Evaluation of the effects of postprocessing settings in digital bitewing radiographs on proximal caries detection.

OBJECTIVE: Radiographs are an integral part of detecting proximal caries. The aim of this study was to evaluate the effect of contrast, brightness, noise, sharpness, and γ adjustment of digital intraoral radiographs on the diagnosis of proximal caries. MATERIALS AND METHODS: In this in vitro study, 40 extracted teeth including 20 premolars and 20 molars with enamel lesions (white spot or dentin discoloration seen through the enamel) were mounted together in groups of eight inside the skull. Bitewing radiographic images of each dental group were obtained by a photostimulable phosphor plate sensor with exposure conditions of 8 mA, 70 kV, and 0.2 s. The images were reconstructed by the built-in software and examined by two oral and maxillofacial radiologists in various settings of contrast, brightness, sharpness, noise, and γ. The teeth were then cut mesiodistally and the presence or absence of caries was confirmed by an oral and maxillofacial pathologist using a stereomicroscope. The data were then analyzed using the κ agreement coefficient, sensitivity, specificity, and accuracy (α = .05). RESULTS: Adjustment of brightness and contrast led to higher diagnostic performance with an accuracy of 82.5% and 83.8 (for observers 1 and 2, respectively) and 82.5% (for both observers), respectively. Noise adjustment was the least helpful approach for diagnosis of proximal dental caries among other adjustments, with an accuracy of 78.8% and 77.5% for observers 1 and 2, respectively. CONCLUSION: Brightness and contrast setting was more efficient in improving the diagnostic potential of bitewing radiographs compared to other adjustments.

Evaluation of the effect of amalgam fillings on the diagnosis of proximal caries using cone-beam computed tomography technique.

Background: Diagnosis of dental caries using cone-beam computed tomography (CBCT) may be hindered due to several introduced and inherent artifacts. The aim of this study was to evaluate the effect of amalgam fillings on the accuracy of diagnosis of proximal caries in CBCT. Materials and Methods: In this in vitro study, 102 extracted human teeth (mandibular and maxillary molars and premolars) were used. Six molars were chosen for mesio-occluso-distal amalgam restorations. Before obtaining the CBCT images, the 96 remaining teeth were stabilized in dental sockets of six dry human skulls in a way that the proximal contacts re-established. Thereafter, six of the molar teeth were replaced by the amalgam-restored teeth and the second group of images was then obtained. All images were evaluated by two independent observers in the panorama view and the presence or absence of caries was recorded. For histopathologic investigations, the teeth were cut and assessed by an oral pathologist using a stereomicroscope. The McNemar test was used for comparison between CBCT assessments and histopathologic evaluations (P < 0.05 was considered statistically significant). In addition, the receiver operating characteristics curve was utilized to evaluate the diagnostic accuracy in different sections of imaging. Results: The result sensitivity and specificity of CBCT imaging in the first group of images before placement of the restored teeth were 0.96 and 0.36, respectively. In the second group of images after placement of the restored teeth, these values were 0.78 and 0.18, respectively. Moreover, statistical analysis showed that there is a good agreement in interproximal caries diagnosis between histopathologic and CBCT imaging findings without placement of amalgam restorations (P < 0.001). However, this agreement does not exist after amalgam restorations (P = 0.84). Conclusion: Diagnosis of proximal caries using CBCT is not an efficient method where there are amalgam restorations adjacent to the suspected teeth.

Digital panoramic radiography and CBCT as auxiliary tools for detection of low bone mineral density in post-menopausal women: a cross-sectional study.

BACKGROUND: Osteoporosis is a chronic, multifactorial skeletal disease that occurs especially in women following a decrease in estrogen levels and decrease in bone mineral density. The aim of this study was to evaluate the relationship between qualitative and quantitative indexes in panoramic radiographs and quantitative indexes in CBCT images with femoral and vertebral BMD in postmenopausal women. METHODS: This comparative cross-sectional study was performed on postmenopausal women aging 40 to 80 years attending for obtaining either panoramic radiograph or mandibular CBCT scan. Dual energy X-ray absorptiometry (DEXA) was performed from the femur and lumbar vertebra. Quantitative parameters of mental index (MI), panoramic mandibular index (PMI), antegonial index (AI) as well as qualitative parameters of mandibular cortical index (MCI) and trabecular bone pattern (TP) were evaluated in panoramic radiographs. Quantitative parameters computed tomography mandibular index (CTMI), computed tomography index (inferior) [CTI(I)] and computed tomography index (superior) [CTI(S)] were analyzed in CBCT images. Kolmogorov-Smirnov tests and Pearson correlation coefficient were used (α = 0.05). RESULTS: In individuals with panoramic radiography, statistically significant correlations were observed between MI with vertebral and femoral T-score, AI with vertebral and femoral T-score (except for the right AI with femoral T-score), and TP with vertebral and femoral T-score (p < 0.05). In the group with CBCT scans, the correlations between CTMI with vertebral and femoral T-score, CTI(I) with vertebral and femoral T-score, and CTI(S) with vertebral and femoral T-score were statistically significant (p < 0.05). CONCLUSIONS: in CBCT images, quantitative indexes of CTMI, CTI(I), and CTI(S), and in panoramic images, quantitative indexes of MI and AI and qualitative index of TP can be used to predict the possibility of osteoporosis in postmenopausal women.

