Expected caries preventive benefits of fluoridating L.A. water supplies.

Water fluoridation at the optimal concentration for the geographic area confers the maximum decay preventive benefits. Numerous communities have suboptimal levels of naturally occurring fluoride. The question of how much additional caries preventive benefits would be obtained if these communities fluoridate is of more than academic interest. Using Los Angeles as an example, this paper estimates the additional caries preventive benefits that may be realized in adjusting the fluoride concentration to the ideal.

Serendipitous results of a pilot study: precaution indicated.

A pilot study was conducted to estimate sample size for a clinical trial in a F area. In 1992, 98 children 14 years of age living in Fall River, MA were examined for dental caries: Fall River was fluoridated in 1973. Residence histories showed that 74% lived there from birth (B), 12% were residents from kindergarten or 1st grade (K1) and 14% moved into the community at a later time (LT). Findings on caries prevalence showed an inverse relation between DMFS and initial age of residence; mean DMFS was 3.00 for Group B, 5.33 for Group K1 and 6.93 for Group LT. A one-way ANOVA indicated significant differences among the groups (p=0.05). Because residence from birth or from early life can be considered a proxy for systemic fluoride exposure, and because controversy currently surrounds the issue of topical versus systemic benefits in explaining the mechanism of action of fluoride, the results appeared to have importance. However, internal analyses of the data comparing surface-specific (pit and fissure) results among the groups for early erupting teeth with varying systemic exposure to fluoridated water and for late erupting teeth, all with appreciable systemic exposure, showed comparable relative differences in DMFS scores. Lack of internal validity, therefore, discounted a conclusion from overall results of the role of systemic fluorides in providing decay preventive benefits. If there is any conclusion that can be drawn it is that serendipitous escapades with data from a pilot study, if not rigorously analyzed and cautiously interpreted, tend to further muddy the waters (fluoridated in this case) on controversial issues and should best be avoided.

Fluorides for the elderly.

With the current decline in the rate of dental caries among school children, the elderly now have the higher rate of decayed coronal surfaces in addition to being susceptible to root caries. The most effective strategy that the profession can take is twofold: thoroughly assess the level of caries risk of the elderly individual, and institute recognized measures of fluoride therapy commensurate with the defined risk. This review article describes risk indicators characteristic of the elderly patient and offers specific fluoride regimens for low, moderate and high risk subjects.

A comparison of the caries-preventive effects of fluoride mouthrinsing, fluoride tablets, and both procedures combined: final results after eight years.

This paper presents final results of an eight-year clinical trial designed to compare the caries-preventive benefits of two self-administered fluoride procedures when used separately and in combination with one another. Children in kindergarten and first grade residing in Springfield, Ohio, a nonfluoridated community, were assigned randomly within school to one of three groups that either (a) rinsed once a week in school with a 0.2 percent neutral NaF solution; (b) chewed, rinsed with, and then swallowed daily in school a neutral 2.2 mg NaF tablet; or (c) carried out both procedures. At baseline (1981), 1,640 participants were examined clinically using the DMF surface index. Findings for 640 children remaining after eight years show that subjects in the combination group experienced a mean caries increment of 2.40 DMFS, 15.2 percent lower than the mean score of 2.83 DMFS for children in the tablet group and 32.8 percent lower than the 3.57 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). The pattern of these findings is similar to that found on the two interim examinations. Even though the combined regimen showed an additional caries-preventive benefit compared with the rinse, considerations of cost effectiveness and feasibility do not support changing an ongoing rinse program to one that employs both procedures. For new programs the best choice appears to be the tablet procedure alone.

Evaluation of the comparative effectiveness of fluoride mouthrinsing, fluoride tablets, and both procedures in combination: interim findings after five years.

This article presents five-year interim findings of an eight-year clinical trial designed 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 nonfluoridated community, were assigned randomly 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 clinically 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.

Prevalence of dental caries and dental fluorosis in areas with optimal and above-optimal water-fluoride concentrations: a 5-year follow-up survey.

In 1980, the prevalence of dental caries and dental fluorosis was assessed among lifetime resident children in four areas of Illinois with water fluoride concentrations of 1x, 2x, 3x, and 4x above the optimal level. In 1985, the same areas were resurveyed to determine if changes occurred in dental caries and fluorosis.

