An economic evaluation of community water fluoridation

OBJECTIVE: The purpose of this research was to assess the local cost savings resulting from community water fluoridation, given current exposure levels to other fluoride sources. METHODS: Adopting a societal perspective and using a discount rate of 4 percent, we compared the annual per person cost of fluoridation with the cost of averted disease and productivity losses. The latter was the product of annual dental caries increment in nonfluoridated communities, fluoridation effectiveness, and the discounted lifetime cost of treating a carious tooth surface. We obtained or imputed all parameters from published studies and national surveys. We conducted one-way and three-way sensitivity analyses. RESULTS: With base-case assumptions, the annual per person cost savings resulting from fluoridation ranged from $15.95 in very small communities to $18.62 in large communities. Fluoridation was still cost saving for communities of any size if we allowed increment, effectiveness, or the discount rate to take on their worst-case values, individually. For simultaneous variation of variables, fluoridation was cost saving for all but very small communities. There, fluoridation was cost saving if the reduction in carious surfaces attributable to one year of fluoridation was at least 0.046. CONCLUSION: On the basis of the most current data available on the effectiveness and cost of fluoridation, caries increment, and the cost and longevity of dental restorations, we find that water fluoridation offers significant cost savings.     

Cost-effectiveness model for prevention of early childhood caries.

This study presents and illustrates a model that determines the cost-effectiveness of three successively more complete levels of preventive intervention (minimal, intermediate, and comprehensive) in treating dental caries in disadvantaged children up to 6 years of age. Using existing data on the costs of early childhood caries (ECC), the authors estimated the probable cost-effectiveness of each of the three preventive intervention levels by comparing treatment costs to prevention costs as applied to a typical low-income California child for five years. They found that, in general, prevention becomes cost-saving if at least 59 percent of carious lesions receive restorative treatment. Assuming an average restoration cost of $112 per surface, the model predicts cost savings of $66 to $73 in preventing a one-surface, carious lesion. Thus, all three levels of preventive intervention should be relatively cost-effective. Comprehensive intervention would provide the greatest oral health benefit; however, because more children would receive reparative care, overall program costs would rise even as per-child treatment costs decline.     

A model to determine the economic viability of water fluoridation

Objectives: In view of concerns expressed by South African local authorities the aim of this study was to develop a model to determine whether water fluoridation is economically viable to reduce dental caries in South Africa. Methods: Microsoft Excel software was used to develop a model to determine economic viability of water fluoridation for 17 water providers from all nine South African provinces. Input variables for this model relate to chemical cost, labor cost, maintenance cost of infrastructure, opportunity cost, and capital depreciation. The following output variables were calculated to evaluate the cost of water fluoridation: per capita cost per year, cost‐effectiveness and cost‐benefit. In this model it is assumed that the introduction of community water fluoridation can reduce caries prevalence by an additional 15 percent and that the savings in cost of treatment will be equal to the average fee for a two surface restoration. Results: Water providers included in the study serve 53.5 percent of the total population of South Africa. For all providers combined chemical cost contributes 64.5 percent to the total cost, per capita cost per year was $0.36, cost‐effectiveness was calculated as $11.41 and cost‐benefit of the implementation of water fluoridation was 0.34. Conclusions: This model confirmed that water fluoridation is an economically viable option to prevent dental caries in South African communities, as well as conclusions over the last 10 years that water fluoridation leads to significant cost savings and remains a cost‐effective measure for reducing dental caries, even when the caries‐preventive effectiveness is modest.     

Caries Incidence and Costs of Prevention Programs

Data on caries increments and costs of prevention programs are presented as background information for participants in the workshop. Estimates of annual caries increments were derived from control groups in clinical trials, epidemiologic studies, and national surveys. Cost data were obtained from dental public health directors, program administrators, fluoridation engineers, and water plant operators in different parts of the US. Caries incidence data are reported for age groups: 5-17 years (fluoridated and nonfluoridated areas), 18–44 years, 45–64 years, and 65 and over. Program costs include direct costs primarily and do not allow for program inefficiencies, nor have they attempted to include social costs. All cost data are expressed in 1988 dollars. Direct program costs are included for community water fluoridation, fluoride supplements, fluoride mouthrinses, school fluoridation, and sealant programs. For professionally and self-applied fluoride programs, only material and salary costs are included because total costs could not be located in the literature nor obtained from program directors. All factors and necessary assumptions included in the cost assessments are described.     

