Community Water Fluoridation in Global and Malaysian context

My assignment (But don't really like it as I didn't spend a lot of time on it)

Dental caries remains a major public health problem in most industrialized countries, affecting 60–90% of school children and adults (1). This is especially important in the third world countries in the region of Africa, Latin America and the poorer parts of Asia which is primarily caused by changing dietary habits of high sugar content with inadequate exposure to fluorides(1).

Much studies in dental research have given focus on fluorides as a key component in preventing dental caries. In fact, fluoridation is probably one of the very few preventive health strategies that has stood the test of multiple trials and studies under varied controlled conditions(2).

Fluoride protects teeth both systemically and topically (3). The enamel becomes more resistant to dental caries when fluoride is incorporated into the crystal structure. In addition, fluoride limits the demineralisation of enamel and promotes remineralisation (2). It also lowers the activity of cariogenic bacteria.

Individuals who are at low risk for dental caries can maintain that status through frequent exposure to small amounts of fluoride (drinking fluoridated water and using fluoride toothpaste) whereas individuals who are at high risk for dental caries would benefit with additional exposure to fluoride (mouthrinse, dietary supplements, and professionally applied products)(4). The Adequate Intake of fluoride to reduce dental decay without causing moderate dental fluorosis is set at 0.05mg/kg/day (3). Meanwhile, the Upper Intake Level is the estimated maximum intake level before any toxicity of fluoride occurs (3). It is set to 0.10 mg/kg/day for children to age of eight years old (3). On the other hand, the Upper Intake Level for older children and adults who are no longer at risk for dental flurosis is set at 10mg/day regardless of weight (3).

A systematic review has shown that a 24% reduction of dental caries in the permanent dentition of children and adolescents is present with use of fluoride toothpaste (5). This is because for every increase of 500ppm of fluoride in fluoridated toothpaste, there is a 6% reduction in caries and vice versa (5). Hence, adult toothpastes contain 1000-1500ppm F(5). However, children toothpaste is limited to a concentration of 500ppm F to reduce the potential risk of fluorosis(5). Also, it is advised for children to use a pea-sized amount of toothpaste because children tend to swallow toothpaste with a mean amount of 0.3g (4).

In the meantime, a reduction of 30% of dental caries has been shown in individuals who rinse for a minute with 10 ml of 0.05% sodium fluoride solution daily(5). Besides that, fluoride varnish of 22mg/ml in fluoride concentration has been shown to reduce dental caries by 46% in the permanent dentition whereas fluoride gels applied in closely fitting trays reduces dental caries by 28%(5). Fluoride supplements are only to be given to children from the age of 6 months old to 16 years old who are living in non-fluoridated areas (3).

Various methods to deliver fluorides to the community were used worldwide which includes flouridated water, milk and salt. According to a systematic review, water fluoridation reduces the prevalence of dental caries by 15% (6). While it remains debatable, water fluoridation has been shown to be the most cost effective anticaries public health measure and is a “great equalizer” as everyone, regardless of age, race or socioeconomic status can access community water fluoridation as a preventive agent (7,8). Moreover, it is highly effective because there is no need of a change of behavior to obtain the benefits of fluoridation(3).

Malaysia is one of the countries that uses water fluoridation and the earliest population to receive fluoridated water is the people of Johor Bahru(9). Recommendations to introduce fluoridated public water supplies in Peninsular Malaysia was approved by the cabinet as a national policy in 1972(9). The optimal flouride concentration range for water fluoridation is determined by various factors such as the natural fluoride concentration of the water, climatic conditions and dietary habits (10). Currently, the water fluoridation programme is set to the value of 0.4 to 0.6 parts per million in Malaysia (9).

On commencement of extensive water fluoridation programme, the prevalence of dental caries for 12-year-olds in Peninsular Malaysia declined from 78.4% (1970/71) to 71.3% (1988) to 57.1 % (1997)(11). Other studies conducted worldwide such as in Newburgh, New York showed that 6-9 year olds had 58% less dental decay than their counterparts in non-fluoridated Kingston, New York after ten years of water fluoridation(10). This data is indeed a strong reflection of the effectiveness of water fluoridation in dental caries prevention.

