July 1, 2010
by Nigel B. Pitts, FRSE, BDS, PhD, FFGDP (UK), FFPH
This article provides an overview of developments in modern, preventive, caries management as well as updates on the evolution of electrical caries detection including a practical new technology now available to use in the practice setting to assist the dental team in caries detection and monitoring.
Dental Caries “remains a ubiquitous, global, dynamic, disease process which still represents a considerable burden for many individual patients and groups in society, while providing a continuing challenge for the dental profession”.1 We do, however, now know a great deal about this complex disease and how to control it over extended timeframes in both adults and children.1 The diagnostic and treatment planning steps are seen as increasingly important and often neglected elements in caries management at a time when the presentation of the disease has changed and the preventive treatment options have expanded.
An International Consensus Workshop looking at the evidence around caries research and outcomes came up with important clarifications of terminology.2 The consensus was to separate out and define three key terms:
lesion detection (which implies an objective method of determining whether or not disease is present)
lesion assessment (which aims to characterize or monitor a lesion, once it has been detected)
caries diagnosis (which should imply a human professional summation of all available data)
It is apparent that, due to the inherent limitations of conventional clinical and radiographic methods, the dental team needs help with both the caries detection and the assessment steps in order to make the most accurate and reliable diagnoses using their clinical judgment.
This approach has led over the past eight years to the development of an International Coordinating Committee and a Charitable Foundation called ICDAS – the International Caries Detection and Assessment System.3,4 The Foundation seeks to promote the use of better quality information to inform decisions about appropriate diagnosis, prognosis and clinical management at both the individual and public health levels (see www.icdas.org ). ICDAS also provides a framework to support and enable personalized comprehensive clinical caries management for improved long-term outcomes.
In order to collate the various elements of the ICDAS framework and the range of evidence behind it, a comprehensive Monograph was published in 2009,5 which is built around the flow diagram presented in Figure 1 for ICDAS-enabled patient-centred caries management. The key elements of this framework addressed by this paper are:
Lesion Detection Aids
Integrated, personalised Treatment Planning
Recall, Reassessment & Monitoring
Electrical caries detection and assessment can make significant contributions to these three areas, but for best results the information generated should be used in the context of this overall framework. This means that the information should be integrated with that on patient caries risk and with other diagnostic/prognostic data in order to choose appropriate care for each patient from an ever- broadening menu of treatment options.
Modern caries management now involves not waiting until end-stage disease is evident (significant dentinal cavitation), but seeking to identify also early-stage disease6 which can be controlled in many cases without ever requiring surgical intervention. The value of early caries detection to the patient is then the ability to control the disease process sufficiently to contain, arrest, or remineralize lesions in order to avoid or delay the burdens and costs associated with a spiral of restoration and re-restoration. If the lesion is left to extend until a conventional filling is needed, then the clinical opportunity for effective prevention has been lost.
This approach is not new; it has been advocated for some years.7 Although the take-up has been very variable in different Countries, there is now a clear international movement towards the preventive, non-surgical approach in Countries who have not already adopted it.7 The cariology evidence and expert opinion regarding best practice favors a preventive and patient-personalized approach to treatment and recall.8 This approach of truly Minimal Intervention Dentistry has also had long support from the FDI World Dental Federation.9 In this model of care accurate diagnosis of disease and lesions is accompanied by, prevention, and (if needed) just in time restoration using minimally invasive operative procedures whilst ensuring the prevention of recurrence.
As this field is evolving and more evidence is coming on stream all the time, it is important to adopt an up-dateable model of Evidence Based Dentistry (EBD), such as that outlined by the American Dental Association. This is where EBD is an approach to oral health care that requires the judicious integration of:
systematic assessments of clinically relevant scientific evidence, relating to the patient’s oral and medical condition and history, with
the dentist’s clinical expertise and
the patient’s treatment needs and preferences.
