Should We Use Milk Fluoridation? a Review1 RODRIGOMARI~~O~

Should We Use Milk Fluoridation? A Review1 RODRIGOMARI~~O~

This article presents the argument that becauseof several demonsfrafed advantages, milk fluoridation provides a valid alternative to water fluoridafion when the latter is not possible. Extensive literature describing study of fl uoride compounds adminisfered with calcium-rich food, as well as clinical trials and laborafo y experimen fs with fluoridated milk, have demonstrated its effectiveness in caries prevention. The main criticisms of milk fluoridation are decreased bioavailabilify of the fluoride, the cost and adminisfrafive burden involved, and (in some cases) lack of sound clinical conclusions regarding ifs preventive efficacy. These S criticisms are reviewed in fhe light of evidence now available.

he World Health Organization has Indeed, oral health surveys have shown T recommended specific goals for oral that in most countries of the Americas health by the year 2000 (I). Among other about 95% of the population has a history things, these goals assert that the de- of dental caries (2). If countries continue cayed, missing, and filled teeth index to rely on programs based on dental caries (DMFT)3 at 12 years of age should be 3 treatment rather than prevention, we or less. In 1990, only 5 of 38 countries cannot expect major improvements in this and territories in Latin America and the picture, especially since there are many English-speaking Caribbean (the Baha- places where a significant part of the mas, Cuba, Dominica, Guyana, and Saint population lacks access to reguIar oral Lucia) had such a DMFT index, while 8 health care. Clearly, a different approach countries had DMFT indices exceeding to the problem must be found. 6.5 (2). Thus, although most countries of Dental caries is a preventable infec- the Americas have significantly im- tious disease caused by bacteria that ac- proved the health conditions of their peo- cumulate in dental plaque. Fermentation ple, oral disease continues to be a highly of common dietary carbohydrates by these prevalent health problem. plaque bacteria leads to formation of acids that cause loss of minerals from the tooth enamel, a process that ultimately pro- ‘This article will also be published in Spanish in duces cavities. Scientific knowledge in- the Boletin de la Oficina Snnitnrin Pnnnmericnrra, Vol. dicates that dental caries can be pre- 120, No. 2, February 1996. Reprint requests and vented by measures that include use of other correspondence should be sent to the author fluorides and fissure sealants, removal of at the following address: School of Dental Science, dental plaque, and reduction of ferment- University of Melbourne, 711 Elizabeth Street, Mel- bourne, Vie 3000, Australia. able carbohydrates. 5chool of Dental Science, University of Melbourne, The mechanism by which fluorides Melbourne, Australia. prevent dental caries has been studied 3The DMFT index is the arithmetic average of the for over 50 years and is now accepted as number of teeth (T) that are decayed (D), missing safe and appropriate (1, 3-6). Fluorides (M), or filled (F) as a result of caries occurring in permanent dentition. The DMFS index uses the are absorbed through the gastrointestinal tooth surfaces as the unit of study. The equivalent tract, with a rate and degree of absorp- indices for temporary dentition are dmft and dmfs. tion that depends on several elements

Bzrlletin of PAHO 29f44),1995 287 (7). After entering the plasma, fluorides These methods provide protection against are either deposited in the bone or de- caries that rivals that provided by fluor- veloping teeth, or else they are removed idated water. In addition, studies have by the kidneys and excreted in the urine. shown that fluoride provided through During tooth formation, fluoride is in- other alternative methods can effectively corporated into each tooth’s mineralized prevent caries (16), such methods includ- structure, providing increased resistance ing use of fluoride solutions or gels top- to demineralization by organic acids. ically applied and fluoridation of sugar After a tooth erupts, systemic fluorides and various beverages including milk (4, no longer play a role in its formation. 5, 9, 17, 28). However, when consumed systemically All these alternatives involve some dis- they are excreted through the saliva and advantages that any country must con- can provide surface protection for the sider within the context of its particular tooth throughout its lifetime (8, 9). This local, regional, or national needs when posteruption effect is responsible for de- deciding what is the best method to em- creased demineralization when teeth are ploy. Such deliberations have led to a exposed to acids and for increased rates variety of conclusions about the merits of of remineralization (10). Fluorides also af- water fluoridation alternatives. Within that fect bacterial metabolism and act in other context, this article reviews scientific data ways to reduce potential tooth enamel on milk fluoridation and analyzes com- destruction (5, 9, II). peting theses in the current debate on The great mass of evidence now avail- the subject to help resolve the question able indicates that a 50-65% reduction in of whether milk fluoridation should be dental caries indices can be achieved by used. To do this, it describes the basic adjusting the fluoride content of unfluor- rationale for using milk as a fluoride ve- idated drinking water to optimal levels hicle and discusses the main objections (0.7 to 1.2 mg/L) (I, 5). However, polit- to milk fluoridation in the light of cur- ical, administrative, geographic, and rently available data. technical factors have commonly pre- cluded drinking water fluoridation, de- RATIONALE FOR THE USE OF nying this benefit to a large part of the MILK FLUORIDATION world’s population (1.2). This lack of a fluoridated water supply From a public health standpoint, the is not an insuperable barrier to receiving community water supply is regarded as the benefits of fluorides. For instance, in the most effective fluoridation vehicle (3, some places where people could not be 27, 19). In the 1980s the International reached by public water supplies, coun- Drinking Water Supply and Sanitation tries have tested and implemented alter- Decade strongly promoted provision of native community-based fluoridation water supply services to the population. programs at the local, regional, or na- Nevertheless, despite efforts made in the tional levels. Various methods-includ- Americas to provide water for all by 1990, ing salt fluoridation (in Colombia, Costa in that year approximately 12% of the Rica, France, Germany, Hungary, Ja- total urban population still lacked house maica, Mexico, Spain, Switzerland, and connections, and in rural zones this pro- Uruguay-Z, 4, l3-25), school water portion was much higher, on the order fluoridation, distribution of fluoride tab- of 45% (20). lets, and use of fluoride mouth rinses (in According to several researchers (2l- the United States-4, 5, l6)-have been 25), when a water supply is not available employed by public health programs. milk should rank first among the alter-

