Fluoride in Dentistry PDF

FLUORIDE IN DENTISTRY Associate Prof. Dr Nurul Asyikin Yahya BDS, MSc, DDPHRCS, PhD Dept. of Family Oral Health, Faculty of Dentistry, Universiti Kebangsaan Malaysia January 2024  History of fluoride use in dentistry Fluoros...

FLUORIDE IN DENTISTRY Associate Prof. Dr Nurul Asyikin Yahya BDS, MSc, DDPHRCS, PhD Dept. of Family Oral Health, Faculty of Dentistry, Universiti Kebangsaan Malaysia January 2024  History of fluoride use in dentistry Fluorosis Fluoride & caries LECTURE OUTLINE Physiology & metabolism of fluoride Fluoride toxicity Fluoride & human health  HISTORY OF FLUORIDE Sir James Crichton Browne remark upon the possible connection between fluoride and the incidence of 1892 (UK) caries. Dr F McKay observed ‘mottled enamel’ in patients. 1901 (Colorado Springs, USA) Dr McKay & Dr GV Black associated the mottled enamel and low incidence of caries with high levels of 1930s (USA) fluoride in drinking water – fluorosis (A) Dr. Black in Colorado Springs, 1909. (B, C) Typical photographic representations of “Colorado brown stain” and mild mottled enamel, respectively.  HISTORY OF FLUORIDE H. Trendley Dean showed that fluoride concentration in water affected the severity of mottling. He observed an association 1930-40 (South between mild fluorosis and low caries experience. A near maximum Dakota, USA) reduction (optimum level) occurred when fluoride was 1ppm. Sodium fluoride was added to drinking water in Grand Rapids, MI 1945 (Michigan, and resulted in a 50%  in caries incidence. USA) Kilmarnock, Watford, and part of Anglesey had 1ppm Fl in water. After five years, 50%  in caries. After Kilmarnock halted 1955 (UK) fluoridation, caries rose steadily to previous levels.  POLITIC AL PROGRESS OF FLUORIDATION IN THE UK 12% population fluoridated 1970s Court case in Scotland 1980s Water (fluoridation) bill 1985 Judicial Review finds legislation inadequate 1998 York Center for Reviews –review of efficacy and safety of 2000 fluoridation  WATER FLUORIDATION IN MALAYSIA (1957) Tebran , G Pulai Johor. Water fluoridation was first introduced in Malaysia in 1957 in the Tebrau & Gunung Pulai Water Treatment Plant in Johor. This plant served the Johor Bahru District. Fluoridation of public water supplies in other towns commenced in 1965. Meanwhile, in Sarawak, water fluoridation was first introduced in the Simanggang water treatment plant in November 1961 at Simanggang (Sri Aman). It was later expanded to Serian in Mac 1962. 15 water treatment plants were involved in water fluoridation in 1976.  WATER FLUORIDATION IN MALAYSIA In 1969, The Committee on Fluoridation of Public Water Supplies in West Malaysia was appointed by the Honourable Minister of Health Malaysia to study and report on the feasibility of introducing the fluoridation of public water supplies as a public health measure in all states in West Malaysia. Based on this recommendation, in 1972, the Cabinet of the Federal Government approved the addition of fluoride to the public water supplies as a primary prevention measure to prevent dental caries. Following this, the nationwide water fluoridation programme has been implemented incrementally since 1974.  WATER FLUORIDATION IN MALAYSIA In early implementation, the recommended optimum level was 0.7 ppm based on the volume of water intake in our climate. However, the level was reviewed by OHP in 2005 to 0.5 ppm after considering the findings from the study on Fluoride Exposure and Fluorosis among Schoolchildren in Malaysia. This is mainly due to the consumption of alternative sources of fluoride in the population. The recommended accepted optimum level of fluoride lies between 0.4 to 0.6 ppm due to difficulty obtaining the exact reading of 0.5 ppm.  In 2010, about 95% of the population received a piped water supply. Most states had a good coverage of 98% to 100% except Sarawak (93.3%), Sabah (79.0%) and Kelantan (57.0%). In 2022, 76.8% of the population benefitted from fluoridated public water supplies.  