Volumetric tomography - a new tomographic technique for panoramic units.

OBJECTIVES: To introduce a new three-dimensional dental imaging technique named volumetric tomography (VT). METHODS: The new VT imaging method utilizes an iterative frequency-based reconstruction technique. With iterative algorithms each voxel value is defined multiple times during reconstruction. Computation time is therefore relatively lengthy. However, multicore processors and graphic board programming reduce the reconstruction time, making it possible to utilize this iterative reconstruction technique in clinical practice. The new VT technique is an add-on to a standard panoramic unit (Orthopantomograph OP 200 D; Instrumentarium Oy, Tuusula, Finland). Unit enhancements include a device for patient positioning and additional software. Preliminary clinical examinations have been performed. RESULTS: Examinations demonstrated that the new VT technique gives satisfactory volumetric patient data from which tomographs may be derived for different clinical applications. CONCLUSIONS: The new VT method may be employed when tomographic examinations are required for dental clinical work.

Decolorization of a mixture of textile dyes using Bjerkandera sp. BOL-13.

The white-rot fungus Bjerkandera sp. BOL-13 was evaluated regarding decolorization of four textile dyes Reactive blue 21, Reactive black 5, Reactive orange 13 and Reactive yellow 206. Experiments were performed in batch and continuous modes. The total dye concentration in all experiments was 100 mg l(-1). The results of the batch experiments showed that the fungus decolorized all dyes but at different rates. There was, however, an increase in the ultraviolet (UV) absorbance when a medium with a low concentration of nitrogen was used. No increase in UV range was observed when the nitrogen concentration was increased. A continuous experiment was performed to study the decolorization of a mixture of three of the dyes Reactive blue 21, Reactive black 5 and Reactive orange 13. Scanning of inlet and outlet samples showed that the absorbance at the peaks in the visible range decreased by 60-66%. The UV absorbance of the outlet increased during the first days of operation after which it decreased again to reach the same level as the inlet. The hydraulic retention time in the reactor was 3 days. The medium containing the higher nitrogen concentration was used in the continuous experiment.

Marginal bone levels measured in film and digital radiographs corrected for attenuation and visual response: an in vivo study.

OBJECTIVE: To compare the accuracy and precision of measurements on marginal bone levels in differently processed digital radiographs and in film-based radiographs. METHODS: Twenty-one patients with a diagnosis of chronic periodontitis were included in this study. Periapical radiographs were exposed with the Dixi digital intraoral radiographic system (Planmeca Oy, Helsinki, Finland) and the F-speed Film (Insight, Eastman-Kodak Co., Rochester, NY), respectively. Digital radiographs were subsequently processed into two sets: (a) correction for attenuation and visual response and (b) the same correction but with an additional shift in grey levels. Patients had periodontal surgery immediately after the radiographs were exposed. The vertical distance from cementoenamel junction to the most apical part of the marginal bone was assessed. The measurements were then employed as reference standard and subtracted by the vertical distance from radiographs accordingly. Altogether, 47 sites were evaluated. Seven observers were employed for evaluation under the same viewing conditions. ANOVA was employed for statistical analysis. RESULTS: No significant differences were found between the absolute differences of the vertical distance obtained from radiographs to their corresponding reference standards when comparing differently processed digital radiographs, but the absolute differences were significantly smaller in digital radiographs than in films. Interobserver variances were not significant. CONCLUSION: Digital radiographs have a favourable measurement accuracy compared with film radiographs when assessing marginal bone levels.

Perceptibility curve test for conventional and colour-coded radiographs.

OBJECTIVE: A colour scale has been developed as a complement to the grey scale in radiographs. The aim of the present study was to compare colour-coded with conventional black-and-white radiographs in terms of the perceptibility curve test. MATERIALS AND METHODS: Twelve digital radiographs were exposed on a test object from low to high exposures and recorded using the DIXI system (Planmeca Oy, Helsinki, Finland). An aluminium test object was used containing ten object details in the form of holes with depths ranging from 0.03 mm to 0.30 mm in steps of 0.03+/-0.01 mm. The new colour scale was used to transform the conventional black-and-white radiographs into colour radiographs by specially designed software. Ten observers were asked to analyse four sets of radiographs, i.e. colour-coded and black-and-white radiographs, and reversed colour-coded and reversed black-and-white radiographs. The object detail having the lowest perceptible contrast in each radiograph was registered for each observer. Perceptibility curves were plotted based on the mean value of observer data. RESULTS: Results from the perceptibility curve test showed that the information in colour-coded radiographs was at least as good as that in black-and-white radiographs. In fact, in the lower exposure range, colour-coded radiographs exhibited better perception than conventional black-and-white radiographs. CONCLUSION: Radiographs that are colour-coded with the applied colour scale may be used as an alternative to conventional black-and-white radiographs.

