Topical fluorides: efficacy, administration, and safety

Fluoride's role in decreasing dental caries has been recognized for decades. The professional fluoride treatment has recently been augmented with home-use fluoride products. The introduction of many attractive products makes it difficult for dental professionals to know which are effective. Both professional and home-use products are described, as are proven techniques for their use. Recognition of fluoride toxicity, and its prevention and treatment, are also discussed.     

Apoptosis: a role in skin aging?

OBJECTIVE: This paper reports findings for dental caries and dental fluorosis in 8-10- and 13-16-year-old schoolchildren who were lifelong residents of communities having either naturally occurring low (Broken Bow and Holdrege, NE; < 0.3 ppm) or optimal (Kewanee, IL; 1 ppm) levels of fluoride in drinking water. METHODS: Findings are reported for participants who received both dental caries and dental fluorosis examinations (n = 495). The DMFS and TSIF indices, respectively, were used to assess dental caries and dental fluorosis. RESULTS: The mean DMFS score adjusted for age, sealant presence, and fluoride use was significantly lower in Kewanee (1.8) than was the adjusted mean caries score in either Holdrege (2.9) or Broken Bow (3.6). Adjusted mean DMFS scores in Broken Bow and Holdrege were not statistically different. The mean percent of fluorosed tooth surfaces per person, adjusted for age and use of dietary fluoride supplements, was similar in the three communities (approximately 15%); more than 80 percent of tooth surfaces in all participants were fluorosis-free. CONCLUSIONS: Findings from the present study suggest that water fluoridation still is beneficial and that dental sealants can play a significant role in preventing dental caries. In addition, findings from this survey appear to support the premise that the difference in dental fluorosis prevalence between fluoridated and nonfluoridated communities has narrowed considerably in recent years.     

Dental fluorosis: its use as a biomarker

Several epidemiological studies, beginning with those of Dean and co-workers in the 1940's, clearly demonstrate the relationship between dental fluorosis in humans and the level of fluoride in water supplies. These studies and others have shown that, in a population, there is a direct relationship among the degree of enamel fluorosis, plasma and bone fluoride levels, and the concentration of fluoride in drinking water. However, dental fluorosis is a reflection of fluoride exposure only during the time of enamel formation, somewhat limiting its use as a biomarker. In addition, the degree of fluorosis is dependent not only on the total fluoride dose, but also on the timing and duration of fluoride exposure. At the level of an individual response to fluoride exposure, factors such as body weight, activity level, nutritional factors, and the rate of skeletal growth and remodeling are also important. These variables, along with an individual variability in response to similar doses of fluoride, indicate that enamel fluorosis cannot be used as a biological marker of the level of fluoride exposure for an individual.     

The effect of fluoride on Streptococcus sanguis 7863 IgA1 protease production and activity

Fluoride was found to affect the production of the bacterial IgA1 protease but to have no effect on IgA1 protease activity. The concentrations of fluoride that do affect Streptococcus sanguis growth and IgA1 protease production are higher than those normally seen in vivo under normal circumstances. The concentrations of fluoride in dental plaque following use of a fluoride rinse or dentifrice would be sufficient to reduce Strep. sanguis IgA1 protease production.     

Commentary on rewards and adolescent health behavior.

Responds to a study by A. K. Lund and S. S. Kegeles (see record 1988-11516-001) on the use of rewards to influence the health behavior of adolescents. It is noted that the study neglected to include any measures of the dependent variable (i.e., dental caries, cavities). It is also suggested that perhaps the particular items used for motivation (e.g., toys, pencils) were not uniformly valued by the participants. A question is raised about the effectiveness of using a fluoride rinse with adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical yield and cost of exercise treadmill testing to screen for coronary artery disease in asymptomatic adults

The authors present the results of a study carried out within the context of a diagnosis of the state of dental health among 300 twelve years old students in school in the province of Kadiogo (Burkina Faso). The data collected by questionnaires explore the range of behaviours linked to dental health: dental hygiene, eating habits, use of fluoride and use of dental health services. Half of students report that they brush their teeth at least once a day. Among them, there are 2 girls out of three, and one boy out of two. For half of the children, their mothers are the main people who teach them how to brush their teeth. For three children out of four, a tooth brush and tooth paste are the most common methods. Roughly 17% understand the usefulness of fluoride and 70% have never heard of it. Four children out of five consume sugared drinks on a daily basis. 85% say they have never been to the dentist. The information collected could serve as a base for the development and implementation of health promotion and education programmes for dental health within schools.     

