mottled enamel: 2-12ppm F -2- Epidemiological Phase 1933-1945 Dr. H. Trendley Dean: National Institute of Health (NIH), DH Unit - Mapped prevalence of mottled enamel across country, to try to eliminate it - Mid-1930s replaced “mottled enamel” with “fluorosis” Developed Dean’s Fluorosis Index, still widely used -2- Epidemiological Phase Dean’s 4 and Dean’s 21-City Studies - Conducted with assistance with US Public Health Service’s National Institute of Health - Both studies: documented caries prevalence using DMFT, fluorosis, and naturally occurring fluoride, children ages 12-14 4 City Study – 4 cities in Illinois w/ different fluoride concentrations in water - Higher fluoride concentration, higher prevalence of mottled enamel Dean’s 21-City Study – examined teeth of children living in 21 different communities Dean’s 21-City Study (Epidemiological Phase) Dean’s 21-City Study findings 1. Higher fluoride in water correlated with fewer caries – inverse relationship 2. Higher levels of fluoride were associated with higher prevalence of enamel fluorosis – direct relationship 1 ppm became benchmark - At fluoride concentrations of 1ppm: Reduction of caries up to 60% Decreased risk of fluorosis - 10% population exhibited mild fluorosis - Mottling not observed -3- Demonstration Phase January 1945 – 1954: community trials where fluoride levels were adjusted in the public drinking water supply Grand Rapids, MI: first city to fluoridate its drinking water to promote dental health and prevent disease Four demonstration cities (including Grand Rapids) were paired with four control cities - Controls: negligible amount of naturally occurring fluoride - Surveys were conducted with dental and medical observations collected over 13-15 years 50-70% reduction of DMFT for children ages 12-14 was observed Resulted in upward adjustment of the natural fluoride level in many community water supplies -4- Technology Transfer Phase 1950: implementation of fluoridation in many large U.S. cities - Phase 3 and 4 overlap Technology transfer extended worldwide, advocated by WHO - Singapore – 1958 (100% of population) - Ireland – 1960 - Israel – 1981 73.9% community water in U.S. optimally fluoridated (204 million people), has increased yearly since Grand Rapids Healthy People 2020 goal: 79.6% of U.S. population community water system should be optimally fluoridated Fluoridation now in 60 countries, 405 million people worldwide Mechanisms of Action of Fluoride Fluoride works in three ways to reduce and prevent tooth decay: 1. Systemic ingestion – incorporated into enamel structure during tooth development 2. Topical action – promoting remineralization and inhibiting demineralization after eruption Incorporated into crystalline structure Converts hydroxyapatite into fluorapatite, a less soluble apatite crystal Critical pH’s 4.5, 5.5, 6.2-6.4 3. Inhibiting bacteria – inhibits enolase Enolase: an enzyme needed by bacteria to metabolize carbohydrates Mechanism: Systemic Systemically – taken into body during consumption of food and beverages Pre-eruptive effect on developing tooth buds - Evidence that systemic exposure to fluoride during tooth formation reduces decay - Can result in shallower occlusal grooves, reducing fissure caries Ingested and incorporated into hydroxyapatite enamel structure during tooth development - Smaller fluoride ions replace the hydroxy ions in crystalline structure of tooth and becomes more resistant to acids Ingested fluoride gets incorporated into saliva, which becomes topical and available at the tooth surface - Fluoridated water is both topical and systemic Enamel fluorosis cannot occur once enamel formation is complete Mechanism: Topical in Plaque and Saliva Topical fluoride concentrates in plaque and saliva Frequent contact with surfaces of teeth - Can reduce decay on coronal and root surfaces Promotes remineralization and inhibits demineralization of tooth surfaces after eruption De- and Remineralization Cariogenic bacteria resides in plaque - Metabolizes sugars and other carbohydrates, producing acids Acids reduce pH and begin to dissolve or demineralize enamel - Calcium, phosphate, carbonate are lost from enamel but can be captured by plaque and saliva - Once pH is restored, minerals in saliva go back onto tooth surfaces Fluoride absorbs to crystal surface and attracts calcium and phosphate ions from saliva Mechanism: Topical on Bacteria Can interfere with growth and metabolism of bacteria - Antimicrobial effects Inhibits glycolysis and enolase, enzyme needed by bacteria to metabolize carbohydrates - Hinders carb break down > reduces acid production > reduces dissolution of tooth enamel Mechanisms of Action of Fluoride Having fluoride available to tooth is key to effectiveness - Frequent exposure is recommended Both systemic