Salivary levels of Streptococcus mutans and lactobacilli and dental caries experiences in a US adolescent population.

Dental caries exams and saliva samples were obtained from 541 adolescents, aged 10-15, initially and after 17 months as part of a 3-yr longitudinal study investigating the relationships of dietary intakes, specific microorganisms in saliva, and the prevalence and incidence of dental caries. The mean DMFS score detected in these subjects initially was 4.61, and they developed an average of 1.38 new DMFS during the first 17-month period. Initially, S. mutans and lactobacilli were detected in 64% and 56% of these subjects, respectively. Subjects with low levels of S. mutans and lactobacilli had significantly lower initial DMFS scores and developed significantly fewer new DMFS than subjects with high counts. The predictive values of a positive result for S. mutans or lactobacilli assays were low (31% and 39%), but those for a negative result were high (81% and 84%).

Prevalence of dental caries and dental fluorosis in areas with negligible, optimal, and above-optimal fluoride concentrations in drinking water.

The prevalence of dental caries and dental fluorosis was assessed in 1,123 children aged 8 to 16 years who were lifelong residents of areas with negligible, optimal, and above-optimal concentrations of natural fluoride in drinking water. Caries prevalence in the optimal fluoride area was 38.1% lower than it was in the negligible fluoride area, and, in the higher-than-optimal fluoride areas, even greater caries protection was evident. Caries protection was compromised in children with severe fluorosis. Findings do not support the contention that definite increases in the prevalence of fluorosis are occurring in communities with negligible and optimal water-fluoride concentrations because of increased total fluoride consumption from various sources.

Amounts of fluoride in self-administered dental products: safety considerations for children.

With the increased use of various fluoride preparations for caries prevention, all dental personnel should know their potential toxicity and the margins of safety associated with their use. An understanding of the body's mechanisms for handling fluoride provides a rational basis for assessing the possible risks of excessive fluoride ingestion. Five to 10 g of sodium fluoride is considered a certainly lethal dose for a 70-kg adult. One quarter of the certainly lethal dose can be ingested without producing serious acute toxicity and is known as the safely tolerated dose. Comparisons of certainly lethal and safely tolerated doses for commonly used fluoride agents and procedures show that they can be applied with little or no risk of adverse acute effects, as long as they are used judiciously. If their use is abused, there is a risk of illness or even death. If amounts of fluoride close to the certainly lethal dose are ingested, the speed of initiating proper treatment is critical for survival. Vomiting should be induced, if it is not spontaneous; fluoride-binding liquids, such as milk or liquid or gel antacids, administered; and the patient taken to the nearest hospital for emergency care. Frequent ingestion of low but excessive quantities of fluoride during the period of tooth formation can lead to dental fluorosis. Particular concern is warranted for the ingestion of fluoride-containing toothpastes by young children and the inappropriate use of dietary fluoride supplements in communities with sufficient fluoride already present in drinking water.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined fluoride, school-based program in a fluoride-deficient area: results of an 11-year study.

In 1972, a school-based fluoride program was initiated in elementary schools in Nelson County, VA, a fluoride-deficient area. For 11 years, participating children ingested daily in school a 1-mgm fluoride tablet and rinsed weekly with a .2% sodium fluoride solution. They also received fluoride dentifrice and toothbrushes for home use. The program was extended into junior high school in 1978 and into high school in 1980. In 1983, dental examinations of children aged 6 to 17 years, who had continuously participated in the program for 1 to 11 years depending on school grade, showed a mean prevalence of 3.12 DMFS, which was 65% lower than the corresponding score of 9.02 DMFS for children of the same ages at the baseline examinations. The preventive program inhibited decay in all types of surfaces: 54% in occlusal surfaces; 59% in buccolingual surfaces; and 90% in mesiodistal surfaces.

Examiner consistency and group balance at baseline of a caries clinical trial.