Factors for changes of caries prevalence among adolescents in Germany

Data on caries prevalence among adolescents in East and West Germany before and after unification (1990) were compared with changes in etiologic and preventive parameters. The postwar increase of total sugar consumption resulted in an increase of caries prevalence among adolescents in both East and West Germany until 1970. Parallel to the introduction of preventive measures, especially systemic fluoridation, the national caries level in East Germany stabilized at 4–5 DMFT (in 13–14–year–olds) with significant regional differences. The introduction of fluoridated toothpaste after 1973 in West Germany was followed by a caries decline in children (1970s) and in adolescents (1980s) from very high caries levels (8.8 DMFT in 13–14–year–olds in 1983) to moderate levels (5.1 DMFT in 1989). The sudden increase from 10% to 90% fluoridated toothpaste in East Germany in 1990 was also accompanied by a caries decline in adolescents. Group prevention, which included fluoride varnish programs and the introduction of free prevention (brushing instructions, fluoridations. sealants) at private dentists for 6–19–year–olds since 1983. seems to be responsible for the latest caries reductions all over Germany.     

Caries prevalence and distribution in individuals aged 3–20 years in Jönköping, Sweden, over a 30-year period (1973–2003)

Background.  Oral health status of individuals aged 3–80 years in the city of Jönköping, Sweden, has been assessed in a series of epidemiological studies over a 30-year period.
Aim.  To analyse the changes in caries prevalence and caries distribution in child population sample groups, based on studies performed in 1973, 1978, 1983, 1993, and 2003.
Design.  Each time point included 500 randomly sampled individuals, divided into age groups of 3, 5, 10, 15, and 20 years.
Results.  Thirty-five per cent of 3-year-olds were caries free in 1973, compared with 69% 30 years later. Decayed and filled primary (dfs) and permanent surfaces (DFS) were reduced by 50–80% between 1973 and 2003. Adolescents aged 10 and 15 years exhibited the most pronounced reduction in DFS on the occlusal surfaces. By 2003, 90% of the proximal carious lesions in 15-year-olds were initial carious lesions. In 2003, about 60% of 15-year-olds had a DFS of ≤ 5, while about 7% exhibited a DFS of ≥ 26.
Conclusions.  Despite the dramatic decline in the prevalence of caries, caries remains a health problem among children, particularly those of preschool age. Continuous epidemiological studies are recommended to evaluate preventive measures.     

Modelling lifelong costs of caries with and without fluoride use

Cost–benefit or cost–cost analyses are becoming increasingly important in dentistry. Therefore, the aim of the present study was to evaluate the economic consequences of caries prevention with fluorides. German epidemiological data were used in a system dynamics model to assess the lifelong costs of caries in a population. Without fluoride prevention, lifelong treatment for caries resulted in mean costs of €6,976 and a present value of €932 per person (5% discounting). In different scenarios of constant, increasing, or decreasing caries-controlling effects, and of limited (age 6–18 yr) or lifelong application, the combination of fluoride salt, fluoride toothpaste, and fluoride gel were most cost-effective. They reduced the costs for caries treatment and prophylaxis to €482, or to a present value of €148 (5% discounting), when applied from age 6–18 yr, and to €211–213 for lifelong use (present value, 5% discounting). In conclusion, a lifelong model of costs of caries demonstrates that the use of fluorides in caries prevention is highly cost-effective.     

