Willingness to pay for dentin regeneration in a sample of dentate adults

What is the evidence on the added value of implant-supported overdentures? A review

Background

Implant‐supported overdentures (IODs) have been reported to increase patients' oral health‐related quality of life (OHRQoL) in comparison with conventional dentures (CDs); however, the conclusiveness of evidence on the clinical effectiveness and value for money of IODs versus CDs remains unclear.

Purpose

To review how the added value of IODs is demonstrated in the literature.

Materials and methods

MEDLINE, EMBASE, and the Cochrane Database were searched for randomized control trials, controlled clinical trials, and prospective cohort studies containing evaluations of the economic and health benefits and costs of IODs. Information about the clinical effectiveness, such as magnitude of bite forces or chewing efficacy, OHRQoL, costs, and cost‐effectiveness of IODs, was extracted.

Results

A total of 17 articles were included, reporting 15 economic evaluations: 11 cost‐utility analyses (CUAs), 2 of which were combined with a cost‐effectiveness analysis (CEA), and 2 cost–benefit analyses (CBAs). Seven CUAs used the Oral Health Impact Profile (OHIP) questionnaire while four used satisfaction questionnaires to assess the OHRQoL. One study applied quality‐adjusted prosthesis years (QAPYs) for this purpose. The CBAs expressed both the beneficial outcome and the costs of the IOD in monetary terms. The included studies employed a large variety of economic evaluation methods, which limited cross‐study comparability.

Conclusions

On the basis of existing economic evaluations, IODs have frequently been suggested to be a cost‐efficient treatment alternative to CDs; however, the comparability between the various economic evaluation studies was limited due to the different outcome measures used. In addition, it remains unclear whether the additional health benefits of IODs outweigh the higher costs. This is largely dependent on the decision maker's valuation of oral health outcomes. Future research is encouraged to further elucidate patient willingness to pay for IODs and the societal return on investing in IODs more generally.

Prevalence of Missing Values and Protest Zeros in Contingent Valuation in Dental Medicine

Background: The number of contingent valuation (CV) studies in dental medicine using willingness-to-pay (WTP) methodology has substantially increased in recent years. Missing values due to absent information (i.e., missingness) or false information (i.e., protest zeros) are a common problem in WTP studies. The objective of this study is to evaluate the prevalence of missing values in CV studies in dental medicine, to assess how these have been dealt with, and to suggest recommendations for future research. Methods: We systematically searched electronic databases (MEDLINE, Web of Science, Cochrane Library, PROSPERO) on 8 June 2021, and hand-searched references of selected reviews. CV studies in clinical dentistry using WTP for valuing a good or service were included. Results: We included 49 WTP studies in our review. Out of these, 19 (38.8%) reported missing values due to absent information, and 28 (57.1%) reported zero values (i.e., WTP valued at zero). Zero values were further classified into true zeros (i.e., representing the underlying preference of the respondent) or protest zeros (i.e., false information as a protest behavior) in only 9 studies. Most studies used a complete case analysis to address missingness while only one study used multiple imputation. Conclusions: There is uncertainty in the dental literature on how to address missing values and zero values in CV studies. Zero values need to be classified as true zeros versus protest zeros with follow-up questions after the WTP elicitation procedure, and then need to be handled differently. Advanced statistical methods are available to address both missing values due to missingness and due to protest zeros but these are currently underused in dental medicine. Failing to appropriately address missing values in CV studies may lead to biased WTP estimates of dental interventions.

An overview of the methodological aspects and policy implications of willingness-to-pay studies in oral health: a scoping review of existing literature

Background

Demands for dental services seem to be beyond the capacities of most healthcare systems these days. Patient preferences have been increasingly emphasized to be considered in the joint decision-making process. Willingness-to-pay (WTP) is a recommended method for measuring the utility of health services; increasingly being used in recent decades. Taking these points into consideration, this article aims to provide an overview of the methodological aspects and policy implications of WTP studies in the field of oral health.