288 Bulletin of PAHO 29(d), 1995 native fluoridation vehicles. After water, fluoride in community fluoridation pro- milk is considered the most important grams if it reached the right people. In contributor to total fluid intake (26-28). accord with the need to find solutions It is also an important food for pregnant appropriate for local conditions (34, 35), women, infants, and children during the it would be particularly valuable in rural period of tooth formation (4, 22, 29, 30). areas, where the population is unlikely Like salt, milk does not require a com- to have access to appropriately fluori- munity water supply system, and so it dated water. can reach communities lacking this serv- Other authors, however, have con- ice and can enable people to have free cluded that milk is not an appropriate choice regarding their fluoride intake. Like vehicle for fluoridation (17, 35-37). Our certain other alternatives, it imposes no review of these criticisms has indicated major administrative burdens on teachers four major areas of concern, these being (23, 31) such as those imposed by pro- (1) decreased bioavailability of sodium grams using fluoride mouth rinses or fluoride (NaF) when ingested with foods supplements at school, nor does it create rich in calcium such as milk (38-40), (2) a need to ensure compliance (8). Indeed, cost (36, 37), (3) administrative burdens an adequate level of compliance (an ad- (production, delivery, storage and distri- equate intake of fluoridated milk) might bution problems) relative to other meth- be assured if fluoridated milk were needed ods (17, 36, 37), and (4) lack of definitive for its nutritional as well as its cariostatic conclusions from clinical trials (28,35,37). value, or if children were expected or required to drink it when provided (32). Ericsson (21), Poulsen et al. (22), Villa BIOAVAILABILITY et al. (32), and Toth et al. (33) have proven that fluoride does accumulate in calcified In the case of fluorides, bioavailability tissues following ingestion of fluoridated is defined as the percentage of a given milk. Ericsson, who administered F as fluoride that is absorbed, reaches the cir- NaF to rats, reported that femoral F up- culation, and is available for use by the take from milk was about 80% of that living organism (7,23,42,42). It therefore from water, and that a tooth’s retention depends on the amount of free forms of of F paralleled that of the skeleton at a fluoride present (7). Hence, any factor comparable stage of growth. Animal ex- that decreases free fluoride levels will de- periments conducted by Poulsen et al. crease bioavailability (7). (22) found increased fluoride levels in rat It is well known that concomitant in- enamel after administration of fluori- take of food and beverages may reduce dated milk. More recently Villa et al. (31), or enhance various drugs’ bioavailability who administered F to rats as MFP in (43). Furthermore, the bioavailability of milk and NaF in water, found that the fluorides in the presence of certain foods, femur fluoride concentration was almost milk, and other proteinaceous beverages two times higher in the milk group than is known to be less than the bioavail- in the water group under normal feeding ability of fluorides administered as NaF conditions. In addition, Toth et al. (33) in water under fasting conditions (39,42). found the fluoride content of children’s (As a standard, studies on fluoride bio- enamel surfaces to be higher after they availability take 100% bioavailability to be had consumed fluoridated milk for a year. that of fluoride administered as NaF in The above considerations and findings water or tablets under fasting condi- suggest that milk would be a particularly tions-7, 39. In these circumstances the suitable vehicle for providing systemic absorption rate reaches a peak plasma