A simplified dental examination for detection of cavitated carious lesions in school setting

Objective:  The objective of the study was to compare a simplified dental examination involving the use of a wooden spatula and a toothpick (TS examination) with the conventional dental mirror and probe examination (MP examination) for detection of cavitated carious lesions in schoolchildren.
Methods:  The study involved three groups of caries-positive schoolchildren aged 4–5, 9–10 and 13–14 years with 179, 188 and 202 children, respectively. All children were examined by a trained and calibrated examiner using a wooden spatula and a toothpick under natural light. After a week the same examiner examined the three groups of children by a dental mirror and a Community Periodontal Index (CPI) probe. 'Teeth' were considered as units of measurement for data analysis. The WHO recommended criteria (2) for decayed, missing and filled teeth were followed for recording dental caries on a specially designed recording form. The sensitivity, specificity, positive predictive value, negative predictive value, false-positive rate and false-negative rate of TS examination were calculated using MP examination as the standard method.
Results:  The specificity of TS examination was well above 95% in three types of dentition. Although the sensitivity of this type of examination in deciduous and mixed dentitions was almost comparable with that of MP examination, it was the lowest for permanent dentition but still within the acceptable limits.
Conclusion:  The TS examination can provide an alternative to traditional MP examination to undertake regular check-ups of schoolchildren for dental caries.     

Theoretical considerations in applying benefit-cost and cost-effectiveness analyses to preventive dental programs

Benefit-cost analysis and cost-effectiveness analysis can be used to evaluate preventive regimens and aid policy-makers in making resource-allocation decisions. This paper demonstrates the application of benefit-cost and cost-effectiveness analyses to preventive dental programs. The two analyses are defined and described, and the purpose of each technic is compared. For a hypothetical community, four dental preventive programs are described: community water fluoridation, school water fluoridation, weekly school-based mouthrinses, and school-based sealants. Benefit-cost ratios and cost-effectiveness ratios are calculated for each program first assuming steady-state conditions, i.e., maximum caries reduction, and then for a 20-year period. Both explicit and implicit costs are included. Underlying assumptions and limitations, as well as the effects of changes in caries rates, differential attack rates, and discount rates on the outcome, are discussed. The analysis reveals that community water fluoridation yields the greatest net benefits and most favorable B/C and C/E ratios. School water fluoridation and mouthrinsing programs are the next most cost-effective, with similar B/C and C/E ratios when the implicit cost of teachers' time is omitted from the calculations. The school-based sealant program yields negative net benefits.     

A comparison of dental treatment utilization and costs by HMO members living in fluoridated and nonfluoridated areas

OBJECTIVES: To compare dental treatment experiences and costs in members of a health maintenance organization (HMO) in areas with and without community water fluoridation. METHODS: HMO members with continuous dental eligibility (January 1, 1990 to December 31, 1995) who resided in Oregon and Washington were identified using administrative databases. Fluoridation status was determined by geocoding subscriber address. Measures were utilization of dental procedures, fluoride dispensings, and associated costs. Costs were based on nonmember fees, adjusted to 1995 dollar values. Data were analyzed using analysis of covariance, controlling for age and interactions. RESULTS: About 85 percent of eligible members (n = 51,683) were classified as residing either in a fluoridated (n = 12,194) or nonfluoridated (n = 39,489) area. Mean age was 40.0 years; 52.3 percent were women. More than 92 percent of members had one or more dental visits. Community water fluoridation was associated with reduced total and restorative costs among members with one or more visits, but the magnitude and direction of the effect varied with locale and age and the effects were generally small. In two locales, the cost of restorations was higher in nonfluoridated areas in young people (age 58). In younger adults, the opposite effect was observed. The impact of fluoridation may be attenuated by higher use of preventive procedures, in particular supplemental fluorides, in the nonfluoridated areas. CONCLUSIONS: These results are particularly relevant to insured populations with established access to dental care. Differences in treatment costs (savings) associated with water fluoridation should be estimated and included in future cost-effectiveness analyses of community water fluoridation.     

Correlation between Laser Fluorescence Readings and Volume of Tooth Preparation in Incipient Occlusal Caries In Vitro