Psychophysical properties of a new F-speed intraoral film.

OBJECTIVES: To compare the psychophysical properties of the new Kodak InSight F-speed intraoral dental film with those for the E-speed Ektaspeed Plus film by means of the perceptibility curve (PC) test. METHODS: A specially designed test object was used. The test object was made of aluminium and was 10 mm thick. It contained ten holes, contrast details, with the same diameter of 1.5 mm but with different depths. The depths ranged from 0.03 mm to 0.30 mm in steps of 0.03 mm. The holes were placed randomly within a square area with a total of 16 possible positions. Radiographs of the test object were obtained over the full exposure ranges of the two films. A Combex DX-907 dental X-ray unit was used operating at 10 mA and two tube potentials, 70 kVp and 90 kVp. The focus-to-object distance was 50 cm. Ten observers evaluated the radiographs under uniform artificial lighting using a view box and stated the number of perceptible representations of contrast details. In order to construct perceptibility curves, absolute values of the reciprocal of the minimum perceptible logarithmic exposure differences, 1/(DeltalogE)min, were plotted as functions of the logarithm of exposures, logE, registered by the tested films. Comparisons between the two films were made separately for the two tube potentials, 70 kVp and 90 kVp. RESULTS: The results are presented graphically. PCs for the InSight film had higher peaks than those for the Ektaspeed Plus film. This indicates that the viewers were able to perceive smaller exposure differences in the former compared with the latter. PCs for the InSight film were shifted towards the left along the exposure axis relative to the PCs for the Ektaspeed Plus film indicating that the former film is more sensitive than the latter. The integrals of the PCs for InSight film were larger than those for Ektaspeed film indicating superior psychophysical properties of the InSight film. CONCLUSIONS: From the point of view of perception, the new InSight film has such psychophysical properties in comparison with Ektaspeed Plus film that it will be the more favourable of the two in clinical radiographic practice.

Transtomography: a new tomographic scanning technique.

OBJECTIVES: To introduce and test a new tomographic technique, namely transtomography, making it possible to expose tomographic images employing the narrow beam of an advanced panoramic machine. METHODS: The working principle of the new technique is described. It combines a translational movement with a pendular movement of the beam that creates motion unsharpness analogous to that of conventional tomography. In order to verify whether the new technique works and results in tomographic images, test radiographs were exposed on phantoms. RESULTS: The principle of transtomography works and give images with properties essentially equivalent to those of conventional tomography. With the transtomographic technique using a narrow beam, tomographic images may be exposed with an advanced panoramic machine. CONCLUSION: Transtomography may be employed to expose tomographic images basically on the same indications as for conventional tomography.

Comparison of the psychophysical properties of various intraoral film and digital systems by means of the perceptibility curve test.

OBJECTIVES: To compare psychophysical properties of two intraoral films and three digital systems using the perceptibility curve (PC) test. MATERIALS AND METHODS: A test object was used to determine the exposures and exposure differences between the total thickness of the test object and details consisting of holes of increasing depth. The PCs for the two intraoral films, UltraSpeed and EktaSpeed Plus, were constructed employing exposure and exposure differences from dose response functions. Integrals of the PCs were calculated to obtain the psychophysical properties of the two films. Psychophysical properties of the two films were compared with those of the three digital systems published previously (CDR, Dixel and Digora). RESULTS: The PC for the EktaSpeed Plus showed a slightly higher peak than that for the UltraSpeed. Available exposure ranges were comparable. The PC for the EktaSpeed Plus was shifted to the left of the exposure axis indicating its higher sensitivity as compared with UltraSpeed. All three digital systems had narrower but higher peaks compared with the films. The integrals for the digital systems were considerably larger than those for the two film types. CONCLUSIONS: All the three digital systems have superior psychophysical properties compared with the two tested films.

Evaluation of endodontic files in digital radiographs before and after employing three image processing algorithms.

