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STATEMENT OF PROBLEM: Some radiographic film holders produce radiographs with geometric distortion that may interfere with diagnosis. However, whether the distortion can be corrected by adjusting the design of the radiographic film holder is unclear. PURPOSE: The purpose of the study was to develop an adapter for a radiographic film holder model aiming to generate radiographs with greater sharpness and a more accurate geometric representation of dental implants. MATERIAL AND METHODS: The 2-piece adapter was designed using the SketchUp software program and was 3-dimensionally (3D) printed. Implants with internal conical connections were installed in 19 maxillary prototypes in the central incisor region. Five dentists obtained 285 digital periapical radiographs with 3 different radiographic film holders: standard Cone Indicator, Rinn XCP, and adapted Cone Indicator. They then evaluated the radiographic sharpness of the implants threads and their dimensions using the ImageJ software program. The data were analyzed using the Friedman test with the Durbin-Conover post hoc test and MANOVA with the Tukey post hoc test (α=.05). RESULTS: On the mesial surface of the implants, the threads were sharper for the adapted than for the standard Cone Indicator radiographic film holder (P<.05). The adapted Cone Indicator showed a smaller difference between the radiographic and actual implant diameters compared with the Rinn XCP and standard Cone Indicator radiographic film holders (P<.05). CONCLUSIONS: The developed adapter provided radiographs of dental implants with improved sharpness and geometric accuracy.

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OBJECTIVES: To assess whether filter and contrast adjustments can improve the accuracy of CBCT in measuring the buccal bone thickness (BBT) adjacent to dental implants by reducing blooming artifacts. MATERIALS AND METHODS: Homogeneous bone blocks with peri-implant BBT of 0.3 mm, 0.5 mm, and 1 mm were scanned using the Orthophos SL system. Three dentists measured the BBT in 234 CBCT scans under different settings of contrast adjustments and 'Sharpen' filter activation. Additionally, implant diameter measurements were taken to assess blooming artifact expression. The differences between tomographic and actual measurements of BBT and implant diameter [(CBCT - actual) * 100 / actual] were subjected to Mixed ANOVA (α = 0.05). RESULTS: The group with the thinnest BBT (0.3 mm) had the greatest difference between tomographic and actual measurements (79.9% ± 29.0%). Conversely, the 0.5 mm (36.1% ± 38.4%) and 1 mm (29.4% ± 12.3%) groups exhibited lower differences (p < 0.05). 'Sharpen' filter activation reduced blooming expression since it resulted in a lower difference for implant diameter (p < 0.05), but it did not influence BBT measurements (p = 0.673). Contrast settings had no impact on BBT (p = 0.054) or implant diameter measurements (p = 0.079). CONCLUSION: Although filter activation reduced blooming artifacts, neither filter nor contrast adjustments improved the accuracy of CBCT in measuring peri-implant BBT; actual BBT influenced this task. CLINICAL RELEVANCE: When assessing the peri-implant buccal bone plate in the CBCT system studied, dental surgeons may find it beneficial to adjust contrast and apply filters according to their preferences, since such adjustments were found to have no adverse effects on the diagnostic accuracy of this task. The use of the 'Sharpen' filter may lead to improved representation of implant dimensions.