Objective:  This study evaluated the correlation between laser fluorescence readings and the extent of incipient occlusal caries as measured by the volume of tooth preparation in vitro.
Materials and Methods:  One hundred and three permanent molars and premolars containing incipient occlusal pit-and-fissure caries and sound occlusal surfaces (1/4 of the sample, control) were selected. DIAGNOdent (KaVo Dental Corporation, Lake Zurich, IL, USA) readings were obtained according to manufacturer instructions. Caries was removed with 1/4 round burs in high speed. The volume of tooth preparation was measured using a surrogate measure based on the amount of composite needed to fill the preparations. Sensitivity and specificity using different cutoff values were calculated for lesions/preparations extending into dentin. The results were analyzed statistically.
Results:  The Pearson correlation for preparation volume and DIAGNOdent reading measurements was low ( r  = 0.285). Sensitivity and specificity of DIAGNOdent for detection of dentinal lesions were 0.83 and 0.60, and 0.66 and 0.73 for the cutoff values of 20 and 30, respectively.
Conclusions:  Within the limitations of this study, laser fluorescence measured with DIAGNOdent does not correlate well with extent of carious tooth structure in incipient occlusal caries.

CLINICAL SIGNIFICANCE

Clinicians should not rely only on DIAGNOdent readings to determine the extension of incipient occlusal caries.
( J Esthet Restor Dent 22:31–41, 2010)     

Issues in the economic evaluation of community water fluoridation

Community water fluoridation has long been recognized as an effective public health intervention in the prevention of dental caries. The recently documented secular decline in dental caries, however, presents for policy makers the challenge of appropriately allocating limited health care resources between a variety of health care programs. Appropriate economic assessment of these alternatives becomes critical for rational distribution of such resources. Cost-benefit and cost-effectiveness analyses are techniques that, when used correctly, can guide policy makers facing such decisions. This paper reviews and critiques the published literature assessing the cost effectiveness and cost benefit of community water fluoridation using criteria developed for economic evaluation. Eight papers met the criteria for inclusion in the present study. In general, the articles failed to incorporate the declining prevalence of dental caries into their analyses and to fully document costs associated with water fluoridation. Treatment savings from dental care averted secondary to water fluoridation were not appropriately incorporated into the cost-effectiveness analyses, thereby overestimating the marginal cost associated with fluoridation. Specification of outcome measures to assess the consequences of water fluoridation failed to incorporate the dynamic nature of dental disease. Suggestions for improving the generalizability and usefulness of future cost-benefit and cost-effectiveness analyses are made.     

Cost of Fluoridation: 44 Florida Communities

Previous data relating to the cost of fluoridation often do not include annualized costs or costs for labor and maintenance. The purpose of this study was to estimate accurately current costs for initiating and maintaining fluoridation and to develop a methodology that can be used to provide the cost basis for further cost-effectiveness studies. The data were collected from 44 Florida communities that had initiated community water fluoridation between 1981 and 1989. Equipment, installation, and engineering costs were derived from copies of actual invoices for equipment and services and then adjusted to 1988 dollars. The chemical costs were calculated from operational reports listing flow rate and pounds used. The cost was then adjusted according to whether the hydrofluosilicic acid was supplied as 15-gallon carboys, 55-gallon drums, in bulk, or as sodium silicofluoride or sodium fluoride. The initial cost was annualized at 2 percent and 4 percent over 15 years. Calculated operational costs included chemical costs, labor costs, and maintenance and repair costs. The operational costs were then added to the annualized depreciation costs and opportunity costs for the initial investment, to produce an estimated cost per person served. The total mean cost per person for all installations was $1.14 per year at 2 percent and $1.25 per year at 4 percent. The mean cost at 4 percent for communities of fewer than 10,000 was $2.12; for communities between 10,000 and 50,000 it was $0.68; and for communities over 50,000 it was $0.31. The total mean cost per person across all installations was $0.41 at 2 percent and 0.45 at 4 percent.(ABSTRACT TRUNCATED AT 250 WORDS)     

Health care savings from microbiological caries risk screening of toddlers: a cost estimation model

OBJECTIVES: Modeling new biomedical technologies and determining their expected cost is necessary before initiating formal clinical trials. This paper estimates an economic model for the potential cost impact of microbiological screening of toddlers for caries risk compared to the traditional method of managing pediatric caries. METHODS: Potential cost savings were calculated based on screening test properties (sensitivity and specificity) derived from a population of 1,180 children aged 1 to 3 years with a caries prevalence of 15 percent. An algorithm was then developed to allocate prevalent and anticipate incident caries, treatment effectiveness assumptions, and existing regional treatment costs. RESULTS: The cost analysis model conservatively predicts savings of 7.3 percent from screening and early intervention. Cumulative dental treatment costs for a child at age 4 years are $367.90 if the child has been screened and $396.70 otherwise. The model further predicts that cost savings increase significantly as caries prevalence increases. CONCLUSIONS: Microbiologic risk assessment for pediatric caries may be an example of a preventive public health screening technique that results in both clinical benefits and cost savings. If the model is validated by randomized clinical trials, microbiologic screening could be used by pediatric primary care providers to identify toddlers who require early referral to dentists for further risk assessment and early caries management.     

