Prioritization, Incentives, and Resource Use for Sustainable Dentistry: The EU PRUDENT Project

KNOWLEDGE TRANSFER STATEMENT

The EU PRUDENT project aims to enhance the financing of oral health systems through novel evidence and implementation of better financing solutions together with citizens, patients, providers, and policy makers. The multicountry nature of the project offers unique windows of opportunity for rapid learning and improving within and across various contexts. PRUDENT is anticipated to strengthen capacities for better oral care financing in the EU and worldwide.

The prevalence of pre-eclampsia in migrant relative to native Norwegian women: a population-based study

OBJECTIVE

To compare the prevalence of pre-eclampsia in migrant women with Norwegian women, and to study the prevalence of pre-eclampsia by length of residence in Norway.

DESIGN

Observational study.

SETTING

The Medical Birth Registry of Norway.

POPULATION

All Norwegian, Pakistani, Vietnamese, Somali, Sri Lankan, Filipino, Iraqi, Thai and Afghan women who gave birth after 20 weeks of gestation during the period 1986-2005 in Norway.

METHODS

The prevalence of pre-eclampsia was calculated by country of birth. The association of country of birth and length of residence in Norway with pre-eclampsia was estimated as the odds ratio (OR) with 95% confidence interval (CI), using Norwegian women as a reference. We made adjustments for maternal age, parity, multifetal pregnancy, year of delivery and maternal diabetes in multivariable analysis.

MAIN OUTCOME MEASURE

Pre-eclampsia.

RESULTS

Migrant women had a lower prevalence of pre-eclampsia than Norwegian women (2.7% versus 3.7%, P < 0.001). Vietnamese (OR, 0.36; CI, 0.29-0.45), Afghan (OR, 0.52; CI, 0.30-0.90) and Thai (OR, 0.57; CI, 0.45-0.73) women had the lowest risk of pre-eclampsia relative to Norwegian women. Adjustment for the variables above or separate analyses for nulliparous women did not change the estimates notably. Using Norwegian women as the reference, the risk of pre-eclampsia increased by length of residence for migrant women: adjusted OR of 0.64 (0.59-0.70) at <5 years and 0.91 (0.84-0.99) at ≥5 years of residence.

CONCLUSIONS

The risk of pre-eclampsia was lower in migrants relative to Norwegian women, but increased by length of residence in Norway.

Equity in access to public dental services: the experience from Norway

The aim of this study was to identify possible factors associated with the marked geographical variation in supply of public dental services in Norway. We identified three sources for this uneven distribution: differences in dental care needs, differences in revenue levels between counties, and differences in the party composition of the county councils. Analyses were undertaken to ascertain whether these factors were related to the variation in the number of man-labor years of public dental officers. The analyses were performed on a set of data from Norwegian counties for the period 1985-92. There was an association between the number of man-labor years of public dental officers and our indicators of dental care needs, county revenue, and party composition of the county councils. Our findings are encouraging, as they indicate that the county councils seemed to respond to the dental care needs of the local population. On the other hand, there were inequalities in supply of public dental services that were due to differences in revenue between counties. From an equity point of view, this inequality is undesirable. The inequality could most likely be reduced by decreasing the variation in revenue between counties. Differences in party composition of the county councils had only a small effect on the geographical variation in the number of man-labor years of public dental officers.

Type of contract and supplier-induced demand for primary physicians in Norway

The focus of the present study is to examine whether supplier-induced demand exists for primary care physician services in Norway. We compare how two groups of physicians, with and without incentives to induce, respond to increased competition. Contract physicians receive their income from fee-for-item payments. They have an incentive to compensate for a lack of patients by inducing demand for services. Salaried physicians receive a salary which is independent of output. Even though increased competition for patients reduces the availability of patients, they have no financial incentive to induce. Neither of the two groups of physicians increased their output as a response to an increase in physician density. This result could be expected for salaried physicians, while it provides evidence against the inducement hypothesis for contract physicians.

[What does affect the general practitioners' choice of contract and plans to relocate?]

BACKGROUND

The aim of this study was to examine general practitioners' choice of contract and location in Norway. GPs can choose between two types of contract: a contract by which they are paid a salary, and a contract by which they are paid on a fee-for-service basis plus a fixed grant.

METHOD

The data were collected by a questionnaire sent to a representative sample of GPs in Norway (N = 1,639).

RESULTS

Salaried physicians and contract physicians show different characteristics. Salaried physicians tend to be younger than contract physicians and to prefer leisure to higher income. Most salaried physicians were located in rural areas. The following tendencies were observed with respect to location: GPs wanted to move from rural to central areas. Physicians who reported that their workload was too high, wanted to move to an area where the workload was lower. Physicians who reported that they had too few patients did not want to move. Physicians who were often on duty to provide emergency services wanted to move.

INTERPRETATION

According to standard market theory, physicians are expected to move to areas where demand is high when demand in their own areas falls. Our results indicate that public regulation is necessary in order to obtain an optimal distribution of physicians.

