Prevention—What Does This Mean?

The synonyms “prevention” and “prophylaxis” are used by many dental professionals to describe any measure that is not linked to„drilling and filling.” Thus, rather differing interventions which either alter the tooth surface macroscopically (sealing) or microscopically (e.g., fluoride application), as well as efforts to change oral health-related behaviors, are brought together under the heading “prevention.” Literally, preventing illness means that some stage of disease occurrence in the future is anticipated and measures (including therapeutic ones) are applied to avoid this stage (Chapter 9). Therefore, it is not surprising that the original publication in the 1960s introducing three levels of prevention presented a broad range of disease conditions that can be approached “preventively.”1 A fourth level, which actually comes first with respect to disease occurrence, is called primordial prevention. This level aims to change underlying risk factors leading to the cause of a disease.

For cariology this means that avoiding transfection of cariogenic bacteria, if possible, would be prevention on the primordial level. Noninvasive interventions such as oral hygiene education or regular low-concentration fluoride applications are efficacious preventions on the primary level, but also on the secondary level. Microinvasive interventions such as caries infiltration or fissure-sealing fulfill the criteria of a measure that is secondary level. Inserting a restoration into a decayed tooth can be seen as tertiary level prevention.2 Even replacing fillings or larger restorations can still be seen in the sense of this tertiary level, before prosthetic measures, such as replacement of teeth come into play. From this wider perspective on prevention it becomes clear that noninvasive interventions and dental health education are important parts of prevention, but not the only ones.

Why Do People Get Sick?

Before an answer can be given to the question of how to implement preventive interventions some theoretical thoughts on how a chronic disease, such as caries, is determined need to be discussed.

A dental professional having a preventive attitude, after working for several years might wonder why his or her efforts to maintain teeth as sound as possible are not successful every time in a single person and/or in certain subgroups of patients. When looking at the caries models (Chapters 4 and 21) it becomes clear that caries is influenced by direct and more distant determinants. The latter cannot be easily changed by an individual, but have also to be seen in the social context.

An example. If a child is born into a family that is living on social benefits, it might not be the family′s first concernto buy toothpaste and toothbrushes on a regular basis. Moreover, their social surroundings might not be supportive to “make the healthy choice” with respect to food, meaning that a cariogenic nutrition would be favored. This would not be a good choice with respect to weight control, either. Thus, the child will be at a higher risk of obesity and in consequence for cardiovascular disease and diabetes. In addition, due to many other more severe problems in life, the importance of oral hygiene might only be considered subordinate to other things that are better supported in the setting the child is living in. All in all, this unfavorable social context might trigger a high prevalence of caries. This means caries cannot only be seen as a personal problem, but also it is a result of structural and contextual influences.4

The thinking that the dental professional is repairing the sequels of unfavorable social contexts has been allegorized by an upstream–downstream model ( Fig. 13.2), which was first proposed for cardiovascular patients.5 For caries, people are either pushed upstream into the “caries river” by the confectionery industry that sells sugar-containing foods, or fall into it if they are “blind” with respect to oral health-related behavior. People are only able to “swim” for a while, meaning that adopted oral hygiene behavior is not sufficient to prevent development of cavitated caries lesions, although fluorides (“lifebelts”) are offered on their way downstream, to “rescue the victims.” Thus, most people need to be saved further downstream from drowning in the “caries river” by dental professionals who refer the “victim” to rehabilitation by a dentist.6 This allegory gives the idea that if “unhealthy choices would be made more difficult (and healthy choices easier),”6 for example, by governmental regulation, caries prevalence at the dentinal level would decrease. Nonetheless, it should be kept in mind that necessary changes in the society as a whole only occur slowly.

