Biomedical subjects
H S Horowitz
Publications and source records attributed to H S Horowitz.
The future of water fluoridation and other systemic fluorides.
School and community water fluoridation, salt fluoridation, and use of dietary fluoride supplements have abundant scientific support as effective caries-preventive methods. Because caries has declined greatly in many developed countries from use of topical fluorides, the absolute caries reduction will be considerably smaller when systemic fluoride methods are implemented now than it was 20 to 40 years ago. For countries with most of the population living in cities with communal water supplies, community fluoridation is the most logical approach from the standpoints of cost-effectiveness and total caries-preventive impact. In countries with a mostly rural population without central water supplies, salt fluoridation is more practical. Dietary fluoride supplements can be recommended only for regions where neither water fluoridation nor salt fluoridation is possible, or as a temporary measure. Although divergent views exist concerning the relative caries-preventive effects of pre-eruptive and post-eruptive fluoride administration, the effectiveness of systemic fluoride methods for preventing dental caries remains unchallenged. Persuasive scientific and public health arguments exist to justify implementing and sustaining their use. The future of these methods will be influenced by the findings of new clinical and epidemiological research. Social, political, economic, and educational factors will be of equal, if not greater, importance. Perceptions of the current severity of dental caries as a health problem and of risks associated with preventing the problem may affect the future uses of systemic fluorides more than will recommendations of scientists.
Current ethical issues in research.
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Grand Rapids: the public health story.
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The prevalence of dental fluorosis.
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Effectiveness of school water fluoridation and dietary fluoride supplements in school-aged children.
School water fluoridation and school-based fluoride tablet programs both have been shown in many studies to be effective in preventing dental caries. These studies indicate that school water fluoridation reduces dental decay by approximately 40 percent and school-based fluoride tablet programs by about 30 percent. However, nearly all the studies were done when the prevalence of caries among US schoolchildren was greater than it is today, which makes it difficult to assess their current effectiveness. Data from dental surveys of school-aged children conducted during the past 30 years indicate that overall caries prevalence has declined by more than 75 percent and that of approximal tooth surfaces by more than 90 percent. Recent national data indicate the difference in caries prevalence between children with lifetime residence in either fluoridated or nonfluoridated areas has also diminished, which raises questions about the cost effectiveness of initiating school-based fluoride programs for all areas. There are still groups of children, however, seriously affected by dental caries. It is safe to assume that implementation of school water fluoridation or fluoride tablet programs will result in traditionally reported benefits among these children. Ongoing school-based fluoride programs should not be discontinued until it is known what impact their cessation will have on dental disease.
Fluoride and enamel defects.
The concentration of fluoride in drinking water is the major determinant of the prevalence and severity of dental fluorosis in a community. Fluorosis is more prevalent and discernible in permanent teeth than in primary teeth; the intensity can range from barely perceptible, whitish striations in enamel to confluent pitting and dark staining. The traditional belief is that fluorosis is produced only during the secretory stages of ameloblastic activity. Some recent reports suggest that the maturation stages of enamel development are as important as or even more important than the secretory stages as the time when fluorosis can be produced. The question of timing remains unresolved. Many questions also remain about general and individual physiologic variations in relation to susceptibility to dental fluorosis. Good criteria for differential diagnosis exist to distinguish dental fluorosis from non-fluoride enamel opacities. An increasing number of reports indicates that the prevalence of fluorosis may be increasing among children in fluoridated and non-fluoridated communities. Reasons for the increases may relate to misuse of dietary fluoride supplements, ingestion of fluoride toothpastes, or increasing amounts of fluoride in foods or the atmosphere. The intensity of the increased fluorosis is in the milder categories and is not generally unsightly. It should be recognized that a small amount of fluorosis may be an alternative to a greater prevalence of dental caries, a disease that may produce cosmetic problems and sequelae worse than those produced by fluorosis.
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.
Evaluation of the comparative effectiveness of fluoride mouthrinsing, fluoride tablets, and both procedures in combination: interim findings after two years.
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Indexes for measuring dental fluorosis.
Dental fluorosis, a hypoplasia or hypomineralization of tooth enamel or dentin, ranges in intensity from barely noticeable whitish striations to confluent pitting and staining. Various indexes or classification systems have been used in surveys to measure the presence and severity of enamel fluorosis. Other systems and indexes record all defects in enamel, based on a premise that an etiology for the condition should not be presumed. If all defects are recorded, a retrospective attempt to reconstruct which of them are fluorosis is inappropriate. Dean's classification system has been used most frequently over the years for assessing fluorosis. Therefore, its continued use is sometimes important for historical comparisons. Dean's system, however, has several shortcomings, principally its inability to measure fluorosis in different tooth surfaces. As it has been traditionally used, it also does not permit specifying the cosmetic importance of the most severe fluorosis detected in a dentition. The Tooth Surface Index of Fluorosis (TSIF) eliminates or reduces some of the shortcomings of Dean's method. Use of the TSIF in a survey in Illinois was able to discriminate between the prevalence and severity of fluorosis in four groups of communities with different concentrations of fluoride in their drinking water.
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.
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)
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.
The National Institute of Dental Research's 1985 survey of working and senior adults.
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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)
Measurement and expression of treatment effects in caries clinical trials.
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