Marilio Milk Fluoridation 289 concentration within 30 minutes of in- It should also be noted that most of the take-7, 43.) studies involved have been carried out Slower and less complete absorption of on fasting individuals or under extreme F as NaF has been reported with parallel conditions. For instance, Ekstrand and intake of foods rich in calcium, such as Ehrnebo (39) reported a decreased bio- milk, the diminished bioavailability being availability of 30% when NaF tablets were 20% to 50% of that obtained with NaF in administered with food; but all the food water alone (21, 42, 43). These findings supplied was milk or dairy products, have been obtained from experiments with which do not constitute an ordinary diet both humans (39,43-45) and animals (21). (42,45, 47). The point is relevant, because This reduced bioavailability might be of findings that this decreased bioavail- caused by the combined action of several ability can be reversed if conditions are factors. Among the most influential: the made to simulate those following a formation of CaF,, which has decreased standard breakfast (with ingestion of milk solubility in water (21, 38, 39, 41, 42); plus food having a low calcium content chemical combination of F with organic such as bread, crackers, or cakes) (42,45- solids; and entrapment of F by milk co- 47). Under these normal conditions, the agulation products in the stomach that ingested foods stay longer in the gas- create a physical barrier preventing ac- trointestinal tract than does milk alone, cess to gastrointestinal surfaces (21, 42- giving the fluoride more time to reach 44, 46-48). absorbing surfaces (42, 46). It has also Other mechanisms causing decreased been suggested that under normal feed- bioavailability have been proposed. One ing conditions the fluoride’s mode of of these is an increase in gastric pH caused administration (e.g., in a beverage, as by milk intake (23, 39, 43, 44), because drops, or as chewed or swallowed tab- when NaF is ingested, it is not F- that lets) would be of greater importance than passes through the gastrointestinal wall its chemical composition (42, 46, 47). but HF, which is pH dependant (30, 42, Within this context, it is noteworthy 46, 47). In an environment with reduced that Shulman and Vallejo (44) got very pH like the stomach, the concentrations different results from an experiment where of HF and of unbound Ca+ + from milk NaF was administered in water, with milk, may be increased, which would in turn and with a normal lunch. Their data in- increase the formation of CaF, (21, 39). dicated that milk consumption did not Nevertheless, this reduced bioavail- significantly affect fluoride absorption, but ability relating to delayed absorption has that addition of a normal lunch decreased been found to prevail mainly during the fluoride absorption by a significant 47%. first hour after ingestion, after which ab- Ericsson .(49) has stated that fluoride sorption rates level out (21, 42, 43, 46), bioavailability would differ if the admin- with fluoride levels in the plasma re- istered compound were MFP rather than maining elevated for a longer period of NaF, suggesting that F bioavailability from time when the fluoride is administered MFP would be less affected by intake of in milk instead of water. This pattern has food with a high calcium content. The been observed in both rats (21) and hu- food’s effect would be negligible-be- mans (42, 46). A similar sort of pattern cause MFP absorption is not pH depen- has been found with respect to urinary dant, involving no formation of HF (21, excretion of fluorides, which proceeds at 42); because of the specific absorption a higher level during the second hour if mechanism involved; and because of the the fluorides are administered with milk higher solubility of the Ca-MFP salts (42, rather than water (22). 46, 49).

290 Bulletin of PAHO 29(4), 1995 Villa et al. (23, 31) measured fluoride When there is an ongoing milk distri- bioavailability in both preschool children bution program in the community, or a and rats, finding that of MFP fluoride in milk program running in schools, kinder- milk to be at least as high as that of NaF gartens, or welfare centers, no additional fluoride in water under fasting condi- outlays are required for administration, tions (which is considered 100%) (39). education, supervision, or distribution (4, They also found that decreased absorp- 26, 34, 52), a circumstance that counters tion of F from MFP under normal feeding criticisms of milk fluoridation’s organi- conditions is less important than de- zational and administrative cost (17, 26, creased bioavailability of F from NaF in 37). Furthermore, supplying fluoridated water or tablets under the same condi- milk to children in this way constitutes tions. Villa et al. (32) have also shown highly effective resource use, because it absorption of F from MFP to be markedly requires a much smaller quantity of fluor- better in the presence of food, an im- ides for a given population than the provement that does not occur when F fluoridation of an entire water supply (26, is administered as NaF. 52) or even a school water system; nor However, Trautner and Einwag have does it entail marketing or subsidy costs presented data (42,46) that fail to confirm as in the case of salt fluoridation. the results reported by Ericsson (49) and In Chile, a food supplement program Villa et al. (23, 32). Specifically, they have has worked efficiently for about 40 years, reported that the bioavailability of F as providing over 80% national coverage for NaF and as MFP was affected compar- children from birth to 6 years (20); dairy ably by several different experimental plants have the know-how to produce a conditions (fasting, ingestion with milk, fluoridated milk product; and addition of and ingestion with breakfast and milk) MFP to milk powder is relatively simple (42). That is, use of MFP instead of NaF and involves a negligible increase in the did not increase F bioavailability. latter’s cost (26, 52). Even adding quality control costs, Villa et al. (26, 52) esti- COST AND ADMINISTRATIVE mated that milk fluoridation under these COORDINATION OF MILK conditions would be over a thousand times FLUORIDATION more cost-effective than water fluoridation, and concluded that it offered an Burt (50) has noted that the cost of al- economical alternative to water fluori- ternative fluoride vehicles must be as- dation in Chile (26). sessed for each situation, partly because However, there is still the problem of the cost depends on the facilities and re- fluoride stability in milk. Variations in sources available in any particular coun- the concentration of ionic fluoride have try. In 1972, Stamm (36) concluded that been studied for 72 hours after fluoride using milk as a vehicle could be costly- was added to milk as NaF (38), the results but this conclusion was based on a 1955 showing estimated recovery at the end New York City study that clearly could of this time to be less than a fifth of the not be expected to reflect the conditions amount added. In fact, fluoride as NaF in any country in the 1990s. More re- should not be added to milk more than cently, the World Health Organization (52) one hour before consumption (38), mak- has classified milk, together with water ing it necessary for trained personnel to and salt, as a highly cost-efficient vehicle prepare and supply the product. for fluorides and has supported milk As this suggests, the stability problem fluoridation as a community health could be overcome if NaF were added measure. immediately before consumption (53), as