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OBJECTIVE: To assess the impact of enhancement filters on the formation of halo artifacts in radiographs of dental implants obtained with a complementary metal oxide semiconductor (CMOS) system. METHODS: Digital radiographs of dental implants placed in dry human mandibles were processed with the Noise Reduction smoothing filter, as well as the Sharpen 1, Sharpen 4, and Sharpen UM high-pass filters available in the CLINIVIEW™ software (Instrumentarium Dental, Tuusula, Finland). Subjective analysis involved evaluating the left, right, and apical surfaces of each implant for the presence of much, few, or no halo. The objective analysis involved measurement of the halo area using the Trainable Weka Segmentation plugin (ImageJ, National Institutes of Health, Bethesda, MD, USA). Data were analyzed using Friedman's test (subjective analysis) and ANOVA (objective analysis) (α = 5%). RESULTS: In the subjective evaluation, the Sharpen 4 filter produced more radiographs with much halo present, and in the objective evaluation, a bigger halo area when compared to the original images and the Noise Reduction filter for all surfaces (p < 0.05). CONCLUSIONS: When evaluating dental implants, priority should be given to original images and those enhanced with smoothing filters since they exhibit fewer halo artifacts. CLINICAL RELEVANCE: Post-processing tools, such as enhancement filters, may improve the image quality and assist some diagnostic tasks. However, little is known regarding the impact of enhancement filters in halo formation on CMOS systems, which have been increasingly used in dental offices.

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OBJECTIVES: To evaluate the effect of the presence and the number of high-density objects in the exomass on the volume of a high-density object in cone-beam CT (CBCT). METHODS: Cylinders of cobalt-chromium (Co-Cr), titanium (Ti), and zirconium (Zi) were inserted into a polymethylmethacrylate phantom in five different combinations of number and position: 1-no cylinder; 2-one cylinder in a posterior region; 3-one cylinder in an anterior region; 4-two cylinders in posterior regions; and 5-three cylinders in anterior and posterior regions. The phantom underwent CBCT scanning using OP300 and X800 systems, with the afore mentioned cylinders of the same composition placed in the exomass and an additional high-density cylinder placed in the centre of the field of view (FOV), corresponding to the left-anterior region. The tomographic volume of the cylinder inside the FOV was measured using semi-automatic segmentation. The volumetric alteration (VA) between the segmented and physical volumes, in percentage, was compared among the experimental groups using repeated measures ANOVA and Tukey post-hoc (α = 5%). RESULTS: The factors material, combination, and their interaction affected the volume or both CBCT systems. In OP300, more cylinders in the exomass reduced the VA, mainly for Co-Cr. In X800, more cylinders in the exomass tended to increase the VA inside the FOV, except for Zi. CONCLUSIONS: In general, the presence of high-density objects in the exomass influences the VA of the object inside the FOV, although this oscillates according to object composition, number and position in the exomass, and CBCT system.

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Aim: To evaluate the influence of notebook computers screens and undergraduate level of dental students in the radiographic detection of carious lesions. Methods: Bitewing digital radiographs were presented to 3rd and 5th year dental students in three different notebooks computers: Notebook 1 with anti-glare screen (1366×768 pixels), Notebook 2 without anti-glare screen (1366×768 pixels), and Notebook 3 with anti-glare screen (1920×1080 pixels). A reference standard based on a consensus analysis was set by three senior professors of Oral Radiology and Cariology. Sensitivity, specificity and accuracy values were measured and submitted to two-way ANOVA at a significance level of 5%. Results: Notebook 2 provided significantly lower sensitivity values (Mean 56.5% ± 2.94) than notebook 3 (71.1% ± 2.82) (p = 0.002). We found no statistically significant differences between the two undergraduate years (p > 0.05). Conclusion: The anti-glare screen of notebook computers screens can influence the radiographic detection of carious lesions, but the undergraduate level of dental students does not influence this diagnostic task

