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Clinical References
Clinical References
The AC Impedance Technique
- The Power of Electrochemical Impedance Techniques
- Method and device for bio-impedance measurement on hard-tissue applications
- Electrical measurements for use in caries clinical trials
- Temperature dependence of the electrical resistance of sound and carious teeth
- Impedance spectroscopy of teeth with and without approximal carious lesions - an in vitro study
- Detection of dental decay and its extent using AC Impedance Spectroscopy
Abstract
Electrical phenomena are ubiquitous in nature. Simple measurements of DC current are widely used to characterise many processes but are limited in the information they provide. AC measurements, especially electrochemicaal impedance spectroscopy (EIS), can, in contrast, characterise all the electrical responses of matter whether materials or biological. A sinusoidal voltage is applied and the corresponding sinusoidal current measured, with the relationship being described by the impedance. By measuring the impedance over a range of frequencies a wealth of diagnostic information is available in fields ranging from batteries to dentistry. The CarieScan impedance platform is an electrochemical measurement system that provides a portable, cost effective alternative to existing benchmark equipment. It can collect, process, analyse and output the results of multiple frequency measurements in less than 1 second. While the first market ready product clearly demonstrates its applicability to dental diagnostics, it could be considered a platform for a number of diverse applications. Its measurement accuracy is >95% which, together with its small size, low power consumption and ultra-low applied current, makes it suitable for a wide range of medical and other applications.
Abstract
Bio-impedance measurements can be used to detect and monitor several properties of living hard-tissues some of which include bone mineral density, bone fracture healing or dental caries detection. In this paper a simple method and hardware architecture for hard tissue bio-impedance measurement is proposed. The key design aspects of such architecture are discussed and a commercial handheld ac impedance device is presented that is fully certified to international medical standards. It includes a 4- channel multiplexer and is capable of measuring impedances from 10kO to 10MO across a frequency range of 100Hz to100kHz with a maximum error of 5%. The device incorporates several user interface methods and a Bluetooth link for bidirectional wireless data transfer. Low power design techniques have been implemented, ensuring the device exceeds 8 hours of continuous use. Finally, bench test results using dummy cells consisting of parallel connected resistors and capacitors, from 10kO to 10MO and from 20pF to 100pF, are discussed.
Abstract
This paper reviews the use of electrical measurements of caries, particularly in relation to caries clinical trials. Electrical measurements change as tooth tissue porosity alters in the caries process, but several other variables also have a significant effect on these electrical measurements and hence upon their diagnostic validity. Available electrical-method data, in the context of clinical trials, relate to the use of the Electronic Caries Monitor (ECM), which measures "bulk" resistance. The device is presently limited in scope to occlusal surfaces, and only limited ECM data from clinical trials are available. In the context of clinical trials, more work is needed to determine the potential role of electrical measurements. Such research will need to focus both on an understanding of those electrical parameters which are most valuable in identifying changes and stages in the caries process in individual teeth and also on identifying the extent of the effects of the variables affecting these measurements.
Abstract
Temperature variations are expected to influence measurement error in electrical resistance of teeth. It was the aim of this study to determine the changes in electrical behavior of extracted human teeth due to temperature changes in the range of room temperature to intra-oral temperature. Nine extracted teeth were selected, and the occlusal or an approximal surface was chosen for measurement. Carious involvement of the surfaces ranged from sound to cavitated. Electrical impedance spectroscopy sweeps in a frequency range of about 100 kHz to 10 Hz were completed at selected temperatures between 22C and 40C. After fitting the data to equivalent circuits that yielded parameter values for components of the equivalent circuit, we calculated the dc bulk resistance (Rb). The temperature dependence of Rb of the surfaces with different carious involvement was very similar, and the mean drop of Rb from 20 to 35C was 45% (SD 2%). It was concluded that the electrical resistance of sound and carious tooth surfaces is inversely related to temperature.