Consumer satisfaction and supplier induced demand

This study examines the relationship between supply of primary physicians and consumer satisfaction with access to, and quality of, primary physician services in Norway. The purpose is to throw light on a long-standing controversy in the literature on supplier inducement (SID): the interpretation of the positive association between physician density and per capita utilization of health services. We find that an increase in the number of physicians leads to improved consumer satisfaction, and that the relationship between satisfaction and physician density exhibits diminishing returns to scale. Our results suggest that policy-makers can compute the socially optimal density of physicians without knowledge about whether SID exists, if one accepts the (controversial) assumption that consumer satisfaction is a valid proxy for patient utility.

Competition and dental services

Dental services for adults are different from all other Norwegian health services in that they are provided by private producers (dentists) who have full freedom to establish a practice. They have had this freedom since the end of World War II. A further liberalization of the market for dental services occurred in November 1995, when the so-called normal tariff was repealed. The system changed from a fixed fee system to a deregulated fee system. In principle, the market for dental services for adults operates as a free competitive market, in which dentists must compete for a market share. The aim of this study was to study the short-term effects of competition. A comprehensive set of data on fees, practice characteristics, treatment profiles and factors that dentists take into account when determining fees was analysed. The main finding was that competition has a weak effect. No support was found for the theory that the level of fees is the result of monopolistic competition or monopoly. The results also provided some evidence against the inducement hypothesis. At this stage, it is interesting to notice that dentists do not seem to exploit the power they have to control the market. One explanation, which is consistent with the more recent literature, is that physicians' behaviour to a large extent is influenced by professional norms and caring concerns about their patients. Financial incentives are important, but these incentives are constrained by norms other than self-interest. The interpretation of the results should also take into account that the deregulation has operated for a short time and that dentists and patients may not yet have adjusted to changes in the characteristics of the market.

Efficiency in provision of public dental services in Norway

The paper examines productivity in the provision of public dental services in Norway. The main responsibility of the public dental services is to provide care for all children up to 18 years of age. Most dental care is provided by public dental officers. Productivity was measured by estimating a stochastic production frontier from input and output data from the public dental service in Norway. The results indicate that there are increasing returns to scale. Our measure of technical efficiency showed that the level of inefficiency is fairly small. However, the inefficiency is greater when estimated from a deterministic production frontier rather than from a stochastic frontier. One limitation of the present methodology is that it does not say anything about the level of efficiency in the Norwegian public dental service in absolute terms. A greater level of inefficiency would have been identified if a few counties had performed clearly better than the rest.

Contract design for primary care physicians: physician location and practice behaviour in small communities

Most western countries employ a combination of fee-for-service, fixed salary and per capita subsidies to finance the services of general practitioners. Based on Norwegian data, the authors demonstrate that these financial schemes have been used in different types of municipalities. The authors argue that the fee-for-service and per capita components should be allowed to vary between primary physicians and municipalities: (a) If the patient population per primary physician is low and patient supply is unstable, the per capita subsidy or work-free income should be differentiated to ensure recruitment of physicians. (b) Physicians in municipalities with low physician coverage should be allotted a low basic grant, whilst per capita subsidy and fee-for-service payments should be used to stimulate service production. The opposite situation exists where there is a potential of supplier inducement due to high physician coverage. (c) The responsibility for designing contracts should be assigned to local rather than national authorities. These suggestions go against important elements in the reform of primary physician services in Norway.

Future demand for dental care in Norway; a macro-economic perspective

The future demand for dental care in Norway is discussed on the basis of economic theory. During the next 30 years gross national income will increase substantially due to a marked increase in national income from the sale of oil and gas. On the basis of the model we predict that this increase in income will lead to an increase in demand for dental services in the short run, say for the next 10-15 years. To a large extent this increase in demand is supported by evidence from dental epidemiology. In particular, an increasing proportion of elderly dentate people will demand more services. This picture is different in the long run, say from the year 2010-15 and onwards. Evidence from dental epidemiology indicates that at that stage there will be a fairly high proportion of disease-free individuals in the population who will demand less dental care. Such a trend is also supported by economic theory as long as disease-free individuals consume less dental care irrespective of their income.

Competition and supplier-induced demand in a health care system with fixed fees

The present paper examines whether supplier-induced demand exists for primary physician services in Norway. The research design is adapted to the institutional setting of Norwegian primary physician services, where there is a fixed fee schedule. More than 50% of primary care physicians receive a payment for treatment from the National Insurance Administration on a fee-for-item basis. The results showed that increased competition, measured as a high physician:population ratio, led to a decline in the number of consultations per contract physician. However, the contract physicians in high physician density areas did not compensate for the lack of patients by providing more items of treatment in order to maintain their income. Contract physicians' revenue from items of treatment per consultation were unaffected both by physician density and by the number of consultations per contract physician. These results are further corroborated by data that showed that contract physicians' gross revenue and profits were declining functions of physician density. This paper argues that, from an efficiency point of view, a deregulated health care market with fixed fees may operate well.

