***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Children in kindergarten and first grade ( mostly 5 and 6 year olds ) in a nonfluori date d city were assigned r and omly in each of 20 schools to : rinse weekly with a 0.2 % NaF solution , ingest daily a 2.2 mg NaF tablet , or carry out both procedures , for 8 years . At baseline ( 1981 ) , 1640 participants were examined clinical ly 3 National Institute of Dental Research ( NIDR ) investigators who used the dmfs ( for primary molars only ) and DMFS indexes . After 2 years ( 1983 ) , 1154 subjects were available for reexamination . For primary teeth , subjects in the combination treatment group had a mean increment of 1.67 dmfs , 18.9 % lower than the mean scores of 2.06 dmfs for children in the tablet group and 33.2 % lower than the 2.50 dmfs for those in the rinse group . Results in primary teeth by type of surface also showed consistently lower scores in the combination group than in the other treatment groups . The differences in overall caries increments among the 3 groups approached statistical significance ( P = 0.06 ) . For permanent teeth , mean increments ( essentially in pits and fissure surfaces of first molars ) for each group were small ( < 1 DMFS/ child ) and similar . The findings of this study suggest that primary molars may receive enhanced anticaries benefits from a combined fluoride program in school when exposure begins in kindergarten and first grade . Also , the findings in primary molars portend more substantial results in permanent teeth as the evaluation continues . Increasing evidence indicates that various combinations of fluoride agents produce additive anticariogenic effects ( Horowitz 1980 ; Federation Dentaire International 1984 ) . Self-administered fluoride procedures that may exert their cariostatic effects by different mechanisms of action are likely to achieve maximum caries-preventive benefits most efficiently . The National Institute of Dental Research ( NIDR ) has published a series of reports of a long-term dental health program in which a combination of fluoride procedures is used . ’ In that program , school children 1 Horowitz et al. 1977 , 1979 ; Horowitz 1980 , 1984 . in Nelson County , Virginia , an area with negligible concentrations of fluoride in its drinking water , ingest a dietary fluoride supplement daily and rinse with a fluoride solution weekly . In addition , fluoride dentifrice is provided for ad libitum use at home . This combination of self-administered methods was selected to provide permanent teeth with systemic exposure to fluoride before eruption ( from dietary supplements ) and topical exposure to teeth after eruption ( from rinse , dentifrice , and dietary supplement ) . Final results after 11 years showed that the prevalence of dental caries among participants was reduced by about 65 % compared with caries scores of school children before the program began ( Horowitz et al. 1986 ) . Striking results were obtained in approximal surfaces of teeth -- a 90 % lower prevalence of dental caries ( Horowitz et al. 1986 ) . The anticaries effects of the combined fluoride regimen observed in Nelson County are greater than those usually reported for any of the individual components , suggesting an additive effect . 2 However , because all participating children received the entire regimen , cl aims of additive effects can not be made ; not all the preventive regimens used may have been necessary to produce the observed benefit . The present study was undertaken by NIDR to determine whether the combined use of school-based programs of fluoride rinsing and fluoride tablets produce additive effects . Because almost 95 % of all dentifrice now sold in the United States contains fluoride ( Heifetz and Horowitz 1986 ) , the present study likely represents an evaluation of the combined fluoride therapies superimposed upon a background of home use Driscol11974 ; ADA Council on Dental Therapeutics 1975 ; Heifetz and Horowitz 1986 . PEDIATRIC DENTISTRY : June 1987/Vol . 9 No. 2 121 of fluoride dentifrice , a situation akin to the Nelson County study A ten-year longitudinal prospect i ve study compared the effect of fluoride on dentition of 1,500 children from infancy through age 10 years . In Kalamazoo , Mich , and Oneida , NY , parallel groups were given a fluoride-vitamin supplement from infancy and from age 4 and compared with fluori date d water and control groups . Incidence of new caries activity in both deciduous and permanent teeth was measured by mean number of new decayed and filled teeth , as well as percentage of children with no caries throughout the periods studied . Prevalence of caries was also studied in six-year molars . The results indicate a consistent ( and , for selected groups , a statistically significant ) diminution in caries activity for both deciduous and permanent teeth for groups ranked from greatest retardation of caries to least : infant fluoride group , water fluoride group , age 4 fluoride group , and controls Two groups of children , initially in the first and second grade s , chewed , rinsed with , and swallowed an acidulated phosphate-fluoride tablet containing 1 mg of fluoride either once or twice a day in school . A control group of children followed the procedure once a day using a placebo tablet . An evaluation after six years of treatments showed that both the once-a-day and the twice-a-day procedures with fluoride tablets effectively reduced the incidence of dental caries A field study of a practice based preventive programme was conducted over 18 months in a health centre in a socially deprived urban area . The programme comprised chairside education , including dietary advice and oral hygiene instruction , and a therapeutic intervention based on home consumption of a 1 mg of fluoride tablet daily .  