Abstract
Caries diagnosis by the measurement of electrical resistance is hampered by polarization effects when dc or single-low-frequency ac currents are used. Electrical impedance spectroscopy, measuring impedance over a large range of frequencies, will provide more detailed information about the electrical characteristics of teeth. It was the aim of this study (a) to characterize the complex impedance behavior of whole extracted teeth, measured at the approximal surface, and (b) to identify parameters of the complex impedance behavior of the teeth which would be useful in distinguishing between degrees of carious involvement. Thirty-nine extracted premolar teeth with 59 unrestored and undamaged (excepting caries) approximal surfaces were selected. The tooth surfaces were divided into three groups according to their macroscopic appearance: sound (group S, n = 16), white- or brown-spot lesion present (group L, n = 33), or cavitated (group C, n = 10). The teeth were inserted into a jig which allowed for counter-electrode contact via a conducting gel. The working electrode consisted of a carbonated fiber material. Electrical impedance measurements were performed over a maximum range of about 1 MHz to 0.1 Hz. We analyzed electrical impedance data by fitting equivalent circuits. Fit was evaluated numerically and visually. The complex impedance spectra divided naturally into three groups which corresponded almost perfectly with the classifications of S, L, and C. The groups differed most in the dc resistance (RdC), as calculated from the impedance parameters. Mean RdC for groups S, L, and C were 68 MQ, 5.9 MQ, and 321 kQ, respectively. These means were significantly different from each other (log-transformed data, ANOVA, p /< 0.001; Tukey multiple comparisons, p < 0.001). It is concluded that the in vitro performance of electrical impedance spectroscopy in differentiating among sound, non-cavitated carious, and cavitated approximal tooth surfaces is excellent.
Abstract
Dental caries (decay), the most prevalent of diseases, represents a health problem of immense proportions. It principally affects posterior (back) teeth on occlusal (biting) and approximal (adjacent contacting) surfaces. Caries Starts as a subsurface demineralization of enamel, may progress to the underlying dentine and, eventually, to cavitation of the surface. diagnosis before cavitationwould permit targeted preventive treatment, thereby significantly improving dental health and reducing the need for expensive drilling and filling. Inaccessinility of caries initiation sites and recent changes in lesion morphology contribute to the relatively poor accuracy of conventional diagnostic methods. Among alternative techniques, measurements of electrical resistance have shown the most promise. Here we describe a new experimental technique that demonstrates an outstanding 100% correlation between ac impedance measurements of whole teeth and the actual extent of approximal caries in-vitro. Only relatively minor modifications should be required to transfer the technique to in-vivo applications.
Papers, Abstracts & Posters
- Diagnostic Accuracy of an optimised ac impedance device
- Hidden Dentinal Caries Detection Using a Novel Electrical Impedance Device
- Intra- and inter-examiner repeatability of ac-Impedance Spectroscopy to detect sound and caries sites in vivo.
