Master of Public Health Integrating Experience Project
Utilizing Community Service Grant Proposal Framework
Hayk Kanchinyan, MD, MPH Candidate
College of Health Sciences
American University of Armenia
Advisor: Robert Bagramian, DDS, MPH DrPH
Reader: Byron Crape, PHD, MSPH
As previously described, delivery of fluoride to a population to prevent development of dental caries can be systemic, topical or a combination (34, 35, 38). The experience of using fluoridated salt and fluoridated water as a successful tool to decrease the prevalence of dental caries led to a study conducted in 1967 by PAHO (Pan American Health Organization), the National Institute of Dental and Craniofacial Research and the University of Antioquia in Medellin, Colombia. This study established that the use of fluoridated salt has the same caries protective effect as fluoridated water (55). In addition, salt fluoridation is a cost-effective preventive program. According to a study conducted in Jamaica, salt fluoridation cost was 6 cents per person annually (64). Cost savings from the program implementation were significant: for each $1 spent on salt fluoridation, $250 can be saved in reducing the need for future dental treatment (64).
The maximum recommended average daily intake of fluoride for adults for caries protection is 4 mg of fluoride (52). This was determined by research, practical experience and evaluation of fluoridation program implementation in several countries. There are several ways to provide fluoride including fluoridated water, toothpaste, mouth rinses, tablets, vitamins, milk, flour, and salt among others. One of the most appropriate methods of fluoride delivery to a population is salt fluoridation. Salt is a very broadly used and affordable product. Many countries cannot afford water fluoridation; and salt fluoridation can be much cheaper. Salt fluoridation, in comparison with water fluoridation, costs from 10 to 100 times less than water fluoridation. When salt fluoridation is used, it does not change the price of salt (53).
According to a study conducted in Mexico in 1986, the consumption of salt increases with age (55). Based on this study, average consumption of salt in children 1-3 years is 1.9 g/day, in age group 4-6 years it is 3.4 g/day and for adults it is up to 6.9 g/day (55).The best concentration of fluoride in the salt, which was determined from many studies, is 250 mg/kg (54). According to these values, the average daily consumption of fluoride through fluoridated salt with a concentration of 250 mg/kg fluoride would be 0.5, 0.8 and 1.3 mg per day for these age groups respectively.
There are two different methods of salt fluoridation process:
1. Wet method
2. Dry method
Potassium fluoride is used for the wet method of salt fluoridation, which is as an aqueous solution continuously sprayed, at a specific ratio, on salt travelling past on a conveyor belt (62).
For the dry method, sodium fluoride is used in continuous mixing of powdered fluoride with salt in special mixers (62). Grain size of the sodium fluoride ranges from 10 to 20 ?m;-so that a homogeneous product is achieved and there is no tendency for separation in the salt packages (62).
Both methods have advantages and disadvantages. The primary advantage of the dry method of salt fluoridation is the cost of the chemicals and equipment used (62). With the dry method, the appropriate granule size of the salt is from 0.2 to 0.8 mm, so the dry method is not suitable for the coarse salt (62).
The wet method of salt fluoridation is suitable for all types of salt, but it is much more expensive than dry method (62).
Many successful programs regarding salt fluoridation were implemented throughout the world. There are many examples of reducing the DMFT index of caries through fluoridation programs in several countries of the Americas and Europe such as Costa Rica (60%), Jamaica (83.9%), and Mexico (29.6%) (see figure 1) (55). In addition, fluoridation programs can reduce the inequalities in dental caries among different social classes (56).
A salt fluoridation program is a long-term intervention, which requires collaboration between different types of institutions inside the country (internal), as well as outside the country (external). An example of the internal institutions can be Ministry of Health, Medical and other universities, public and private laboratories and clinics, NGOs, dental associations, salt plants, etc. Donor governments and other foreign organizations can be external sources of cooperation in a national salt fluoridation program implementation (55).
There are some advantages and disadvantages to use salt as a vehicle for fluoride. The advantages to use salt to provide fluoride to the population at large for caries prevention are: in comparison with fluoridated water, fluoridated salt provides consumers the free choice. The use of fluoridated salt does not require lifelong daily compliance. Fluoridated salt is not ingested once a day such as drops and tablets with their peak of concentration in saliva but, the fluoridated salt is consumed in small amounts during the day. The process of fluoridation does not increase the price of the salt (45).In addition, fluoridated salt helps to eliminate the inequalities between different socio-economic classes in terms of or dental care affordability.
One disadvantage is that a high consumption of the salt is a risk factor for hypertension (45). Thus, the increase in consumption of fluoridated salt should not be encouraged, but detailed information regarding the benefit of fluoridated salt should be provided. Fluoridated salt should be labeled and detailed information about content of the salt should be described on the packages. Non-fluoridated salt should also be available for consumers.
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