More physicians: improved availability or induced demand?

A number of empirical studies have shown that there is a negative association between population:physician ratio and utilization of medical services. However, it is not clear whether this relationship reflects supplier-inducement, the effect of lower prices on patient demand, a supply response to variation in health status, or improved availability. In Norway, patient fees and state reimbursement fees are set centrally. Therefore, the correlation between utilization and population:physician ratio either reflects supplier-inducement, a supply response or an availability effect. We applied a theoretical model which distinguished between an inducement and an availability effect. The model was implemented on a cross-sectional data set which contained information about patient visits and laboratory tests for all fee-for-service primary care physicians in Norway. Since population:physician ratio is potentially endogenous, an instrumental variable approach is used. We found no evidence for inducement either for number of visits or for provision of laboratory services.

Local government decision-making and access to primary physician services in Norway

Public responsibility for health care can be justified by ambitious egalitarian objectives, as it is commonly believed that the private sector generates greater disparities than the public sector. Government institutions can be designed to achieve equality in provision of health services. The article addresses the geographical distribution of primary care physicians in Norway, where primary physician services are the responsibility of local governments, primarily financed by general taxation. The authors analyze the allocation of physicians using a local government demand model, a synthesis of consumers' demand and local government resource allocation. Analyses were performed on a panel data set of all Norwegian municipalities covering the period 1986-1992. The results are encouraging. A decentralized system of primary physician services does seem to be fairly effective in securing equity in access to these services for the municipal population. In particular, local governments seem to respond well to the health care needs of their populations. Distribution of physicians is only to a very small extent dependent on the wealth of the municipality.

Future treatment needs in children, adults and the elderly

Future treatment needs for dental services are discussed in the perspective of the objective which the services are meant to fulfill. These are, broadly speaking, equal distribution of services and economic efficiency. Within the Nordic countries, the emphasis has been on equity, perhaps less on efficiency. Equity of utilization is best understood as being a situation where patients with equal needs for oral health care receive equal treatment, in terms of both the volume and the quality of the services. The justification for arguing that equality of utilization is the appropriate measure is mainly based on the externality argument: health-care consumption by one person may be the source of utility to another person. According to that view there are two beneficiaries of dental care: the patient who is sick, and the rest of society who care for the sick patient and who derive utility from seeing the patient become healthy. The public dental services for children in the Nordic countries are organized according to the principle of equity of utilization. Equity of access is best understood as being a situation where people with equal needs have equal opportunity to use dental services. It is a supply-side phenomenon; equal access is achieved when patients with the same needs face the same costs of dental-care consumption in terms of both time and money. The oral health situation among children, adults and the elderly is exemplified by national service data and recent studies.

[Physicians employed by municipalities--how big are the differences?]

The present paper discusses the geographical distribution of physicians employed in municipal primary care. In Norway, primary medical services are the responsibility of the local public authority (the municipality) and are financed primarily by the general taxation. The allocation of physicians is analysed using a municipal demand model. The model is a synthesis of consumers' demand and allocation of municipal funds. Analyses were performed on a panel data set of all Norwegian municipalities covering the period 1986-92. The results are encouraging, since they indicate that a decentralised system of primary medical services does seem to be fairly effective in securing the municipal population equity of access to the services. In particular, the municipalities seem to respond well to the health care needs of their population. Distribution of physicians depends to only a very small extent on the wealth of the municipality.

Subsidized dental care for young men: its impact on utilization and dental health

An important part of Norwegian welfare policy is provision of free dental care for children up to the age of 18. After that age some counties have introduced a public subsidy scheme for young people aged 19-20 years, where 75% of their dental care expenses are covered. After the age of 21, all patients have to pay the costs for dental care themselves. The focus of the present work was to examine the effect that the public subsidy scheme for young adults had on demand for dental care, and its effect on dental health. The analyses were performed on 2 extensive sets of survey data. The major finding was that the public subsidy scheme had no effect on demand for dental care. In addition, there was no relationship between whether these young adults were covered by the subsidy scheme and dental health.

Can a public health care system achieve equity? The Norwegian experience

Equity in health care provision is an important policy goal in Norway. This article addresses equality in the services provided by primary care physicians. These services are the responsibility of local government financed mainly through public funding. Patient fees are low. The local government system results in geographical variation in the number of physicians relative to local health demands. The authors present the hypothesis that this generates inequalities in health care utilization. The system of government finance is based on the assumption that utilization of health services is independent of patient income. Therefore, variation in income is expected to have only a small impact on utilization. The authors estimate a demand model by combining extensive micro data with aggregate data on municipal supply. There is very little relationship between indicators of access and health care utilization. The estimated income elasticities approximate zero, supporting the argument that equality in utilization has been achieved. However, the authors results also raise the question of whether equality has been achieved at the cost of limiting supply of services for people who could afford to consume more, or to pay for services of higher quality.