- AC-Impedance Spectroscopy technique for the detection of dental caries in human teeth
- AC-Impedance Spectroscopy technique for monitoring dental caries in human teeth
- Caries Detection by optimal clinical visual, radiographic, laser fluorescence and AC-Impedance Spectroscopy Technique
- Morphology of natural carious lesions related to ac impedance characteristic of teeth
- Comparison of Visual and Micro-CT Examination to Detect Natural Caries in Extracted Teeth
- Utility of Micro-CT Examination as a Caries Validating Method with Reference to Histological Serial Sections
- Neural Network Classification Algorithms for the AC Impedance Method of Clinically Evaluating Dental Caries
- Artificial Neural Network (ANN) analyses of ac-Impedance spectroscopy derived dental caries data
- Statistical Analysis of the Effectiveness of AC Impedance in Detection of Early Caries in-vitro
- The Use of Ac Impedance Spectroscopy in Clinical Caries Diagnosis - An Initial Evaluation
- Sensitivity and Specificity of Selected Methods for Diagnosing Early Carious Changes
- A New Electrical Method for Rapid Caries Detection
Abstract
Accurate caries detection and an ability to monitor initial lesions over time are both important in modern clinical caries management. Traditional detection methods have recognised limitations in sensitivity, but enjoy high specificity, while newer methods typically trade-off decreased specificity for improved sensitivity. The aim of this work was to balance both components of diagnostic accuracy in an ac impedance device in order to be able to inform the dental team and patients. Building on earlier work, a device certified to international standards was developed with reference to repeatability data from an in vivo study with sensors adapted to occlusal and free smooth surfaces in the first instance. ac-Impedance measurements were undertaken by 4 dentists on 137 extracted teeth (80% humidity, - body temperature). Reference evaluations were a consensus of at least 3 dentists using micro-CT and magnified visual techniques. Results were presented in 3 groups: Green (G) - Sound, Yellow (Y) - caries where preventive care is advised and Red (R) - caries where operative care is advised. For occlusal surfaces: sensitivity (R vs G+Y) = 92.5%, specificity (G vs Y + R) = 92.5%, accuracy for Y lesions alone = 79.4%. For smooth surfaces: sensitivity (R vs G+Y) = 92.5%, specificity (G vs Y+R) = 92.5%, accuracy for Y lesions alone = 80.5%. It is concluded that an ac impedance device can be optimized to aid caries detection and monitoring by displaying results with symmetrically high values for both sensitivity and specificity.
Abstract
The aim of this in vitro study was to assess the ability of a new electrical ac-impedance device to detect 'hidden dentinal' occlusal caries. 128 occlusal sites on 72 extracted human molar and premolar teeth were scored for caries by a single examiner experienced in the ICDAS caries coding system - a 6-point visual assessment of clean dry teeth. The teeth were subjected to X-ray micro-Computed Tomography (XCT) and the resulting image slices scored independently for caries on a 7-point visual + XCT reference scale by 3 different examiners, using a consensus method to resolve any disagreements. The teeth were also examined using the novel electrical device by one experienced examiner. For this analysis, "hidden dentinal" occlusal caries was defined as sites scored as visually non-cavitated lesions (using ICDAS criteria) but showing dentine lesions on the reference scale (XCT). 42 sites were found by XCT to have a score of 6 (caries extending into outer half dentine) and 7 to have a score of 7 (caries into inner half dentine) where the ICDAS code was either 1 or 2 (i.e. where an enamel lesion is visible, but the surface is intact). Of the 49 sites with any dentinal caries, the novel device detected 15 as being into dentine (= 31%) and a further 23 as being in the inner 1/3 of enamel (= 47% of "hidden dentinal" lesions). Of the 7 sites with score 7 by XCT, the novel device detected 7 (100%) as being deep in dentine; of the 42 sites scoring 6 by XCT, the novel device detected 5 (12%) as being in dentine. Conclusion: a novel 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.
Abstract
The aim of this study was to determine the intra-and inter-examiner repeatability of an ac-Impedance Spectroscopy device in vivo and was part of a larger clinical study. To determine intra-examiner repeatability, four dentists examined five surfaces on two adjacent teeth in each of 19 patients using a pre-production ac-Impedance Spectroscopy (ACIST) device. A repeat ACIST examination was performed by the same dentists on the same teeth in the same patients with the same ACIST devices and sensors later on the same day. There was at least one additional patient examination performed between repeat ACIST evaluations. To determine inter-examiner repeatability, two additional groups of four dentists examined five surfaces on two adjacent teeth in each of a different group of 19 patients using an ACIST device. ACIST examinations to determine inter-examiner repeatability were performed on the same day. Each ACIST examination was able to determine if the tooth surface was sound (G), advised to have preventive care (Y) or advised to have operative care (R). For intraexaminer repeatability data from 173 surfaces were available for analysis and demonstrated agreement of 74% (95% CI 67-80%). For inter-examiner repeatability, data from 148 surfaces were available for analysis and demonstrated agreement of 71% (95% CI 63-78%). In conclusion, these results demonstrate substantial agreement for both intra- and interexaminer repeatability of an ACIST device to detect sound and carious sites in vivo.