Mariiio Milk Fluoridation 291 according to Duff (38) the recovery level dentai caries. However, posteruptive is on the order of 97% during the first administration of fluoride caused signif- hour. Alternatively, the problem could icant caries reduction on the buccolingual be overcome by using MFP as the fluor- surfaces, even though no effect could be idated compound (26, 31, 52), because demonstrated on the occlusal or proximal the F added in MFP has demonstrated surfaces. These authors did not observe stability for a period of 10 months with- any effect attributable to the fluoridation out alteration (23, 26). For these reasons, vehicle (milk or water). the WHO Group of Experts on Fluorides The value of milk as an alternative ve- concluded in 1994 (4) that the binding of hicle for fluoride administration to hu- fluoride to Ca or proteins is not a major mans has been noted since the 1950s. problem in milk fluoridation. Clinical studies using this method have been carried out in Brazil (55), Hungary (53, 56, 57), Israel (58), Japan (59), Scot- MILK FLUORIDATION STUDIES land (21, 60), Switzerland (61, 62), and the United States (30, 32). Tables 1 and Kiinig (54) performed experimental 2 summarize some features of the studies caries prevention studies by administer- relating to permanent and temporary ing NaF in water, milk, and food to young dentition, respectively. rats. Female rats receiving NaF during The first work indicating the effective- pregnancy and lactation exhibited in- ness of milk as a vehicle was done in creased skeletal fluoride levels. However, Switzerland by Ziegler (62) in the 1950s. in all the experimental groups caries in- He undertook a longitudinal study of hibition was observed only when fluor- 1 302 children (749 test subjects, 553 con- ide was given posteruptively. Similar re- trols) 9 to 44 months old at the start of sults were obtained by Poulsen et al. (22), the study. After six years Ziegler found who studied the effect of pre- and post- significant caries reduction in both pri- eruptive exposure in rats receiving fluor- mary dentition (up to 31%) and perma- idated milk or water and found that pre- nent dentition (about 65% in permanent eruptive exposure had little effect on molars), establishing that optimal results

Table 1. Clinical and community experiences with fluoridated milk; permanent dentition comparisons.

% canes Age at Country Duration reduction start References Brazil 16 months Not sigmficant 6-12 years Sampaio et al. (55) Bulgaria* 5 years 79-89 (DMFT) 3-10 years BDMF (67) Hungary IO years 36.8 (DMFT) 2-5 years Cyurkovics et al. (57) 40.0 (DMFS) Israel 30 months 64.0 (DMFT) 4-7 years Zahlaka et al. (58) Japan 5 years 33.8 (DMFT) School age lmamura (59) Scotland 5 years ,.. 31.2 (DMFT) 4.5-5.5 Stephen et al (12) years 43.1 (DMFS) Switzerland 6 years 65.2 (DMFT) 9-44 months Ziegler (62) United States of America 3.5 years 70’ (DMFT) 6-9 years Rusoff et al. (30) United States 3 years 21.8 (DMFS) 6-9 years Legett et al. (32) of America (Not significant) * Community trial. + First and second bicuspids and second permanent molars.

292 Bulletin of PAHO 29(4), 1995 Table 2. Clinical and community experiences with fluoridated milk; deciduous dentition comparisons.