The concept of examining teeth for caries using an electrical signal is not new, reports in the literature from the UK date from the 1950s.10 Perhaps the most significant early device for use in everyday practice was the “Vanguard” fixed frequency electrical caries monitor designed in the US in the 1970s;11 this showed very encouraging diagnostic performance when evaluated in the 1980s.12 In the early 1980s a Japanese device (13) was also available commercially as the “Caries Meter L”.13 These devices were not available widely and were, to an extent, before their time. A Dutch meat-processing Company, Lode, produced a close copy of the Vanguard device in the 1990s as the ECM. Once again, the caries detection performance was very encouraging and superior to alternatives available at that time.14
A major technological advance came in 1996 when Nature Medicine reported the first use of multiple electrical frequencies using a method known as the AC Impedance Spectroscopy Technique (ACIST) being applied to caries detection in the laboratory setting.15 The use of variable frequencies allowed a major step forward in characterising the status of the dental hard tissues more accurately and being able to differentiate both health and disease more clearly.15,16 Although these breakthroughs laid the foundation for a clinical device, it took many years of work to move from a large computer-driven, mains powered, laboratory stack of instrumentation to a regulatory approved, battery powered hand held device. However, the comparative promise of the technique in terms of helping dentists plan appropriate caries care was well recognised.17
In the late 1990s, a number of developments using optical methods were applied to the clinical caries detection problem. These included the use of a laser fluorescence system,18 which sold very well internationally as a caries detection aid. Unfortunately optical detection methods suffer from a number of inherent limitations. Although the method could find established dentinal lesions and cavities better than conventional visual and radiographic methods,19 it was inherently less able to detect early lesions and gave rise to a number of false positive readings, particularly in the presence of staining.20 The authors o
f this systematic review concluded that “the increased likelihood of false-positive diagnoses compared with that with visual methods limits its usefulness as a principal diagnostic tool”. A further problem emerged with an evaluation of the influence on performance of autoclaving the re-useable optical tips. This study showed that “consecutive sterilization of probes in autoclave alters readings, downgrading its performance”.21
The earlier laboratory work on the variable frequency ACIST method of electrical caries detection and monitoring has now been translated into a small, ergonomic and easy to use clinical device produced by a Scottish Company called CarieScan (www:cariescan.com). The technology has been miniaturized and tested with clinicians in a number of formats to produce a clinically useful and easy to use aid to caries detection and monitoring (see below).
Steps in the development process reported at recent scientific meetings have included:
a) Demonstrating that the clinical ACIST method has superior detection performance to optimal clinical visual, bitewing radiography and laser fluorescence methods for evaluating early lesions;22
b) Recognising that, as newer caries detection methods typically trade-off decreased specificity for improved sensitivity, it is desirable to build-in a balance between performance of both components of diagnostic accuracy in a clinical ACIST device so as to be able to better inform the dental team and patients. The study showed that the device can be optimized to aid caries detection and monitoring by displaying results with symmetrically high values for both sensitivity and specificity.23
c) Detecting so-called “Hidden Dentinal Caries” which remains an issue for many dentists. This is where surfaces which are apparently sound when assessed clinically, are found radiographically or operatively to have significant internal dentinal spread of caries. A presentation at the Toronto IADR meeting showed that the electrical impedance device was able to detect 31% of all the hidden dentine lesions not detected by optimal clinical visual assessment and 100% of deep hidden dentine lesions.24
This section and the accompanying figures describe a practical new technology that is available for use in the practice setting to aid the dental team in more effective caries detection and monitoring.
The CarieScan Pro™ device has been developed to embody high accuracy, low price and ready ease of use. A key benefit for patients and practice staff is the absence of any risks associated with ionizing radiation. This safety consideration is especially important when there is a desire to monitor preventive treatments.
This detection aid for primary coronal caries should be used in conjunction with the wider patient information outlined in Fig 1. It should not be used to justify the premature placement of restorations in tooth surfaces with small initial lesions. It should also not currently be used for interproximal sites, secondary caries, root caries or assessing the depth of cavity preparations. Care should also be taken in interpreting results for recently erupted teeth.
Caries detection and monitoring are important parts of planning care and delivering modern caries management. Multiple frequency electrical caries detection and monitoring is now (with the with ACIST-based CarieScan Pro™) a practical and available method which can supplement clinical visual assessments, without the use of ionising radiation, to help support the dental team in delivering personalized modern caries management to their patients. This should allow the team to better control the disease where possible and ensure that just in time restorations are placed when lesions are found to be more extensive. OH
Dr. Nigel Pitts is Director of the Centre for Clinical Inovations at the University of Dundee, Scotland, UK. He is also Chairman of the Scientific Advisory Board for CarieScan Ltd.
Oral Health welcomes this original article.