Abstract
The aim of the study was to apply a theory of classification TREE widely used in data mining algorithms to clinical detection based on the ac-Impedance in vitro measurements of teeth at different stages of the caries process. Classification TREE is a rules-derived technique. A TREE is grown by binary recursive partitioning using the response in the specified formula and choosing splits from the variables obtained from ac-Impedance results e.g. Rb - dc conductivity, Z' - real part of the impedance. The ac-Impedance measurements were carried out using a pre-production IDMoS ac-Impedance Spectroscopy (ac-IS) device on teeth equilibrated to conditions similar to those in the mouth, i.e. humidity of 80% with temperature approximating body temperature. More than 100 teeth were studied by 4 dentists. The clinical reference evaluations of the teeth were carried out on the basis of a consensus by at least 3 dentists and with regard to micro CT images and optimal clinical visual techniques. The ac-Impedance data were analyzed using TREE classification approach and a success ratio defined as: Success ratio = number of samples in agreement with the reference standard divided by the total number of samples used was produced. The performance results were presented for all types of tooth surfaces and in 3 clinical groups: Green (G) - Sound, Yellow (Y) - caries where preventive care is advised and Red (R) - caries where operative care is advised. The following results were obtained for occlusal surfaces: G and Y + R - 93%, smooth surfaces: G and Y + R - 92%, interproximal surfaces: G and Y + R - 94%. It is concluded that the results of diagnostic accuracy are very promising.
Abstract
The aim of the study was to apply a theory of classification TREE widely used in data mining algorithms to clinical detection based on the ac-Impedance in vitro measurements of teeth at different stages of the caries process. Classification TREE is a rules-derived technique. A TREE is grown by binary recursive partitioning using the response in the specified formula and choosing splits from the variables obtained from ac-Impedance results e.g. Rb - dc conductivity, Z' - real part of the impedance. The ac-Impedance measurements were carried out using a pre-production IDMoS ac-Impedance Spectroscopy (ac-IS) device on teeth equilibrated to conditions similar to those in the mouth, i.e. humidity of 80% with temperature approximating body temperature. More than 100 teeth were studied by 4 dentists. The clinical reference evaluations of the teeth were carried out on the basis of a consensus by at least 3 dentists and with regard to micro CT images and optimal clinical visual techniques. The ac-Impedance data were analyzed using TREE classification approach and a success ratio defined as: Success ratio = number of samples in agreement with the reference standard divided by the total number of samples used was produced. The performance results were presented for all types of tooth surfaces and in 3 clinical groups: Green (G) - Sound, Yellow (Y) - caries where preventive care is advised and Red (R) - caries where operative care is advised. The following results were obtained for occlusal surfaces: G and Y + R - 93%, smooth surfaces: G and Y + R - 92%, interproximal surfaces: G and Y + R - 94%. It is concluded that the results of diagnostic accuracy are very promising.
Abstract
The aim of this study was to compare in vitro the diagnostic performance of several techniques, optimal clinical visual (ICDAS), simulated bitewing radiography (BW), and laser fluorescence (Dd-pen), with pre-production ac impedance spectroscopy (ac-IS) devices, using a combined clinical/micro-CT method as validation. 23 extracted human (permanent) premolars and molars were set in quasi-quadrant blocks and examined, at 34 occlusal and 34 free smooth surface sites, using each of the detection methods at occlusal and free smooth surface sites. The ICDAS and Ddpen methods were carried out (twice) by one examiner. The BW and Validation methods were carried out by 3 examiners (using a consensus method) and the ac-IS method was completed by two examiners (3 times). The performance data is presented as a success ratio = number of correct measurements/ total number of measurements (x100) for 2 classes: (i) sound, (ii) enamel and dentine caries, i.e. the D1 threshold. The ac-IS results were obtained using a TREE method of analysis of assessing electrical parameters. The results demonstrate that, at the D1 threshold, the ac-IS method has a superior detection performance to the other techniques.