OBJECTIVES: Two digital image processing algorithms, one aimed at correction for exponential attenuation and one at correction for visual response, have been developed. The aims of the present study were to test whether digital radiographs processed with these algorithms improve determination of the length of endodontic files and whether such processed radiographs are comparable with the radiographs processed with a default image processing method employed by one commercially available digital intraoral system. METHODS: A dried human skull embedded in an acrylic compound was used for exposing radiographs of the upper and lower premolars and molars with endodontic files (Kerr files size 10 and size 15) positioned to the full length of the roots or 1.5 mm short of it. Radiographs were then processed in three sets. In one set, the radiographs were processed to compensate for exponential attenuation and the response of the human visual system. In the second, the radiographs were processed with the same compensation but with an additional shift in grey levels so that the output luminance in dentin at root tips corresponds to the mean of the luminance range of a computer monitor. In the third, the radiographs were processed with the default processing method in the Sidexis program. Ten viewers evaluated all radiographs. Receiver operating characteristic (ROC) curves were obtained and areas under the curves were calculated. RESULTS: For file size 10, ROC curves for processed radiographs were higher than that for originals, while for file size 15, ROC curves for processed and original radiographs were close to each other. Significant differences were found between processed and original radiographs regarding areas under ROC curves for file size 10 but not between the differently processed radiographs. For file size 15, no significant differences were found. CONCLUSION: Radiographs processed to correct for attenuation and visual response may improve determination of the length of thin endodontic files. Such processed radiographs are comparable with the radiographs processed with the default processing method in the Sidexis program.

Precipitation of heavy metals from landfill leachates by microbially-produced sulphide.

Four leachates from two landfills in Sweden were treated for the removal of heavy metals with the aid of sulphate-reducing bacteria (SRB). Both continuous and batch experiments were performed. A packed-bed process was used for sulphide production. The metals studied were As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. The continuous experiments showed that Cd and Cu were most efficiently removed and that Cr was the most difficult to precipitate. In a continuous experiment with one of the leachates, the removal of Cd, Cu and Zn depended upon the retention time in the system. In the batch experiments, precipitation of the metals was a relatively fast process. No significant differences in metal concentrations were found between experiments terminated after a day and those terminated after a week. In a batch experiment involving one of the leachates, the precipitation of Cd and Cu was shown to be dependent upon the metal:sulphide ratio. Removal of the metals increased with an increase in the sulphide:metal ratio up to 45:1. The process with SRB showed an interesting potential for removal of heavy metals from leachates. One of the two leachates for which the highest metal removals were obtained came from a landfill for hazardous waste.

Degradation of phenol and cresols at low temperatures using a suspended-carrier biofilm process.

Degradation of phenol and o-, m- and p-cresol at a concentration of 150 mg l(-1) of each compound was studied in a suspended-carrier biofilm process consisting of two aerobic stages. The fungus Mortierella sarnyensis Mil'ko dominated the microflora in the first reactor, while bacteria dominated in the second reactor. The process was studied at 4, 7, 11 and 15 degrees C. The results from the experiments showed the process to be relatively efficient even at 4 degrees C. The degradation rate was 33% of that at 15 degrees C for o-cresol. Both phenol and the cresols were degraded in the first reactor and a new peak appeared in the HPLC-chromatograms indicating the formation of one or more intermediate compounds in the first stage. These compounds were however degraded to below the detection limit in the second reactor. Small new peaks appeared in the chromatograms of the outlet from the second reactor at the maximum loading rates.

Perceptibility curves for the Digora system.

OBJECTIVES: To construct perceptibility curves (PCs) for given calibration settings in order to define psychophysical properties of the Digora storage phosphor system and to evaluate the effects of automatic exposure correction (AEC) on the PCs. METHODS: The Digora system was calibrated at two exposures, 80 microC kg(-1) (high calibration) and 40 microC kg(-1) (low calibration). Since the grey levels displayed in the radiographs are adjusted by AEC, dose-response functions at high calibration were obtained using AEC on and off modes. The dose-response function at low calibration was obtained with AEC off. The PC at each experimental setting was calculated using known physical parameters of the system and the performance of the average observer used in a previous study. In addition, PCs were also constructed using transmitted radiation flux behind the test object calculated from the attenuation coefficient in order to study observer and system performance. PCs obtained under these conditions were compared. RESULTS: The PC using calculated transmitted radiation flux behind the test object showed a wide plateau at the peak owing to AEC, while the PC obtained by a modified approach showed a higher but narrower peak. There were no differences between the two PCs using AEC on and off modes when the PCs were constructed using a modified approach. There were no differences between the two PCs obtained at high and low calibration settings or between the three PCs obtained with AEC on except for the position along the exposure axis. CONCLUSIONS: Psychophysical properties of the Digora system may be determined if we employ registered exposures from a dose-response function with AEC off under a given calibration setting. Under these circumstances the shape and height of the PCs will be unchanged irrespective of the AEC mode.