% caries Age at Country Duration reductron start References Bulgaria* 5 years 40 (dmft) 3-10 years BDMF (67) Hungary 5 years 40.1 (dmfs) 2-5 years Ban6czy et al. (53) 40.1 (dmft) Israel 30 months 62.9 (dmft) 4-7 years Zahlaka et al. (58) Scotland 5 years Nor significant 4.5-5.5 years Stephen et al. (12, 60) Switzerland 6 years 14.8-31.5 (dmft) 9-44 months Ziegler (62) *Community trial. are achieved when fluoridated milk in- In Hungary, Banbczy et al. (53, 56) take begins in early childhood. studied the effects of fluoridated milk in In the United States, Rusoff et al. (30) 269 institutionalized children 2-5 years conducted a pilot study with 129 school- old. After five years of fluoridated milk children initially 6 to 9 years old. At the consumption, comparison of test and end of almost four years of study, they control groups showed statistically sig- found a 70% reduction in the incidence nificant reductions in the DMFS (66.6%) of caries on bicuspids and second molars and DMFT (60%). A lo-year follow-up erupting after the study began, and a 36% that involved a 2-year interruption of the reduction on first molars newly erupted program and included only 162 subjects at the start of the study. However, even showed the test group to exhibit signif- though there was a significant overall re- icantly less caries increase in permanent duction in the DMFT index of the study dentition (36.8% lower DMFT and 40.0% group, when broken down by age group lower DMFS) relative to the controls (57). the only children to show significant re- No information was provided about pos- duction were the 9-year-olds, those 16 sible combined effects resulting from ex- children who were 6 years old at the be- posure to other fluoridated products, in- ginning of the study. cluding toothpaste. Stephen et al. (22) reported on a five- In Japan, Imamura (59) reported that year double-blind milk fluoridation study when NaF (as the vehicle for the fluoride of 187 Scottish children (94 test subjects ion) was added to milk and soup served and 93 controls) who were 4 years 6 daily as part of school meals, after four months to 5 years 6 months of age. After years a 36.3% reduction in the DMFT in- five years of milk fluoridation, despite dex was achieved in the study group. attrition of participants in both the test Effects of milk fluoridation on decid- and control groups, significant reduc- uous teeth have been described less fre- tions were observed in both the DMFS quently. The five-year study by Banoczy index (43.1%) and the DMFT index (31.2%) et al. (53) found mean dmft and dmfs for permanent teeth in the test group as values lower by about 40% in the test compared to the controls, while perma- group. Ziegler in Switzerland (62) found nent first molars exhibited a significant a dmft reduction between 14.8% and 74.6% fewer interproximal caries. For 31.5% for temporary dentition in the buccolingual lesions the difference be- fluoridated group. However, Stephen et tween the two groups was not significant al. (12, 60) reported no significant caries but showed a trend in favor of the group reduction in previously erupted primary receiving fluoridated milk. teeth (see Table 2).

Marifo Milk Fluoridation 293 Taken together, these clinical studies Because some uncertainty exists about demonstrate that fluoridated milk con- whether benefits observed in controlled sumption can have a significant preven- environments and clinical trials can be tive impact on dental caries. Unfortu- obtained in the ecologically complex and nately, while the studies are numerous, uncontrolled world of a community, long- some suffer from shortcomings that make term community-wide studies have been their interpretation, comparison, and undertaken in collaboration with the evaluation difficult. Specifically, some World Health Organization’s Oral Health were done with small groups of subjects Program. So far, five of these have be- (12, 30) or under conditions (such as in- gun-in Bulgaria, Chile, China, the Rus- appropriate selection of control groups) sian Federation, and the United King- that might invalidate results (53, 57). dom (4, 67). One of them, which started Others only gave fluoridated milk for short in September 1988 in Bulgaria (67-70), periods of time (no more than three years) has provided a regular supply of fluori- (32, 55, 58); and indeed only five clinical dated milk to 12 000 nursery school chil- studies reported results for periods longer dren 3-10 years old (68). Results after than three years (12, 30, 53, 57, 59, 62). five years showed that mean DMFT and According to Stephen et al. (12), prior to dmft increased in the control group (which the fourth year of consumption of fluor- received no fluoridated milk), while the idated milk, study findings may not show study group exhibited improvement. significant reduction in dental caries, even Compared to baseline data, those who while favoring milk fluoridation. received fluoridated milk for five years There is also the question of how much had 40% fewer caries in their primary the observed benefits were derived from dentition than those in the control group. topical rather than systemic effects of Regarding permanent dentition the effect fluoride. The American Dental Associa- was more significant, with a 79-89% re- tion suggests that while it is difficult to duction in the caries experienced by the quantify the relative importance of pre- study group (67). eruptive and posteruptive exposure to More recently, a milk fluoridation systemic fluoride, the measured benefits demonstration project has started in Chile result from the two combined (5, 16, 63). using powdered milk and MFP as the Hence, while the reviewed study results source of fluoride (67, 70, 77). This project point mainly to systemic influences, the includes all children living in a rural com- effects observed on erupted teeth suggest munity, where milk is distributed free of that the topical action of fluorides re- charge under the national complemen- ceived in milk deserves consideration (53, tary feeding program. Within this context 60). A great deal of evidence also indi- it is worth noting that Villa et al. (23, 31) cates that milk in any form may reduce have obtained a homogeneous concen- tooth decay. According to Reynolds and tration of MFP in powdered milk and Del Rio and other authors (64-66) milk excellent stability over the course of a has an additional topical effect on tooth one-year test. When this product was enamel, because its casein phosphopep- prepared for consumption, the fluid milk tides produce a protective coating over obtained was stable, and no sign of Ca- the tooth resulting in an anticariogenic MFP was observed. effect in animals (64) and a decreased demineralizing rate in vitro (64). Also, be- CONCLUSIONS cause of its calcium, phosphate, and protein content, milk could facilitate remin- The decision regarding what is the most eralization of enamel lesions (64). effective vehicle to use in administering