Abstract
The aim of this study was to evaluate subjectively the variation in lesion morphology in relation to ac-Impedance Spectroscopy results. Human extracted teeth were subjected to X-ray computerised microtomography to produce a series of tomographic slices at 40 micron intervals. From these tomographic slices, naturally occurring caries lesions at various sites on the teeth could be identified and characterised. The same sites were then evaluated using ac-Impedance Spectroscopy. Ac-Impedance Spectroscopy was used to categorise caries sites into broad strata using Rb values. Rb values are correlated directly with the porosity of the lesion. The range of computerised micro-tomographic appearances of the lesions was evaluated within these strata. Naturally occurring lesions within specific Rb strata on all surfaces of teeth demonstrated variation in both two-dimensional and three-dimensional characteristics. This is in contrast to simplistic, hard-edged representations of lesions when viewed classically on dental radiographs and as often characterised in textbooks. It is concluded that lesion morphology is an important element to consider when assessing lesion behaviour and that the ability of ac-Impedance Spectroscopy to characterise variable lesion morphology in three dimensions should facilitate the monitoring of progression, arrest or regression of naturally-occurring caries lesions over time.
Abstract
The aim of this work was to determine the agreement of clinical visual and micro-CT evaluation to detect natural caries lesions in extracted human teeth. The experimental approach involved collection of forty extracted teeth, stored at all times in a saturated solution of thymol with physiological saline. The teeth comprised 10 deciduous molars and a total of 30 permanent molars and premolars. All tooth surfaces were photographed at x10 magnification using a dissecting microscope and digital camera. All teeth were exposed to X-radiation to create micro-tomographic slices at approximately 40 micron intervals in three axes: apical to coronal, mesial to distal and buccal to palatal/lingual. Image stacks were collated and manipulated using computer software to facilitate demarcation of the enamel-dentine junction and the presence of any stage of dental caries. Images were then viewed by two authors to determine the presence and site of any caries lesions (lesion site was marked on images of the teeth stored on a PC). Separately, and without knowledge of the micro-CT evaluation, the teeth were dried for 5 seconds using compressed air and examined under a halogen light source by one author. The presence of caries was marked on print-outs of pictures of the teeth taken earlier. A comparison was made of the two evaluations to determine the agreement (Cohen's kappa) between the two methods. The result for the kappa score for all surfaces was 0.48, while individual surfaces demonstrated higher kappa scores: 0.85 occlusal, 0.55 approximal and 0.71 free smooth surfaces. It is concluded that, for these teeth and these examiners new to the method, moderate to good agreement can be obtained between caries detection using visual and micro-CT evaluation.
Abstract
The aim of this work was to compare the depth of caries as determined by a) conventional histology and b) micro-CT evaluation at approximal sites in deciduous molar teeth. Ten extracted deciduous molars, stored in thymolised physiological saline, were subjected to micro-CT (XCT) imaging. XCT images were produced in the mesio-distal plane of the teeth in 40 micron 'steps' and the sequential images viewed on a pc, by two independent observers, to determine the presence and depth of any caries present on the approximal surfaces. The scoring codes for caries were: 1-Sound; 2-Uncertain if sound or enamel caries present; 3-caries in outer third enamel; 4-caries in middle third enamel; 5-caries in inner third enamel including EDJ; 6-caries in outer 1/2 dentine; 7-caries inner 1/2 dentine. Three months later the teeth were serially sectioned in the mesio-distal plane to produce 250 micron sections, then examined (by the same observers) using x10 transmitted light-microscopy and scored for caries using the same scale as for XCT. The level of agreement of the scores for XCT and histology was determined using a linear correlation coefficient. Results: Prevalence by histology scores were: sound=7, uncertain=1, enamel caries=5, dentine caries=7. The correlation coefficient between XCT and histology was r2 =0.87. Cross-tabulation of the XCT and histology scores revealed that: 15/20 sites were in total agreement in relation to sound status or lesion depth; for 3/20 histology score > XCT; 1/20 XCT > histology. In 1/20 sites histology scored a caries lesion scored sound by XCT. In conclusion, for approximal sites on deciduous molar teeth XCT shows promise as a non-destructive method of validation for the presence and depth of caries lesions.