Methods

The research was conducted in ISPOR, PubMed and Google Scholar databases. In addition, reference lists of included articles were checked to identify the relevant studies. All studies published were included that were in the English language and reported using WTP for oral health-related goods and services. A data-charting form was developed by a focus group discussion panel of seven experts to derive the main methodological aspects of WTP. Also, Core policy suggestions were categorized through thematic content analysis of the included papers.

Results

The search strategy yielded 389 studies of which 52 were included. WTP studies in oral health show an increasing trend in global publications. The UK and Canada have a greater share in published material than in any other country. The dominant field of these researches is in restorative and prosthetic dentistry, and a wide range of different methodological aspects was documented. Policy suggestions were categorized in three main themes: (A) setting new tariffs or subsidizing the item, (B) provision of the item due to population preferences, and (C) improving literacy regarding the item.

Conclusions

An urgent need for a common framework regarding the design of WTP studies in dentistry seems paramount. Some policy suggestions seem not to be applicable, perhaps due to insufficient familiarity of the researchers with the complexities of the public policymaking process.

Patients' and Parents' Valuation of Fluoride

PURPOSE

This study aimed to elicit willingness to pay (WTP) values for fluoride varnish application from participants using the publically-funded health services in Brazil and the UK, and to identify differences in the variables impacting these values. A secondary aim was to compare WTP values from parents for their own preventive treatment and their child's.

MATERIALS AND METHODS

This was a cross-sectional analysis of quantitative data collected from participants attending routine dental appointments. The clinics were hosted by the Pontifical Catholic University of Rio Grande do Sul (PUCRS), Brazil and Newcastle Dental Hospital, UK.

RESULTS

The mean WTP for Brazilian adults was R$60.37 (=£15.97). WTP was highly variable and factors affecting it were difficult to identify. UK parents valued fluoride varnish at mean values of £28.21 and £28.12 for themselves and their child, respectively. Regression modelling found those with higher incomes had higher WTP in both samples. In the UK, parental and child WTP increased when parents had higher self-perceived need for dental treatment, had experienced recent dental pain, or their child had received restorations in the last 2 years.

CONCLUSIONS

WTP for fluoride varnish varied dramatically between individuals. In both countries, it was difficult to predict this variance, as factors which would likely impact upon on WTP had a limited effect and were sometimes counter-intuitive. WTP values for a parent and their child were not statistically significantly different.

Willingness to pay for osteoporosis risk assessment in primary dental care

BACKGROUND

Fragility fracture related to osteoporosis among postmenopausal women is a significant cause of morbidity. The care and aftercare of these fractures are associated with substantial costs to society. A main problem is that many individuals suffer from osteoporosis without knowing it before a fracture happens. Dentists may have an important role in early identification of individuals with osteoporosis by assessment of dental radiographs already included in the dental examination. The aim of this study was therefore to investigate postmenopausal women's preferences for an osteoporosis risk assessment in primary dental care.

RESULTS

Most respondents (129 of 144 (90%)) were willing to pay for an osteoporosis risk assessment in primary dental care. The overall mean willingness to pay (WTP) including respondents that denoted none or zero WTP was 44.60 € (CI 95% 38.46-50.74 €) (median 34.75 €). A majority (80.6%) of the respondents that denoted WTP also gave a motivation for their answer. The two most common reasons denoted for being willing to pay for osteoporosis risk assessment were the importance of early diagnosis and preventive care to avoid fractures (41.0%) and the importance of knowledge of a risk of osteoporosis (26.4%). A majority of respondents (67.8%) considered it valuable if dental clinics would offer osteoporosis risk assessment.

CONCLUSIONS

Postmenopausal women seem to find it valuable to be offered osteoporosis risk assessment in primary dental care and are willing to pay for such a risk assessment. From a societal perspective early diagnosis of osteoporosis by risk assessment in primary dental care could prevent osteoporotic related fractures and benefit women's health and quality of life, as well as have a major impact on the health-care budget in terms of cost-savings.