A Little More Upstream: Setting-Approaches

A realistic way to implement health promotion further upstream is to choose approaches that take into account the setting of an individual. The roots of this approach can be traced back to the first International Conference on Health Promotion in 1986. Its publication is known as the Ottawa-Charter.7 It was said:

“Health promotion is the process of enabling people to increase control over, and to improve, their health. To reach a state of complete physical, mental and social well-being, an individual or group must be able to identify and to realize aspirations, to satisfy needs, and to change or cope with the environment. Health is, therefore, seen as a resource for everyday life, not the objective of living. Health is a positive concept emphasizing social and health personal resources, as well as physical capacities. Therefore, health promotion is not just the responsibility of the health sector, but goes beyond healthy life-styles to well-being.”

Besides others, two key health promotion action means were defined:

• Creation of health supporting environments

• Development of personal skills

Both these key action means are covered by setting-approaches. Here, low-threshold, systematic interventions in real living conditions (school, neighborhood, etc.) are implemented by involving all stakeholders. The focused group should be empowered to actively assume responsibility for health-related issues. This approach is somehow in contrast to the situation where the individual or a group is just the recipient of offers and messages being supportive for one′s health. Setting-approaches are considered as being appropriate to diminish restricted health chances due to social inequities.8

An example. A young mother from a low socioeconomic background shows some of the unfavorable behaviors (see previous example) that set the child at a higher risk to develop severe tooth decay. Her surroundings do not reflect her attitudes and behaviors as being “false”; the common offers by dental professionals are either ignored or the mother cannot adopt suggestions to improve her and/or the child′s oral health. In this case a more educated member belonging to the setting the young mother lives in might be the only person to get the message across, since the young mother will identify herself with this person to a greater extent than with a dental professional coming from a high socioeconomic stratum or different cultural background.

Most Upstream: the Population-Based Common Risk Factor Approach

As will be outlined a little later, current efforts in dental health promotion mainly focus on the prevention of either one of the two most prevalent diseases in the oral cavity, namely caries and periodontitis. This is quite a narrow approach to maintaining health, since many risk factors are related to several diseases and vice versa—some diseases have similar risk factors in common. If oral health programs are implemented in isolation from other general or specific health programs, this bears the risk of conflicting messages that might overburden the public. Therefore, a common risk factor implemented through a comprehensive health promotion strategy has been proposed.10 Examples are considerable changes in Food Policy and the Health Promoting School Initiative. The latter was originally linked to preventing injuries,10 but can be easily extended to obesity, caries, or cancer prevention.11 All these efforts on changing policy in surroundings or even countries depend on collaborative working among several stakeholders. For the Health Promoting School Initiatives this means that staff, students, parents, education authorities, local government, and health professionals coming from various backgrounds have to agree and work together.10

With respect to the implementation of upstream approaches a lot can be learned from the field of tobacco control, “where in many parts of the westernized world significant success has been achieved”.9 Smoking has been known as a strong risk factor for many diseases for many decades. To change smoking habits, as a first step, awareness of smoking being the cause of many health problems had to be conveyed to policy makers. A pre-requisite for this was high-quality epidemiological studies. Then, policies (e.g., taxation, labeling packages with health warnings) and environmental measures (e.g., smoking restrictions in various places) were introduced. As a result, the “manufacturers of illness,”9 the tobacco industries, were regulated. This seemed to have more impact on smoking habits than more downstream options such as health campaigns or individualized preventive measures (i.e., behavior change under the unfavorable contexts) to control diseases related to smoking.9 Nonetheless, with respect to caries prevention, changing food policy seems to be rather difficult as shown in an analysis on “reported commitments and practice of 25 of the world′s largest food companies” in response to recommendations on nutrition.12

Despite of all these New Public Health approaches, it should be kept in mind that not everybody will be willing and able to refrain from falling into the “caries river,” even under more desirable social circumstances. In addition, those who have already fallen into the river, can no longer be rescued in the sense of a restitutio ad integrum. These patients will still need individualized (re-) dentistry, at least in the next decades.