Abstract
The aim of this study was to explore the use of fitting methods and classification algorithms based on neural network applications to caries detection by the ac impedance method. Fifty one extracted human teeth, with lesions representing a range of different stages in the development of the caries process were studied. The teeth were stored in thymolised physiological saline. The experimental conditions were similar to the oral cavity. Measurements were made in vitro using a prototype caries detection device (IDMoS Dental Systems Ltd., UK). More than 600 ac impedance curves were measured and fitted to determine values for both the Rb (dc resistivity) and f (phase angle) parameters. Rb and f values were then used to build a neural network to enable the evaluation of caries stages in a clinically meaningful way. Following impedance measurements, teeth were studied using the microCT method to obtain validating information as to the true status of each tooth surface. The Rb values were classified initially for sound surfaces, incipient lesions and cavitated lesions. Clinical classification of Rb and f values was then carried out using a Learning Vector Quantization neural network. The network consists of neurons that are represented by a vector of parameters. In this experiment each neuron is a triplet (Rb, f, class). The neural network classifies the measurement result as a class of a neuron on the basis of the lowest distance from a certain neuron defining a clinical class.
Abstract
The aim of this study was to explore further the use of fitting algorithms based on artificial neural network in caries detection on teeth surfaces using the ac-Impedance method. One hundred and two extracted teeth, representing different caries development stages were studied. The teeth were stored in thymolised physiological saline. The experimental conditions were similar to oral cavity and all measured surfaces were blotted dry for 5 seconds. Measurements were made using IDMoS manufactured sensors connected to pre-production caries detection devices. Registered ac impedance curves were fitted to determine values for both the Rb (dc resistivity) and f (phase angle). More than two thousand measurements were carried out for this study. Rb and f values were used to build neural networks to enable clinical evaluation of caries. Following impedance measurements, teeth were studied using the visual, microCT and histology methods. The Rb values were classified accordingly: above 0.5 MOhm, from 0.25 to 0.5 MOhm and below 0.25 MOhm for sound surfaces, caries where with preventive care adviced (PCA) and caries with operative care adviced (OCA), respectively. Clinical classification was based on the experimental Rb and f values. In current approach neuron was a triplet (Rb, f, class). Success ratio = number of samples in agreement with the reference standard divided by the total number of samples used was produced. Values of success ratio obtained using these ANN for occlusal surfaces were: 90% for sound, 88% for caries with PCA, 91% for caries with OCA; for smooth surfaces: 97%, 83%, 100% and for approximal surfaces: 94%, 84%, 83%, respectively. It is concluded that the ANN method with ac-Impedance Spectroscopy is capable of high diagnostic accuracy.
Abstract
Abstract: The aim of study was to develop a new method of ac impedance spectra analysis to improve still further the resolution of the measurements of the early caries lesion. Whereas in most previous studies on electrical properties of teeth the values of the resistance parameters were used directly for clinical applications, in the present work capacitance parameters were also analyzed. The measurements were carried out using a small radius microelectrode in a simulation of oral cavity conditions. Radiographic, photographic and scanning electron microscopic analysis methods were used to evaluate the true carious status of each of 20 un-restored human premolar teeth. The smooth surfaces of the samples were assigned to one of two groups according to their macroscopic condition by the consensus of four examiners by visual inspection: S (sound) and L (lesion), if a white or brown spot carious lesion. A student's t test for the differences between the means of deferent groups at different variances was used to statistically analyse results and assumed the null hypothesis is the absence of differences between the means in the compared groups. The probability of the appearance of a type I error is determined, rejecting the null hypothesis, thus the differences between the averages of compared tests results from chance. The maximum admissible probability of committing type I error risk, i.e. level of confidence, is 0.05 (Bland, 2000). The results for the couples of SB (sound buccal) - L (lesion): T- 0.0044 and psi- 0.0000, and SD (sound distal) - L (lesion): T - 0.0000 and psi - 0.0000 are lower than the assumed level of confidence and it was statistically impossible to make an error in caries detection. Consequently, 100% sensitivity and specificity of early caries detection on smooth surfaces are reported in vitro analysing resistance and capacitance parameters.