PUFA – An index of clinical consequences of untreated dental caries

Monse B, Heinrich-Weltzien R, Benzian H, Holmgren C, van Palenstein Helderman W. PUFA – An index of clinical consequences of untreated dental caries. Community Dent Oral Epidemiol 2010; 38: 77–82. © 2009 John Wiley & Sons A/S   Abstract – 
Rationale:  Dental caries is a global public health problem, especially in children. Most caries in developing countries remains untreated. Only limited data are available on the clinical consequences of untreated dental caries because there is no measure to quantify the prevalence and severity of oral conditions resulting from untreated dental caries.
Objectives:  To present a new index to evaluate the prevalence and severity of oral conditions resulting from untreated dental caries. To validate the index within the Philippines National Oral Health Survey, 2006.
Methods:  The PUFA index records the presence of severely decayed teeth with visible pulpal involvement (P/p), ulceration caused by dislocated tooth fragments (U/u), fistula (F/f) and abscess (A/a).
Results:  Good kappa values show the reliability of the index. The prevalence of PUFA/pufa >0 was 85% and 56% for 6- and 12-year-olds, respectively. The mean number of teeth affected (PUFA/pufa) was 3.5 and 1.2 for 6- and 12-year-olds, respectively. In 6- and 12-year-olds, 40% and 41% of decayed teeth had progressed to odontogenic infections.
Conclusion:  The PUFA index complements classical caries indices with relevant information for epidemiologists and health care planners.     

Pit-and-fissure sealants on primary molars are a cost savings

BackgroundIn this study, the authors examine the cost-effectiveness of light-polymerized resin-based fluoride sealants on primary molars in high caries risk children younger than 6 years.MethodsThe authors examined the cost-effectiveness of pit-and-fissure sealant (PFS) treatment on primary molars by comparing sealed and unsealed molars treated in the outpatient clinic or operating room. Using 1,884 primary molars followed over a 5-year period, the authors used a mixed-effects regression model to estimate the probability of caries development. They used restricted means to estimate years free of caries for carious molars. They used a decision tree to address uncertainty due to PFS treatment failure, predict the expected value associated with each strategy, and estimate the incremental cost-effectiveness ratio using a 3% discount rate to adjust future cost and outcomes to present value.ResultsOver 5 years, the cost of care was $90 for unsealed molars and $75 for sealed molars. Unsealed molars remained caries free for 4.32 years compared with 4.85 years in sealed molars. The cost-effectiveness of PFS treatment was dominant, leading to a savings of $25 for each caries-free year gained and overall savings of $742 million for the United States dental health system over a 5-year period.ConclusionsPFS treatment is associated with cost savings and a delay in caries development and should be considered in children with high caries risk.Practical ImplicationsPolicy makers should consider reimbursement of PFS treatment on primary molars in high caries risk children.     

Modeling an economic evaluation of a salt fluoridation program in Peru

Objective: This article models the cost‐effectiveness, from a societal viewpoint, of a dental caries prevention program using salt fluoridation for children 12 years of age, compared with non‐intervention (or status quo) in Arequipa, Peru. Methods: Standard cost‐effectiveness analysis methods were used. The costs associated with implementing and operating the salt‐fluoridation program were identified and measured using 2009 prices. Health outcomes were measured as dental caries averted over a 6‐year period. Clinical effectiveness data was taken from published data. Costs were measured as direct treatment costs, programs costs and costs of productivity losses as a result of dental treatments. The incremental cost‐effectiveness ratio was calculated. A hypothetical population of 25,000 12‐year‐olds living in Arequipa, Peru was used in this analysis. Two‐way sensitivity analyses were conducted over a range of values for key parameters. Results: Our primary analysis estimated that if a dental caries prevention program using salt‐fluoridation was available for 25,000 6‐year‐old children for 6 years, the net saving from a societal perspective would total S/. 11.95 [1 US$ = S/. (2009) 3.01] per diseased tooth averted when compared with the status quo group. That is, after 6 years, an investment of S/.0.32 per annum per child would result in a net saving of S/.11.95 per decayed/missing/filled teeth prevented. Conclusions: While the analysis has inherent limitations as a result of its reliance on a range of assumptions, the findings indicate that for the situations prevailing in Peru, there are significant health and economic benefits to be gained from the use of salt fluoridation.     