Investigation of the effect of fibrin glue as a sealant in the unilateral alveolar bone grafting successes.

Background: Bone grafting is the primary treatment for the alveolar cleft. Due to the reduced complications by the sealant materials, this study aimed to evaluate fibrin glue's effect on the success rate of unilateral alveolar bone grafting. Materials and Methods: This study was a single-blind clinical trial performed on 20 patients with a unilateral alveolar cleft. Patients were randomly divided into groups: group A patients as a control group underwent bone grafting without fibrin glue, and in Group B, patients were grafted using fibrin glue. The subject was followed up through routine examination and the cone-beam computed tomography systems technique for up to 4 months. Paired t-test and Chi-square tests were used to analyze the data and the P < 0.05 was considered the significance threshold. Results: The mean age, gender, and cleft side distribution did not represent significant differences. Before surgery, the average alveolar cleft volume in Group A and B patients was 0.95 ± 0.25 cm3 and 0.99 ± 0.22 cm3, respectively, which was not statistically different. After the surgery procedure, the alveolar cleft volume in Group A and B patients was determined to be 0.31 ± 0.10 cm3 and 0.23 ± 0.11 cm3, which represented 66.7% ± 8.9% cm3 and 76.2 ± 11.4 cm3 bone formation, respectively, with no remarkable difference. Our examination did not reveal any necrosis and infection in both groups. However, despite no dehiscence observation in fibrin glue treatment patients, one subject showed dehiscence complication in the control group. Conclusion: According to results, fibrin glue may increase the percentage of bone volume formed and prevent dehiscence.

Comparison of Accuracy Between Pulp/Tooth Ratio and Tooth Coronal Index Methods for Dental Age Estimation Using Digital Panoramic Radiographs

ABSTRACT Objective: To evaluate the reliability and the accuracy of Tooth Coronal Index (TCI) and Pulp/Tooth Ratio (PTR) methods in dental age estimation using digital panoramic radiography. Material and Methods: In this cross-sectional study, 237 dental panoramic images were collected. The two methods (TCI and PTR) were applied to all left mandibular first and second molars based on inclusion and exclusion criteria. In order to analyze the acquired data, statistical methods were used. The estimated ages derived by exclusive formula were compared to the chronological age, and the error ranges for each indicator were measured to determine their accuracy. Results: There were negative correlations between PTR in the first molar (r=-0.89) and in the second molar (r=-0.788), as well as TCI in the first molar (r=-0.587) and in the second molar (r=-.242). In this study, we found that the Pulp/Tooth Ratio (PTR) accuracy rate for mandibular first and second molar teeth was 79.21% and 62.09 %, respectively, although the Tooth Coronal Index (TCI) value for these teeth was 34.45% and 5.85%. Conclusion: Pulp/Tooth Ratio and Tooth Coronal Index are potential age estimation indices. Although PTR was the more accurate one in our study. The results also demonstrated that indices related to the first molar tooth could be used to estimate age with greater accuracy and validity.

Comparison of dental and skeletal indices between patients under haemodialysis and peritoneal dialysis with healthy individuals in digital panoramic radiography.

OBJECTIVE: The aim was to compare dental and skeletal indices in panoramic radiography between patients undergoing haemodialysis, peritoneal dialysis and age- and sex-matched control group. METHODS: In this comparative cross-sectional study, quantitative Indices including Antegonial Index (AI), Mental Index (MI), Panoramic Mandibular Index (PMI) and qualitative indices including Mandibular Cortical Index (MCI) and Trabecular Pattern (TP) were evaluated in panoramic images of 32 haemodialysis patients, 14 patients under peritoneal dialysis and 52 healthy individuals. The images were also investigated for pulp canal calcification, pulp stones, soft tissue calcification, changes in or loss of lamina dura, radiolucencies associated with brown tumour and ridge resorption. The indices were compared between the three groups and were investigated for association with the patients' blood test parameters and their diseases causing chronic renal failure (CRF). Intraobserver agreement for the 2-week interval of assessment was calculated for the indices. RESULTS: MI (p = 0.574) and PMI (p = 0.100) were not significantly different, but AI (p = 0.01), MCI (p < 0.001) and TP (p = 0.002) were significantly different between the two case groups and the control group. The prevalence of pulp calcification (p = 0.03) and ridge resorption (p = 0.005) was higher in the haemodialysis group. Soft tissue calcification (p = 0.85) and lamina dura changes (p = 0.9) showed no significant difference. Brown tumours were observed in only one case in the haemodialysis group. CONCLUSIONS: AI, MCI and TP showed a reduction in mineral density of the cortical and trabecular bone in CRF patients and more severely in patients under haemodialysis than those under peritoneal dialysis.