Abstract
It is important to be able to detect dental caries. Among the many techniques developed, several utilise changes in electrical impedance of the tooth as a result of increasing porosity of dental enamel caused by carious demineralisation. The present study uses Alternating Current Impedance Spectroscopy Technique (ACIST) to detect dental caries. Although widely used in other fields, there have been few studies using AC impedance spectra in relation to dentistry. In order to carry out AC impedance measurements in the mouth a suitable device had to be constructed that would be safe, rapid and accurate.
Abstract
The main aim of this study was determining the sensitivity and specificity of chosen diagnosing methods for early caries lesions detection on the occlusal surfaces of molars in relation to the development of changes validated histologically.
Abstract
The electrical properties of dental tissues have been recognised for many years as potentially useful in the early detection of dental caries. Several devices have been constructed in recent years as an aid to diagnosis that measure the response to a single ac frequency applied through a tooth. Other workers have realised the advantage of using a range of frequencies when measuring the response to ac voltage or current signals. The work presented here shows the development of a new device for rapid measurement of the response over a range of frequencies when applied to human teeth. Preliminary results from in-vitro experiments on whole human teeth indicate that this device may be a very useful clinical aid for caries diagnosis.
Caries Detection and Management
- A systematic review of the performance of a laser fluorescence device for detecting caries
- Systematic Reviews of Selected Dental Caries Diagnostic and Management Methods
- Autoclaving and battery capacity influence on laser fluorescence measurements
- Dental Caries
- Are we ready to move from operative to non-operative/preventative treatment of dental caries in clinical practice?
- Clinical Literature Review
Abstract
The DIAGNOdent, or DD (KaVo America, Lake Zurich, Ill.), a device for detecting caries using laser fluorescence,has been growing in popularity during the past three years. Although several evaluations of its diagnostic performance have appeared in the literature, the range of reported performances is extensive. Types of Studies Reviewed. The authors conducted a systematic review of the literature to assess the diagnostic performance of the DD. Of 115 articles identified in the search, 25 studies were included in the review according to criteria requiring histologic validation and outcomes expressed as sensitivity and specificity values. For detection of dentinal caries,sensitivity values ranged widely (0.19 to 1.0), although most tended to be high. Specificity values exhibited a similar pattern, ranging from 0.52 to 1.0. In comparison with visual assessment methods, the DD exhibited a sensitivity value that was almost always higher and a specificity value that was almost always lower. The body of evidence is characterized largely by in vitro studies, so that generalization to the clinical setting is uncertain. Because caries thresholds varied substantially across the studies, synthesized estimates of performance were not possible. Conclusions and Clinical Implications. The DD clearly is more sensitive than traditional diagnostic methods; however, the increased likelihood of false-positive diagnoses compared with that with visual methods limits its usefulness as a principal diagnostic tool.
