Oral Health Group

Electrical Caries Scanning

July 1, 2012
by George Freedman, DDS FAACD, FACD, FADFE

Dental caries is a major global disease! It is found worldwide, in a majority of the population, and it affects all ages, from the very young to the very old. While increasingly treatable, this condition remains a significant health and financial burden to many individuals, and to the population as a whole.

From a dental diagnostic perspective, how can the practitioner determine whether a tooth is carious, demineralized, remineralized, or simply stained? If it is carious, what is the most appropriate course of action? Can preventive and remineralizing procedures suffice? Or is it time to surgically intervene, and restore the tooth? Most importantly, how can the practitioner utilize predictable evidence-based data to guide treatment planning?


Lesion detection determines whether disease is or is not present. Lesion assessment characterizes and monitors a lesion once disease has been detected. Caries diagnosis is a professional human summation of all the available data.1

The traditional caries diagnostic tools include the dental explorer, dental radiography, and operator vision and judgment. Unfortunately, the explorer is as likely to transfer dental disease to healthy tooth surfaces as it is to find it diseased ones. Digital radiographs, while a great improvement over analogue techniques, still offer a two-dimensional representation of a three-dimensional structure; it is difficult to conclusively identify and locate early decay. The practitioner’s vision, even when assisted by magnification loupes and lighting, is at best a subjective tool that, combined with varying judgment parameters, makes it difficult to standardize the diagnostic process.

Traditional caries therapy strategy has involved “watch and wait” inaction, recommending only the monitoring of the disease process until the cavitation is significant enough to require surgical intervention. This approach has led to an inevitable outcome: large restorations and eventual tooth loss. Early stage dental disease can be identified and often controlled without tooth preparation.2 The ability to assess and control the disease process, averting or delaying restoration (and then re-restoration) is the greatest advantage of early detection.3 Dental professional care must be personalized and preventive in outlook.4 Current state of the art caries management requires proactive intervention, a comprehensive protocol of early detection, continued assessment, and differential diagnostic intervention.5

The parameters of an acceptable method for caries diagnosis include simple, non-invasive, reliable, sensitive, specific, and valid measurements based upon specific biologic processes directly related to the caries process.6 The process and technology must also be affordable, user-friendly, and readily implemented in the general practice.

Electrical caries detection can contribute significantly to clinical detection and assessment but should be integrated with other diagnostic/prognostic methods and patient risk data to develop appropriate and effective early interception and conservative treatment options. Numerous electrically-based diagnostic devices have been developed over the past half century.7-11 Some were introduced commercially and enjoyed varying, but limited, short-term popularity. In the mid 1990s, a novel process utilizing multiple electrical frequencies was proposed.12 This technology was better able to differentiate between health and disease in the hard dental tissues.13 Light-based optical caries detection systems available at that time were somewhat limited in detecting early lesions and were often confused by the presence of staining to give false positive readings.14,15

AC Electrical Impedance Spectroscopy (ACIST) is a technology that can characterize and differentiate the electrical responses of all materials, whether biological or restorative. The technique involves the application of a sinusoidal voltage to a surface, and the subsequent measurement of the sinusoidal current; the relationship between these is described as impedance. The analysis of the hard tissue impedance over a range of frequencies yields a significant quantity of data that provides repeatable diagnostic information in dentistry. (Fig. 1) The technique can optimize the often conflicting parameters of specificity and sensitivity to strike a balance with symmetrically high values for both.16

The process is completely safe and innocuous. A minute electrical current is passed through the patient’s tissues. The diagnostic voltage does not pose any health risks, and patients cannot detect it.

The CarieScan PRO (CarieScan Ltd. Dundee, United Kingdom) with its innovative Remote View Software, represents major advances both in dental diagnostics and in clinical and patient-oriented documentation. (Fig. 2) Lesions can be identified and evaluated very early in the dental caries process with a minimum of false positives.15 This enables the practitioner to develop specific treatment planning options and to improve maintenance and restorative outcomes. In addition, the scanner’s significantly enhanced ability to detect hidden dentinal caries (invisible to traditional diagnostic tools) is a major clinical advantage.16

The Remote View Software acquires data wirelessly from the PRO and files it in the custom database. (Fig. 3) Since the data is patient-based, it can be directly linked and accessed from practice management software. This allows it to present patient data in a variety of useful formats for both the professional and the patient. An intuitive graphic user interface generates vivid numeric and graphic data. The readily visible and highly understandable imagery are utilized as both a patient education tool (Fig. 4) and an accessible patient chart documentation. (Fig. 5) Various reports can be generated in .pdf format that can be immediately printed for the patient to take home.