Willingness to Pay for Mandibular Overdentures: A Societal Perspective

OBJECTIVES

Dental services in many countries are funded out-of-pocket by patients whose acceptance of a dental treatment depends on their valuation of it. Using a willingness-to-pay (WTP) strategy, this study aimed to determine how people who do not wear dentures value the benefits of dentures retained by implants and what factors explain variations in WTP among subjects.

METHODS

Telephone numbers of a representative Canadian sample were obtained from a consumer database provider. Respondents completed either an internet-based or telephone survey with 3 payment scenarios: paying oneself (out-of-pocket), coverage with private health insurance, and publicly financed through additional taxes. Personal information data (e.g., age, income) were used as independent variables in regression models to assess the determinants of WTP amounts.

RESULTS

Among 1,096 respondents, 317 participated in the survey (response rate, 28.9%). The mean WTP of participants (mean ± SD age: 41.2 ± 0.6 y; 54.3% male) who were dentate/partially edentate was $5,347 for implant overdentures. Considering a 1 in 5 chance of becoming edentate, they were willing to pay $26.93 as monthly payments for private insurance. They were also willing to pay an additional yearly tax of $103.63 to support a public program. WTP private payments increased substantially with increase in household income and dental needs.

CONCLUSION

This preference study provides information to dentists, insurance companies, and policy makers on what dentate people are willing to pay for implant overdentures, whether directly or with insurance/government coverage.

KNOWLEDGE TRANSFER STATEMENT

This study provides results of interest to many stakeholders. For clinicians, the results reveal what people are willing to pay for implant overdentures for themselves. It also provides information to employers and insurance companies on how people value having coverage for this kind of service. Furthermore, it provides public policy makers the value that people place on public funding of such treatments and how they would support a decision to publicly fund such a treatment.

A within-subject clinical trial on the conversion of mandibular two-implant to three-implant overdenture: Patient-centered outcomes and willingness to pay

OBJECTIVES

To examine the impact of adding a third midline implant with stud attachment to a mandibular two-implant overdenture on patient-oriented outcomes.

METHODS

In this pre-post design clinical trial, following the standard procedures, mandibular two-implant overdentures of 17 edentulous individuals (61.9 ± 6.6 years) were converted to three-implant overdentures by adding a stud attachment to an unloaded midline implant. Patient-oriented outcomes included patient expectations and satisfaction with implant overdenture as well as willingness to pay the cost of conversion. Data were collected at baseline and at the 6-week follow-up using visual analog and binary scales as well as open-ended questions. Statistical analysis included descriptive statistics, Spearman's correlation, Fisher exact test, Mann-Whitney U test, and the exact sign test.

RESULTS

After connecting the third midline implant to the mandibular two-implant overdenture, there was a statistically significant decrease in the anteroposterior movement (p = 0.005) as evaluated by clinicians. Moreover, study participants reported an increase in perceived stability of the overdenture (95% CI; 0.68-1.00, p = 0.002) and in their ability to speak (95% CI; 0.63-1.00, p = 0.008). The addition of a third implant met the expectations of 94% of patients in regard to lower denture stability, 100% for retention, and 82.4% for comfort. The mandibular three-implant overdenture increased patient general satisfaction over a short period of time, but this improvement was not statistically significant. About 80% of patients would recommend this type of prosthesis to their peers but only 47% of them would agree to pay a large increase in the cost of treatment compared to a two-implant overdenture.

CONCLUSIONS

The addition of a midline third implant to an existing mandibular two-implant overdenture resulted in several improved patient-reported outcomes.

The value of orthodontics: Do parents' willingness to pay values reflect the IOTN?

Introduction

Given the limited evidence about the benefits of orthodontic treatment, many health care systems have rationed access to orthodontic care with the Index of Orthodontic Treatment Need (IOTN) being one tool used to attempt to allocate resources based on need. However, it is not clear whether patient and public valuations of different levels of need (as described by the IOTN) reflect the resource allocation decisions. The aim of this project was therefore to determine the values parents placed on correction of malocclusions at different IOTN levels using the willingness to pay (WTP) technique.