Participants were 242 boys and girls aged 11 - 13 years accepting routine dental care . They were allocated at r and om to a test and control group . Control subjects received all routine operative treatment needed to maintain dental fitness while test subjects received similar routine treatment but with the addition of the preventive regimen . Although the test subject 's knowledge of dental self-care improved during the course of the study , this was evidently not translated into change of behavior and no significant differences in dental health between test and control groups could be detected at the conclusion The Manchester fluoride tablet trial was a pragmatic study to assist the Health Authority to decide whether to provide fluoride tablets daily to all primary schoolchildren in the District prior to water fluoridation being introduced . Twenty-two primary schools took part , half being allocated at r and om to the public health programme while the other half remained untreated . The average age at baseline was 5 yr 3 months .  Costs were monitored throughout the trial and tangible and intangible benefits assessed . 263 children in the test schools and 266 in the control schools completed the trial . The cost per child was 4.39 pounds for the 3 yr of the trial . Economies result ing from an increase in size of a substantive scheme were estimated producing a cost of 1.98 pounds/child over a 3-yr period for a tangible benefit of 3.23 pounds . In addition , the intangible benefits of less anxiety , less treatment , and fewer experiences of general anaesthesia need consideration This article presents five-year interim findings of an eight-year clinical trial design ed to compare the relative caries-preventive benefits of weekly fluoride mouthrinsing , daily fluoride tablet administration , and both procedures combined . Children in kindergarten and first grade residing in Springfield , Ohio , a nonfluori date d community , were assigned r and omly in school to one of three groups that ( 1 ) rinses once a week in school with a 0.2 percent neutral NaF solution ; ( 2 ) chews , rinses with , and then swallows daily in school a neutral 2.2 mg NaF tablet ; or ( 3 ) carries out both procedures . At baseline ( 1981 ) , 1,640 participants were examined clinical ly using the DMF surface index . After five years , 789 children were available for reexamination . Findings show that subjects in the combination group experienced a mean caries increment of 1.47 DMFS , 16.5 percent lower than the mean score of 1.76 DMFS for children in the tablet group and 31.3 percent lower than the 2.14 DMFS for those in the rinse group . Only the difference in incremental caries scores between the combined fluoride procedure and the fluoride rinse was statistically significant ( P less than .05 ) . Despite the finding of an additive caries-preventive benefit among children who followed the combined regimen , it would be premature to judge which procedure is best before results of the final examinations become known Field demonstration trials of preventive agents or methods are needed so that the effectiveness and acceptability of such methods can be evaluated when used as part of the prevailing system and life style in a particular community . Agents so tested should have already been shown in a clinical trial to have a positive effect . Field demonstration trials differ from clinical trials in having no traditional control group ; the study is not ' blind ' ; there is no special supervision and there is no special selection of participants . Results of two field demonstration trials , one in a population in Thail and with moderate but increasing caries severity and the other in French Polynesia , where caries severity is very high , are reported . The trials compared the effectiveness of various chewing gum formulations with the effectiveness of a fortnightly supervised sodium fluoride rinse . One gum formulation contained fluoride and was sweetened with sucrose or xylitol and sorbitol , the other was fluoride free and was sweetened with xylitol and sorbitol . The important information from these field trials is that a fluoride-containing chewing gum sweetened with xylitol/sorbitol appears to be effective in controlling caries experience even in communities apparently experiencing an increase of the disease ; and that the apparent effectiveness was achieved in a field situation subject to all the problems of a programme not under a rigid clinical trial type of control . The fluoride-containing chewing gum-sucrose regime , in both the trials , and the non-fluoride chewing gum-xylitol/sorbitol regime in the French Polynesia trial failed to exhibit any notable preventive effect OBJECTIVES A total of 3373 12-year-olds agreed to participate in an intervention study evaluating different caries preventive measures .  