Supplier inducement in a public health care system

The present paper examines whether supplier inducement exists for primary physicians' services in Norway. Our model assumes optimization behavior of the physician. The research design is adapted to the institutional setting of Norwegian primary physician services, where there is a fixed fee schedule. According to our model, the physician has three choices: to rational services, to supply an optimal amount of services, or to induce demand for services. The analyses revealed no indication of inducement with respect to physician-initiated visits. However, supplier inducement effects were found for provision of laboratory tests.

A comparative study of costs for dental services and dentists' income in the United States and Norway

The United States and Norway have approximately the same per capita Gross Domestic Product (GDP) and average personal income, but their per capita health spending patterns are quite different. In 1982, the US spent 6.5% of its total health expenditures on dental services while Norway spent 5.4%. A higher percentage of Norwegian adults see a dentist annually as compared to US adults. In 1984, the mean net income of dentists in private practice was $66,940 in the US and $27,125 in Norway; this is respectively 5 and 1 3/4 times the average per capita income in those countries. The American publicly-employed dentist earned approximately two-thirds of what the American private practitioner made, while still earning approximately 50% more than his Norwegian counterpart. Some basic information concerning the ratios of dentists, specialists, and dental hygienists to the population is given. The relative proportion of women dentists in the two countries is contrasted. Finally, data on graduates from the dental schools, enrollment cuts, and estimated dentist to population ratios by the year 2000 are described to compare future manpower that will be available to the two countries. Several dissimilarities in the political and social systems are described and discussed. It is emphasized that caution should be used when interpreting and comparing data about countries with different dental delivery, political, and social systems.

Accessibility of dental services according to family income in a non-insured population

The aim of this study was to examine the effect of family income on accessibility to dental services among adults in Norway. The analysis was performed on a set of national data collected in 1989, which was representative of the non-institutionalized Norwegian population aged 20 years and above. The sample size was 1200 individuals. The data were analyzed according to a two-part model. The first part determined the probability of whether the consumer had demanded the services or not during the last year according to family income. The second part estimated how the amount of services utilized depended on family income, for those with demand. The elasticity of the odds of having demanded the services with respect to family income was 0.48. Family income had no effect on the amount of services utilized. Additional analyses also showed that there was no effect of family income on the probability of having received a filling or a crown when visiting the dentist. In Norway, almost all costs for dental services are paid by the consumer. It is not possible from the data alone to say whether subsidized dental care is an effective way of reducing the inequalities in demand.

Supply decisions among dentists working within a fixed-fee system of dental care provision

In Norway fees for dental treatment did not increase at the same rate as prices for other goods and services during the 1980s. The aim of this study was to examine how this decrease in fees in real terms has influenced dentists' work decisions with respect to supply of services. Data on characteristics of the dentist and the dental practice were collected for 1979, 1984, and 1986. The dependent variable was supply of dental services, measured as the number of patient care hours worked per annum. The hourly fee for dental care was equivalent to dentists hourly wage rate. Supply increased as fees decreased. This could be explained either as a response of the patient or the dentist to reduced fees. Although the data did not give conclusive evidence as to which effect was most important, the authors have put forward the view that the main effect was dentists' response to reduced fees. The main argument put in favor of this view is that dentists have an overall knowledge of the effect of a change in fees on their income. The impact of a change in fees is much greater on the provider who supplies the services to many individuals over a long period of time, than on an individual consumer who buys the services once or twice a year. It was concluded that, in the short run, a fixed-fee schedule may not be very effective in limiting costs for dental care.

Accessibility of Norwegian dental services according to family income from 1977 to 1989

During the last 10-20 yr there has been a marked increase in demand for dental services in most western countries. An important issue is how this increase in demand has influenced inequalities in use of services among different income groups in the population. It is of particular interest to study this in Norway, as almost all the costs for dental care among adults are borne by the patient. The aim of the present study was to examine how the effect of family income on demand for dental services has changed over time. The analyses were performed on three sets of national data from 1977, 1983, and 1989. The samples were representative of the non-institutionalized Norwegian population aged 20 yr and above. Inequalities in use of dental services among different income groups have decreased between 1977 and 1989. However, separate analyses on the data from 1989 showed that some inequalities still exist. A non-selective subsidizing policy for dental care is unlikely to have any great effect in reducing these inequalities. Subsidized dental care is likely to raise the total amount of dental care demanded. However, it is difficult to assess accurately the size of this increase as the elasticity of demand for dental care in Norway with respect to price is unknown.

