Background and aims
With the introduction of Cone Beam Computed Tomography (CBCT) in dentistry, a question has been raised whether the technique significantly increases the diagnostic accuracy in comparison with other techniques or not. Therefore, the present study was undertaken to assess the accuracy of CBCT modality in detecting proximal carious lesions as compared to conventional periapical radiographs.
Materials and methods
This diagnostic study was carried out on 84 human extracted molars and premolars. The teeth were mounted and divided in 28 blocks of 3 teeth. Periapical and CBCT images of teeth were obtained. Five observers scored the images for the detection of proximal carious lesions using a 2-point scale (caries, present; caries, absent). The gold standard was determined by histopathologic sections. Sensitivity, specificity, PPV, NPV and receiver operating charac-teristics (ROC) curves were traced for observers in both systems. The results were analyzed by paired t-test.
The area under the ROC curve, sensitivity, specificity, accuracy, positive and negative predictive values of CBCT images were 0.568, 0.835, 0.637, 0.714, 0.598 and 0.856, respectively. These parameters were 0.432, 0.837, 0.722, 0.77, 0.687 and 0.858 for the periapical conventional technique, respectively.
The CBCT images did not enhance detection of proximal caries in comparison with periapical images.
Cone Beam CT; periapical imaging; proximal caries
The aim of this in vitro study was to evaluate the effect of two different chemomechanical caries removal (CMCR) agents on dentin microhardness.
Materials and Methods:
In this study, the crown portion of ten carious-free and ten caries-affected teeth were selected. In carious-free samples, the teeth were decoronated at the level of cemento – enamel junction. Only the crown portion of the teeth was selected. Occlusal one-third of the crowns were cross-sectioned and discarded to expose the dentin, and it was divided into two groups, five teeth in each group. Then, they were further sectioned longitudinally through the centre. In one group, no agent was applied on one half and Carisolv was applied on other half. In another group, no agent was applied on one-half and Carie-Care was applied on the other half for 1 min. In carious samples, the crowns were sectioned through the centre of carious lesion. Carisolv was applied on one-half and Carie-Care was applied on the other half. After using CMCR agents, surface hardness of dentin was examined using Vickers hardness number (VHN).
Statistical Analysis and Results:
The data were analyzed using t-test and one-way analysis of variance (ANOVA). There were no significant difference among normal dentin (62.91 ± 2.76), Carisolv-treated normal dentin (61.72 ± 2.89), and Carie-Care-treated normal dentin (61.90 ± 3.19). In carious samples, the results of Carisolv-treated dentin (58.57 ± 2.62) was not statistically significantly different from those of the Carie-Care-treated dentin (56.77 ± 4.41).
In conclusion, neither of the CMCR methods caused a significant change in the microhardness of normal dentin and the treated carious dentin.
Chemomechanical caries removal; carisolv; carie-care; dentin microhardness
Several studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to nondestructively measure the severity of demineralization in the important occlusal surfaces. The purpose of this study was to assess the potential of PS-OCT and OCT methods for the measurement of the depth of natural occlusal carious lesions. Teeth were screened for potential occlusal lesions using near infrared imaging (NIR). A PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of the area of interest on the occlusal surface. The teeth were serial sectioned to 200 μm thickness and examined with polarized light microscopy (PLM) and Transverse Microradiography (TMR) for comparison. The lesion depth measured nondestructively with PS-OCT was compared to the lesion depth measured with PLM and TMR to assess the performance of these methods and determine if polarization sensitivity is required. The lesion depth measured using OCT correlated well with the lesion depths measured with TMR and PLM. Although polarization sensitivity provided better contrast it was not necessary to have polarization sensitivity to identify deep occlusal lesions.
near-IR imaging; optical coherence tomography; dental enamel; dental caries; polarization; microradiography; occlusal lesions
To compare different radiographic methods for assessing endodontically treated teeth.
Materials and Methods
Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 mm3 and 0.2 mm3 voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p<0.05).
The intra-observer kappa for each observer ranged between 0.327 and 0.849. The inter-observer kappa for each observer for both readings ranged between 0.312 and 0.749. For the ideal root canal treatment group, CBCT with 0.2 mm3 voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores.
CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.