and topical mechanisms important Systemic fluoridation provides topical effect as it is incorporated into saliva Greatest effect on reducing and preventing decay is topical - Has immediate effects Water Fluoridatio n Dentistry’s most significant contribution to solving a public health problem Method of delivery prevents tooth decay by adjusting the concentration of fluoride in public water supplies Water fluoridation most effective because populations consume small quantities of water throughout the day – not just when brushing teeth Replenishes small quantities of fluoride to plaque and saliva Benefits and Effectiveness of Water Fluoridation Systemic aspect of ingested fluoride - Helps to maintain bones Children in fluoridated communities experience 50-60% fewer caries (dmfs) Topical aspect of fluoride in water - Promotes remineralization/ inhibits demineralization Antimicrobial properties 35% decrease in tooth decay in adults Cost-effective  Fluoride important in adults – longer teeth retention w/ improved dental practices and prevention such as fluoride - Susceptibility to coronal and root caries Root caries: may become problematic Adults ages 35-44, but doubles in 45-54, and redoubles 55-66 - Ages 65+: root caries in 67% men, 61% women Fewer coronal and root caries in communities with higher levels of fluoridated water Cost of Water Fluoridation Cost-effective Water fluoridation easily funded through local/state/federal budgets, but usually carried out through government at local level CDC estimates populations larger than 20k ~$0.50pp - Every $1 invested = ~$38 savings in dental tx costs Estimates of water fluoridation cost vary, based on: - Size and complexity of the water system - Equipment and installation - Purchase of fluoride, labor, and maintenance - Size of community: higher population, lower cost Cost-Saving Benefits Cost per person is low Cost of water fluoridation over a person’s lifetime is less than the cost of one dental restoration Dental treatment cost savings - Minimizing dental related missed workdays - Treatment costs - lower dental care bills - Higher in non-fluoridated communities - Lower insurance premiums Fluoride is the most cost-efficient and cost effective method of prevention of dental caries for almost all communities Measuring Benefits of Water Fluoridation Effectiveness seemingly decreased over time - Previously no other sources of fluoride available - Reduction rates were easily measurable and significant - Measurable benefits less absolute Dilution and diffusion most likely responsible for decline in dental caries rates in nonfluoridated communities Dilution and Diffusion Dilution – results from increased availability of fluoride from multiple sources - Diluted impact of any one source of fluoride including water - Most universally available source of fluoride: TP Diffusion or Halo Effect – extension of benefits of community water fluoridation to fluoride-deficient communities -Weaker associations not from lessening effects, but from extension through diffusion of fluoride - Eating / drinking foods processed in fluoridated areas, thousands of miles away - Increased mobility of populations contribute to diffusion, e.g. military bases Optimal Levels Timeline Optimal fluoride level provides best balance of protection from dental caries while limiting risk of dental fluorosis 1930, Dean’s 21-City Study: benchmark of 1ppm 1962, US Public Health Service: optimal fluoridation range from 0.7ppm to 1.2ppm - Question: Why would there be a recommended range of water fluoridation, rather than one set amount? Optimal Levels Timeline 1986, Congressional “Safe Drinking Water Act” primary standard: maximum natural level in public water set at 4ppm to protect against unwanted health effects 1986, EPA: Higher than 2ppm was a cosmetic influence, required public notification 2011, US Dept of Health and Human Services (HHS) and CDC: standardized fluoride concentration to 0.7mg/L in the U.S. - Why? Monitoring Water Fluoridation American Water Works Association (AWWA) - Sets standards and testing for product’s design, installation, performance, and manufacturing and guidelines related to engineering National Sanitation Foundation International - Sets criteria for purity of drinking water additives EPA monitors fluoride content of water supply Monitoring Water Fluoridation Quality assurance – monthly testing Engineering designs prevent excess fluoride from entering supply: - Limited amount of fluoride in reservoir tanks - Electrical metering pumps - Continuous reading of concentration Properly trained operators Barriers to Water Fluoridation Bottled water consumption Less consumption of community fluoridated water Most bottled water contains low fluoride concentrations Lack of community support for