Estudios

Caries Res 2004;38:182–191

DOI: 10.1159/000077753

Changing Paradigms in Concepts on Dental Caries: Consequences for OralHealth Care

O. Fejerskov

Royal Dental College, Faculty of Health Sciences, University of Aarhus, Aarhus, Denmark

Ole Fejerskov

Royal Dental College, Faculty of Health Sciences

University of Aarhus, Vennelyst Boulevard

DK–8000 Aarhus C (Denmark)

Tel.+45 33181950, Fax +45 33150626, E-Mail of@dg.dk

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Fax + 41 61 306 12 34

E-Mail karger@karger.ch

www.karger.com

© 2004 S. Karger AG, Basel

0008–6568/04/0383–0182$21.00/0

Accessible online at:

www.karger.com/cre

Key Words

Biofilms W Caries W Dental plaque W Fluoride W Preventive dentistry

Abstract

Kuhn proposed in his Structure of Scientific Revolutions (1962)that the theoretical framework of a science (paradigm) determines how each generation of researchers construes a causal sequence. Paradigm change is infrequent and revolutionary; thereafter previous knowledge and ideas become partially redundant. This paper discusses two paradigms central to cariology. The first concerns the most successful caries-preventive agent: fluoride. When it was thought thatfluoride had to be present during tooth mineralisation to ‘improve’ the biological apatite and the ‘caries resistance’ of the teeth, systemic fluoride administration was necessary for maximum benefit. Caries reduction therefore had to be balanced against increasing dental fluorosis. The ‘caries resistance’ concept was shown to be erroneous 25 years ago, but the new paradigm is not yet fullyadopted in public health dentistry, so we still await real breakthroughs in more effective use of fluorides for caries prevention. The second paradigm is that caries is a transmittable, infectious disease: even one caused by specific microorganisms. This paradigm would require caries prevention by vaccination, but there is evidence that caries is not a classical infectious disease. Rather it resultsfrom an ecological shift in the tooth-surface biofilm, leading to a mineral imbalance between plaque fluid and tooth and hence net loss of tooth mineral. Therefore, caries belongs to common ‘complex’ or ‘multifactorial’ diseases, such as cancer, cardiovascular diseases, diabetes, in which many genetic, environmental and behavioural risk factors interact. The paper emphasises how these paradigmchanges raise new research questions which need to be addressed to make caries prevention and treatment more cost-effective.

Copyright © 2004 S. Karger AG, Basel

One of the buzzwords in the health sciences literature

is ‘evidence-based medicine’. The word ‘evidence’ is often

used uncritically, implying that any written communication which has found its way into the scientific literatureis considered as having a value of its own which adds to

‘scientific knowledge’. Even when dealing with scientific

contributions published in the most prestigious international journals it is important to appreciate that the evidence normally drawn on by scientists is dictated by an

overriding contemporary paradigm. This concept was

forcefully argued by Kuhn [1962/1970], who emphasisedhow a paradigm will shape the way in which any givenChanging Paradigms in Cariology Caries Res 2004;38:182–191 183

generation of researchers construes a causal sequence.

The term ‘paradigm’ is in this case used to describe the

guiding theoretical concepts of a science. In other words, a

paradigm will form an umbrella under which a given discipline establishes a common view whichoften sets the

rules and norms for how theories, methods etc. are handled in relation to the discipline. Moreover, results or data

analysis and interpretations are conducted within the

framework of the paradigm. Most established textbooks

within a given discipline bring the paradigms in a ‘digested form’ to the next generations of students and young

researchers and they often falsely...