Method

401 parents of children attending hospital-based orthodontic clinics in the North of England were recruited to complete a questionnaire eliciting WTP for the correction of seven malocclusions with different IOTN scores. In addition demographic and orthodontic history characteristics were collected. Results were analysed with appropriate pairwise significance tests and regression.

Results

A significant difference in WTP was noted between all the possible pairs of malocclusions with the exception of overjets with moderate versus great need of treatments. At moderate levels, correction of crowding was valued less than overjet but this was reversed at great need levels. Very little of the variance in WTP was explained by the variables collected. When looking at factors affecting percentage difference between values for different pairs of malocclusions, in general, no factors predicted the magnitude of difference.

Conclusion

Median valuations for correction of malocclusions vary significantly for different levels of need (as judged by IOTN), with increasing levels of need generating higher values. However, there was a limited effect of demographic or orthodontic characteristics on the magnitude of percentage difference in values for correcting malocclusions different levels of need.

Critical review of willingness to pay for clinical oral health interventions

OBJECTIVES

This critical review aimed to identify, consolidate and evaluate the quality of Willingness to Pay (WTP) studies applied to clinical contexts in the field of dentistry.

METHODS

PubMed and Web of Science databases were systematically searched for relevant publications. Screening and data extraction was then performed. Primary literature in English-language were included to assess the WTP for oral health interventions, when the valuations were applied to a clinical measure. Twenty-six publications met the inclusion criteria.

RESULTS

WTP was elicited mainly via face-to-face interviews (13 publications) and questionnaires (12 publications). The majority (24) of publications selected an out-of-pocket payment vehicle. Eleven publications adopted a bidding method, nine publications adopted an open-ended format, and the remaining six studies adopted a payment card or choice method. Pre-testing was reported in only nine publications, and few studies accounted for starting point bias. Eight of 11 publications found that higher incomes were associated with higher WTP values. The female gender, a younger age and higher education levels were associated with a higher WTP in select studies.

CONCLUSIONS

Only a small minority of the studies used strategies to avoid well documented biases related to WTP elicitation. Cost versus benefit of many clinical scenarios remain uninvestigated.

CLINICAL SIGNIFICANCE

WTP studies in dentistry may benefit from pre-testing and the inclusion of a script to minimise hypothetical bias. They may also be better conducted face-to-face and via a shuffled payment card method. Income levels, and potentially education levels, gender and age, should be assessed for their influence on WTP values.

Economic evaluation of diagnostic methods used in dentistry. A systematic review

OBJECTIVES

To review the literature of economic evaluations regarding diagnostic methods used in dentistry.

DATA SOURCES

Four databases (MEDLINE, Web of Science, The Cochrane library, the NHS Economic Evaluation Database) were searched for studies, complemented by hand search, until February 2013.

STUDY SELECTION

Two authors independently screened all titles or abstracts and then applied inclusion and exclusion criteria to select full-text publications published in English, which reported an economic evaluation comparing at least two alternative methods. Studies of diagnostic methods were assessed by four reviewers using a protocol based on the QUADAS tool regarding diagnostic methods and a check-list for economic evaluations. The results of the data extraction were summarized in a structured table and as a narrative description.

RESULTS

From 476 identified full-text publications, 160 were considered to be economic evaluations. Only 12 studies (7%) were on diagnostic methods, whilst 78 studies (49%) were on prevention and 70 (40%) on treatment. Among studies on diagnostic methods, there was between-study heterogeneity methodologically, regarding the diagnostic method analysed and type of economic evaluation addressed. Generally, the choice of economic evaluation method was not justified and the perspective of the study not stated. Costing of diagnostic methods varied.

CONCLUSIONS

A small body of literature addresses economic evaluation of diagnostic methods in dentistry. Thus, there is a need for studies from various perspectives with well defined research questions and measures of the cost and effectiveness.