Two experienced investigators (G.L. & H.H.) independently examined 629 children in grades 6-9 (ages 10-17 yr) for baseline DMFS data in a clinical trial of a caries preventive. The examiners used the same written and visual (slides) criteria for dental caries diagnosis, but did not standardize or calibrate their methods before or during the survey. Results showed overall mean DMFS scores for Examiners 1 and 2 that were remarkably similar, 8.35 and 8.16, respectively; coefficients of variation were identical, C.V. = 87%. The reliability coefficient for the two sets of data showed that only 4% of the variability in DMFS scores was due to examiner inconsistency and other measurement errors. The findings indicate that, without undergoing clinical calibration, the two experienced examiners attained a high level of agreement in scoring dental caries merely by adhering to clearly defined written and visual criteria. Only the 308 children in the 6th grade (ages 10-14 yr) participated in the study (children in grades 7-9 were a reference population). Participants were randomly assigned to one of two treatment groups. The allocation procedure produced mean DMFS scores for Groups I and II of 7.87 and 6.17 (Examiner 1) and 8.07 and 6.41 (Examiner 2), respectively. The mean scores differed by about 21% (II compared with I) for each examiner. Both differences were clinically and statistically significant (P less than 0.05). Randomized assignment had generated an imbalance of baseline DMF scores by group.

Eight-year evaluation of a combined fluoride program in a nonfluoride area.

The purpose of this study is to measure the long-term effects of a combination of self-applied fluoride methods among schoolchildren living in a rural area with low concentrations of fluoride in drinking water. Participating children rinse weekly with a 0.2% sodium fluoride solution and ingest daily a 1-mg fluoride tablet in school under supervision of their teachers, and received fluoride toothpaste and toothbrushes for use at home. In 1980, dental examinations of children ages 6-14, who had continuously participated in the program for 1 to 8 years, depending on their school grade, had an overall mean caries prevalence of 3.22 DMFS, 49% lower than the corresponding mean score of 6.31 DMFS for children of the same ages at the baseline examination. The preventive program inhibited decay in all types of tooth surfaces: 37% in occlusal, 41% in buccolingual, and a striking 86% in mesiodistal. At each succeeding follow-up survey, benefits have continued to improve; the reductions in caries prevalence were 18% after 2 years, 35% after 4 years, 45% after 6 years, and 49% after 8 years. Findings in approximal tooth surfaces have also continued to improve as the length of the program has increased; reductions in caries in mesiodistal surfaces were 32%, 69%, 85%, and 86% after 2,4,6, and 8 years, respectively. Internal analyses of data indicate that the decline in dental caries prevalence resulted from the fluoride program and not from an unexplained natural decline in caries prevalence. The self-applied combined fluoride regimen used in this program has been shown to produce a pronounced anticaries effect.

A new method for assessing the prevalence of dental fluorosis--the Tooth Surface Index of Fluorosis.

A new index for measuring the prevalence of dental fluorosis, the Tooth Surface Index of Fluorosis (TSIF), was used to assess the condition in the permanent teeth of 807 children, aged 8 to 16, who had resided all their lives in one of seven Illinois communities with an optimal concentration of fluoride in its water or with 2, 3, or 4 times the optimal concentration. Fluorosis was absent in 84.5% of all tooth surfaces examined in the community with optimal fluoride. In contract, only 31.9% of tooth surfaces had no fluorosis in the community with 4-times the optimal fluoride level. In the optimal fluoride area, 79% of facial surfaces of maxillary anterior teeth, which are esthetically conspicuous, had no fluorosis, whereas only 15.8% of these surfaces in the 4-times optimal area were unaffected. The percentages of all tooth surfaces affected by fluorosis characterized by staining, pitting, or both were 1%, 8%, 19%, and 38%, respectively, in communities with 1-, 2-, 3-, and 4- times optimal fluoride. Differences in fluorosis based on maximum score for all tooth surfaces in a child were statistically significant (an extended chi 2 statistic) among all communities. First molars and incisors in children 8 to 10 years old were affected by more fluorosis than were the same teeth in children 13 to 16 years old. These teeth had been erupted for about 5 years longer in the older age group. The difference might result from abrasion or remineralization of these teeth in the older children or from greater consumption of fluoride by the younger children during tooth development.(ABSTRACT TRUNCATED AT 250 WORDS)

The amounts of fluoride in current fluoride therapies: safety considerations for children.