Comparison of intraoral digital radiography and cone-beam computed tomography in the measurement of periodontal bone defects.

BACKGROUND: Periodontal disease has a high prevalence in many countries. Thus, the early detection of periodontal disease is important in order to obtain the most appropriate treatment plan to prevent tooth loss, and subsequently, to maintain the patient's general health. OBJECTIVES: The aim of this study was to compare the accuracy of cone-beam computed tomography (CBCT) and intraoral parallel digital radiography in measuring the dimensions of periodontal bone defects. MATERIAL AND METHODS: In this in vitro study, 236 periodontal bone defects were artificially created in dry human mandibles using a burr. Defects included horizontal, one-, two-, and three-wall defects, craters, dehiscences, and fenestrations. Intraoral digital radiographs were obtained using the parallel technique with photostimulable phosphor plates (PSP) and CBCT scans were performed. Two calibrated observers evaluated the images and measured the dimensions of the defects. Clinical probing was performed and considered as the gold standard. The measurements of digital radiography and CBCT were compared to those achieved by probing to evaluate their accuracy. RESULTS: Cone-beam computed tomography had a significantly stronger correlation with the gold standard than intraoral parallel digital imaging. In the total assessment of the periodontal defects, the intraclass correlation coefficient (ICC) was calculated at 0.93 for CBCT-probe and at 0.78 for PSP-probe (p < 0.05). CONCLUSIONS: The accuracy of CBCT was superior to that of intraoral digital radiography for measuring horizontal, one-, two-, and three-wall defects, craters, dehiscences, and fenestrations.

Comparison of skeletal changes related to patients with chronic kidney disease and healthy individuals in digital panoramic radiography.

BACKGROUND: Chronic kidney disease (CKD) is a prevalent condition affecting bone metabolism. Bone changes in CKD patients also known as renal osteodystrophy happen due to disorders in the regulation of water and electrolytes caused by the disease. The aim of this study is to investigate the bone changes of CKD stages 3-5 patients without dialysis using digital panoramic radiography. MATERIALS AND METHODS: In this cross-sectional study, panoramic radiographs were obtained from 30 patients with CKD stages 3-5 and 30 age and gender matched healthy individuals. The mean values of quantitative parameters such as mental index (MI), panoramic mandibular index (PMI), and antegonial index (AI) were measured and qualitative parameters such as mandibular cortical index (MCI) and trabecular bone pattern (TP) were recorded based on Kelemetti and Lindh calcifications, respectively. Statistical analysis was performed using t-test, Chi-square, and Mann-Whitney test (α = 0.05). RESULTS: The mean values of MI, PMI, and AI in the two groups were not statistically significant (P > 0.05). MCI and TP were significantly different between the two groups. MCI showed more defects in mandibular cortex of CKD patients (6.7% of patients vs. 0% of control group were C3, P = 0.038), and TP showed more porosity in mandibular bone of CKD patients (10% of patients vs. 0% of control group were sparse, P = 0.001). CONCLUSION: The amount of MI, PMI, and AI were not related to CKD. While MCI and TP were significant parameters that showed mandibular cortical situation and trabecular bone pattern, they assess osteoporosis level in a more reliable manner in CKD stages 3-5 patients without dialysis.

Comparison of accuracy between panoramic radiography, cone-beam computed tomography, and ultrasonography in detection of foreign bodies in the maxillofacial region: an in vitro study.

