The comparative detectability of the artificial periapical defects among Ektaspeed Plus film, digitized and digora images was evaluated. The artificail defects were made in the cancellous bone and cancellous-cortical junction with the size of 1.0x0.8mm2, 1.4x1.1mm2 and 2.8x2.2mm2. The defects in cancellous-cortical junction extended into cortical bone with the depth of 0, 0.5 and 1.0 mm. The results were as follows : 1. In junctional defects Ektaspeed Plus film for 2.8x12.2mm2 defect showed the highest detectability. But siginificant difference were only found between Ektaspeed Plus films and digitized images(p<0.05). 2. Almost all defects within cacellous bone were not detected except a few digitized and Digora images for the size of 2.8x2.2mm2. Digora images for them showed significant differences with Ektaspeed Plus films and digitized images(p<0.05). 3. The sensitinity of all imaging modalities were 0.9 or 1.0 in junctional defects for the size of 1.4x2.2mm2 and 2.8x2.2mm2. For cancellous defects, Digora image showed the highest sensitivity of 0.6 for the size of 2.8x2.2mm2. 4. Siginificant differences for change of exposure time were found in most group of Ektaspeed Plus films and digitized images(p<0.05). But there was no significant differences in Digora images for cacellous defects.
Radiography, Dental, Digital*

The purpose of this study was to evaluate the accuracy and usefulness of spiral tomography through the comparison and analysis of SCANORA cross-sectional tomographs and DentaScan computed tomographic images of dry mandibles taken by a SCANORA spiral tomographic machine and a computed tomographic machine. Thirty-one dry mandibles with full or partial edentulous areas were used. To evaluate the possible effect of location in the edentulous area, it was divided into 4 regions of Me (region of mental foramen), M1 (the midportion between Me and M2), M2 (the midportion between mental foramen and mandibular foramen) and S (the midportion of the mandibular symphysis). A ZPC column (sized 4 mm X 5 mm) was seated on the edentulous regions of Me, M1, M2 and S using the acrylic stent. Then SCANORA spiral tomography and computed tomography were taken on the edentulous regions which contained the ZPC column. The ZPC columns and cross-sectional images of the mandible were measured in the radiographs by three observers and the differences between the two imaging modalities were analysed. The results were as follows: 1. In comparing the actual measurements of the ZPC column and measurements in the radiographs, the mean error of the DentaScan computed tomography was 0.07 mm in vertical direction and -0.06 mm in horizontal direction, while the mean error of the SCANORA spiral tomography was 0.06 mm in vertical direction and -0.12 mm in horizontal direction. There was a significant difference between the two radiographic techniques in the horizontal measurement of the ZPC column of the symphysis region (p<0.05). but there was no significant difference in the measurements of other regions>0.05). 2. In measurements of the distance from the alveolar crest to the inferior border of the mandible (H), and of the distance from the alveolar crest to the superior border of the mandibular canal (Y), there was no significant difference between the two radiographic techniques (p>0.05). 3. In measurements of the distance from the lingual border of the mandible to the buccal border of the mandible (W), and of the distance from the lingual border of the mandible to the lingual border of the mandibular canal (X), there was a significant difference between the two radiographic techniques in measurements of the midportion between the mental foramen and the mandibular foramen (M2) (p<0.05). but there were no significant differences in measurements of the other regions of symphysis>0.05). 4. Considering the mean range of measurements between observers, the measurements of SCANORA spiral tomography showed higher value than those of DentaScan computed tomography, except in measurements of symphysis (S). 5. On the detectability of the mandibular canal, there was no significant difference between the two radiographic techniques (p>0.05). In conclusion, SCANORA spiral tomography demonstrated a higher interobserver variance than that of DentaScan computed tomography for implant site measurements in the posterior edentulous area of the mandible. These differences were mainly the result of difficulty in the detection of the border of the mandible in SCANORA spiral tomography. But considering the cost and the radiation exposure, SCANORA spiral tomography can be said to be relatively good radiographic technique for implant site measurement.
Mandible* ; Radiography, Dental, Digital ; Stents