Health services research in oral health care: an empirical example

Health services research is mainly applied research which can contribute to the production of knowledge necessary to appropriate decisions in health care. As an example, a study of the occurrence of tooth extractions is presented. Two hypotheses were tested: a negative relationship between provider density and consumer income, and the probability of tooth extractions and the number of teeth extracted, conditional upon extraction. A nationwide sample of 1286 non-institutionalized Norwegians 20 yr and above was interviewed by a public survey institute. The data were analyzed using a two-part model including logistic regression and multiple regression analysis. One third of the sample had had a tooth extraction during the last 5 yr. The majority of the sample had few teeth extracted at the time of extraction. The probability of tooth extraction was related to provider density and not to consumer income. The number of teeth extracted was related neither to provider density nor to income. Tooth extraction was not related to age. Some policy implications are discussed.

Supplier inducement--its relative effect on demand and utilization

The present study examined the relative effect of supplier inducement on demand as opposed to on utilization. Supply of dentists was measured as population: dentist ratio at the level of trade areas. The dependent variable was number of dental visits during the last year. The probability of having any visit was used as the measure of demand. Number of visits, conditional upon having any visit, was used as the measure of utilization. The data were analyzed using Tobit analysis. This analysis gave the fraction of the total effect of a marginal increase in supply that is due to an increase in utilization as opposed to an increase in demand. The analysis was performed on a national sample comprising 1186 adult Norwegians. Supplier inducement had nearly the same effect on demand as on utilization. This finding may be a result of the payment system for dental care, which relates each item of service to the average time it takes to perform that item. Income opportunities for dentists are then fairly independent of whether they spend their time doing check-ups or treatment. The finding indicates that supplier induced demand is a factor to consider in addition to supplier induced utilization when one tries to explain how supplier inducement may affect the unequal distribution of dentists.

The effect of the price of dental services on their demand and utilisation in Norway

The aim of the present study was to examine the effect of the price of dental services on their demand and utilisation. These effects cannot be examined in cross-sectional studies when prices are fixed, as they are in Norway, but they can be studied over a period of time, as the price for dental services has changed relative to the prices for other goods. The analyses were performed on 7 sets of data, collected every second year, over the period 1977 to 1989. The samples were representative of the non-institutionalised Norwegian population aged 20 years and over. Price had a different effect on demand than on utilisation. There was no statistically significant association between price and demand. Utilisation decreased with increasing price, and this can be explained in two ways. First, it may express patients' response to reduced prices, and second, it may express the dentists' response to reduced prices. If the latter explanation is correct, this means that the dental care market is rather special. Consumers are not dominant. Dentists, as providers, can, to a certain extent, influence the uptake of the services they provide.

Recent changes in health related dental behaviors in Norway

There has been a substantial decrease in the prevalence of caries in younger age groups in the western world during the last 15 years. A corresponding increase has been reported regarding use of preventive remedies. Since prevention and control of dental disease is highly dependent upon personal behavior, investigations of dental health behaviors within subgroups of the population are important for future preventive strategies. Occurrence and changes in individual dental health behaviors in Norway were studied through four sets of cross-sectional data collected in 1981, 1983, 1985, and 1987. Personal interviews performed by trained interviewers were held with probability samples, each of about 1400 persons, covering the Norwegian population aged 15 and above. During the 6-yr period the proportion of individuals who brushed their teeth and used fluoride dentifrice every day increased. The number of people who used toothpicks or dental floss every day also increased from 1981 to 1985. A marked decrease was, however, observed in use of interdental remedies from 1985 to 1987. Daily use of dental floss was reduced by 10 percent points. Logistic regression showed that the reduction in the probability of using interdental aids was most pronounced among those with few teeth. Lower importance attached to dental health education, at all levels, combined with difficult economic times since 1987, might account for the decrease in daily use of interdental aids in Norway.

The effect of supplier inducement on Norwegian dental services; some empirical findings based on a theoretical model

The aim of the present study was to ascertain whether the amount of dental care demanded and the amount of dental care received in Norway were influenced by supplier inducement. There is a fixed price schedule for dental care in Norway, which establishes the framework for the theoretical model on which the empirical studies were based. The model has been developed by Birch (1988), and it describes how the utilisation of dental services may be influenced both by supplier inducement and reduced shadow prices (access costs) when the population to dentist ratio decreases. The sample of 1200 individuals was representative of the non-institutionalised Norwegian population aged 20 years and over. Variables measuring access costs, rationing of care, oral health, unmet need, family income and socio-demographic characteristics of the population were included as control variables. Supplier inducement effects were found on dentist-initiated visits, and on the cost per visit. It was concluded that dentists in areas of excess supply were able to maintain their workload by increasing the demand for and the utilisation of their services. Also, that the existing maldistribution of dentists between the northern and southern parts of Norway is not likely to be altered by allowing market mechanisms to operate on the dental care market.

[Periodontal epidemiology and the estimate of treatment needs]

This article reviews the present status on the prevalence and distribution of periodontal diseases in the population. The relationship between periodontal diseases and tooth loss is described. Epidemiological data have limitations when they are used to describe treatment needs in the population. Some of these limitations are discussed.