The study , titled ' Evaluation of caries preventive measures ' , was performed between 1995 and 1999 at 26 dental health clinics throughout Sweden . At the start of the study , the subjects were classified as individuals at high or low risk of developing caries . The high-risk group consisted of 1165 subjects . The children in the high-risk group were r and omly assigned to one of four preventive programs . The programs represent a step-wise increase in fluoride content , contact with dental personnel and cost . The aim of the present cost-effectiveness analysis ( CEA ) study performed from a societal perspective is to compare costs and consequences of  caries preventive programs  in a caries high-risk population . By ' costs ' is meant both treatment costs and costs contributed by the patient and the patient 's family . Costs contributed by patients and their families consist of out-of-pocket expenses , transportation costs , and time . Conclusions are that it is important to consider the perspective from which a study is carried out . Costs contributed by the patient and the patient 's family have a high impact on total costs for children and younger adolescents but decrease with time as the adolescents get older . The present study shows an incremental cost-effectiveness of 2043 SEK ( 8.54 SEK = 1 US dollar , December 1999 ) per averted decayed enamel and dentine missing and filled surface ( DeMFS ) , of which treatment costs represent 1337 SEK using the unit cost for a nurse . This means a yearly cost of approximately 334 SEK Abstract 705 children took part in a controlled trial in which they were given the vitamin A and D drops routinely supplied by Swedish child-welfare centres with or without a supplement of sodium fluoride . The children were examined by a dentist each year from the age of one to the age of six ( longer in some cases ) . At the third , fourth , fifth , and sixth examinations the mean number of decayed teeth was around 50 % lower in the fluoride group . It is recommended that fluoride be given in vitamin drops where the local fluoride content of drinking-water is below 0.6 p.p.m . Such a scheme could be voluntary . Other advantages would be simplicity and cheapness This study measured the fluoride in tooth enamel of 338 schoolchildren after daily use of acidulated phosphate-fluoride ( APF ) tablets  , and investigated the relationship between observed amounts of enamel fluoride and incidence of caries .  R and omly selected study groups received under supervision either one placebo tablet , one APF tablet containing 1 mg fluoride , or 2 APF tablets ( 3 hours apart ) each school day . An abrasive enamel-type biopsy of a maxillary central incisor was taken 30 months after the start of fluoride tablet treatments at the time of the follow-up examinations . Mean fluoride levels in the biopsied enamel from each of the three groups were similar despite a significant restriction in caries in the group receiving two APF tablets per day . These findings suggest that fluoride can restrict dental caries by some mechanism other than fluoride uptake in the enamel Many dental research ers have been expressing the response to treatment with anticariogenic agents  in terms of per cent reduction of caries incidence . Although they have found it desirable from time to time to calculate confidence limits and certain probabilities associated with true per cent reduction in caries incidence , they have not done so because they did not have access to any analytical tool for this purpose . Procedures for calculating confidence intervals associated with a single mean or difference between two means from normal distributions are commonly discussed in statistical texts , but a procedure for calculating a confidence interval associated with the 
    Output:
    
The effect of fluoride supplements was unclear on deciduous or primary teeth .
In one study , no caries-inhibiting effect was observed on deciduous teeth while in another study , the use of fluoride supplements was associated with a substantial reduction in caries increment .
When fluoride supplements were compared with topical fluorides or with other preventive measures , there was no differential effect on permanent or deciduous teeth .
The review found limited information on the adverse effects associated with the use of fluoride supplements .
AUTHORS ' CONCLUSIONS This review suggests that the use of fluoride supplements is associated with a reduction in caries increment when compared with no fluoride supplement in permanent teeth .
The effect of fluoride supplements was unclear on deciduous teeth .
When compared with the administration of topical fluorides , no differential effect was observed .