PURPOSE: To know whether there would be a difference among spiral tomograms of different slice thicknesses in the measurement of distances which are used for dental implant planning. MATERIALS AND METHODS: 10 dry mandibules and 40 metal balls are used to take total 120 Scanora tomograms with the slice thickness of 2 mm, 4 mm and 8 mm. 3 oral radiologists interpreted each tomogram to measure the distances from the mandibular canal to the alveoalr crest and buccal, lingual and inferior borders of mandible. 3 observers recorded grades of 0, 1 or 2 to evaluate the perceptibility of alveolar crest and the superior border of mandibular canal. For statistical analysis, ANOVA with repeated measure, Chi-square tests and intraclass correlation coefficient(R2, alpha) were used. RESULTS: There was not a statistically significant difference among spiral tomograms with different slice thicknesses in the measurement of the distances and in the perceptibility of alveolar crest and mandibular canal(p>0.05). All of them showed a good relationship in the reliability analysis. The perceptibility of alveolar crest and mandibular canal was almost similar and an excellent relationship was seen on all of them. CONCLUSIONS: There would be no significant difference, no matter which spiral tomogram of any slice thickness may be used in dental implant planning, considering the thickness of dental implant fixture.
Dental Implants* ; Mandible ; Radiography, Dental, Digital

PURPOSE: To evaluate the effect of deviation of mandibular positioning, by changing the mandibular plane inclination, on the measured height and width of mandible in spiral conventional tomography. MATERIALS AND METHODS: By means of the Scanora multifunctional unit, cross-sectional tomograms were taken from two human dried mandibles at the mandibular angulations: -15 degrees, -10 degrees, -5 degrees, and 0 degree. Twenty-eight sites in two dried mandibles were imaged. One examiner measured the bone heights and widths at selected sites on the images and the actual bone heights were recorded. RESULTS: The bone heights at the four mandibular inclinations overestimated real bone heights and the mean difference between actual heights and image heights on 0 degree was the smallest (P< 0.01). The bone widths on -15 degrees were narrowest and there were significant differences between bone widths measured at the four mandibular inclinations (P< 0.001). We found statistically significant differences between both bone heights and widths as measured according to the mandibular plane angle for the posterior region (P< 0.01). CONCLUSION: The use of different mandibular positioning may result in discrepancies in heights and widths when measured from the cross-sectional tomographic images. It is suggested that the mandibular positioning may play a significant role in the measurement of mandibular heights and widths.
Dental Implants ; Humans ; Mandible ; Radiography, Dental, Digital

PURPOSE: To evaluate the differences in bone height, bone width, and visibility of posterior spiral tomographic images according to various exposure directions, image layer thickness, and inclination of the mandibular inferior border. MATERIALS AND METHODS: Six partially and completely edentulous dry mandibles were radiographed using Scanora spiral tomography. Spiral tomography was performed at different exposure directions (dentotangential and maxillotangential projection), image layer thicknesses (2 mm, 4 mm and 8 mm), and at various inclinations to the mandibular border (+/-10, 0 and -10 ). The bone height and width was measured using selected tomographic images. The visibility of mandibular canal, crestal bone, and buccal and lingual surfaces were graded as 0, 1, or 2. RESULTS: The bone width at the maxillo-tangential projection was wider than at the dento-tangential projection (p< 0.05). The visibility of buccal and lingual surface at the maxillo-tangential projection was higher than at the dento-tangential projection (p< 0.05). Thinner image layer thicknesses resulted in greater visibility of buccal and lingual surfaces (p< 0.05). Bone height was greatest in the -10 group, and at the same time the bone width of the same group was the narrowest (p< 0.05). The visibility of alveolar crest and buccal surface of the+/-10 group was the highest, while the visibility of the mandibular canal was greatest in the 0 group. CONCLUSION: When spiral tomography is performed at the mandibular posterior portion for visualization prior to implant surgery, it is important that the inferior border of mandible be positioned as parallel as possible to the floor. A greater improvement of visibility can be achieved by maintaining a thin image layer thickness when performing spiral tomography.
Dental Implants ; Mandible* ; Radiography, Dental, Digital