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STATEMENT OF PROBLEM: Misfits in the abutment-prosthesis interface represent a setback for implant-supported prostheses. Periapical radiographs have been used as an auxiliary method in the evaluation of prosthesis fit to the abutments; however, the evidence supporting the use of this method is still restricted to studies of low to moderate quality. Furthermore, studies on the diagnostic accuracy of different periapical techniques used to detect misfits in the abutment-prosthesis interface, especially in the esthetic zone, are lacking. PURPOSE: The purpose of this in vitro study was to assess the discrimination power of 3 periapical radiographic techniques in detecting misfits at the abutment-prosthesis interface in the esthetic zone and evaluate whether the magnitude of the misfit influenced the diagnosis. MATERIAL AND METHODS: A total of 15 implants with an internal conical connection were installed in the central incisor region in polyamide jaws. Custom ceramic copings for cemented crowns were made by using a computer-aided design and computer-aided manufacturing (CAD-CAM) system. Misfits of 50, 100, and 150 µm were simulated by interposing 1, 2, or 3 50-µm-thick polyester strips at the abutment-prosthesis interface; the absence of the strip represented the control group. Digital radiographs were obtained by using film holders for the following periapical techniques: bisecting angle (PBA), standard paralleling (PSP), and modified paralleling (PMP). Two radiologists and 1 prosthodontist evaluated a total of 180 radiographs. The values of the area under the receiver operating characteristic curve (Az) were regarded as a measure of diagnostic accuracy and subjected to the Friedman test with post hoc Durbin-Conover (α=.05). RESULTS: The PSP (Az=0.873) had higher Az values than the PBA (Az=0.753) for the 50-µm misfits (P<.05). Larger misfits resulted in greater accuracy than smaller misfits (P<.05). Interactions between the factors radiographic technique and misfit magnitude resulted in statistically significant differences for all comparisons (P<.05), except between the PSP for the 100-µm misfits (Az=0.976) and the PMP for the 150-µm misfits (Az=0.998). CONCLUSIONS: The PSP was more accurate than the PBA in detecting the 50-µm misfits at the abutment-prosthesis interface; larger misfits resulted in more accurate diagnoses, regardless of the technique used.

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STATEMENT OF PROBLEM: Misfits at the implant-prosthesis interface may increase complications in dental implants and affect peri-implant tissue health. Periapical radiographs are the most used imaging examinations for detecting misfits at the implant-prosthesis interface, although digital systems have largely replaced film-based radiographs. Whether postprocessing tools such as enhancement filters assist diagnosis by highlighting misfits is unclear. PURPOSE: The purpose of this in vitro study was to assess the influence of enhancement filter application in the diagnostic accuracy of misfit detection at the implant-prosthesis interface. MATERIAL AND METHODS: A total of 32 dental implants were placed in dry human mandibles. A polyester strip was inserted at the implant-prosthesis interface to simulate a 50-µm misfit; prosthetic crowns installed directly on the implant platforms were used as controls. Standard paralleling periapical images were acquired by using a semidirect system (photostimulable phosphor plate) with the application of Highlight, Invert, and Colorization filters, as well as a direct system (metal oxide complementary semiconductor sensor) with filters Sharpness 3, Invert, and Pseudocolorization. Oral radiologists evaluated the images with and without the application of filters. The areas under the receiver operating characteristics curves (Az values), sensitivity, specificity, accuracy, positive predictive value, and negative predictive values were calculated. The Az values were compared with the receiver operating characteristic (ROC) curves comparison test of the Epidat 3.1 software (α=.05). RESULTS: Although images without filter application presented descriptively higher diagnostic values than those with filter application, the Az values for images with and without filter application in both semidirect and direct systems showed no significant differences (P>.05). CONCLUSIONS: Enhancement filter application did not significantly influence the diagnostic accuracy of misfit detection at the implant-prosthesis interface.

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OBJECTIVE: To compare the expression of the volumetric alteration (VA) artifact between cylindrical and convex triangular fields of view (FOVs) using high-density materials in different positions in two cone-beam computed tomography (CBCT) devices. MATERIALS AND METHODS: Cylinders of five high-density materials (amalgam, chromium-cobalt, gutta-percha, titanium, and zirconium) with known physical volume were individually submitted to CBCT acquisition in four positions inside a polymethylmethacrylate phantom using two different FOV shapes (convex triangular and cylindrical) on the Veraviewepocs® R100 (R100) and Veraview® X800 (X800) devices. Two oral radiologists obtained the tomographic volumes by segmenting each cylinder. The difference between the tomographic and physical volumes corresponded to the VA. These values were analyzed by intraclass correlation coefficient and analysis of variance for repeated measures with Tukey post hoc test (α = 5%). RESULTS: The FOV influenced the VA only in the X800 device (p = 0.014): the VA in the triangular FOV was greater than in the cylindrical FOV. The VA in the triangular FOV of the X800 device was greater than the R100 device (p < 0.0001). The material influenced the expression of the VA only in the R100 device (p < 0.0001); gutta-percha presented the highest VA, being underestimated, and differing from the other materials (p < 0.01). CONCLUSION: The triangular FOV increased the VA of high-density materials in the X800 device. CLINICAL RELEVANCE: It is important to know if there is an influence on the volumetric alteration artifact of dental materials due to the different image formation geometry in the convex triangular FOV.