High-Risk versus Population-Based

As presented thoroughly in Chapter 8, caries experience is very unequally distributed throughout the population. It is skewed in particular for children, meaning that the majority do not have any or only low numbers of affected teeth and that a minority shows most of the affected teeth. In a graphic showing cumulative percentages of children in relation to DMFT, the typical picture of a “mountain” on the left and a “tail” on the right is depicted ( Fig. 13.3 ). Large variations with respect to the extent of this caries polarization exist between countries and also within countries such as Denmark, for example. In 1999, the lowest and highest DMFS scores for the 15-year-olds were 0.88 and 8.73, respectively, with a national mean of 3.52. The proportion of individuals with no cavitated caries (D3-level plus filled and extracted teeth due to caries) ranged from 10% to 71%.13

This distribution with relatively low numbers of children having several affected tooth surfaces calls for the so-called high-risk strategies that concentrate on those presumably being at a high risk for further caries development. This strategy comprises the need to identify those who are at a high risk, which is sometimes not so easy (Chapter 7) at affordable cost without making an unreasonable number of errors as is the case with any screening procedure that relies on the rules of testing statistics. Depending on the validity of the screening procedure, there will inevitably be false positives (wrongly allocated to the high-risk group) and false negatives (wrongly missed out of the high-risk group). In addition, the individual protection for the high-risk patients must be efficient enough to justify the effort of screening.14

On the contrary, population-based strategies aim “to shift the risk distribution of the entire population to a more favorable level. If such efforts are successful, the average risk of the population decreases and the frequency distribution of disease and risk is pushed to the left. Even a smallish decrease in the average level of a risk factor may result in a considerable reduction in the incidence of a health problem”.14 Thus, the main difference is that the population approach steps in more “upstream,” whereas high-risk approaches are trying to protect diseased individuals from developing more disease further “downstream,” by changing their risk factors.15 Several other advantages and disadvantages can be defined for both strategies within the field of caries prevention,4 according to the basic publication on preventive medicine of Rose.16 In general, the efficacy, effectiveness, and efficiency of the high-risk strategy has been be challenged ( Table 13.1 and Fig. 13.3 ).

The directed population strategy tries to combine the elements of the high-risk and population strategies. This strategy seeks “sick communities” or well-definable groups according to underlying determinants of oral health, such as lower socioeconomic status. For example, in Germany students that attend a secondary school orientated to the world of work, which is compulsory for all pupils (Hauptschule), can be defined as a group with lower socioeconomic status and referred to particular preventive measures as a whole, with no previous screening. Thus, for those being defined as “high-risk” by their social determinants, the principles of the whole population strategy can be applied.14

Current strategies being implemented differ from country to country and even within countries, mainly due to high-quality scientific evidence at a higher level being missing with respect to the effectiveness of the several interventions or their combinations, as well as due to varying political and historical backgrounds. In this clinical textbook we will focus in due course on the existing evidence from epidemiological studies with respect to caries prevention. Later on, an individualized population strategy for children will be introduced separately (Chapter 21).

Noninvasive Interventions versus Behavioral Change in Caries Prevention

As outlined so far the effectiveness of an oral health-related program seems to rely to some extent on the strategy employed. Within the chosen strategy various options can be adopted for differing recipients: as whole populations, as certain communities or groups in a specific setting, as well as in a one-to-one situation. For prevention of caries, the various applicable options can be divided into noninvasive (medical) interventions and educational ones. Medical means that the intervention mainly focuses on mineralization or biofilm modification on a tooth surface level. Educational options subsume oral health education, as teaching oral hygiene techniques and giving recommendations for use of self-applied fluorides, but also mass campaigns to change the diet of individuals as well as (teacher) supervised tooth brushing ( Table 13.2 ). At least supervised tooth brushing and oral health education focus on the prevention of gingivitis, as well. Most of the time, oral (dental) health-related programs rely on various options.

Definition

Health-related behaviors are influenced by both internal and external factors and are conceptualized apart from risky behaviors. They may be defined thus: “Any activity undertaken by an individual regardless of actual or perceived health status, for the purpose of promoting, protecting or maintaining health, whether or not such behavior is objectively toward the end.”17