A survey of general dentists in Ontario, Part II: Knowledge and use of topical fluoride and dental prophylaxis practices

A mail questionnaire was used to assess variations in the knowledge and practices of Ontario dentists with respect to topical fluoride and prophylaxis procedures. The questionnaire was answered by 1,276 general dentists. A high percentage (72 to 83 per cent) of respondents identified six months as the optimal time interval at which both procedures should be repeated for all patients under 19 years of age. Relatively few dentists (< 10 per cent) indicated that there should be no specific time interval for re-treatment (i.e. that it should be individually selected). The respondents' preventive knowledge was found to be deficient in two areas: few dentists (16 per cent) knew that it is not necessary to provide a prophylaxis prior to topical fluoride application to achieve maximum caries protection; and most dentists overestimated the speed of caries progress from outer enamel to the dentinoenamel junction (DEJ) in both primary (83 per cent) and permanent (82 per cent) approximal tooth surfaces. In bivariate analysis, three variables were found to be consistently and significantly related to optimal time intervals selected for both topical fluoride application and prophylaxis procedures: year of graduation from dental school; level of hygienist employment; and percentage of patients with private insurance. Multivariate analysis also identified three significant variables: year of graduation from dental school; level of dental hygienist employment; and practice business. Continuing education courses are suggested as a means of updating dentists' knowledge regarding preventive services. Studies are needed to determine the extent to which recent recommendations regarding the professional application of topical fluorides have been followed.     

Oral health profile of schoolchildren, mothers and schoolteachers in Zanzibar

The piped water of Kuopio, Finland, was fluoridated in 1959. Owing to strong opposition by different civic groups, water fluoridation was stopped at the end of 1992. OBJECTIVES: The aim of this study was to examine the consequences of the discontinuation on dental health. METHODS: In 1992 and 1995, independent random samples of all children aged 6, 9, 12 and 15 years were drawn from Kuopio and Jyv?skyl?, a nearby low fluoride town whose distribution of demographic and socio-economic characteristics was fairly similar to Kuopio's. The total number of subjects examined was 550 in 1992 and 1198 in 1995. Caries was registered clinically and radiographically by the same two calibrated dentists in both towns. RESULTS: In 1992, the mean DMFS values were lower in the fluoridated town for the two older age groups, the percentage differences for 12- and 15-year-olds being 37% and 29%, respectively. For the two younger age groups no meaningful differences could be found. In 1995, the only difference with possible clinical significance was found in the 15-year-olds in favor of the fluoridated town (18%). In 1995, a decline in caries was seen in the two older age groups in the nonfluoridated town. In spite of discontinued water fluoridation, no indication of an increasing trend of caries could be found in Kuopio. The mean numbers of fluoride varnish and sealant applications decreased sharply in both towns between 1992 and 1995. In spite of that caries declined. CONCLUSIONS: These findings suggest that the decline of caries has little to do with professional preventive measures performed in dental clinics.     

Fluoride profiles in dental calculus from Japanese, Chinese and British residents

Whether the fluoride concentrations and profiles differ in human dental calculus obtained from different countries was investigated. A total of 203 dental calculus deposits on 203 permanent teeth from residents (mean age, 52.1 years) of Nagoya (Japan), Shanghai (China), Leeds (Great Britain) and the Wuhan mountainous area (China, fluoridated area) were analysed. An abrasive microsampling procedure was used to examine fluoride distribution. There were five types of fluoride profiles in dental calculus in each area/country (designated types L, J, U, T, W). In supragingival calculus, type L (highest in the outermost layers) and type J (highest in the innermost layers) both had significantly higher values than type U (high in the surface and innermost layers) but were relatively identical. In subgingival calculus, type W (high in the outermost, mid and innermost layers) was characteristics. Calculus from the Wuhan mountainous area (fluoridated) had the highest fluoride concentration, followed by Leeds (non-fluoridated), and Nagoya and Shanghai (non-fluoridated) calculus had the lowest. Fluoride concentrations in supragingival calculus were higher in teeth extracted because of periodontal diseases than dental caries. It is concluded that fluoride concentrations and distribution in dental calculus differ from country to country, probably due to different fluoride environments.     

Culture, dental professionals and oral health values in multicultural societies: measuring cultural factors in geriatric oral health research and education

Culture has significant impacts upon professional practice and patient health behaviours, especially in multicultural societies. This paper introduces the concept of culture and examines how it may be of importance to dental health professionals. Using the Dental Impact Profile and other dental social science measures, dental researchers and students can be engaged in studying cultural values and characteristics as a way of dealing with cultural differences.     