OBJECTIVES: Foreign bodies (FBs) account for 3.8% of all pathologies of the head and neck region, and approximately one third of them are missed on initial examination. Thus, FBs represent diagnostic challenges to maxillofacial surgeons, rendering it necessary to employ an appropriate imaging modality in suspected cases. MATERIALS AND METHODS: In this cross-sectional study, five different materials, including wood, metal, glass, tooth and stone, were prepared in three sizes (0.5, 1, and 2 mm) and placed in three locations (soft tissue, air-filled space and bone surface) within a sheep's head (one day after death) and scanned by panoramic radiography, cone-beam computed tomography (CBCT), and ultrasonography (US) devices. The images were reviewed, and accuracy of the detection modalities was recorded. The data were analyzed statistically using the Kruskal-Wallis, Mann-Whitney U-test, Friedman, Wilcoxon signed-rank and kappa tests (P<0.05). RESULTS: CBCT was more accurate in detection of FBs than panoramic radiography and US (P<0.001). Metal was the most visible FB in all of modalities. US was the most accurate technique for detecting wooden materials, and CBCT was the best modality for detecting all other materials, regardless of size or location (P<0.05). The detection accuracy of US was greater in soft tissue, while both CBCT and panoramic radiography had minimal accuracy in detection of FBs in soft tissue. CONCLUSION: CBCT was the most accurate detection modality for all the sizes, locations and compositions of FBs, except for the wooden materials. Therefore, we recommend CBCT as the gold standard of imaging for detecting FBs in the maxillofacial region.

Effect of Filtration and Slice Thickness of Cone-Beam Computed Tomography Images on Occlusal Caries Detection: An Ex Vivo Study.

OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy of different filtrations and slice thicknesses of cone-beam computed tomography (CBCT) in the detection of occlusal caries. MATERIALS AND METHODS: One-hundred teeth were selected for this ex-vivo experimental study. The CBCT images of the teeth were evaluated and scored by two observers in panoramic and cross-sectional views using different slice thicknesses and filtrations. Paired t-test, repeated-measures analysis of variance (ANOVA), and the least significant difference (LSD) test were used to compare the data with the histological gold standard. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy of each slice thickness and filtration (P<0.05). RESULTS: The mean score of true caries detection in cross-sectional views was lower than that in panoramic views (P<0.05). Repeated-measures ANOVA showed a significant difference in the mean of true detections in different thicknesses of cross-sectional views, but this difference was significant only between 5 mm thickness and other thicknesses in panoramic views. On all the views, increasing the thickness decreased the accuracy of caries detection. Repeated-measures ANOVA showed a significant difference between different filtrations; on all the views, increasing the filtration increased the accuracy of caries detection. CONCLUSIONS: An increase of filtration of CBCT images increases the accuracy of occlusal caries detection; however, an increase in slice thickness results in a lower diagnostic accuracy.

Effect of Filtration and Thickness of Cross-Sections of Cone Beam Computed Tomography Images on Detection of Proximal Caries.

OBJECTIVES: When a patient has cone beam computed tomography (CBCT) images based on the treatment plan, it is possible to use these images for evaluation of caries, and there is no need for new radiographs, according to the "as low as reasonably achievable" (ALARA) principle. The aim of this study was to determine the effect of filtration and thickness of CBCT cross-sections on detection of proximal caries. MATERIALS AND METHODS: In this in-vitro study, 100 teeth were placed in the dental sockets of a dry skull, and were fixed in normal proximal contacts. CBCT images were taken and were evaluated by two observers on the panoramic view at 1-, 3- and 5-mm-thick cross-sections, with the use of filtrations 0, 1 and 2. Afterwards, the samples were sectioned and underwent a histological evaluation. McNemar's test was used to compare the findings on CBCT images and histological evaluation. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate the diagnostic accuracy of different cross-sections. RESULTS: The maximum AZ-value was achieved at 3-mm thickness/filtration 2. However, the differences between 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1 were not significant (P=0.728 and 0.868, respectively). The minimum AZ-value was achieved at 5-mm thickness/filtration 0. CONCLUSIONS: Although CBCT is not sufficiently effective in detecting caries, the best cross-sections for detection of proximal caries were achieved at 3-mm thickness/filtration 2, 1-mm thickness/filtration 2 and 1-mm thickness/filtration 1.

In Vitro Comparison of Cone Beam Computed Tomography with Digital Periapical Radiography for Detection of Vertical Root Fracture in Posterior Teeth.