CLINICAL SIGNIFICANCE

Economic resources in healthcare are finite. For diagnostic methods, an understanding of efficacy provides only part of the information needed for evidence-based practice. This study highlighted a paucity of economic evaluations of diagnostic methods used in dentistry, indicating that much of what we practise lacks sufficient evidence.

An economic evaluation of maxillary implant overdentures based on six vs. four implants

BACKGROUND

The purpose of the present study was to assess the value for money achieved by bar-retained implant overdentures based on six implants compared with four implants as treatment alternatives for the edentulous maxilla.

METHODS

A Markov decision tree model was constructed and populated with parameter estimates for implant and denture failure as well as patient-centred health outcomes as available from recent literature. The decision scenario was modelled within a ten year time horizon and relied on cost reimbursement regulations of the German health care system. The cost-effectiveness threshold was identified above which the six-implant solution is preferable over the four-implant solution. Uncertainties regarding input parameters were incorporated via one-way and probabilistic sensitivity analysis based on Monte-Carlo simulation.

RESULTS

Within a base case scenario of average treatment complexity, the cost-effectiveness threshold was identified to be 17,564 € per year of denture satisfaction gained above of which the alternative with six implants is preferable over treatment including four implants. Sensitivity analysis yielded that, depending on the specification of model input parameters such as patients' denture satisfaction, the respective cost-effectiveness threshold varies substantially.

CONCLUSIONS

The results of the present study suggest that bar-retained maxillary overdentures based on six implants provide better patient satisfaction than bar-retained overdentures based on four implants but are considerably more expensive. Final judgements about value for money require more comprehensive clinical evidence including patient-centred health outcomes.

Are people who still have their natural teeth willing to pay for mandibular two-implant overdentures?

AIM

Oral health in Canada and most developed and developing countries is funded by private payers, whose acceptance of treatment depends on their valuation of it. This study aims to determine how dentate individuals in Quebec, Canada, would value the benefits of mandibular two-implant overdentures based on their willingness to pay (WTP) for the treatment, either directly or with insurance/government coverage.

METHODS

A total of 39 individuals (23-54 years) completed a Web-based WTP survey that consisted of three cost scenarios: (a) out-of-pocket payment; (b) private dental insurance coverage; and (c) public funding through additional taxes. Variations in WTP amounts were measured using regression models.

RESULTS

Among respondents who were dentate or missing some teeth, average WTP out of pocket for implant overdentures was CAD$5419 for a 90% success rate. They were willing to pay an average CAD$169 as one-time payment for private dental insurance, with a one in five chance of becoming edentate. WTP amounts increased substantially with the probability of success of implant overdenture therapy. The results of regression analyses were consistent with theoretical predictions for education level and income (P < 0.05).

CONCLUSIONS

The results of this study, within its limitations, suggest that dentate individuals would be willing to pay a significant amount to receive mandibular two-implant overdentures if and when they become edentate.

A framework for costing diagnostic methods in oral health care: an application comparing a new imaging technology with the conventional approach for maxillary canines with eruption disturbances

OBJECTIVES

The aims were (i) to propose a framework for costing diagnostic methods in oral health care and (ii) to illustrate the application of the framework to the radiographic examination of maxillary canines with eruption disturbances.

METHODS

The framework for costing, following Drummond et al. (2005), includes three elements: (i) identification of different resources used in producing and delivering the service, (ii) measurement of the amount of each resource required and (iii) valuation of the resources in monetary terms. Four data collection instruments were designed - a protocol for apportioning the cost of capital equipment to each diagnostic procedure, separate forms for recording consumable items, for the time of different health care providers used for a diagnostic examination and a patient survey for calculation of the total cost to the patient associated with the examination. The framework was applied to the radiographic examination of maxillary canines with eruption disturbances comparing two imaging methods: (i) a new method with cone beam computed tomography and panoramic radiography and (ii) a conventional method using intraoral and panoramic radiography. The primary analysis was performed from the perspective of the health care system. A separate analysis included patient costs with health care system costs to provide a societal perspective. Comparison of the two perspectives allows consideration of whether any costs savings to the health care system are generated at the expense of greater costs for patients and their families. Data for the cost-analysis were retrieved from 47 patients (mean age 14 years) referred to a department of radiology for examination of maxillary canines.