Accidental ingestion of fluoride dental products occurs mostly in children younger than six years old (6). However, only mild and self-limited gastro-intestinal symptoms were present (6). There have only been three incidents of fatalities involving dental fluoride products due to negligence but otherwise, it is extremely rare for fluoride to cause acute fatal poisoning (6). In fact, there is no significant health risks related to fluoridated water (6). In addition, we should be reminded that the “window of vulneralbility” to fluoride overexposure is between 1 and 4 years old, and the child would not be at risk around 8 years old (12). Furthermore, fluorosis caused by water fluoridation were mostly mild and not usually of aesthetic concern (7). Nonetheless, possibilities of fluoride toxicity should also be discussed to stregthen the case for water fluoridation. It has been shown that excessive fluoride in drinking water (>2mgF/liter/day) will lead to dental fluorosis (12,5).

For every $1 spent on water fluoridation, it would save $38 in dental treatment costs(3). It has been projected that dental caries would increase if water fluoridation is stopped unless other measures are taken such as a topical fluoride program that was adopted in La Salud, Cuba(3). Hence, when water fluoridation was ceased in 1960 in Antigo, Wisconsin, without any other intervention, there was 200% more decay in 8 year olds after five and the half years without water fluoridation(3).

Although, the “halo” effect due to distribution of food and beverages with fluoride to non-fluoridated communities has caused a smaller difference of decay rates when comparing between fluoridated areas and non-fluoridated areas, the difference is still significant (3). Therefore, further research to find a biomarker of fluoride to estimate a person's fluoride intake and the amount of fluoride in the body is important to enhance the evaluation of the impact of water fluoridation (4). Also, more research is needed to evaluate the effects of new fluoride modalities and various combinations among groups and persons at high risk(4). Moreover, research on the influence of environmental, physiological, and pathological conditions on the pharmacokinetics and effects of fluoride should continue to ensure the safety of fluoride (4).

Currently, only 67.3% of the United States population receives fluoridated water despite the many evidence of the benefits of water fluoridation(3). This is because some communities are still confused about this public health measure(3). Therefore, the public must be accurately informed of the the advantages of water fluoridation(3).

In conclusion, the World Health Organization recommends fluoridation to continue in areas of high sugar consumption. However, health authorities should not be overzealous and overdependent on fluoridation because dental caries is not caused by lack of fluoride but a multifactorial process. A colloborative effort between the dental surgeons and the health authorities in prevention of dental caries is important to enable lives to be transformed through oral wellness.

References:
1. Petersen PE, Lennon MA. Effective use of fluorides for the prevention of dental caries in the 21st century: the WHO approach. Community Dent Oral Epidemiology 2004; 32: 319–21.
2. Can Fam Physician 1988; 34:1333
3. Fluoridation Facts, American Dental Association
4. Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States August 17, 2001 / 50(RR14);1-42
5. Essentials of Dental Caries by Edwina A.M. Kidd
6. J Dent Res 71 (5) : 1255 – 1265 may1992
7. Yeung CA (2008). "A systematic review of the efficacy and safety of fluoridation". Evid Based Dent 9 (2): 39–43.
8. Concepts in Dental Public Helath by Jill Mason
9. MINISTRY OF HEALTH MALAYSIA (2008) History of Dentistry In Malaysia http://ohd.moh.gov.my/modules/xt_conteudo/index.php?id=99
10. Appropriate Use of Fluorides for Human Health by J.J Murray
11. R. Esa, I. A. Razak. Dental fluorosis and caries statusamong 12-13 year-old schoolchildren in Klang District, Malaysia. Annal Dent Univ Malaya 2001; 8: 20-24.
12. Alvarez JA, Rezende KMPC, Marocho SMS, Alves FBT, Celiberti P, Ciamponi AL (2009). "Dental fluorosis: exposure, prevention and management" (PDF). Med Oral Patol Oral Cir Bucal 14 (2): E103–7.