Root Canal Therapy; Radiography, Dental; Cone-Beam Computed Tomography
Objectives. To compare the ability of endodontists to determine the size of apical pathological lesions and select the most appropriate choice of treatment based on lesions' projected image characteristics using 2 D and 3 D images. Study Design. Twenty-four subjects were selected. Radiographic examination of symptomatic study teeth with an intraoral periapical radiograph revealed periapical lesions equal to or greater than 3 mm in the greatest diameter. Cone-beam Computed tomography (CBCT) images were made of the involved teeth after the intraoral periapical radiograph confirmed the size of lesion to be equal to greater than 3 mm. Six observers (endodontists) viewed both the periapical and CBCT images. Upon viewing each of the images from the two imaging modalities, observers (1) measured lesion size and (2) made decisions on treatment based on each radiograph. Chi-square test was used to look for differences in the choice of treatment among observers. Results. No significant difference was noted in the treatment plan selected by observers using the two modalities (χ2(3) = .036, P > 0.05). Conclusion. Lesion size and choice of treatment of periapical lesions based on CBCT radiographs do not change significantly from those made on the basis of 2 D radiographs.
The aim was to assess the accuracy and reproducibility of measurements of chemically created periapical lesions using limited cone beam CT.
Periapical lesions were chemically created in 18 mandibular cadaver teeth. Mandibles were dissected buccolingually using a bone-cutting burr. Diameters and depths were measured directly in the cross-sectional slices using a precision digital caliper. The cross-sectional slices were then embedded in wax, and cone beam CT images were acquired using a NewTom® 3G Plus scanner with both 6 inch and 9 inch fields of view (FOVs). Two oral radiologists measured the diameter and depth of periapical lesions on the cross-sectional images using the built-in measurement tools. Measurements were repeated after a 1 week interval. Inter- and intraobserver agreement was calculated by ANOVA. Regression analysis was used to test the correlation between the cone beam CT and digital caliper measurements.
No significant differences were found in diameter or depth measurements between or within observers or between 6 inch and 9 inch FOV images. Regression analysis of diameter and depth measurements made by direct caliper versus 6 inch or 9 inch FOV images revealed a high regression coefficient (for diameter: 6 inch FOV, R2 _ 94.6%; 9 inch FOV, R2 _ 94.8%; P<0.001; for depth: 6 inch FOV, R2 _ 99.3%; 9 inch FOV, R2 _ 99.3%; P<0.001) showing a strong linear relationship. For the diameter, the mean deviation from direct caliper measurements was 0.0625 mm and 0.08958 mm, respectively; for the 6 inch FOV and 9 inch FOV images, and for depth, the mean deviation was, respectively, −0.1001 mm and 0.09875 mm.
Cone beam CT yielded highly accurate and reproducible results in the quantitative assessment of periapical lesions.
cone beam computed tomography; periapical lesion; quantitative measurement
A prospective study was initiated in order to detect changes in the levels and proportions of Streptococcus mutans, S. sanguis, and lactobacilli before and at the time of caries development on occlusal fissures. The bacteriological analysis was performed on 195 teeth that received four examinations at approximately 6-month intervals. The data obtained from 42 carious fissures and 153 caries-free fissures strongly indicated an etiological role for S. mutans in most of the diagnosed fissure lesions. This was demonstrated by the longitudinal analysis, which showed the proportions of S. mutans to increase significantly at the time of caries diagnosis, and by cross-sectional comparisons, which showed that the proportions of S. mutans in the carious fissures were significantly higher than in caries-free fissures. Three subjects who had a low caries expereince developed five new carious lesions. Lactobacilli were prominent members of the caries-associated flora in these subjects greatly outnumbering S. mutans. The levels and proportions of S. sanguis tended to be higher in the caries-free fissures. Altho1gh the results are striking in that they implicate S. mutans in fissure decay, they show that clinical decay can occur in a few instances in the absence of detectable S. mutans, as was observed in the fissures high in lactobacilli.
Radiography plays an important role in the detection of interproximal caries.
The aim of the present study was to determine diagnostic accuracy of chargecoupled devices (CCD), Photo Stimulable Phosphor (PSP) and film radiography in detecting non-cavitated caries.
Patients and Methods
Seventy-two non-cavitated approximal surfaces of extracted human posterior teeth were radiographed under standardized conditions using three intraoral modalities: CCD Dixi3 (Planmeca, Finland), PSP Digora PCT (Soredex, Finland),and E-speed film (Kodak, USA). Radiographs were interpreted by four observers and caries lesions were classified as sound (R0), restricted to enamel (R1), reaching the dentinoenamel junction (DEJ) and the outer half of the dentin (R2) and the inner half of the dentin (R3). The teeth were subsequently sectioned for histological analysis which served as the gold standard for radiographic examination.