Effect of time costs on demand for dental services among adults in Norway in 1975 and 1985

The aim of the present study was to assess the effect of travel time, time spent on a waiting list and time spent in the waiting room on demand for dental services in Norway. The analysis was performed on two sets of national data from 1975 and 1985, and on one set of local data from 1987. The national data were representative of the non-institutionalized Norwegian population aged 20 yr and above. Travel time had an effect on demand in 1975, but not in 1985. Time spent on a waiting list had no opportunity cost, and did not influence demand. There was a statistically significant association between time spent in the waiting room and demand. However, this association disappeared when the effect of dental attendance pattern was controlled for. Regular attenders had shorter waiting times than those who were irregular attenders. This study has shown that factors such as presence of teeth, family income, and age are more important than travel time on demand for dental services.

Is there a long-term caries-preventive effect of sugar restrictions during World War II?

Wartime decrease in caries prevalence among children explained by restrictions in sugar availability and consumption is widely documented. The aim of the present investigation was to study possible long-term effects of this regimen on dental caries. Norwegian age cohorts who were 7 years old during World War II were reexamined in 1983. On the basis of DMF recordings of their first permanent molars, a long-lasting beneficial effect of the wartime caries decrease could not be demonstrated.

Relationship between number of teeth and periodontal pockets

The relationship between number of teeth and the prevalence of periodontal disease is an important factor to consider when planning future needs for periodontal care. This is of particular relevance today, when the level of tooth loss is steadily reducing. The aim of the present study was to examine this relationship. Three dependent variables associated with periodontal disease were included in the analysis: 1. The probability of having pockets 4 mm or more. 2. The mean pocket depth for individuals with pockets 4 mm or more. 3. The number of pockets for individuals with pockets 4 mm or more. Age was included in the analysis as a control variable. The study population comprised 2219 individuals in the county of Trøndelag, Norway. The data were analyzed using logistic regression and multiple regression analysis. The probability of having pockets 4 mm or more increased with increasing number of teeth. The average pocket depth decreased with increasing number of teeth. There was no relationship between number of pockets and number of teeth. The increase in the probability of having pockets with a marginal increase in number of teeth was greatest for those aged 53 years and above. It is concluded that this group of people are likely to have the greatest need for periodontal care.

How age influences expenditure for dental services in Norway

Several studies have shown that demand for dental services decreases with increasing age. There is a lack of research to examine how utilization (as opposed to demand) varies with age. This relationship is likely to depend on family income and number of teeth. This study had two aims: Firstly, to examine the relationship between age, family income, number of teeth, and expenditure for dental services in Norway. Secondly, to compare a model where expenditure was the dependent variable with a model where demand was the dependent variable, using the same set of explanatory variables (age, income, and number of teeth). The analysis was performed on a set of national data collected in 1987, which was representative of the non-institutionalized Norwegian population 20 yr and above. The sample size was 1216 individuals. The data were analyzed according to a path analysis design, using regression analysis (OLS). Age had no effect on expenditure after controlling for family income and number of teeth. Expenditure decreased and demand increased with increasing number of teeth. This has two implications: Firstly, expenditure will rise and demand decrease with increasing age because number of teeth decreases with age. Secondly, utilization of dental services is likely to decrease, and demand increase as oral health improves.

[100,000 more adults visit the dentist: a few results of November 1989]

The aim of the present study was to describe the Norwegian adult population according to: 1. number of teeth present, 2. demand and utilization of dental services, 3. travel time from home to the dentist, 4. dental health behaviour, 5. fear for dental treatment. The analyses were performed on a set of national data collected in 1989, which was representative of the non-institutionalized Norwegian population 20 years and above. The sample size was 1260 individuals. About 75% of the people had 20 teeth or more present. Nine percent were edentulous. Seventy-seven percent who had demanded dental services during the last year. The average expenditure for dental treatment for those who had demanded the services during the last year was NOK 826. Fifty-three percent travelled 15 minutes or less from home to the dentist. Eighteen percent travelled 30 minutes or more. Almost everybody with their own teeth present brushed their teeth regularly once a day. Thirty-three percent of all dentate people used woodsticks regularly once a day, while 20% used toothfloss regularly. Seventy-five percent had no to mild fear of the dentist, while 7% had a strong fear. Fear of the dentist was higher among women than among men. Fear of the dentist decreased by increasing age. Few people, less than 4%, had cancelled a dental appointment because of dental anxiety. There has been an improvement in dental health and dental health behaviour in Norway during the 1970's and 1980's. These improvements are discussed with special attention paid to the findings from the present study.

[Costs of dental care and medical care paid by the patients]

The National Health Insurance covers a minor part of the expenditures for adults' dental care in Norway. This paper describes the present principles for charging patients for health care services. The paper has 3 aims, 1) to describe patient charges assessed as personal expenditures for dental treatment, 2) to relate patient charges for dental treatment to patient charges for other health services, and thirdly 3) to compare the level of spending for dental care to other household-consumption. Patient charges are higher for dental care than for other non-institutionalized health services. There is an upper limit to patient charges for health services (dental services are not included). The upper limit was approximately 90 in 1987. Above that limit health services are free. Altogether 137,000 persons reached that level of personal expenditures for health services in 1987. The price per unit of dental services is considered rather low in Norway. However, approximately 600,000 adults had expenditures for dental services which exceeded 90. The inconsistency in the present level of patient charges is discussed.