1. Selwitz R H, Ismail A I, Pitts N B. Dental caries. Lancet 2007 369: 51-59
2. Pitts N B and Stamm J. ICW-CCT Statements. Journal of Dental Research 2004 83: Special Issue C: 125-128.
3. Pitts NB (Editorial). “ICDAS” – an international system for caries detection and assessment being developed to facilitate caries epidemiology, research and appropriate clinical management. Community Dental Health 2004 21: 193-198
4. Ismail A I, Sohn W, Tellez M, Amaya A, Sen A, Hasson H, Pitts N B. The International Caries Detection and Assessment System (ICDAS): an integrated system for measuring dental caries. Community Dentistry and Oral Epidemiology 2007 35: 170-178
5. Detection, Assessment, Diagnosis and Monitoring of Caries – Editor NB Pitts, Karger Monographs in Oral Science Vol. 21, ISBN 978-3-8055-9184-3, S. Karger AG, Basel (Switzerland), 2009.
6. Pitts N B, Longbottom C. Preventive Care Advised (PCA) / Operative Care Advised (OCA) – categorising caries by the management option. Community Dent Oral Epidemiology 1995; 23: 55-59.
7. Pitts N B. Are we ready to move from operative to non-operative/preventive treatment of dental caries in clinical practice? Caries Research 2004; 38:294-304
8. National Collaborating Centre for Acute Care, National Institute for Clinical Excellence (NICE). Dental Recall – Recall Interval between routine dental examinations: Methods, Evidence and Guidance. pp118, Royal College of Surgeons of England, London, October 2004. www.nice.org.uk/CG019fullguideline
9. Tyas M J, Anusavice K J, Frencken J E and Mount G J. Minimal intervention dentistry – a review. International Dental Journal 2000 50, 1-12.
10. Mumford, J.M. Relationship between the electrical resistance of human teeth and the presence and extent of dental caries. Br Dent J 1956 100, 239-244.
11. White, G.E., Tsamtsouris, A. & Williams, D.L. Early detection of occlusal caries by measuring the electrical resistance of the tooth. J Dent Res 1978 57,195-200.
12. Rock, W.P. & Kidd, E.A. The electronic detection of demineralisation in occlusal fissures. Br Dent J 1988 164, 243-7.
13. Sawada, K. Newly designed caries meters. Japanese Journal of Conservative Dentistry 1983 26, 353-360.
14. Huysmans M-C D N J M, Longbottom C, Pitts N B. Electrical Methods of occlusal caries diagnosis: an in-vivo comparison with visual inspection and bitewing radiography. Caries Research 1997; 31: 119-124.
15. Longbottom C, Huysmans M-C D N J, Pitts N B, Los P, Bruce P G. Detection of dental decay and its extent using AC Impedance spectroscopy. Nature Medicine 1996 2: 235 237.
16. Huysmans M-C D N J M, Longbottom C, Pitts N B, Los P, Bruce P G. Impedance spectroscopy of teeth with and without approximal carious lesions – an in vitro study. J Dent Res 1996; 75(11): 1871-1878.
17. Pitts N B. Diagnostic tools and measurements – impact on appropriate care. Community Dent Oral Epidemiol.1997; 25: 24-35.
18. Lussi A, Longbottom C, Imwinkelried S, Pitts N B. Performance and reproducibility of a laser fluorescence system for detection of occlusal caries in vitro. Caries Research 1999; 33: 261-266.
19. JD Bader, DA Shugars, AJ Bonito. Systematic reviews of selected dental caries diagnostic and management methods. J Dental Education 2001 65; 960-968.
20. JD Bader, DA Shugars. A systematic review of the performance of a laser fluorescence device for detecting caries. J Am Dent Assoc 2004 135; 1413-1426.
21. Rocha-Cabral R M et al., Autoclaving and battery capacity influence on laser fluorescence measurements. Acta Odontologica Scandinavica 2008 66: 1
22. Longbottom C, Hall AF, Czajczynska-Waszkiewicz A, Pitts NB, Los P, Kochan, S, Ricketts DJN. Caries detection by optimal clinical, radiographic, laser fluorescence and ac-Impedance spectroscopy techniques. Caries Res 2007 41:296-7.
23. N.B. Pitts, C. Longbottom, A.F. Hall, A. Czajczynska-Waszkiewicz, P. Los, M. Masalski, P. Biecek and A.M. Christie. Diagnostic Accuracy of an Optimised AC Impedance Device to Aid Caries Detection and Monitoring. Caries Res 2008 42:185-238.
24. Pitts N.B., Longbottom C., Ricketts D. and Czajczynska-Waszkiewicz A. Hidden Dentinal Caries Detection Using a Novel Electrical Impedance Device. http://iadr.confex.com/iadr/2008Toronto/techprogram/abstract_108999.htm
25. A Guimer et al., Method and device for bio-impedance measurement with hard-tissue applications. Physiol. Meas. 2008 29 S279.
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