Microscopic examinations showed that the distribution of caries were 63.9% sound, 18.1% enamel, 9.7% DEJ and outer half of the dentin and 8.3% into the inner half of the dentin.
The sensitivity and specificity of film, CCD and PSP for the detection of enamel caries were 38% and 98%; 15% and 96 %; and 23% and 98%, respectively.
The sensitivity and specificity of film, CCD and PSP for the detection of both dentin and enamel caries were 55% and 100%; 45% and 100% ; and 55% and 100%, respectively.
The results demonstrated that the diagnostic accuracy of digital images is similar to that of conventional film radiography in the detection of non-cavitated approximal caries.
Radiography, Dental, Digital; Dental Caries; Diagnosis
The aim of this study was to compare the accuracy of cone beam CT (CBCT) with intraoral radiographs for detection of occlusal caries.
A set of 60 extracted teeth were imaged using a Sirona Galileos CBCT system (Sirona Dental Systems, Bensheim, Germany) and an intraoral Planmeca® system (Planmeca OY, Helsinki, Finland). Six observers looked at both modalities and used a five-point confidence scale to evaluate presence or absence of occlusal caries. Histology was used as the gold standard. Receiver operating characteristic analysis and weighted kappa statistics were used for statistical analysis. Differences in the area under the curve (AUC) values between observers and modalities were analysed using analysis of variance (ANOVA). Differences in sensitivity and specificity were analysed using the Wilcoxon test. Interobserver and intraobserver reliability was assessed by weighted kappa scores.
The mean value and standard deviation of AUC was 0.719 ± 0.038 for CBCT and 0.649 ± 0.062 for the intraoral radiographs. The ANOVA results demonstrated that there was no significant difference between the modalities and the observers. The interobserver kappa for pairs of observers ranged from fair to substantial for bitewings (0.244–0.543) and CBCT (0.152–0.401). Four out of six observers reported higher sensitivity but lower specificity with CBCT. The Wilcoxon exact p-value showed no difference in sensitivity (0.175) or specificity (0.573) between the two modalities.
Based on the results we conclude that the Sirona CBCT unit cannot be used for the sole purpose of looking at occlusal caries.
caries; cone beam computed; cone beam computed tomography; dental; tomography
The aim of this study was to determine (1) the effect of various scan delays on pixel intensity measurements and (2) the diagnostic accuracy of occlusal caries detection.
72 non-cavitated extracted human permanent molar teeth with sound and carious occlusal surfaces were radiographed using the DIGORA® storage phosphor plates (SPPs) (Soredex Corporation, Helsinki, Finland). Plates were scanned immediately and 10 min, 30 min, 60 min and 120 min after exposure. Three different plates were used for each scan delay. An aluminium (Al) wedge was used to evaluate the change in mean grey values (MGVs) for scan delays. Diagnostic accuracy for occlusal caries detection was performed by scoring all the digital images. The true presence of caries was determined by stereomicroscopy. Comparison of MGVs of the Al wedge for immediate and delayed scans was made using repeated measures analysis of variance (ANOVA) and Tukey–Kramer tests. The accuracy was expressed as the area under the receiver operating characteristics curves (Az). Azs were compared using two-way ANOVA and t-tests. Kappa was used to measure inter and intraobserver agreement.
The mean Azs of immediately scanned plates were higher than the Azs of plates scanned with four different delays (p < 0.05). The Az of immediately scanned images was significantly higher than the Azs of images with 60 min and 120 min scan delays (p < 0.05) but not for 10 min and 30 min delays (p > 0.05). MGVs of immediately scanned plates were significantly higher than the plates scanned with four different delays (p < 0.05). Agreement decreased with increasing scan delays.