The practitioner’s ability to provide an exhaustive and historically comparable series of records that can assess the patient’s personal success in their oral health management (or lack thereof) is of great value to both. Any sudden changes in oral health or maintenance habits can be identified and monitored. Individual teeth that exhibit early demineralization or caries formation can be identified and proactively treated; the outcome of the intervention can then be assessed regularly and accurately.

The CarieScan PRO System should be checked on a daily basis. Insert the blue cable test adaptor into the unit. Close the contact with the cable and complete the test. (Fig. 6)

Snap the single use sensor with the wire tufts on the CarieScan PRO and click into place. (Fig. 7)

Attach the lip hook cable to the scanner and hang the metal hook passively anywhere over the patient’s lips (or hold in the patient’s fingers) to close the ACIST electrical circuit. (Fig. 8)

Isolate the teeth to be scanned with cotton rolls on both sides of the quadrant, suction devices (Fig. 9) or under rubber dam. (Fig. 10)

The teeth to be tested are air-dried to eliminate debris and saliva. (Fig. 11)

The CarieScan PRO “ENTER” button is pressed to start the measurement. (Fig. 12) Once the blue indicator light flashes, the sensor is placed directly at the specific site on the tooth surface to be measured. (Fig. 13) and (Fig. 14)

The device applies a frequency sweep to the tooth surface, and analyzes each spectrum in less than one second.

Customized software extracts a clinically relevant diagnostic score and after 4 audible beeps, both numeric and visual results are displayed on the unit. (Fig. 15) The CarieScan PRO unit can operate independently or communicate to a co
mputer via Bluetooth.

To proceed to another surface or another tooth, simply reposition the sensor to the new site and begin measuring again.

Once the carious tooth structure is positively identified and located, tooth preparation can proceed with confidence. (Fig. 16) The decayed material is removed (Fig. 17) and the occlusal surface is restored (Fig. 18).

The CarieScan PRO is an impedance platform electrochemical measurement system that works by subjecting the tooth to a very low level, multiple frequency electrical current. It then collects, processes, and analyzes the information against a scientifically established database to detect, assess, and assist in diagnosing the presence of demineralization and dental caries from the very earliest stages. This offers the clinical practitioner an affordable and cost-effective device for protecting the integrity of their patients’ dentition and oral health. It is small, cordless, and ergonomic for easy utilization multiple times every day. The associated Remote View Software links the CarieScan PRO to the patient management system and provides data organization and presentation tools for patient monitoring and education. OH

Dr. George Freedman is a founder and past president of the American Academy of Cosmetic Dentistry, cofounder of the Canadian Academy for Esthetic Dentistry, Diplomate of the American Board of Aesthetic Dentistry and Regent of the IADFE. His most recent textbook is “Contemporary Esthetic Dentistry” (Elsevier). Dr. Freedman sits on Oral Health’s Editorial Board (Dental Materials and Technology), is a REALITY Team Member and lectures internationally on dental esthetics and technology. A McGill graduate, Dr. Freedman maintains a private practice limited to Esthetic Dentistry in Markham, ON. Oral Health welcomes this original article.

1. Pitts N.B, How Electrical Caries Detection and Monitoring With CarieScan Can Help Deliver Modern Caries Management, Oral Health Journal, July 2010 p.

2. 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.

3. 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

4. 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

5. Goldstep F, Proactive Intervention Dentistry: A Model for Oral Care Through Life, Compendium, June 2012, 394-404

6. Freedman G, Contemporary Esthetic Dentistry, Ch. Cariology and Caries Management, Elsevier, December 2011, p.17

7. 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.

8. 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.

9. Sawada, K. Newly designed caries meters. Japanese Journal of Conservative Dentistry 1983 26, 353-360.

10. Rock, W.P. & Kidd, E.A. The electronic detection of demineralisation in occlusal fissures. Br Dent J 1988 164, 243-7.

11. 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.

12. 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.

13. Pitts N B. Diagnostic tools and measurements — impact on appropriate care. Community Dent Oral Epidemiol.1997; 25: 24-35.

14. JD Bader, DA Shugars, AJ Bonito. Systematic reviews of selected dental caries diagnostic and management methods. J Dental Education 2001 65; 960-968.

15. 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.

16. 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

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