Denitrification at low temperatures using a suspended carrier biofilm process.

The denitrification process was studied in a stirred lab-scale suspended carrier biofilm reactor at low temperatures (3-20 degrees C). The reactor was filled to 50% with Kaldnes K1 carriers. The denitrification rate showed only a rather weak dependence on the temperature, the rate at 3 degrees C being approximately 55% of that at 15 degrees C. The maximum denitrification rate obtained at 15 degrees C was 2.7 g NO(x)(-)-Nm(-2)carrier d (-1). The maximum denitrification rate at 3 degrees C during an 8-day period was found to be constant. During the 8 days, the hydraulic retention time was approximately 1.5h and the inlet NO(3)(-)-N concentration was 30 mg x l(-1).

Perceptibility curve test for digital radiographs before and after correction for attenuation and correction for attenuation and visual response.

OBJECTIVE: Two digital image processing methods, correction for X-ray attenuation and correction for attenuation and visual response, have been developed. The aim of the present study was to compare digital radiographs before and after correction for attenuation and correction for attenuation and visual response by means of a perceptibility curve test. MATERIAL AND METHODS: Radiographs were exposed of an aluminium test object containing holes ranging from 0.03 mm to 0.30 mm with increments of 0.03 mm. Fourteen radiographs were exposed with the Dixi system (Planmeca Oy, Helsinki, Finland) and twelve radiographs were exposed with the F1 iOX system (Fimet Oy, Monninkylä, Finland) from low to high exposures covering the full exposure ranges of the systems. Radiographs obtained from the Dixi and F1 iOX systems were 12 bit and 8 bit images, respectively. Original radiographs were then processed for correction for attenuation and correction for attenuation and visual response. Thus, two series of radiographs were created. Ten viewers evaluated all the radiographs in the same random order under the same viewing conditions. The object detail having the lowest perceptible contrast was recorded for each observer. Perceptibility curves were plotted according to the mean of observer data. RESULTS: The perceptibility curves for processed radiographs obtained with the F1 iOX system are higher than those for originals in the exposure range up to the peak, where the curves are basically the same. For radiographs exposed with the Dixi system, perceptibility curves for processed radiographs are higher than those for originals for all exposures. Perceptibility curves show that for 8 bit radiographs obtained from the F1 iOX system, the contrast threshold was increased in processed radiographs up to the peak, while for 12 bit radiographs obtained with the Dixi system, the contrast threshold was increased in processed radiographs for all exposures. When comparisons were made between radiographs corrected for attenuation and corrected for attenuation and visual response, basically no differences were found. CONCLUSION: Radiographs processed for correction for attenuation and correction for attenuation and visual response may improve perception, especially for 12 bit originals.

Detection of approximal caries in digital radiographs before and after correction for attenuation and visual response. An in vitro study.

OBJECTIVE: To evaluate if digital compensation for exponential attenuation and the characteristics of the human visual system improves the diagnosis of approximal caries from digital radiographs. MATERIAL AND METHODS: Forty premolar teeth were mounted in plaster blocks. Radiographs of the teeth were exposed with the Dixi digital intraoral system employing a Prostyle Intra dental X-ray unit (Planmeca Oy, Helsinki, Finland). Thirteen radiographs were then processed to compensate for the exponential attenuation and for the characteristic of the human visual system using equations presented in the paper. Ten observers were asked to diagnose approximal caries in all radiographs. ROC analyses were performed. The teeth were subsequently sectioned for histological validation of the lesions. The areas under ROC curves of original and processed radiographs were compared and analysed using Wilcoxon's signed-ranks test. RESULTS: There were significant diagnostic differences between the two types of radiographs (all lesions P=0.005. enamel P=0.028, and dentine P=0.050). CONCLUSION: Digital radiographs processed to compensate for exponential attenuation and the characteristics of the human visual system significantly improves the diagnosis of approximal caries in vitro.