Supplier inducement. Its effect on dental services in Norway

In many western countries, supply of dental services exceeds demand, mainly because of the marked reduction in the prevalence of dental diseases during the last 10-15 years. An important issue is whether dentists can counteract this fall in demand by stimulating increased demand and/or utilization for their services. Some evidence that this may be the case was found in the present study, in Norway. The results indicate that demand and utilization for dental services are influenced by supplier inducement.

Validity of CPITN's hierarchical scoring method for describing the prevalence of periodontal conditions

CPITN has been a frequently used index in periodontal epidemiology during the last decade. It was originally designed to describe treatment needs in populations. For this purpose, it was decided to record only the worst periodontal condition around each index tooth. Such a recording procedure can be regarded as a hierarchical scoring method. Recently, CPITN has been used and recommended for describing the prevalence of periodontal conditions. For this purpose, the index should give a valid estimate of the true periodontal conditions of the index tooth, and not only a recording of the worst condition. The aim of the present study was to test whether the hierarchical assumption of CPITN concerning treatment needs was valid for describing the prevalence of periodontal conditions in a Scandinavian population. The study population comprised 3330 persons from a rural and an urban area in the county of Trøndelag, Norway. The clinical recording was carried out so that it was possible to analyze the indicators both hierarchically and non-hierarchically. The results showed that nearly all the CPITN indicators scored hierarchically gave a correct estimate of the prevalence of bleeding in the population. CPITN codes 3 and 4 overestimated the prevalence of calculus. The degree of overestimation varied by age and tooth type. Most overestimation of calculus occurred on molar teeth with pockets 3.5-5.5 mm and for individuals 13-14 yr of age. There was almost no overestimation of calculus for those aged 65 yr and above.(ABSTRACT TRUNCATED AT 250 WORDS)

[Family income, demand and use of dental health care among Norwegian adult population 1983-1987]

The aim of this study was to describe changes in demand and utilization of dental services according to family income among adults in Norway from 1983 to 1987. The analysis was performed on two sets of national data, which were representative of the Norwegian population aged 20 years and above. The sample size was 1,289 individuals in 1983 and 1,166 individuals in 1987. The data were analyzed according to a two-part model. The first part determined the probability of whether the consumer had demanded the services or not during the last year. The second part estimated how expenditure depended on income, given some expenditure. Family size, number of teeth present, age, gender and education were entered into the analysis as control variables. For edentulous people, and people with few remaining teeth, there were marked differences in demand and utilization of dental services according to family income both in 1983 and in 1987. During this period, there has been an increase in demand, while utilization has stayed constant. In the population as a whole, the turnover of dental services has increased by the equivalent of 80 "dentists' years work" from 1983 to 1987 due to the increase in demand.

[Prerequisites for bacterial invasion of the periodontal tissues]

Bacterial invasion of the periodontium has recently been described by several authors. The conditions necessary for this to occur in vivo are being discussed. The anatomical relations of the periodontal pocket are described macroscopically and microscopically as well as the postulated mechanisms for colonization, adhesion and penetration. It is necessary for the microorganisms to colonize and adhere in order to be able to invade tissues. The possibility of establishment of microorganisms in the tissues and the importance of the immune system are also being described. The conclusion is that there is a possibility of bacterial invasion of the periodontal connective tissue. However, the human body with help from the immune system will in most cases be able to neutralize and get rid of these microorganisms.

[CPITN (Community Periodontal Index of Treatment Needs)--what is its use and what does it mean?]

CPITN was originally designed for describing periodontal treatment needs in populations. It has also been used to describe the prevalence of periodontal conditions and as a screening test to identify patients who need complex or simple treatment. The results from the present study show that the index will over-estimate the prevalence of calculus, but will give a correct estimate of bleeding. The index is acceptable as a screening test if "1 or more sextants with CPITN score 4" is chosen as a screening criterion.

Some characteristics of patients given dental treatment under general anesthesia

The attitude to treatment of dental diseases under general anesthesia has been rather restricted in the dental profession in Scandinavia. Yet, some patients with certain medical conditions and patients haunted by anxiety may not be able to have conventional dental treatment. During the period 1975-1983, 1067 patients were treated in a group practice in Oslo. These patients are described with regard to gender, age, reasons for treatment, place of residence, source of referral, and type of treatment given. Some of the data are related to the year of treatment. The profile of patients changed during the observation period. At the beginning most of the patients came from Oslo and were less than 6 years old, whereas at the end most of the patients were more than 15 years old, lived outside Oslo, and had more conservative than radical treatment. It is concluded that there will probably always be a small group for whom dental treatment under general anesthesia will be necessary.