PURPOSE: The purpose of this study is to examine the effects of X-ray beam angulation on the fractal dimension of trabecular bone structure of human dry mandible using the tile counting method. MATERIALS AND METHODS: We divided 5 human dry mandibles into an angle and a molar groups depending on the regions and deciding the region of interest (ROI). When contrasted with the ROI, the inferior cortex was appointed to be low and the lines perpendicular to the buccal cortex were appointed to be the standard angle. Direct digital intraoral radiographs were obtained from 9 different projection angles. We analyzed statistically the fractal dimension using the tile counting method. RESULTS: There was a statistically significant difference in the fractal dimension of the regions and the mandibles, but there was no statistically significant difference in the fractal dimension according to the X-ray beam angulation. CONCLUSION: There is no statistically significant effect of the angle of the projection on the fractal dimension of trabecular bone structure of a human dry mandible according to the tile counting method.
Fractals* ; Humans* ; Mandible* ; Molar ; Radiography, Dental, Digital

ABSTRACT Dental anomalies may occur due to the complex interactions among genetic, epigenetic, and environmental factors during dental development. The current study aimed to determine the prevalence and gender significance of developmental dental anomalies (DDA) in dental patients. This was a cross-sectional study of 260 subjects (123 males and 137 females) with an age range of 6–35 years old. Clinical and radiographic examinations were performed to determine the prevalence of anomalies in tooth number, shape, size, position, and structure. Descriptive statistics was performed, the chi-square test was used for analysis and p-value was set at 0.05. The findings showed that 203 subjects (78.1%) had DDA, which included 86 males (33.1%) and 117 females (45%). A significant gender difference was found regarding the prevalence of two anomalies (p < 0.05). The most prevalent anomaly was displacement 51.2%, followed by dilaceration 24.2%. A significant gender difference (p < 0.05) was found regarding hypodontia 16.5% and impaction 14.6%, with more predominant in females. Some anomalies were not observed such as microdontia, dentin dysplasia, ectopic eruption, gemination, and taurodontism. The study concluded that displacement and dilacerations were the common abnormalities. These findings may lead to various dental complications. Therefore, early diagnosis and follow-up observation are required to reduce the potential dental problems. In addition, it is helpful to increase the knowledge of practitioners with regards to DDA and its occurrence. Furthermore, it is good to highlight the importance of early diagnosis of DDA, especially in the mixed dentition, which can lead to reducing the complication of an orthodontic treatment plan.
Tooth Abnormalities ; Radiography, Dental, Digital ; Libya

OBJECTIVE: To compare the effects of different imaging methods on radio-opacity. Digital imaging and traditional film imaging were used to determine the radio-opacity of dental composite resin materials. METHODS: Fourteen dental composite resins commonly used in clinic were prepared for disc samples with thickness of 1 mm and diameter of 15 mm respectively. The aluminum step wedge was used as the reference and the disc samples were irradiated with X-rays by the traditional film imaging, phosphor imaging plate and charge-coupled device(CCD) intra-oral X-ray sensor respectively. Exposure was set at 65 kV and 7 mA, with 300 mm focus to film distance and the exposure time was 0.25 s. After developing and fixing the film, the optical density of the image of the sample and that of each step of the aluminum step wedge were measured using the densitometer. The digital image file was exported to grey scale analysis software of Adobe Photoshop^® to measure the average grey value in the sample image and aluminum step wedge image. The curves were drawn corresponding to the optical density/gray value of each step of the aluminum step wedge and its thickness, and the equivalent thickness of the aluminum plate was calculated according to the optical density/gray value of the actual measured thickness of the sample, so as to evaluate the radio-opacity of dental composite resin material. RESULTS: For the same sample, the aluminum equivalent measured by traditional film imaging and two other digital imagings had significant differences among the 14 composite resins (P < 0.05), and the aluminum equivalent measured by the two digital imagings were greater than that of the traditional film. Moreover the aluminum equivalent measured by the two digital imagings was also different, and the aluminum equivalent measured by the CCD intra-oral X-ray sensor in most composite resins was larger than that measured by phosphor imaging plate. The same sample was photographed with the same imaging method, and the aluminum equivalent was different after three exposures. The standard deviation of aluminum equivalent measured by phosphor imaging plate was the largest, while that measured by CCD intra-oral X-ray sensor was the smallest. Among the 14 dental composite resin materials, the aluminum equivalent of Tetric N-Ceram and Te-Econom Plus measured by traditional film imaging and phosphor imaging plate was significantly higher than other composite resins. CONCLUSION Based on clinical significance, three kinds of sensors designed to measure the radio-opacity of dental composite resin, the value of aluminum equivalent will change according to different types of sensors. The aluminum equivalent measured by CCD intra-oral X-ray sensor was higher than that measured by phosphor imaging plate, and the aluminum equivalent measured by phosphor imaging plate was higher than that measured by traditional film imaging. Moreover, even though the same sensor was used, the aluminum equivalent measured by multiple exposures was different. The standard deviation of the aluminum equivalent measured by phosphor imaging plate was greater than that measured by traditional film imaging and CCD intra-oral X-ray sensor. The three sensors in this study could be used for evaluating the radio-opacity of dental composite resin materials. But no matter what kind of sensor was used to measure the radio-opacity of dental composite resin, it complied to ISO 4049: 2019 standard, the materials were suitable for clinical use.
Aluminum ; Composite Resins ; Radiography, Dental, Digital