294 Bulletin of PAHO 29(4), 1995 systemic fluorides will always depend on using milk fluoridation as a community certain unique conditions that apply in measure for preventing dental caries, re- any given situation. However, clinical cent evidence suggests that milk fluori- trials over more than 30 years have re- dation may be regarded as a valid alter- ported favorable results and seem to sup- native in areas where water fluoridation port the conclusion that fluoridated milk cannot be used to provide the desired can have a significant preventive impact benefits. on dental caries. Information from these trials indicates that fluoride-containing milk has a caries-preventive effect, though it should be noted that some of these REFERENCES trials were done under conditions that call their findings into question or make 1. World Health Organization. Prevention them hard to interpret. Community trials, methods and programmes for oral diseases. like those now underway in Bulgaria and Geneva: WHO; 1984. (Technical report Chile, will test fluoridated milk’s effec- series, 713). tiveness under normal conditions pre- 2. Pan American Health Organization. Oral health regional data bank. Washington, vailing in the study communities and will DC: PAHO; 1990. help to provide final evidence regarding 3. Pan American Health Organization. Con- the desirability of using milk as a vehicle ference on Fluorides, Vienna, Austria, 3- when implementing community-based 5 October 1982; conclusions and recom- fluoridation programs. mendations. In: Gillespie GM, Roviralta Clearly, when certain administrative G, eds. Salf fluoridation. Washington, DC: PAHO; 1986:15-16. (Scientific publication conditions are present (such as an on- 501). going milk distribution program in the 4. World Health Organization. Fluorides and community), using milk as the vehicle oral health. Geneva: WHO; 1994. (Tech- may improve the cost-effectiveness of nical report series, 846). fluoridation because no additional costs 5. American Dental Association. Accepted or administrative loads are required. dental therapeutics. 39th ed. Chicago: ADA; Studies of fluoride metabolism have 1982. demonstrated that ingestion of F from 6. American Dietitian Association. Position of the American Dietitian Association: the fluoridated milk raises ionic F in the cir- impact of fluoride on dental health. J Am culation, thereby paving the way for its Dietitian Assoc 1994;94:1428-1431. deposition in hard tissues including teeth. 7. Rao GS. Dietary intake and bioavailability Although some studies have concluded of fluoride. Ann Rev Nufr 1984;4:115-136. that milk is an unsatisfactory vehicle for a. Szapunar SM, Burt BA. Evaluation of ap- fluoride because of fluoride’s decreased propriate use of dietary fluoride supple- bioavailability in calcium-rich environments in the US. Community Dent Oral Epidemiol 1992;20:148-154. ments, no final consensus on bioavail- 9. Horwitz HS. Fluorides to prevent dental ability has been reached. Some experi- decay: an update. In: Frazier J, ed. Pro- ences have indicated that the bioavail- ceedings of the Minnesota Conference on Dental ability of fluoride in milk may be satis- Caries Prevention in Public Healfh Programs. factory when MFP rather than NaF is used Minneapolis: Minnesota Department of as the source of F-because MFP does Health; 1983. not bind with Ca and because F from 10. O’Mullane DM. Introduction and rationale for the use of fluoride for caries pre- MFP is absorbed better under normal vention. Int Dent J 1994;44:257-261. feeding conditions. 11. Shellis RI’, Duckworth RM. Studies on The conclusion of this review is that, the cariostatic mechanism of fluoride. Int contrary to traditional arguments against Dent 1 1994;44:263-273.