RESULTS

Application of the framework for costing allowed us to compare the resources used to perform examinations of the two methods. The mean total cost per examination for the new method was 128.38€ and 81.80€ for the conventional method, resulting in an incremental cost per examination of the new method of 46.58€.

CONCLUSIONS

The application of the framework demonstrates the feasibility of measuring and comparing the total costs as well as the distribution of total costs between providers and patients for different approaches to this common examination.

Overview of methods in economic analyses of behavioral interventions to promote oral health

BACKGROUND

Broad adoption of interventions that prove effective in randomized clinical trials or comparative effectiveness research may depend to a great extent on their costs and cost-effectiveness (CE). Many studies of behavioral health interventions for oral health promotion and disease prevention lack robust economic assessments of costs and CE.

OBJECTIVE

To describe methodologies employed to assess intervention costs, potential savings, net costs, CE, and the financial sustainability of behavioral health interventions to promote oral health.

METHODS

We provide an overview of terminology and strategies for conducting economic evaluations of behavioral interventions to improve oral health based on the recommendations of the Panel of Cost-Effectiveness in Health and Medicine. To illustrate these approaches, we summarize methodologies and findings from a limited number of published studies. The strategies include methods for assessing intervention costs, potential savings, net costs, CE, and financial sustainability from various perspectives (e.g., health-care provider, health system, health payer, employer, society). Statistical methods for estimating short-term and long-term economic outcomes and for examining the sensitivity of economic outcomes to cost parameters are described.

DISCUSSION

Through the use of established protocols for evaluating costs and savings, it is possible to assess and compare intervention costs, net costs, CE, and financial sustainability. The addition of economic outcomes to outcomes reflecting effectiveness, appropriateness, acceptability, and organizational sustainability strengthens evaluations of oral health interventions and increases the potential that those found to be successful in research settings will be disseminated more broadly.

Willingness to pay for implant therapy: a study of patient preference

AIMS

This study determined the amount of willingness to pay (WTP) for implant treatment and identified the factors affecting WTP.

METHODS

Subjects attending a university dental hospital were recruited (n=59). They were presented with two hypothetical clinical scenarios: missing one anterior/posterior tooth. The clinical procedures, outcome and plausible complications of various replacement options (fixed and removable partial dentures, implants) and sequelae of no treatment were presented. They were then asked how much they were willing to pay for tooth replacement under the two situations using a bidding method, with a starting bid of Hong Kong (HK)$20,000 in HK$1000 increment/decrement if they were willing/unwilling to pay that amount (1 USD=7.8 HKD). The amount was recorded at which the subject chose the opposite option or it reached HK$0. Demographic data were also collected. WTP values were compared between anterior and posterior replacements, and among various demographic subgroups. Spearman's correlations and linear regression analysis were also conducted.

RESULTS

Ninety-four percent and 84% of the subjects chose implant treatment to replace missing anterior and posterior teeth, respectively. The mean WTP amounts for anterior/posterior tooth replacement were HK$11,000/HK$10,000 (P>0.05). Higher WTP amounts were obtained from females, subjects without missing teeth or restorative need, and had attained higher level of education (P<0.05). Gender (P<0.05), level of education (P=0.042), and the presence of missing teeth (P=0.001) were independent predictors of WTP.

CONCLUSIONS

The estimated WTP value for a single tooth replacement using dental implants was HK$10,000. Gender, level of education and presence of missing teeth were independent predictors that influenced WTP.

Implant overdentures for edentulous elders: study of patient preference

BACKGROUND

Studies show that elders wearing implant overdentures have improved nutrition and quality of life. However, upfront costs of this therapy are high, and the income of elderly edentulous populations is low.