Longitudinal study of dental health behaviors and other caries predictors in early childhood

This longitudinal study of 231 preschoolchildren from a medium sized Norwegian town had three aims: firstly, to examine the children's early dental behavior, secondly to study the variation of dental health behavior according to mother's education, mother's dental health, and her dental attendance pattern, and thirdly to identify any behavioral or social predictors of dental caries in 36-month-old children. Data were collected at health centers, using precoded questionnaires and examinations, when the children were 6, 18, and 36 months old. Data about the mothers were collected at the maternity ward. At 36 months of age, 80% of the children were caries free. Favorable dental behaviors were related to toothbrushing and use of fluorides. These behaviors were so well established and consistent at all ages that they can be regarded as norms for this community. The most unfavorable and inconsistent behavior was related to sugar consumption. Dental health education could be most usefully applied to this area, where the greatest potential for improvement in behavior exists. A relationship was found between the children's caries experience and the number of missing teeth of the mother, her dental attendance pattern and her level of education. None of the social or behavioral variables tested had a strong enough association with caries experience to justify their use as caries predictors in this age group.

Synergistic antibacterial effects of copper and hexetidine against Streptococcus sobrinus and Streptococcus sanguis

The aim of this study was to determine whether a combination of copper and hexetidine had a synergistic antibacterial effect against Streptococcus sobrinus OMZ 176 and S. sanguis 10556. Concentration ranges of the test agents alone and in combination were prepared by serial dilutions in microtiter trays with brain-heart infusion (BHI) broth as the bacterial growth medium. After incubation at 37 degrees C for 24 h, the minimum inhibitory concentration (MIC), corresponding to the lowest concentration showing no visible growth, was determined. Evaluated by the fractional inhibitory concentration index, a strong synergistic effect ranging from 0.39 to 0.40 was observed. A similar effect was also demonstrated by growth curves, which were constructed on the basis of growth in BHI broth with addition of MIC/4 of each agent alone or MIC/8 of each agent in combination. A probable explanation for these findings is that the surface-active hexetidine molecule alters the bacterial cell surfaces and thereby enables an increased amount of copper to be transported into the cell.

Effect of a combination of copper and hexetidine on the acidogenicity and copper accumulation in dental plaque in vivo

A double-blind crossover study on 4 adult volunteers was performed to evaluate the effect of hexetidine on Cu2+ accumulation in dental plaque as well as a possible enhanced effect of copper on inhibition of acid production in the presence of hexetidine. The experimental period was 5 days. No oral hygiene was allowed, and sucrose-containing chewing gum was used to enhance plaque formation during the test period. In order to evaluate the effect on pH, the test persons rinsed with a 15% glucose (w/v) solution on the 5th experimental day. Plaque pH values recorded before and 5 min after the rinse served as control values. One hour later the test persons rinsed with 10 ml of the test solutions for 1 min. Glucose rinses with pH measurements 5 min after the rinse were carried out 0, 3, and 7 h after the test agents were used. The combination of 1.0 mM copper and 2.0 mM hexetidine gave a significant (p less than 0.05) inhibition of acid production at all times compared both to the controls and to each of the test agents separately. Plaque samples were collected with a toothpick immediately before a 1-min rinse with 10 ml of the test solutions. Subsequent plaque samples were taken 5 min and 3 and 8 h after a rinse from corresponding tooth surfaces. Dry weight was estimated, the plaque bacteria digested by HNO3, and the amount of Cu2+ determined by atomic absorption.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of a combination of copper and hexetidine on plaque formation and the amount of copper retained by dental plaque bacteria

Zn++ in combination with hexetidine exerts a synergistic plaque inhibition. Studies in our laboratory on the mechanism of this effect suggested that Cu++ and hexetidine may have a similar combination effect. This hypothesis was tested in vivo on a human test panel in a double-blind crossover study. The amount of Cu++ retained by plaque bacteria in vitro was also evaluated. Seven volunteers rinsed with the solutions for 1 min twice daily for 5 days. The test solutions were H2O, 1.0 mM CuSO4, 2.0 mM hexetidine, and the last two in combination. During the test period no oral hygiene was allowed, and sucrose-containing chewing gum was used to enhance plaque formation. The plaque index scores after rinsing with the combination were significantly (p less than 0.05) lower than those of the other solutions. The effect of hexetidine on Cu++ retention in plaque bacteria was evaluated in plaque samples (n = 3) grown anaerobically overnight in PPLO medium. The bacteria were washed five times, digested in concentrated HNO3, and Cu++ determined by atomic absorption. The presence of hexetidine resulted in a significantly greater amount of Cu++ retained by bacteria at all CuSO4 concentrations. It is suggested that the nonpolar nature of the hexetidine molecule enables Cu++ bound to hexetidine to pass into the bacterial cell. Within the cell, Cu++ can interfere with bacterial metabolism, giving a reduction in plaque growth.