With the increased use of various fluoride preparations for caries prevention, all dental personnel should know their potential toxicity and the margins of safety associated with their use. An understanding of the body's mechanisms for handling fluoride provides a rational basis for assessing the possible risks of excessive fluoride ingestion. Five to 10 grams of sodium fluoride is considered a Certainly Lethal Dose (CLD) for a 70 kg adult. One quarter of the CLD can be ingested without producing serious acute toxicity, and is known as the Safety Tolerated Dose (STD). CLDs and STDs for most commonly used fluoride agents and procedures show that they can be applied with little or no risk of adverse effects, as long as they are handled judiciously. If their use is abused, there is a risk of illness or even death. If amounts of fluoride close to the CLD are ingested, the speed of initiating proper treatment is critical for survival. Vomiting should be induced, if it is not spontaneous; fluoride-binding liquids, such as milk, administered; and the patient taken to the nearest hospital for emergency care. Frequent ingestion of low, but excessive quantities of fluoride during the period of tooth formation can lead to dental fluorosis. Particular concern is warranted for the ingestion of fluoride-containing toothpastes by young children and the inappropriate use of dietary fluoride supplements in communities with sufficient fluoride already present in drinking water. Parents should brush the teeth of preschool children or, at the very least, dispense only small amounts of toothpaste for them (a pea-size portion). Dentists and physicians should know the fluoride concentration of a patient's water supply before prescribing fluoride supplements. Fluoride preparations should be dispensed in appropriate quantities; labeled with suitable cautionary statements; packaged, when appropriate, with childproof closures or in tearproof materials; and stored in safe locations. Practitioners should use only FDA- or ADA- approved products, employ recommended methods for their delivery; know their toxicity; and be familiar with emergency measures for treating accidental overdosages. The risk of adverse effects is small, when fluorides are handled judiciously.

Prevalence of dental caries and dental fluorosis in areas with optimal and above-optimal water fluoride concentrations.

The prevalence of dental caries and dental fluorosis was assessed among 807 schoolchildren in four areas of Illinois where the respective water supplies contained natural fluoride at concentrations of 1, 2, 3, and 4 times the recommended optimal for the geographic area. Mean caries scores in all three above-optimal fluoride areas were significantly lower than in the optimal area. The prevalence of dental fluorosis was characteristically low in the optimal fluoride area. Substantial increases in fluorosis occurred in the above-optimal fluoride areas, with the condition being most pronounced in the 4-times optimal area.

Caries-preventive effects of fluoride tablets in schoolchildren four years after discontinuation of treatments.

The Wayne County data indicate that administration of fluoride tablets in school should be recommended in nonfluoridated areas as an effective public health measure to prevent dental caries. In addition to reducing dental caries effectively, administering fluoride tablets in school has a number of other desirable features; it is safe and relatively inexpensive; it requires no paper products and thus eliminates waste disposal; it takes little time to administer (less than three minutes per day for a classroom of average size); it is easy for young children to learn and to do; and it can be supervised by teachers, aides, or volunteers after minimal training. Findings that benefits still persist, although perhaps to a slightly lesser degree, four years after treatment is discontinued further accentuate the public health appeal of the procedure. The data give no indication that two fluoride tablets a day are more protective than one tablet a day. Therefore, a single one-mg fluoride tablet daily is recommended for school programs because of lower cost and greater feasibility.

Evaluation of the retention of two types of pit and fissure sealants.

The aim of this study was to statistically compare the retention of a chemically polymerized sealant (Delton, Johnson & Johnson Co., East Windsor, N.J.) with a widely tested UV-polymerized system (Nuva-Seal, L.D. Caulk Co., Milford, Del.) Two hundred children aged 5-16 years who resided in Fairfax County, Virginia (a fluoridated community) and who had one or more pairs of homologous permanent posterior teeth free of decay or fillings were admitted to the study. Posterior teeth on one side of the mouth of each subject were randomly assigned to receive Nuva-Seal; teeth on the other side were treated with Delton. Treated teeth were examined for sealant loss approximately every 6 months for a period of 2 years. Scores for complete retention of Nuva-Seal were 86% after 6 months and 78% at the end of 2 years. The corresponding values for Delton-treated teeth were 96% and 92%. For both sealants, scores of total retention were highest in mandibular first premolars and lowest in mandibular second molars. The greatest rate of sealant loss occurred within the first 6 months after placement. A comparison of overall retention scores (net gain) for Delton and Nuva-Seal revealed that Delton scores were significantly higher than Nuva-Seal at each semi-annual examination. The McNemar test was used to compare the retention of the two sealants for each tooth type. The test showed that the retention scores for Delton were significantly higher than those for Nuva-Seal only on maxillary and mandibular first molars.