Scanning of DIGORA SPPs should not be delayed beyond 30 min for accurate occlusal caries diagnosis.
radiography; dental; digital images; storage phosphor plates
Reflectance and transillumination imaging show demineralization with high contrast in the near-IR. The objective of this study is to use lesion size and contrast acquired in reflectance and transillumination near-infrared imaging modes to estimate the severity of natural occlusal caries lesions. Previous studies have shown that near-infrared (NIR) light can be used to effectively image artificial carious lesions. However, its efficacy on natural lesions requires further exploration. Fifty extracted teeth with varying amounts of occlusal decay were examined using a NIR imaging system operating at 1310-nm. Image analysis software was used to calculate contrast values between sound and carious tooth structure. After imaging, teeth were histologically sampled at 1-mm intervals in order to determine lesion depth. Lesion contrast in transillumination mode significantly increased with lesion depth (p<0.001), while lesion contrast in reflectance mode did not increase. The lesion area demonstrated a significant increase with lesion severity in both imaging modes. These results suggest that lesion contrast and area can be used to estimate lesion severity in NIR images.
Near-IR imaging; occlusal surfaces; dental caries; transillumination; reflectance imaging
Optical caries detection has the potential to be incorporated in telehealth medicine for preventive dental screening. The objective of this study was to evaluate and compare visible and near infrared detection methods for identifying early non-cavitated ex vivo occlusal demineralization.
Six blinded examiners were used to compare the accuracy of the following three examinations in detecting occlusal demineralization: Midwest Caries ID™ (MID), visual photographic examination (CAM) and Cross Polarization Optical Coherence Tomography (CP-OCT). For each diagnostic method, two examiners assessed the extracted tooth samples 1–2 weeks apart. Teeth were then sectioned and lesion depth was confirmed (n = 42) by a blinded histological examination using a glycol based caries indicator dye. The sensitivity (Sen), specificity (Sp), Intraclass Correlation Coefficient (ICC), and Area under the Receiver Operator Curve (AUC) were calculated.
For detecting any demineralization versus sound pit and fissure enamel, the mean Sen/Sp found was 46.9/85.0 for MID, 80.5/52.5 for CAM, and 83.4/45.0 for CP-OCT. For detecting non-cavitated demineralization that progressed into the dentin, the mean Sen/Sp found was 17.3/88.0 for MID, 48.0/57.8 for CAM, and 44.2/72.7 for CP-OCT. AUC values were statistically significant (P < 0.05) in three out of four examiner assessments when MID and CP-OCT were used to detect any demineralization. AUC values were significant for a single CAM examination. When assessing deeper non-cavitated lesions, none of the assessment methods were able to yield AUC values that were significantly different than a random ‘coin flip’ test. When examining reliability, MID demonstrated the highest ICC score (0.83) and CP-OCT had the lowest (0.49).
Although MID and CP-OCT were useful in detecting the presence of demineralization, examiners were not able to utilize these devices to adequately assess the depth of the demineralization. This study found that MID and CP-OCT did not have markedly superior diagnostic values from simple CAM assessment for use in teledentistry.
Telehealth; Caries; Imaging; Optical Coherence Tomography; Detection system; Light-Emitting Diode
The purpose of this study was to assess the in vitro diagnostic ability of visual inspection, film, charge-coupled device (CCD) sensor, photostimulable phosphor (PSP) sensor and cone beam CT in the detection of proximal caries in posterior teeth compared with the histological gold standard.
Visual inspection, film, CCD, PSP and cone beam CT images were used to detect proximal caries in the mesial and distal surfaces of 138 teeth (276 surfaces). Visual inspection and evaluation of all intraoral digital and conventional radiographs and cone beam CT images were performed twice by three oral radiologists. Weighted kappa coefficients were calculated to assess intra- and interobserver agreement for each image set, and scores were compared with the histological gold standard using receiver operating characteristic (ROC) analysis to evaluate diagnostic ability.
Intraobserver kappa coefficients calculated for each observer for each method of detecting caries ranged from 0.739 to 0.928. Strong interobserver agreement ranging from 0.631 to 0.811 was found for all detection methods. The highest Az values for all three observers were obtained with the cone beam CT images; however, differences between detection methods were not statistically significant (P > 0.05).
Visual inspection, film, CCD, PSP plates and cone beam CT performed similarly in the detection of proximal caries.
detection; cone beam computed tomography; digital radiography; film; proximal caries
This study was performed to assess the compatibility of cone beam computed tomography (CBCT) synthesized cephalograms with conventional cephalograms, and to find a method for obtaining normative values for three-dimensional (3D) assessments.
Materials and Methods
The sample group consisted of 10 adults with normal occlusion and well-balanced faces. They were imaged using conventional and CBCT cephalograms. The CBCT cephalograms were synthesized from the CBCT data using OnDemand 3D software. Twenty-one angular and 12 linear measurements from each imaging modality were compared and analyzed using paired-t test.