PURPOSE: To compare radiographic images of Digora system and Ektaspeed Plus film obtained from normal adults. MATERIALS AND METHODS: Storage phosphor plate(SPP) was placed in a film holder behind Ektaspeed Plus film package without lead foil. The effect of film on SPP was studied in a separate in vitro experiment. Forty-seven sets of images were prepared for the evaluaton. The regions of interest(ROI) for evaluation were designated at seven sites including normal anatomical structures. The image quality for each ROI was evaluated on enhanced and unenhanced storage phosphor(SP) images and Ektaspeed Plus film. RESULTS: Two film-SPP configurations showed significantly different grey levels at each step of the aluminum step wedge(p<0.05). The contrasts were comparable. Enhanced SP images were significantly superior to unenhaned images and film in all anatomical sturctures(p<0.01). The differences between unenhanced SP images and film were significant(p<0.05) except root canal and cortical bone on alveolar crest. For anatomical items, there were statistically significant difference among five observers(p<0.05). CONCLUSIONS: The image quality of enhanced SP images were superior to Ektaspeed Plus film, and Digora system is potentially applicable to clinical diagnosis.
Adult ; Aluminum ; Dental Pulp Cavity ; Diagnosis ; Humans ; Radiography, Dental, Digital

PURPOSE: Contrast, sharpness, enhancement, and density can be changed in digital systems. The important question is to what extent the changes in these variables affect the accuracy of caries detection. MATERIALS AND METHODS: Forty eight extracted human posterior teeth with healthy or proximal caries surfaces were imaged using a photostimulable phosphor (PSP) sensor. All original images were processed using a six-step method: (1) applying "Sharpening 2" and "Noise Reduction" processing options to the original images; (2) applying the "Magnification 1:3" option to the image obtained in the first step; (3) enhancing the original images by using the "Diagonal/" option; (4) reviewing the changes brought about by the third step of image processing and then, applying "Magnification 1:3"; (5) applying "Sharpening UM" to the original images; and (6) analyzing the changes brought about by the fifth step of image processing, and finally, applying "Magnification 1:3." Three observers evaluated the images. The tooth sections were evaluated histologically as the gold standard. The diagnostic accuracy of the observers was compared using a chi-squared test. RESULTS: The accuracy levels irrespective of the image processing method ranged from weak (18.8%) to intermediate (54.2%), but the highest accuracy was achieved at the sixth image processing step. The overall diagnostic accuracy level showed a statistically significant difference (p=0.0001). CONCLUSION: This study shows that the application of "Sharpening UM" along with the "Magnification 1:3" processing option improved the diagnostic accuracy and the observer agreement more effectively than the other processing procedures.
Dental Caries* ; Humans ; Image Enhancement ; Noise* ; Radiography, Dental, Digital ; Tooth