Abstract
A systematic review of the English-language literature was conducted to address three related questions concerning the diagnosis and management of dental caries: a) the performance (sensitivity, specificity) of currently available diagnostic methods for carious lesions, b) the efficacy of approaches to the management of noncavitated or initial carious lesions, and c) the efficacy of preventive methods among individuals who have experienced or are expected to experience elevated incidence of carious lesions. From 1,328 caries diagnostic and 1,435 caries management reports originally identified, thirty-nine diagnostic studies and twenty-seven management studies were included in the final evidence tables. Point estimates or reasonable range estimates for the diagnostic validity of methods for the diagnosis of carious lesions could not be established from the literature reviewed. There are insufficient numbers of reports of diagnostic performance involving primary teeth, anterior teeth, and root surfaces. For posterior occlusal and proximal surfaces, quality issues and the variation among studies precludes establishing such estimates. The apparent differences in sensitivity among methods are generally smaller than the variation reported within methods. The literature on the management of noncavitated carious lesions consisted of five studies describing seven experimental interventions. Because these interventions varied extensively in terms of management methods tested as well as other study characteristics, no conclusions about the efficacy of these methods were possible. The literature on the management of individuals at elevated risk of carious lesions consisted of twenty-two studies describing twenty-nine experimental interventions. The strength of the evidence for the efficacy of fluoride varnish for prevention of dental caries in high-risk subjects was fair, and the evidence for all other methods was incomplete. Because the evidence for efficacy for some methods, including chlorhexidine, sucrose-free gum, and combined chlorhexidine-fluoride methods, is suggestive but not conclusive, these interventions represent fruitful areas for further research.
Abstract
Aim. To evaluate the influence of probe tip autoclaving and depleted alkaline batteries on laser fluorescence (LFDIAGNOdent) device performance. Material and methods. One-hundred-and-twenty occlusal sites were analyzed with an LF device in nine conditions: No autoclaved probe and probe after 5, 10, 15, 20, 25, 30, 40, and 50 autoclaving cycles. Subsequently, the performance of the device was analyzed with: New batteries, batteries with 1.49/1.39 V, 1.38/1.37 V, 1.36/1.34 V, 1.33/1.32 V, and lower than 1.32 V. LF values, sensitivity, specificity, accuracy, and area under the ROC curve were compared. Results. In the probe study, sensitivity was lower after 50 sterilizing cycles, though specificity was higher than the assessment performed using a new tip. In the batteries study, specificity was higher for depleted batteries, but LF performance did not differ significantly among the groups. Conclusion. Batteries do not significantly influence device performance, but consecutive sterilization of probes in autoclave alters readings, downgrading its performance.
Abstract
Dental caries, otherwise known as tooth decay, is one of the most prevalent chronic diseases of people worldwide, individuals are susceptible to this disease throughout their lifetime. Dental caries forms through a complex interaction over time between acid-producing bacteria and fermentable carbohydrate, and many host factors including teeth and saliva. The disease develops in both the crowns and roots of teeth, and it can arise in early childhood as an aggressive tooth decay that affects the primary teeth of infants and toddlers. Risk for caries includes physical, biological, environmental, behavioural, and lifestyle-related factors such as high numbers of cariogenic bacteria, inadequate salivary flow, insufficient fluoride exposure, poor oral hygiene, inappropriate methods of feeding infants, and poverty. The approach to primary prevention should be based on common risk factor. Secondary prevention and treatment should focus on management of the caries process over time for individual patients, with a minimally invasive, tissue preserving approach.
Abstract
This review focuses on the clinical interactions between patients and the dental team, not on caries prevention at a public health level. Many dentists no longer take a narrow surgical view seeking to apply interventive treatments as a one-off event at a certain trigger point of disease severity and the evidence that caries is an initially reversible chronic disease with a known multi-factorial aetiology is being appreciated more widely. The caries process should be managed over time in an individualized way for each patient. Very few individuals can be considered to be truly 'caries free' when initial lesions as well as more advanced dentine lesions are considered. It is now clear that, by itself, restorative treatment of the disease does not 'cure' caries. The caries process needs to be managed, in partnership with patients, over the questions posed in the title should be, in many cases, that we are ready to move to non-operative/preventive care (if we have not done so already). However, this should be for appropriate stages of lesion extent and in patients who respond to advice on recall frequency and preventive behaviours.
Abstract
In the literature on caries detection and diagnosis there is a wide variation in the classifications of caries and the methods used to validate these classifications. This article reviews existing classification methods and presents a robust clinical validation technique. The review continues to discuss electrical methods, in particular impedance spectroscopy, for caries detection and compares with other clinical diagnostic tools.