Visual linearization of the display of digital radiographs.

OBJECTIVES: To derive and test a method to linearize the visual response of the display of digital radiographs so that equal steps in gray levels will be perceived as equal steps in brightness. METHOD: A mathematical analysis was performed and expressions for visual linearization were derived. Twenty-four test images were computer generated to confirm that visual linearization may be achieved. Each image had three groups of square areas of different size placed in three rows. The left and right squares in each row were given different gray levels to simulate various contrast levels. The middle squares were initially given the same gray level value as one of the outer squares. The images were examined by ten observers who could change the gray levels of the middle squares so that the step in brightness between the middle square and the outer squares become subjectively equal. The test was performed three times employing two different monitors. RESULTS: The experimental test confirmed that visual linearization could be achieved. Linear regression analyses gave determination coefficients of 0.9926 amd 0.9942 for monitors with gamma-values of 1.93 and 2.50. respectively. The mean data from the ten observers perfectly fitted those theoretically calculated. CONCLUSION: Visual linearization of gray levels can be achieved but further clinical research is needed to determine if this improves diagnosis.

The effect of hyaluronan on bone and soft tissue and immune response in wound healing.

BACKGROUND: The aims of this study were to investigate the anti-inflammatory effect and the effect on bone regeneration of hyaluronan in surgical and non-surgical groups. METHODS: In each of 15 individuals, 2 teeth with defects of similar character and magnitude in the upper or lower jaw were chosen. There were at least 2 teeth between the test and the control sites. In the surgical group, a bioabsorbable membrane was used for both test and control sites, and hyaluronan was placed in the intrabony pocket of the test site. In the non-surgical group, the periodontal pockets were scaled and hyaluronan was administered 3 times with an interval of 1 week in the test pockets. Alveolar bone height and bone healing patterns were analyzed using digital intraoral radiographs. Measurements of bone height were performed in the original digital black-and-white radiographs to obtain quantitative data on bone gain or loss. Bone healing patterns were studied with color-coded radiographs, using specially designed software in a personal computer with subsequent combinations of radiographs. Gingival crevicular fluid immunoglobulin (Ig)G, C3, and prostaglandin E2 (PGE2) responses; periodontal probing depth; bleeding on probing; and the presence of plaque were studied to evaluate the anti-inflammatory effect. Data were obtained at baseline before treatment, and at 2 weeks, and 1, 3, 6, and 12 months after treatment. RESULTS: For the surgical treatments, bone height was increased in the test group treated with hyaluronan (mean value 2.2%, corresponding to an average increase of approximately 0.5 mm) and reduced in the control group (mean value -1.8%, corresponding to an average decrease of approximately - 0.4 mm) (P<0.05) after 12 months. For the non-surgical treatments, bone height was reduced by a mean value of -1.1% (corresponding to an average decrease of approximately -0.25 mm) in the test group treated with hyaluronan and -3.3% (corresponding to an average decrease of approximately -0.75 mm) in the control group after 12 months (N.S.). According to the digital color-coded radiographs, the test sites in the surgical and non-surgical groups showed apposition of bone minerals. Immune responses showed no differences during the 12 months studied for the surgical and non-surgical sites. Mean periodontal probing depths were reduced between 2.5 mm and 4.1 mm in the surgical and non-surgical groups. CONCLUSIONS: The observed difference in bone height between test and control sites in the surgical group after 12 months was less than 1 mm, which was only detectable on radiographs. No statistical difference was found on radiographs in the non-surgical group, where a decrease in bone height was found for both groups after scaling. Probing depth reduction after the surgical treatment, as well as after scaling and root planing, was as expected. Hyaluronan in contact with bone and soft tissues had no influence on the immune system in this study. Further studies are needed to determine the extent to which hyaluronan can lead to clinically significant healing of periodontal lesions.

Conventional and predicted perceptibility curves for contrast-enhanced direct digital intraoral radiographs.