Dental tissue effects of fluoride

It is now well-established that a linear relationship exists between fluoride dose and enamel fluorosis in human populations. With increasing severity, the subsurface enamel all along the tooth becomes increasingly porous (hypomineralized), and the lesion extends toward the inner enamel. In dentin, hypomineralization results in an enhancement of the incremental lines. After eruption, the more severe forms are subject to extensive mechanical breakdown of the surface. The continuum of fluoride-induced changes can best be classified by the TF index, which reflects, on an ordinal scale, the histopathological features and increases in enamel fluoride concentrations. Human and animal studies have shown that it is possible to develop dental fluorosis by exposure during enamel maturation alone. It is less apparent whether an effect of fluoride on the stage of enamel matrix secretion, alone, is able to produce changes in enamel similar to those described as dental fluorosis in man. The clinical concept of post-eruptive maturation of erupting sound human enamel, resulting in fluoride uptake, most likely reflects subclinical caries. Incorporation of fluoride into enamel is principally possible only as a result of concomitant enamel dissolution (caries lesion development). At higher fluoride concentrations, calcium-fluoride-like material may form, although the formation, identification, and dissolution of this compound are far from resolved. It is concluded that dental fluorosis is a sensitive way of recording past fluoride exposure because, so far, no other agent or condition in man is known to create changes within the dentition similar to those induced by fluoride. Since the predominant cariostatic effect of fluoride is not due to its uptake by the enamel during tooth development, it is possible to obtain extensive caries reductions without a concomitant risk of dental fluorosis.     

Recognition of a non-standard base pair by thermostable DNA polymerases

Fluoride is a potent preventive agent of caries. It acts at two levels: local and systemic. At the local level it prevents the surface demineralisation of enamel by strengthening the superficial layers, and inhibiting the local bacterial activity. At the systemic level it improves the resistance of the enamel by forming with calcium, fluorapatite which is stronger than hydroxyapatite. Main sources are naturally fluorinated water, artificially enriched water, fluorinated salt, and fluoride medication. Recommended mean daily intake is 0.05 mg/kg, the risk of dental fluorosis occurring when daily intake exceeds 1 mg/kg. The large benefits of regular fluoride supplementation on children dental health must not live down the risk of dental fluorosis resulting from over administration. Therefore when prescribing fluoride to a child, the practitioner must carefully examine his/her possible other fluoride sources.     

Acute fluoride ingestion: recognition and management

Occasionally, the Oral Health Division of the Indiana State Department of Health receives inquiries regarding diagnosis and treatment of acute fluoride ingestion. Because a wide variety of fluoride preparations are available in the dental setting and over the counter, excessive ingestion of fluoride can occur if these products are not used properly. The following article is meant to be a quick and easy guide in the recognition and management of instances of acute fluoride ingestion.     

Potential adverse outcomes of psychotropic and narcotic drug use in Canadian seniors

Infants who ingest high amounts of fluoride can be at risk of dental fluorosis. The authors analyzed the fluoride concentration of 238 commercially available infant foods. Fluoride concentrations ranged from 0.01 to 8.38 micrograms of fluoride per gram, with the highest fluoride concentrations found in infant foods containing chicken. Infant foods, especially those containing chicken, should be considered when determining total fluoride intake.     

The effect of bicarbonate/fluoride dentifrices on human plaque pH

The acidogenic response in dental plaque after rinsing with sodium bicarbonate/fluoride dentifrice slurries was studied using three intra-oral models. In the first model, resting plaque pH was monitored in mesiobuccal plaque on upper molars and premolars in six healthy subjects after abstinence from normal oral hygiene for three days. These measurements were followed by a three-minute rinse with 10% sucrose and, following a two-minute interval, a three-minute rinse with a test dentifrice slurry. After the test dentifrice rinse, pH was monitored at regular intervals up to 60 minutes. Flow rate, pH and buffer capacity of stimulated saliva were also determined. Changes in resting pH, plaque pH minima, and maximum pH drop were calculated. A clear elevation in the resting pH was observed after bicarbonate/fluoride dentifrice rinses, and a significant increase was obtained in the pH minima. The smallest pH drop also was found after treatment with the bicarbonate/fluoride dentifrice rinse treatment (p < 0.02). A second model using telemetric partial dentures with interproximally placed micro-antimony pH electrodes was used to study the effects of rinsing with increasing concentrations of sodium bicarbonate and calcium carbonate solutions, and with a fluoride dentifrice containing sodium bicarbonate. The response to these treatments was found to be rapid, dose-dependent, and was the greatest from the sodium bicarbonate. A third model used 24 subjects to assess the effects of sodium bicarbonate/fluoride dentifrice on plaque pH before and after a glucose challenge. The use of the bicarbonate/fluoride dentifrice resulted in significantly less measurable plaque acid than the fluoride dentifrice treatment. Collectively, these results indicate bicarbonate in dentifrice to be an effective buffering agent for stabilizing the pH and neutralizing plaque acids in dental plaque.     