implementation of community water fluoridation Lack of government support Anti-fluoride activists, influencers Internet, social media Unscientific or no evidence based reports Fluoride Opposition Has always been controversial: 1964 film Dr. Strangelove “Fluoridation is the most dangerous Communist plot we have ever had to face” Constitutional Right of Choice – choosing medical treatment - Mass medication by government - Gov’t overreach Poison Misinformation/ no evidence-based research - Some websites claim link to cancer, diminished intelligence, birth defects, heart disease w/o studies This Photo by Unknown Author is licensed under CC  Claims to cause severe fluorosis - Can be misleading to public: frequently exhibit images of children and/or adults with severe enamel fluorosis - Inaccurately describes severe enamel Fluoride fluorosis to affect all ages Some suggest hexafluorsilicates Opposition (sodium fluorosilicate and fluorosilicic acid) are industrial waste and contaminate water with harmful residue - No differences between the sources of fluoride, remains in drinking water at equilibrium  Dental fluorosis = enamel fluorosis; varying degrees - Determined by total dose and duration of exposure, caused by ingesting large amounts of fluoride during tooth formation First 3 years of life are critical in development of fluorosis Results from Fluorosis Not all children react the same to the hypomineralization (hypoplasia) in enamel same amount of exposure Defective calcification of teeth - Normal activity of the ameloblasts may be inhibited and can result in defective enamel matrix or discontinuity of crystal growth - Pitted enamel could lead to an increased risk for dental caries by diminishing protective function of enamel  Causes - Toothpaste: significant source of overexposure and fluorosis by ingestion - Excessive fluoride levels in well water - Inappropriate amounts of fluoride supplements Fluoride toxicity Fluorosis - Acute toxic dose 5.0-8.0 mg F/kg – immediate therapeutic intervention Lethal dose for 70kg person is estimated at 5-10g - Ingestion of excess fluoride can produce gastrointestinal discomfort - Chronic exposure to fluoride in large amounts interferes with bone formation (typically naturally occurring in water) Diagnosing Fluorosis Not all enamel opacities Diseases and conditions or irregularities are (e.g. Celiac) can cause caused by fluorosis enamel hypoplasia Other causes of Diagnosing fluorosis: irregularities: need positive metabolic, identification of fluoride physiological, other levels available to trace elements, and community before malnutrition confirming  Greatest likelihood of exposure to excess fluoride in children: 1. Inadvertent ingestion of toothpaste containing very high concentrations Minor of fluoride Fluorosis 2. Inappropriate ingestion of prescribed fluoride supplements Or supplements w/o checking content of child’s water supply Can cause questionable, very mild, or mild Fluorosis  Shows location and severity of fluorosis - Normal – usual translucent semivitriform type structure; smooth, glossy, pale creamy-white color - Questionable – slight deviation from normal translucency ranging from a few white flecks to occasional white spots Dean’s - Very Mild – Less than 25% of the tooth surface affected; small, opaque paper-white areas Fluorosis scattered irregularly; tips of cusps often show “snow capping” Index - Mild – More than 25% but less than 50% of the tooth surface affected; more extensive, opaque, paper-white areas - Moderate – All enamel surfaces affected, frequently with brown staining - Severe – All enamel surfaces affected with widespread brown staining and discreet or confluent pitting. Can appear corroded.  CDC, 2001 – All persons should know whether the fluoride concentration in their primary source of drinking water is below optimal (less than 0.7ppm), optimal (0.7- 1.2ppm), or above optimal Parent/ guardian involvement - Fluoridated TP should be used with supervision to ensure only a small Reducing Risk of amount used (smear or pea-sized,.25 grams) and do not swallow Fluorosis - Parents should brush teeth of children under 6 - Parents should consult dentist or health care provider prior to introducing fluoride TP to a child under 2 years Where community water has above 2ppm F, children under 9 years should have alternative source of drinking water (preferable w/ optimal fluoride) Effects of Discontinuing Water Fluoridation “Demonstrate the effectiveness of a 1960s, Antigo, WI After six years, therapeutic agent by discontinued elementary school observing if the benefits community fluoridated children had increased are lost when the agent water after having for caries rates from 70- is removed” –US Public 11 years 200% Health Service report 2002 systematic review: stopping