Maritio Milk Fluoridation 295 12. Stephen KW, Boyle IT, Campbell D, 24. JIones S, Crawford AC, Jenner AM, Rob- McNee S, Boyle P. Five-year double-blind eBrts JTP, Lennon MA. The possibility of fluoridated milk study in Scotland. Com- School milk as a vehicle for fluoride: ep- munity Dent Oral Epidemioi 1984;12:223-229. demiological, organizational, and legal 13. 1Marthaler TM, Menghini G, Steiner M, et Cmonsiderations. Comm Dent Health 1992; al. Excretion urinaria de fluoruro en nirios 5,:335-342. que consumen suplementos de fluoruro 25. White CH. Milk, milk products, and den- en la sal o el agua. Arch Odontoesfomatol al health. J Dairy Sci 1987;70:392-396. Prev Commun 1992;4:27-35. 26. Jilla A, Guerrero S, Cisternas I’, Moncke- 14. Marthaler TM. Salt fluoridation experi- ,erg F. La prevention de la caries a traves ences in Europe. In: Pan American Health le un vehiculo nutritional. Arch Lafinoam Organization. Papers submitted at the Con- vutr 1990;40:197-209. ference on Fluorides, Vienna, Austria, 3-5 27. 3phaug R, Singer L. Fluoride intake of October 1982. Washington, DC: PAHO; nfants and young children and the effect 1984. lf supplemental and nondairy sources of 15. Pan American Health Organization. IIZ- fluoride. Compendium 1988;9(1):68-75. formefinal, Prilneru Reunion de Expertos sobre 28. Zlovis J, Hargreaves J. Fluoride intake from Fluoruracio’n y Yodacion de la Sal de Consumo Jeverage consumption. Community Denf Humano, Anfigua, Guatemala, 1986. Wash- 3ud Epidemiot 1988;16:11-15. ington, DC: PAHO; 1990. 29. Borrow EW, Davis JG. The fluoridation of 16. Ripa LW. A half-century of community milk and its methodology. Food Trade Rev water fluoridation in the United States: 1975;46:557-563. review and commentary. J Public Health 30. Rusoff LL, Konikoff BS, Fyre JB, Johnston Dent 1993;53:17-44. JE, Fyre WW. Fluoride addition to milk 17. Horwitz HS. Epidemiology of fluorides: and its effect on dental caries in school- range of effectiveness. In: Pan American children. Am J Clin Nufr 1962;11:94-101. Health Organization. Papers submitted at 31. Villa A, Guerrero S, Cisternas I’, Moncke- the Conference on Fluorides, Vienna, Austria, berg F. Fluoride bioavailability from di- 3-5 October 1982. Washington, DC: PAHO; sodium monofluorphosphate fluoridated 1984. milk in children and rats. Curies Res 1989; 18. World Health Organization. Prevention of 23:179-183. oral diseases. Geneva: WHO; 1987:51-58. 32. Legett B, Garbee W, Gardiner J, Lancaster (WHO offset publication 103). DN. The effect of fluoridated chocolate ” 19. Pan American Health Organization. Ap- flavoured milk on caries incidence in ele- propriate use of fluorides for human mentary schoolchildren: two- and three- health: salt fluoridation. In: Gillespie GM, year studies. J Dent Child 1987;54(1):18-21. Roviralta G, eds. Salt fluoridation. Wash- 33. Toth 2, Zimmermann I’, Gintner Z, ington, DC: PAHO; 1986:7-12. (Scientific Bdnoczy J. Changes of acid solubility and publication 501). fluoride content of the enamel surface in 20. Pan American Health Organization. Health children consuming fluoridated milk. Acta conditions in the Americas, 1990. Washing- Pkysiol Hung 1989;74:135-140. ton, DC: PAHO; 1990. 34. Tala H. Practical considerations concern- 21. Ericsson Y. The state of fluorine in milk ing alternative uses of fluorides. In: Pan and its absorption and retention when ad- American Health Organization. Papers ministered in milk: investigation with ra- submitted at the Conference on Fluorides, dioactive fluorine. Acfa Odontol Stand Vienna, Austria, 3-5 October 1982. Wash- 1958;16:51-77. ington, DC: PAHO; 1984. Poulsen S, Larsen MJ, Larson RH. Effect 22. 35. of fluoridated milk and water on enamel Ki.inzel W. Systemic use of fluoride-other methods: salt, sugar, milk, etc. Caries Res fluoride content and dental caries in the 1993;27(suppl 1):16-22. rat. Caries Res 1976;10:227-233. 23. Villa A, Torti H. Informe final: desarrollo y 36. Stamm JW. Milk fluoridation as a public elaboracio’n de leche fluorurada. Santiago: health measure. J Can Dent Assoc Fondo de Desarrollo Productive (FDP), 1972;12:446-448. Corporation de Foment0 a la Production 37. Federation Dentaire Internationale. The (CORFO); 1988. prevention of dental caries and periodon-