Effectiveness of fluoride in preventing caries in adults

To date, no systematic reviews have found fluoride to be effective in preventing dental caries in adults. The objective of this meta-analysis was to examine the effectiveness of self- and professionally applied fluoride and water fluoridation among adults. We used a random-effects model to estimate the effect size of fluoride (absolute difference in annual caries increment or relative risk ratio) for all adults aged 20+ years and for adults aged 40+ years. Twenty studies were included in the final body of evidence. Among studies published after/during 1980, any fluoride (self- and professionally applied or water fluoridation) annually averted 0.29 (95%CI: 0.16-0.42) carious coronal and 0.22 (95%CI: 0.08-0.37) carious root surfaces. The prevented fraction for water fluoridation was 27% (95%CI: 19%-34%). These findings suggest that fluoride prevents caries among adults of all ages.     

Risk perception and water fluoridation support and opposition in Australia

Objectives: A considerable body of evidence confirms that water fluoridation effectively reduces the community incidence of dental caries with minimal side effects. However, proposals to introduce this widely endorsed public-health measure are often perceived as controversial, and public opinion frequently plays a role in the outcome. Despite this, the public's perception of risk associated with water fluoridation has not been well researched and remains poorly understood. Our objectives were to determine whether risk perceptions reflecting various "outrage" factors are associated with water fluoridation support and opposition.
Methods: We conducted a cross-sectional questionnaire survey of a national sample of 517 Australian adults (response rate = 34.7 percent) aged 18-92 years.
Results: Approximately 70.5 percent of respondents supported water fluoridation, with 15.1 percent opposed and 14.3 percent neutral. Sixteen of the 20 assessed outrage factors were significantly associated with water fluoridation stance in the predicted direction, with greater outrage being related to increased water fluoridation opposition. An overall outrage index computed from the 16 significant outrage factors accounted for a statistically significant 58 percent of the variance in water fluoridation stance beyond the effects of age, gender, socioeconomic status, and age and presence of children.
Conclusion: Outrage factors are important aspects of the public's perception of risk in relation to water fluoridation. Given that water fluoridation appears to be a low-risk, high-outrage controversy, efforts to mitigate the level of public outrage, rather than continuing to deny possible hazards, may offer a worthwhile strategy in gaining public acceptance for the extension of water fluoridation.     

Oral health programme for preschool children: a prospective, controlled study

Background.  New perspectives are needed for oral health programmes (OHPs). The aim was to evaluate the preventive effect of a risk-based OHP in comparison with a traditional programme.
Design.  An age cohort of 794 Finnish children, 446 in the intervention group and 348 in the control group, was followed from 18 months to 5 years of age. The children were screened for mutans streptococci (MS) in the dental biofilm. The main outcome measure was the proportion of children with dental caries (decayed, missing, or filled primary teeth > 0) at the age of 5 years. The intervention, targeted to MS-positive subjects in the intervention group only, was based on repeated health education to the caretakers and xylitol lozenges for the child. Dental hygienists carried out the programme.
Results.  OHP was effective in white-collar families [numbers needed to treat (NNT) = 3, 95% CI 2–11]. Factors significantly associated with caries at 5 years were MS colonization at 18 months, occupation of caretaker, but also gender when incipient carious lesions were included in the index.
Conclusion.  Early risk-based OHP, targeted to the families of MS-positive children, can reduce the risk for caries in white-collar families. For blue-collar families, different kinds of methods in caries prevention and support are needed.