OBJECTIVES: To construct Perceptibility Curves (PCs) for contrast-enhanced digital intraoral radiographs. METHODS: Radiographs of a test object having holes of increasing depths were exposed using three digital systems, the CDR (Schick Technologies, Long Island, NY, USA), the Dixel (J Morita MFG, Kyoto, Japan) and the Sens-A-Ray (Regam Medical Systems, Sundsvall, Sweden). The radiographs were contrast-enhanced and PCs constructed in the conventional way using 10 observers. Predicted PCs were calculated and compared with observer data. RESULTS: The PCs showed that contrast enhancement is effective for the perception of small contrast details, especially in the low exposure range. Predicted PCs demonstrated excellent agreement with observer data. CONCLUSIONS: Contrast enhancement should be advantageous in digital radiography. The effects of contrast enhancement on PCs may be predicted without previous knowledge of observer performance.

Eruption pattern of autotransplanted premolars visualized by radiographic color-coding.

Eruption patterns and root growth were visualized with the use of a new technique, radiographic color-coding, for comparison of the development of autotransplanted premolars with contralateral control teeth. Rates of eruption and root growth were studied. The eruption pattern and rate was assessed relative to the first molar. Maximum rates were found to occur between 30 and 60 days after transplantation. There were no significant differences between transplants and their contralaterals. Two distinct categories of eruption patterns were demonstrated. One group showed a tendency toward an initial rate of transplant eruption that was somewhat faster than that of the contralaterals. The other group showed initially retarded eruption. Possible explanations were discussed. Because no significant differences between the transplants and the contralaterals were observed, it was concluded that autotransplantation is a sound treatment option for substitution of missing teeth, at least from a tooth development point of view.

Tuned-aperture computed tomography for detection of occlusal caries.

OBJECTIVES: To evaluate the use of tuned-aperture computed tomography (TACT) for the detection of primary occlusal caries. MATERIALS AND METHODS: The material comprised 76 extracted posterior teeth, 51 with caries. Radiographs were recorded both with the Sens-A-Ray (Regam Medical Systems Int. AB, Sundsvall, Sweden) digital radiographic system and with Kodak EktaSpeed Plus film (Eastman-Kodak Co., Rochester NY, USA) employing an Orthopantomograph OP 100 (Instrumentarium Imaging, Tuusula, Finland) and a Prostyle Intra (Planmeca, Helsinki, Finland) dental unit respectively. The Sens-A-Ray radiographs were used to construct TACT slices and TACT iterative slices. The teeth were subsequently sectioned in 300 microm thick slices. Microradiographs were exposed and analysed with respect to the true presence of lesions. Seven observers subjectively evaluated the radiographs and ROC analyses performed. Conventional radiographs were compared with TACT images by means of the area under the ROC curves, Az. Paired t-test was used to compare Az values. Interobserver agreement was evaluated using the Kendall coefficient and the Friedman Anova. RESULTS: TACT radiographs were significantly better than conventional radiographs for diagnosing all types of occlusal caries combined (P(TACT) (slices)=0.02. P(TACT) (iterative slices)=0.01). However, neither TACT system was significantly better than film for enamel and dentinal caries separately. Observer agreement was moderate. However, observers demonstrated significant systematic differences in their readings (P<0.001). CONCLUSION: TACT may be a feasible method for diagnosing primary occlusal caries.

Occlusal caries detection with KaVo DIAGNOdent and radiography: an in vitro comparison.

A new laser fluorescence method, KaVo DIAGNOdent, was tested with respect to reproducibility and validity and compared with radiography regarding accuracy in the detection of occlusal caries. Seventy-six extracted premolar and molar teeth were measured twice with DIAGNOdent under both wet and dry conditions, at an interval of 2 weeks. Conventional film radiographs were exposed. Microradiographic analysis of sections of the teeth served as the gold standard. Intra-class correlation coefficient and Pearson's correlation coefficient were used to assess the reproducibility and the validity of the method, respectively. The influence of time and varying humidities on DIAGNOdent readings were analysed by two-way repeated measure ANOVA. ROC curves were plotted for DIAGNOdent readings and radiographic registration of caries by 6 observers, and the areas under the curves were compared using Student's t test. Under both wet and dry conditions, the reproducibility of the DIAGNOdent method was excellent: R = 0.97 and 0.96, respectively. The diagnostic accuracy of DIAGNOdent was significantly better than that of radiography (p< or =0.001). In this in vitro study of detection of occlusal caries, the diagnostic performance of the DIAGNOdent method was superior to that of radiography.