The linear measurements between the two imaging modalities were not statistically different (p>0.05) except for the U1 to facial plane distance. The angular measurements between the two imaging modalities were not statistically different (p>0.05) with the exception of the gonial angle, ANB difference, and facial convexity.
Two-dimensional cephalometric norms could be readily used for 3D quantitative assessment, if corrected for lateral cephalogram distortion.
Cone-Beam Computed Tomography; Cephalometry
New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-μm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper we attempt to determine the earliest stage at which we can detect significant differences in lesion severity. Automated methods of analysis were used to measure the depth and severity of demineralized bovine enamel produced using a simulated caries model that emulates demineralization in the mouth. Significant differences in the depth and integrated reflectivity from the lesions were detected after only a few hours of demineralization. These results demonstrate that cross polarization OCT is ideally suited for the nondestructive assessment of early demineralization.
polarization; optical coherence tomography; tooth demineralization; dental caries
Laser removal of dental hard tissue can be combined with optical, spectral or acoustic feedback systems to selectively ablate dental caries and restorative materials. Near-infrared (NIR) imaging has considerable potential for the optical discrimination of sound and demineralized tissue. Last year we successfully demonstrated that near-IR images can be used to guide a CO2 laser ablation system for the selective removal of artificial caries lesions on smooth surfaces. The objective of this study was to test the hypothesis that two-dimensional near-infrared images of natural occlusal caries can be used to guide a CO2 laser for selective removal. Two-dimensional NIR images were acquired at 1310-nm of extracted human molar teeth with occlusal caries. Polarization sensitive optical coherence tomography (PS-OCT) was also used to acquire depth-resolved images of the lesion areas. An imaging processing module was developed to analyze the NIR imaging output and generate optical maps that were used to guide a CO2 laser to selectively remove the lesions at a uniform depth. Post-ablation NIR images were acquired to verify caries removal. Based on the analysis of the NIR images, caries lesions were selectively removed with a CO2 laser while sound tissues were conserved. However, the removal rate varied markedly with the severity of decay and multiple passes were required for caries removal. These initial results are promising but indicate that the selective removal of natural caries is more challenging than the selective removal of artificial lesions due to varying tooth geometry, the highly variable organic/mineral ratio in natural lesions and more complicated lesion structure.
image-guided laser ablation; near-infrared imaging; CO2 laser; selective caries removal; polarization sensitive optical coherence tomography
Background and aims
Radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. Digital subtraction radiography has recently been used to improve the diagnostic quality of these le-sions. The purpose of this study was to compare the caries depth estimated by digital subtraction radiog-raphy in combination with barium sulfate in diag-nosing proximal dental caries with histopathologic evaluation.
Materials and methods
In this study 30 molars and premolars (24 demineralized lesions with cavity, 8 without cavity) were studied. Direct digital images were taken (kVp: 68, mA: 8; t: 0.12 for premolars and t: 0.16 for molars) whereas the position of X-ray tube and CCD receptor and teeth was fixed. To prepare the second images 135 gr/L barium sulfate was used. The images obtained with the same exposure and geometry and then subtracted. The depth of the lesions in direct digital and subtracted images were assessed and compared with the depth measured in histopathologic assessments.
The mean depths (± SD) of the lesions were 1.80 ± 0.77 mm in direct digital radiography, 2.32 ± 0.76 mm in subtracted images after barium sulfate treatment, and 2.51 ± 0.43 mm in histopathologic sections. The statistical difference between direct digital radiography and the other methods was significant (P < 0.05). However, the differences were not statistically significant between subtracted images and histopathologic sections. The average intra-class correlation coefficient was 0.7241 (CI: 95%).
The present study has demonstrated that digital subtraction radiography images have the potential to measure the depth of proximal caries with no significant difference with histopathologic evaluation.
Barium sulfate; dental caries; digital subtraction radiography
The aim of this study was to assess the accuracy of cone beam CT (CBCT) in detecting vertical root fractures and to compare the accuracy with images from an intraoral sensor and from conventional intraoral film.