Effectiveness of autologous blood replacement in rheumatoid arthritis surgery--a report of 10 years experience

The use of a wood stick (meswak or chewing stick) for brushing the teeth continues to be an important tool for oral hygiene care in many Afro-Asian communities. It is inexpensive, customary and used for religious reasons as well. Despite the wide use of meswak, information on its chemical and pharmaceutical contents are scant, particularly in regard to an anticaries effect. In the present study, sticks from Salvadora persica, the most common source for meswak, were analyzed for their soluble and total content of fluoride, calcium, phosphorus and silica. Results showed that the fluoride released from meswak soaked in water was negligible (< 0.07 microgram/ml). Approximately 39% of the total fluoride in the sticks was in a form that could be leached out. The leached calcium and phosphorus averaged 582 micrograms/ml and 34 g/ml, respectively, representing 19.6% and 26.4% of their total content in the sticks. There was a substantial amount of silica in the ashes of meswak. It appears that meswak is probably not particularly active against caries through its fluoride content, but it does act as a brush for removing dental plaque and polishing the teeth.     

Caries prevalence and salt fluoridation among 9-year-old schoolchildren in Strasbourg, France

The 9-year-old group (236 children) of an epidemiological study carried out in 1991 in Strasbourg on children aged 6 to 15 years was selected with the aim of determining if the caries prevalence reduction observed could be related to the use of salt fluoridation (FS) introduced in France in 1987. From these 236 children, 143 answered a questionnaire which showed that 36 of them were fluoridated salt users and 107 were not. The dft index was significantly lower in the FS consumers which showed 35.5% dft reduction compared to the non-FS-consuming children. When using the Generalized Linear Model, this reduction was significant (P = 0.03). Although lower in the FS group, the DMFT and DMFS indices showed no statistical significant difference. It appeared that 72.2% of the users took simultaneously fluoride tablets but no dental fluorosis was observed. The use of fluoride tablets had a significant effect on the DMFS (P = 10(-2)). The children who consumed FS used more frequently fluoridated mouthrinses (P = 10(-3)) and had more frequent professional application of fluoridated gel and varnishes than non-consumers (P = 0.02). The DMFS index increased with the number of meals (P = 10(-6)), which was the most significant variable entered into the Generalized Linear Model. The children who brushed their teeth once a day had a DMFS value 2.6 times higher than those who brushed regularly three times a day (P = 10(-3)). The DMFS value was 4.4 times higher among the children who brushed their teeth irregularly when compared with those who brushed three times a day (P = 10(-2)).     

Familiarity with content and conditional reasoning.

Examined the relationship between familiarity of content and conditional reasoning. It was hypothesized that there would be an interaction between Ss' familiarity with content in the premises and their conditional reasoning performance. 43 graduate students in education and 53 1st-yr dentistry students took a 30-item test of conditional reasoning that was based on 5 logical arguments each repeated twice with symbolic, lay dental, and professional dental content. Data were analyzed using a 2-way multivariate analysis of variance with repeated measures with the 5 arguments as dependent variables. The interaction between student type and content was not supported. Significant main effects for content were attributed to the lay and professional vs symbolic contrast. It is concluded that conditional reasoning performance was not influenced by Ss' familiarity content in the premises. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Model investigations of caries inhibition by fluoride-releasing dental materials

Fluoride-releasing dental materials are generally believed to reduce or prevent secondary caries. The evidence for this is largely anecdotal and centers on clinical experience with silicate cements and, more recently, with glass-ionomer cements. Unfortunately, corroborating evidence from controlled clinical trials is inadequate to establish precisely how effective these materials are or under what conditions they might be effective. Even less is known about the clinical effectiveness of newer materials that, often, release less fluoride. In vitro model systems have been used to study the effects of dental materials on de/remineralization of surrounding tooth structure. Fluoride-releasing materials have been shown in these models to reduce demineralization of both enamel and dentin compared with a material that does not release fluoride. This is useful from a mechanistic standpoint, but without clinical "standards" to guide model results, it is not possible to define an acceptable level of fluoride release or the length of time such release is required. A limited number of in situ model studies has been conducted, and some fluoride dose-response information has been obtained. These models are closer to the real situation and perhaps provide the best means to define required levels of fluoride release from materials in the absence of adequate clinical information.