community Similar effect in Wick Dilution and diffusion water fluoridation and Straener, Scotland: make replicating studies resulted in avg 18% caries rates increased hard increase in dental caries after discontinuation Discussion Pretend you are talking to a patient with concerns about water fluoridation. The best way to be prepared for a conversation is to know both sides – the pros and cons, so that you’re able to discuss the rationale Community Alternatives to Water Fluoridation When communities are unable to fluoridate the water supply, some alternatives: School-based programs: - Water fluoridation program - Fluoride rinse program Fluoride varnish program Salt fluoridation Milk fluoridation Fluoride tablet supplements School Water Fluoridation Works with a requirement Less successful and more - More expensive because that schools must have a expensive to implement than population is smaller stand-alone water system community water fluoridation  School Water Fluoridation - Due to limited time in Children are exposed to school Why is the level higher a slightly greater than than the optimal Exposure only occurs during optimal concentration of school days concentration of fluoride in the school School not in session in fluoride? drinking water certain times Weekends, school breaks  School Fluoride Rinse/ Tablets School-based program Nurses or teachers responsible for delivery of fluoride rinse and/or tablets Less successful - Due to provider non-compliance - Parental consent may be an issue  Fluoride Varnish Successful when Considered most Can be safely implemented with effective applied, even to Fluoride varnish other social service professional fluoride children aged 1 if program programs (such as tx for primary caries indicated by Head Start or well- – 45% reduction of pedodontist baby clinics) caries - Refer children to Applied every 3 PCPs encouraged to pedodontist by age months for high risk; conduct periodic 1 to advocate 6 months for low oral health exams preventative oral risk health care  Fluoride Supplements Parents/caregivers need to carefully monitor the amount of fluoride Only when fluoridated NOT recommended for Available in different Tablets (chewed, containing products the water is not consumed breastfeeding infants forms: swished, and swallowed) child is exposed to due to risk of fluorosis of unerupted teeth Must have Rx from Fluoride-vitamin Lozenges Drops/Liquids (infants) doctor – usually preparations pediatrician Supplement Schedule Should be prescribed only for children who are at high risk for developing caries, in areas with low fluoride in drinking water Fluoride Supplement (Tablets and Drops) Dosage Schedule 2010 (Approved by the American Dental Association Council on Scientific Affairs) Other Fluoridation Vehicles Milk fluoridation - In formulas Can be more complicated than tablets or drops Insufficient studies to show effectiveness in preventing tooth decay but do suggest beneficial to school children Other Fluoridation Vehicles Salt fluoridation - Countries w/o central water systems - Table salts (similar to iodized salts) - Works better in developing countries than the US (higher rate of heart disease) Not rec’d for those at risk for HTN Not appropriate for countries w/ water fluoridation Topical Fluorides Professionally administered via gel/foam/rinse/varnish School based fluoride rinse/sealant programs OTC home fluoride rinses Fluoridated toothpastes  - Stay current with literature Use knowledge to educate yourself and your patients Patients depend on Hygienists’ Role Risk of developing v mild professionals to assist fluorosis vs. benefit of with understanding decreased caries (associated tx costs) should scientific data be discussed Level of fluoride should be maintained – benefits are lost when fluoridation is discontinued Questions Ideally, the optimum concentration of fluoride in community drinking water is: A. 0.2 – 1.0 ppm B. 0.7 - 1.2 ppm C. 1.0 – 2.0 ppm D. 1.2 – 2.5 ppm Which of the following dosages of a fluoride tablet supplement should be prescribed for a preschooler (3-5 years old) who consumes optimally fluoridated drinking water? A. 0.25 mg B. 0.50 mg C. 1.00 mg D. None of the above Various degrees of dental fluorosis depends on which of the following factors? A. Amount of fluoride delivered B. B. Source of fluoride delivered C. C. Duration of fluoride delivered D. D. Total dose of fluoride from all available sources and duration of exposure Fluorides protect teeth from caries by which of the following mechanisms: A. Killing all bacteria in the mouth B. Inhibition of glycolysis C. Convert hydroxyapatite to fluorapatite D. Reduction in enamel solubility E. Enhancement in remineralization 1. (a), (b), (d) and (e) 2. (a), (c) and (d) 3. (a), (c) and (e) 4. (b), (c), (d) and (e)