STATEMENT OF THE PROBLEM: The diagnosis of vertical root fracture (VRF) is a challenging task. PURPOSE: This in vitro study compared cone beam computed tomography (CBCT) imaging with digital periapical radiography (DPR) made by three different horizontal angels (20°mesial, 0° and 20° distal) for accurate diagnosis of VRF. MATERIALS AND METHOD: Among 120 posterior teeth included in this study, 60 were vertically fractured. Fractured and non-fractured teeth were randomly distributed into three groups defined as group 1 with no filling in the root canal, group 2 with gutta-percha in the canal, and group 3 with the intracanal post. All samples were placed in a dry mandible and imaged with CBCT and DPR techniques. Two blind observers investigated the images. RESULTS: CBCT had higher sensitivity but lower specificity compared with DPR, except for the intracanal post group in which the sensitivity of DPR was higher; though the chi-square test showed the differences to be statistically insignificant. The sensitivity, specificity, and accuracy of CBCT and DPR were reduced in the cases that gutta-percha or post were present in the canal. Inter-observer agreement was higher for CBCT. A set of three DPRs with different horizontal angels were significantly more sensitive for VRF recognition than a single orthogonal DPR. CONCLUSION: Based on our results, there was no significant difference between CBCT and a set of three DPRs with different angulations for VRF detection in posterior teeth. Therefore, it is suggested to consider DPRs with three different horizontal angels (20°mesial, 0° and 20° distal) for radiographic evaluation before CBCT examination.

Accuracy of Digital Bitewing Radiography versus Different Views of Digital Panoramic Radiography for Detection of Proximal Caries.

OBJECTIVES: Dental caries are common and have a high incidence among populations. Radiographs are essential for detecting proximal caries. The best technique should be recognized for accurate detection of caries. The aim of this study was to compare the accuracy of detection of proximal caries using intraoral bitewing, extraoral bitewing, improved interproximal panoramic, improved orthogonality panoramic and conventional panoramic radiographs. MATERIALS AND METHODS: In this descriptive cross sectional study, 100 extracted human teeth with and without proximal caries were used. Intra and extraoral radiographs were taken. Images were evaluated and scored by two observers. Scores were compared with the histological gold standard. The diagnostic accuracy of radiographs was assessed by means of receiver operating characteristic (ROC) curve analysis (P<0.05). RESULTS: Microscopic evaluation of proximal surfaces revealed that 54.8% of the surfaces were sound and 45.2% were carious (with different depths). The differences in the area under the ROC curve (Az value) among the five techniques were not statistically significant. CONCLUSION: Improved interproximal panoramic and extraoral bitewing radiographs were superior to conventional panoramic radiography for detection of proximal caries ex vivo and should be considered for patients with contraindications for intraoral radiographs.

Accuracy of linear measurements of galileos cone beam computed tomography in normal and different head positions.

Introduction. The aim of this study was to determine the accuracy of linear measurements in dry human skulls in ideal position and different deviated positions of the skull. Methods. 6 dry human skulls were included in the study. Opaque markers were attached to alveolar bone. Buccolingual and mesiodistal distances and heights were measured in 5 different regions of either jaws using a digital caliper. Radiographic distances were measured in ideal, rotation, tilt, flexion, and extension positions of the skulls. The physical and radiographic measurements were compared to estimate linear measurement accuracy. Results. The mean difference between physical measurements and radiographic measurements was 0.05 ± 0.45. There was a significant difference between physical measurements and radiographic measurements in ideal, rotation, tilt, and extension positions (P value < 0.05). Conclusions. The accuracy of measurements in GALILEOUS CBCT machine varies when the position of the skull deviates from ideal; however, the differences are not clinically significant.

Effect of object location on the density measurement in cone-beam computed tomography versus multislice computed tomography.

BACKGROUND: 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. RESULTS: 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. CONCLUSIONS: Density values in CBCT are not real because they are affected by the position of the object in the machine.

Radiographic Evaluation of Bone Formation and Density Changes after Mandibular Third Molar Extraction: A 6 Month Follow up.

BACKGROUND: There is a controversy about exact time of bone healing. The aim of this study was evaluation of bone formation and change of density after mandibular third molar extraction. METHODS: Radiographs were taken from 16 empty tooth sockets immediately after extraction of mandibular third molars and 2, 4 and 6 months later under similar condition. The radiographs were digitized and the density numbers of pixels were calculated. Then, socket and neighbor regions were compared using Photoshop software. Three expert observers evaluated and compared the radiographs by the longitudinal radiographic assessment (LRA) method. Paired t-test and McNemar test were used to analyze the data and investigate the inter-observer reliability, respectively. RESULTS: Analysis of the quantitative digital subtraction radiography (QDSR) data indicated that the difference between the digital numbers of interest points and reference points has been decreased during the months 2, 4 and 6 but the difference between the month 4 and 6 was not significant. The alternative method indicated that the mean digital numbers in the socket within 0and 2 months period was less than 128 and within 4 and 6 months was more than 128. In evaluation of LRA method, lamina dura started to change gradually in month 2 and it might disappear completely after 6 months. CONCLUSION: Both QDSR and LRA methods can be used in evaluation of the rate of bone formation in the tooth socket but the former is more precise.