60 extracted, single-rooted human teeth were divided equally into two groups: a control group of 30 teeth and an induced fracture group of 30 teeth. All teeth were randomly placed into sockets in six dry mandibles. Each tooth was imaged by three modalities: CBCT, intraoral digital radiography and intraoral F-speed film. Three beam angulations (an orthogonal projection and additional projections with ±20° horizontal shifts of the central ray) were used when radiographs were made using film and a digital sensor. Three oral and maxillofacial radiologists evaluated the presence of root fractures twice in each image modality using a five-point confidence rating scale. Areas under receiver operating characteristic curves (Az) were computed for each observer and modality and were tested for statistical differences using the Kruskal–Wallis test.
There was no statistical difference in the performance of the three modalities (mean of Az values: CBCT = 0.811, film = 0.797 and sensor = 0.775; p = 0.771).
There was no significant difference between intraoral film, a high-resolution complementary metal oxide semiconductor digital imaging system and CBCT in detecting vertical root fractures in mandibular single-rooted teeth.
cone beam computed tomography; vertical root fracture
The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography (CBCT) images and bitewing images in detection of secondary caries.
Materials and Methods
One hundred and twenty proximal slots of Class II cavities were randomly prepared on human premolar and molar teeth, and restored with amalgam (n=60) and composite resin (n=60). Then, artificial secondary caries lesions were randomly created using round steel No. 4 bur. The teeth were radiographed with a conventional bitewing technique and two CBCT systems; Pax-500ECT and Promax 3D. All images were evaluated by five observers. The area under the receiver operating characteristic (ROC) curve (Az) was used to evaluate the diagnostic accuracy. Significant difference was tested using the Friedman test (p value<0.05).
The mean Az values for bitewing, Pax-500ECT, and Promax 3D imaging systems were 0.882, 0.995, and 0.978, respectively. Significant differences were found between the two CBCT systems and film (p=0.007). For CBCT systems, the axial plane showed the greatest Az value.
Based on the design of this study, CBCT images were better than bitewing radiographs in detection of secondary caries.
Dental Caries; Cone Beam CT; Radiography, Bitewing; Diagnosis
Enamel is highly transparent in the near-IR (NIR) at wavelengths near 1300-nm, and stains are not visible. The purpose of this study was to use NIR transillumination and optical coherence tomography (OCT) to estimate the severity of caries lesions on occlusal surfaces both in vivo and on extracted teeth.
Extracted molars with suspected occlusal lesions were examined with OCT and polarization sensitive OCT (PS-OCT), and subsequently sectioned and examined with polarized light microscopy (PLM) and transverse microradiography (TMR). Teeth in test subjects with occlusal caries lesions that were not cavitated or visible on radiographs were examined using NIR transillumination at 1310 nm using a custom built probe attached to an indium gallium arsenide (InGaAs) camera and a linear OCT scanner. After imaging, cavities were prepared using dye staining to guide caries removal and physical impressions of the cavities were taken.
The lesion severity determined from OCT and PS-OCT scans in vitro correlated with the depth determined using polarized light microscopy (PLM) and transverse microradiography (TMR). Occlusal caries lesions appeared in NIR images with high contrast in vivo. OCT scans showed that most of the lesions penetrated to dentin and spread laterally below the sound enamel.
This study demonstrates that both NIR transillumination and OCT are promising new methods for the clinical diagnosis of occlusal caries.
NIR imaging; optical coherence tomography; dental caries; caries detection; occlusal caries
Bone density measurement in a radiographic view is a valuable method for evaluating the density of bone quality before performing some dental procedures such as, dental implant placements. It seems that Cone-Beam Computed Tomography (CBCT) can be used as a diagnostic tool for evaluating the density of the bone, prior to any treatment, as the reported radiation dose in this method is minimal. The aim of this study is to investigate the effect of object location on the density measurement in CBCT versus Multislice computed tomography (CT).
Materials and Methods:
In an experimental study, three samples with similar dimensions, but different compositions, different densities (Polyethylene, Polyamide, Polyvinyl Chloride), and three bone pieces of different parts of the mandibular bone were imaged in three different positions by CBCT and Multislice CT sets. The average density value was computed for each sample in each position. Then the data obtained from each CBCT was converted to a Hounsfield unit and evaluated using a single variable T analysis. A P value <0.05 was considered to be significant.
The density in a Multislice CT is stable in the form of a Hounsfield Number, but this density is variable in the images acquired through CBCT, and the change in the position results in significant changes in the density. In this study, a statistically significant difference (P value = 0.000) has been observed for the position of the sample and its density in CBCT in comparison to Multislice CT.
Density values in CBCT are not real because they are affected by the position of the object in the machine.