OBJECTIVES

This study was designed (i) to measure the preferences of edentulous patients for mandibular two-implant overdentures using Willingness-To-Pay (WTP) and Willingness-To-Accept (WTA), (ii) to assess the effect of long-term financing on WTP and (iii) to assess the desired role of health care plans in financing dental prostheses.

METHODS

Edentulous elders (68-79 years; n = 36) wearing maxillary dentures and either a mandibular conventional denture (CD, n = 13) or a two-implant overdenture with ball attachments (IOD, n = 23) participated in this study. All had received their prostheses 2 years previously, as part of a randomised clinical trial. A three-part questionnaire was completed during a 20-min interview with a trained researcher.

RESULTS

Forty-six per cent (6/13) of the CD wearers and 70% (16/23) of the IOD wearers were willing to pay three times more than the current cost of conventional dentures for implant prostheses. These percentages were increased to 77% (CD) and 96% (IOD) if participants could pay for implant overdentures in monthly instalments. Eighty-six per cent (31/36) of all participants in both groups (21/23 IOD; 10/13 CD) thought that the government should cover at least some of the cost of implant overdentures.

CONCLUSIONS

This study shows that, the majority of elderly edentate individuals who have not experienced mandibular two-implant overdenture therapy are willing to pay the cost, particularly when payment can be made in monthly instalments.

Prevention versus cure: measuring parental preferences for sealants and fillings as treatments for childhood caries in Southern Thailand

OBJECTIVES

To determine the parental relative preferences for prevention versus cure in the treatment of caries in children to inform service planning for publicly funded children's dental care services. We measure parents' Willingness to pay (WTP) for two basic dental treatments: prevention (sealant) and cure (filling) and consider whether the relative preferences between the two services are affected by differences in parents' incomes.

METHODS

Two hundred and five parents of primary school children in Southern Thailand were asked questions about their WTP for the different services as well as background information. Comparative information on caries process, treatment procedure and effectiveness was presented to subjects. Each subject's WTP was determined for sealants and fillings provided in hospital dental clinic using a bidding game approach.

RESULTS

Mean WTP for sealants and fillings were not significantly different. After adjustment for parents' characteristics, the WTP for sealants and fillings remained similar. Adjusted WTP for both services among higher income group were greater than those in lower income group.

CONCLUSIONS

Valuing of prevention versus cure was similar after controlling for parents' characteristics. Parent's income was a factor affected to WTP. Parental preferences might be a constraint to extending service utilization for the prevention of caries among primary school children.

Caries management: technical solutions to biological problems or evidence-based care?

Caries-related clinical decision-making remains a centrepiece of clinical dentistry. However, the oral disease patterns are rapidly changing towards the better among major sections of the populations, most notably in the high-income countries. The caries decline is well documented among children and younger adults, and is gradually seen to trickle into middle and old age as well. Although it is tempting for the dental profession to take the credit for this development, the evidence points in a different direction. The major contribution of dentistry seems primarily related to changes in the treatment philosophies towards a less interventionist approach. This review aims to spur a further change in the diagnostic and treatment criteria used in the management of dental caries for the benefit of the oral health status of our patients. We must come to terms with the fact that our traditional core skills, our manual dexterity and technical competence, have less to offer to oral health than we have been accustomed to think. The dental schools and the professional dental organizations must carry the responsibility for promoting the necessary changes in the caries related clinical decision-making strategies to allow practicing dentists to provide appropriate oral health care to our populations.

Willingness-to-Pay and Demand Curves: A Comparison of Results Obtained Using Different Elicitation Formats

Health economists use "willingness-to-pay" to assess the prospective value of novel interventions. The technique remains controversial, not least with respect to the formats under which values are elicited. The paper analyses the results of a series of studies of the same intervention valued by the same population, in which different elicitation formats were employed. The findings support the hypothesis that data collected using different formats give rise to different demand curves, from which different inferences about demand elasticity, profitability and consumer surplus will be derived. Judgements as to the relative merits of rival interventions depend crucially upon whichever format has been used to evaluate each intervention.