296 Bulletin of PAHO 29(4), 1995 tal disease: technical report no 20. Inf Dent 53. Bbnoczy J, Zimmermann I’, Hadas E, Pin- 1 1984;34:141-158. ter A, Bruszt V. Effect of fluoridated milk 38. Duff EJ. Total and ionic fluoride in milk. on caries: 5-year results. J R Sot Health Caries Res 1981;15:406-408. 1985;105(3):99-103. 39. Ekstrand J, Ehrnebo M. Influence of milk 54. Kiinig K. Pre- and posteruptive inhibition products on fluoride availability in man. of experimental rat caries by fluorine ad- Ezzr ] Clin Pharmacol 1979;16:211-215. ministered in water, milk, and food. He/v 40. Muhler JC, Weddle DA. Utilizability of Odontol Acta 1960;4:66-71. fluorine for storage in the rat when 55. Sampaio Lopes E, de Magalhaes Bastos administered in milk. ] Nufr 1955;55: JR, Zaniratto JE. Prevencao da carie den- 347-352. taria atraves da fluoretacao do leite ser- 41. Konikoff BS. The bioavailability of fluoride vido a escolares de Agudos-SP, durante in milk. Lozzisiana Dent J 1974;22:37-42. 16 meses. Rev Assoc Paul Cir Dent 1984;38(6):419-426. 42. Trautner K, Einwag J. Influence of milk and food on fluoride bioavailability from 56. Banbczy J, Zimmermann I’, Pinter A, NaF and Na,FPO, in man. ] Dent Res Hadas E, Bruszt V. Effect of fluoridated 1989;68(1):72-77. milk on caries: 3 years’ results. Commu- nity Denf Oral Epidemiol 1983;11:81-85. 43. Spak CJ, Ekstrand J, Zylberstein D. Bio- availability of fluoride added to baby for- 57. Gyurkovics C, Zimmermann P, Hadas E, mula and milk. Caries Res 1982;16:249-256. Banoczy J. Effect of fluoridated milk on caries: 10 years’ results. 1 Clin Dent 1992; Shulman ER, Vallejo M. Effect of gastric 44. 3:121-124. contents on the bioavailability of fluoride in humans. Pediatric Dent 1990;12:237-240. 58. Zahlaka M, Mitri 0, Munder H, et al. The effect of fluoridated milk on caries in Arab 45. Trautner K, Einwag J. Influence of food children. Clin Prev Dent 1987;9(4):23-25. on the relative bioavailability of fluoride from medical preparations. Caries Res 59. Imamura Y. Treatment of school meals 1991;25(3):236. (Abstract 86). with sodium fluoride as means of preventing tooth decay. j Oral Dis Acad 1959; 46. Trautner K. Influence of food on relative 26:180-199. bioavailability of fluoride in man from NaF and Na,FPO, containing tablets for the 60. Stephen KW, Boyle IT, Campbell D, et al. treatment of osteoporosis. lnf 1 Clin Pharm A $-year double-blind fluoridated milk Ther Toxic01 1989;27(5):242-249. study in a vit-d deficient area. Br Dent J 1981;151:287-292. 47. Trautner K, Einwag J. Factors influencing 61. Wirz R. Ergebnisse des Grossversyches the bioavailability of fluoride from cal- mit fluoridieter milch in winterhur von cium-rich health food products and CaF, 1958 bis 1964. Schweiz Monafsschr Zahn- in man. Arch Oral Biol 1987;32(6):401-406. heilkd 1964;74:767-784. 48. Patterson C, Ekstrand J. The state of 62. Ziegler E. Bericht iiber den winterhurer fluoride in milk. J Denf Res 1978; grossversuch mit fluorzugabe zur haush- 57(special):336. (Abstract 1045). altmilch. Helv Paediafr Acta 1964;19:343-354. 49. Ericsson Y. Monofluorphosphate physi- 63. Aasenden R, Peebles TC. Effects of fluor- ology: general considerations. Caries Res ide supplementation from birth on hu- 1983;17(suppl 1):46-55. man deciduous and permanent teeth. Arch Oral Biol 1974;19:321-326. 50. Burt BA. The costs of fluoride pro- 64. grammes in dental public health. In: Pan Thwaites T. Milk yields up ally in fight American Health Organization, Papers against dental caries. New Sci 1991;131, 20 submitted at the Conference on Fluorides, July. Vienna, Austria, 3-5 Ocfober 1982. Wash- 65. Reynolds EC, Del Rio A. Effect of casein ington, DC: PAHO; 1984. and whey-protein solutions on caries ex- perience and feeding patterns of the rat. 51. World Health Organization. Recent advances Arch Oral Biol 1984;29:927-933. in oral health. Geneva: WHO; 1992. (Tech- 66. Dorr KK, Reynolds EC. Enamel lesion re- nical report series, 826). mineralization using soluble casein phospho- 52. Villa A. Caries dentaria: una nueva so- pepfide-calcium phosphate complex. Perth: lucidn para un antiguo problema. Creces IADR, Australia and New Zealand Sec- April 1988:50-56. tion; 1993. (Abstract 69).

Marizio Milk Fluorzdation 297 67. Barrow Dental Milk Foundation. Advances 7-15 Nov 1991, Barrow Dental Milk in milk fluoridation research. Portsmouth, Foundation; 1991. England: BDMF; 1995. 70. Barrow Dental Milk Foundation. Interna- 68. Federation Dentaire Internationale. Milk tional Milk Fluoridation Programme: UP- DATE. Portsmouth, England: BDMF; 1992. fluoridation in Bulgaria. FDI News. July/ August 1989, no 166, p 3. 71. Villa A, Godoy D, Guerrero 5, Maririo R. Dental caries prevention through pow- 69. Pakhomov GN, Moller IJ. Evaluation of the dered milk fluoridation in Chile. In: Fourth milkfluoridation project in Plovdiv and Asen- World Congress on Preventive Dentistry. ovgrad, Bulgaria. Portsmouth, England: In- Umea, Sweden: WHO/IADR; September ternational Milk Fluoridation Programme, 1993. (Abstract SlO).

Meeting on Vitamin A Deficiency

“Virtual Elimination of Vitamin A Deficiency: Obstacles and Solutions for the Year 2000” is the theme of the XVII Meeting of the Interna- tional Vitamin A Consultative Group (IVACG), to be held from 18 to 22 March 1996 in Guatemala. The program will include invited ad- dresses on the meeting theme, as well as other oral, poster, and video presentations that will be selected from submitted abstracts. Those presentations will focus on population assessment and biological sig- nificance of vitamin A deficiency and marginal vitamin A deficiency, and appropriate interventions, especially food-based approaches and food fortification. More than 300 participants are expected to attend the meeting, including policymakers, scientists, and program implementors. The meeting is sponsored by the IVACG and a local organizing committee coordinated by PAHO’s Institute of Nutrition of Central America and Panama (INCAP). For further information about the meeting, contact: IVACG Secretariat ILSI Research Foundation 1126 16th Street, N.W. Washington, D.C. 20036, U.S.A. telephone: (202) 659-9024; fax: (202) 659-3617 e-mail: [email protected]

298 Bulletin of PAHO 29(4), 1995