In most states, more than 90% of the population received fluoridated water except for Pahang, Sabah, Kelantan and Sarawak. In Sarawak, about 61.1% of the population received fluoridated water in 2022. Approximately 13.6% of the population in Kelantan received fluoridated water. While in Sabah and Pahang, the percentages were 4.9% and 0.0%, respectively. The cessation of water fluoridation programmes in Sabah, Kelantan and Terengganu occurred in 1988, 1995 and 2000, respectively. With the efforts of OHP and OHD, the programmes were reinstituted in 1996 in Sabah, 2006 in Kelantan and 2008 in Terengganu. However, in 2010, the Sabah State Cabinet agreed on the expansion of water fluoridation, as the coverage in 2009 was only 4.5%.  DENTAL FLUOROSIS A developmental disturbance of dental enamel caused by excessive exposure to high concentrations of fluoride during tooth development. Thin, white opaque lines Snowcapping of incisal Cloudy areas of opacity edges and cusp tips Chalky white appearance Opacity with small pits Pits merged to form bands Loss of enamel: irregular Loss of enamel > ½ Anatomical changes  DENTAL FLUOROSIS The risk of developing fluorosis is strongly correlated to the regular intake of fluoride during tooth mineralization and particularly during the maturation phase of the enamel Chronological pattern corresponding to time & duration of exposure Dose dependent  FLUORIDE & C ARIES ’ Fluoride  caries ’ Pre-eruptive mechanism ’ Post-eruptive mechanism  FLUORIDE & C ARIES Pre-eruptive Mechanism Post-eruptive Mechanism* Fluoride is ingested and incorporated Fluoride acts directly on the tooth into the enamel during mineralization surface: of the developing tooth, favouring the Forms fluoroapatite, which is less soluble crystallization of larger and more than hydroxyapatite regular fluoroapatite crystals, which Inhibits demineralization by lowering the are less susceptible to acid dissolution critical pH for dissolution of tooth enamel Enhances remineralization by lowering of the energy needed for reformation of * Post-eruptive mechanism is calcium fluoride the primary mode of caries Inhibits acid formation by prevention microorganisms involved in caries formation Interferes with growth and metabolism of these microorganisms at higher fluoride concentrations PHYSIOLOGY & METABOLISM OF F Absorption Excretion Storage GIT Rapid, through kidney Has an affinity for the Lungs (inhalation of Also lost through calcified tissue i.e. fluoride gas & dust) sweat, feces bone and developing Absorbed fluoride Traces can be found in teeth begins to leave the milk, hair, saliva, tears Storage is dynamic blood within minutes Bone: 800-10,000ppm Outer enamel: 400- 3000ppm  FLUORIDE TOXICITY Probable Toxic Dose (PTD) The minimum dose that can cause toxic signs & symptoms; including death Require immediate intervention & hospitalization PTD = 5 mg F for each kg body weight FLUORIDE TOXICITY A one-year-old child weighs 10kg. PTD = 5mg F x 10kg This is equivalent to the ingestion of: 50 one-mg F tablets 50 g of 1000ppm F toothpaste 50ml of 0.2% NaF rinse 50ml of 0.4% SnF2 rinse 85 gallons of 1ppm water  FLUORIDE TOXICITY Diffuse  Plasma To induce Signs Treatment Symptoms abdominal calcium vomiting pain  Plasma ASAP e.g. Diarrhea & potassium emetic vomiting  Pulse To bind Excessive rate fluoride e.g. salivation  BP consuming Perspiration milk, gastric lavage with Painful calcium/ spasms of activated the limbs, charcoal convulsions Headache  LONG-TERM EFFECTS: YORK REVIEW(2000) Studies Conclusion included 29 studies No association was found between fluoridated water and bone fractures or bone development problems 26 studies No association was found between water fluoridation and bone, thyroid and all other cancers 32 studies No clear evidence on the association of water fluoridation with various different outcomes, including Down’s Syndrome, Mortality, Senile Dementia, Goitre & IQ.  FLUORIDE Systemic Topical Use Use Water Toothpaste Milk Mouthrinse Salt Floss, tape, toothpicks Tablets Gel Chewing gum Prophylaxis paste Varnish  REFERENCES Duffin S, Duffin M, Grootveld M. Revisiting Fluoride in the Twenty-First Century: Safety and Efficacy Considerations. Front Oral Health. 2022 Jul 4;3:873157. doi: 10.3389/froh.2022.873157. PMID: 35860375; PMCID: PMC9289262. Karim, F. A., Yusof, Z. Y. M., & Nor, N. A. M. (2020).Water Fluoridation And Oral Health In Malaysia: A Review Of Literature: Received 2020-02-22; Accepted 2020-09-15; Published 2020-12-14. Journal of Health and Translational Medicine (JUMMEC), 23(2), 76-91. Murray, J. J., Nunn, J. H., & Steele, J. G. (Eds.). (2003).The prevention of oral disease. Oxford University Press, USA. (Chapter 3)