Bone density; cone-beam computed tomography; implant
The high transparency of dental enamel in the near-infrared (NIR) at 1310-nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study was to determine whether the lesion contrast derived from NIR transillumination can be used to estimate lesion severity. Another aim was to compare the performance of a new Ge enhanced complementary metal-oxide-semiconductor (CMOS) based NIR imaging camera with the InGaAs focal plane array (FPA). Extracted human teeth (n=52) with natural occlusal caries were imaged with both cameras at 1310-nm and the image contrast between sound and carious regions was calculated. After NIR imaging, teeth were sectioned and examined using more established methods, namely polarized light microscopy (PLM) and transverse microradiography (TMR) to calculate lesion severity. Lesions were then classified into 4 categories according to the lesion severity. Lesion contrast increased significantly with lesion severity for both cameras (p<0.05). The Ge enhanced CMOS camera equipped with the larger array and smaller pixels yielded higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.
Near-IR imaging; occlusal surfaces; dental caries; transillumination
(1) Quantify at which carious lesion depths dentists intervene surgically for cases of varying caries penetration and caries risk; (2) Identify characteristics that are associated with surgical intervention.
Dentists in a practice-based research network who reported doing at least some restorative dentistry were surveyed. Dentists were asked to indicate whether they would surgically intervene in a series of cases depicting occlusal caries. Each case included a photograph of an occlusal surface displaying typical characteristics of caries penetration, and a written description of a patient at a specific level of caries risk. Using logistic regression, we analyzed associations of surgical treatment with dentist and practice characteristics, and patient caries risk levels.
519 DPBRN practitioner-investigators responded, of whom 63% indicated that they would surgically restore lesions located on inner enamel surfaces, and 90% of lesions located in outer dentin surfaces in a low caries risk individual. Regarding individuals at high caries risk, 77% reported that they would surgically restore inner enamel lesions and 94% reported restoring lesions located on the outer dentin surface. Dentists who did not assess caries risk were more likely to intervene on dentin lesions (p=.004). Practitioner-investigators who were in private practice were significantly more likely to intervene surgically on enamel lesions, compared to dentists from large group practices (p<.001).
Most dentists chose to provide some treatment to lesions that were within the enamel surface. Decisions to intervene surgically in the caries process differ by caries lesion depth, patient caries risk, assessment of caries risk, type of practice model, and percent of patients who self-pay.
caries diagnosis; treatment threshold; organized dentistry; practice model; private practice; large group practice; public health; risk assessment
The aim of this study was to compare the diagnostic quality of a new wireless handheld unit (ADX4000; Dexcowin Co. Ltd, Korea) on conventional bitewings and its LCD screen for the detection of approximal caries in primary teeth.
In total, 108 approximal surfaces of primary teeth were examined in vitro by 3 observers. Conventional films were viewed under subdued lighting conditions on a conventional view box. Digital 3.5 inch images were displayed on the built-in monitor of the ADX4000 and digital 17 inch images were viewed on a 17 inch monitor. The true caries diagnosis was based on histological assessment of the approximal surfaces after sectioning the primary teeth. Receiver operating characteristic (ROC) curve (Az) analysis was used to assess the diagnostic quality of imaging modalities.
The areas under the ROC curves ranged from 0.786 (digital 17 inch) to 0.813 (digital 3.5 inch). No statistically significant differences were found between the three modalities for detecting approximal caries.
It was concluded that the diagnostic quality of conventional film and digital images, which were exposed and viewed by a new wireless handheld unit, was comparable.
approximal caries; bitewing radiographs; handheld unit; receiver operating characteristic curve; primary teeth
The purpose of this article is to review the current status of dental caries diagnosis using cone beam computed tomography (CBCT).
Materials and Methods
An online PubMed search was performed to identify studies on caries research using CBCT.
Despite its usefulness, there were inherent limitations in the detection of caries lesions through conventional radiograph mainly due to the two-dimensional (2D) representation of caries lesions. Several efforts were made to investigate the three-dimensional (3D) image of lesion, only to gain little popularity. Recently, CBCT was introduced and has been used for diagnosis of caries in several reports. Some of them maintained the superiority of CBCT systems, however it is still under controversies.
The CBCT systems are promising, however they should not be considered as a primary choice of caries diagnosis in everyday practice yet. Further studies under more standardized condition should be performed in the near future.
Cone-Beam Computed Tomography; Dental Caries; Diagnosis