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STATEMENT OF PROBLEM: Misfits at the implant-prosthesis interface may compromise implant-supported prostheses. Periapical radiographs are frequently used to detect misfit and can be obtained by using digital or film-based systems; however, which radiographic acquisition method and visualization software program provides the greatest accuracy is unclear. PURPOSE: The purpose of this ex vivo study was to evaluate the influence of 3 radiographic acquisition methods (complementary metal oxide semiconductor [CMOS] sensor, phosphor plates, and radiographic films) and 2 visualization software programs (proprietary and third-party) on the detection of misfits at the implant-prosthesis interface. MATERIAL AND METHODS: Thirty-two dental implants were placed in dry human mandibles. Misfits were simulated by inserting a 50-µm polyester strip at the implant-prosthesis interface; prosthetic crowns installed directly over the implant platforms were considered as controls. Standard parallel periapical radiographs were obtained by using a CMOS sensor, a phosphor plate, and radiographic films. Five dentists assessed the digital radiographs for the presence or absence of misfits at the implant-prosthesis interface by using the proprietary software program and a third-party software program; film-based radiographs were evaluated on a light box. The area under the receiver operating characteristic curves (Az values) were compared (α=.05); sensitivity, specificity, accuracy, positive predictive value, and negative predictive values were also estimated. RESULTS: All diagnostic and Az values were higher for the phosphor plate than for the CMOS sensor and the film-based methods (P<.05), regardless of the viewing software program used (proprietary or third-party) (P>.05). CONCLUSIONS: The use of phosphor plates positively influenced the diagnostic accuracy for the detection of misfits at the implant-prosthesis interface, irrespective of the viewing software program used.

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INTRODUCTION: This study assessed the influence of voxel size and filter application in detecting second mesiobuccal (MB2) canals in cone-beam computed tomographic (CBCT) images. METHODS: Using the OP300 CBCT system (Instrumentarium, Tuusula, Finland) and 3 voxel size protocols (80 µm, 125 µm, and 200 µm), we scanned 40 first molars: 20 with an MB2 canal and 20 without. All molars received silver palladium pins on the palatal root, whereas the non-MB2 molars were also filled with gutta-percha. Five oral radiologists assessed the presence of an MB2 canal under 3 filter application conditions: without filter, with sharpen 1 × filter, and with sharpen 2 × filter. Intra- and interobserver reproducibility was evaluated using the weighted kappa index. We compared the area under the receiver operating characteristic curves with SPSS Statistics v.20.0 (IBM Corp, Armonk, NY) using 2-way analysis of variance and the Tukey post hoc test with 5% significance level. RESULTS: Our analysis found median intra- and interobserver agreement values of 0.70 and 0.56, respectively. The 80-µm voxel with sharpen 1 × filter image group had the highest sensitivity, accuracy, and negative predictive values. As for specificity and positive predictive, the 80-µm voxel group without filter application presented the highest values. The areas under the receiver operating characteristic curve were higher in the 80-µm groups than in the 125-µm and 200-µm voxel size groups (P < .05). We found no differences among the filters used (P = .22) or for the filter-voxel size interactions (P = .88). CONCLUSIONS: A smaller voxel size increased the accuracy in detecting MB2 canals, whereas the enhancement filters did not.

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