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Lee SH, Yun PY, Yi YJ, Kim YK, Lee HJ, Jo DW. Low Bone Density Predictability of CBCT and Its Relation to Primary Stability of Tapered Implant Design: A Pilot Study. J ORAL IMPLANTOL 2023; 49:556-563. [PMID: 35881816 DOI: 10.1563/aaid-joi-d-21-00159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 04/04/2022] [Accepted: 05/31/2022] [Indexed: 11/22/2022]
Abstract
Research regarding bone density assessment using cone beam computed tomography (CBCT) in low bone density regions is sparse. This in vitro study aimed to evaluate the predictability of CBCT for low bone density regions and its correlations with primary implant stability when placing tapered design implants with a stepped osteotomy. Eighteen porcine mandibular condyles were used as simulated low bone density regions. Hounsfield units (HU), obtained via multislice computed tomography, and gray values (GVs), obtained via CBCT, were measured 3 times at 1-month intervals. The maximum implant insertion torque (MIT) and implant stability quotient (ISQ) were recorded as the taper design implants were placed using a stepped osteotomy. Hounsfield units and GV were measured as 335.05-803.07 and 389.98-906.40, respectively. For repeated measurements of HU and GV, the intraclass correlation coefficients were 0.989 and 0.980; the corresponding value for mean HU and GV was 0.768. Bland-Altman plots showed a mean difference between HU and GV of -78.15. Pearson correlation coefficients revealed a strong correlation between HU and GV (r = 0.91, P < .01). The mean ± SD values for MIT and ISQ were 36.44 ± 6.64 Ncm and 80.85 ± 2.03, respectively, but no statistically significant correlations were found with GV and HU. Within the study's limitations, GV showed similar bone density estimation compared with HU in soft bones. Tapered implant placement with a stepped osteotomy achieved stable primary implant stability in soft bones. However, these in vitro results need to be approved in further clinical studies.
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Affiliation(s)
- Sang-Hoon Lee
- Department of Prosthodontics, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Pil-Young Yun
- Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
- Department of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Yang-Jin Yi
- Department of Prosthodontics, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
- Department of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Young-Kyun Kim
- Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Hyo-Jung Lee
- Department of Periodontology, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Deuk-Won Jo
- Department of Prosthodontics, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
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Lan Y, Huang X, Fan M, Yu H, Xie Z, Zhou Y. Accuracy evaluation of cone beam computed tomography applied to measure peri-implant bone thickness in living patients: an ex vivo and in vivo experiment. Clin Oral Investig 2022; 26:6347-6359. [PMID: 35802190 DOI: 10.1007/s00784-022-04590-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/19/2022] [Indexed: 11/03/2022]
Abstract
OBJECTIVES This study aims to study the accuracy of cone beam computed tomography (CBCT) for measuring peri-implant bone thickness in living patients via a novel visualization method (NVM). MATERIAL AND METHODS The validity of the NVM was verified ex vivo by measuring the same peri-implant bone thicknesses in bovine ribs by using raw postoperative CBCT (clinical measurement, CM), the visualized fused images obtained using the NVM (visualized fused measurement, VF), and hard tissue sections (gold standard measurement, GS). The NVM was applied by deconstructing the postoperative CBCT model into the Modelpost-bone and Modelimplant and replacing it with bone from preoperative CBCT and standard implant models, respectively. In vivo, 52 implants were included, and the VF of each implant was obtained using data processing methods similar to those used ex vivo. Then, we compared the results of CM and VF. RESULTS Ex vivo, the VF was similar to GS, while CM usually underestimated the peri-implant bone thickness, especially at the implant shoulder (P < 0.01). In vivo, on CBCT, areas with a peri-implant bone thickness of 0-0.50 mm were not visible, while those with a thickness of 0.50-1.00 mm were occasionally visible. There was less underestimation of bone along the implant long axis. CONCLUSIONS Thin peri-implant bones could be completely underestimated on CBCT. CBCT scans alone are insufficient to warrant surgical intervention. Our NVM facilitates the accurate visual assessment of implant dimensions. CLINICAL RELEVANCE The thickness of peri-implant bone could be completely underestimated when thinner than 1.0 mm in living patients. Familiarity with these confusing CBCT results may help clinicians and patients avoid further unnecessary evaluation, misdiagnosis, and invasive treatment.
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Affiliation(s)
- Yanhua Lan
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China
| | - Xiaoyuan Huang
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China
| | - Mingxing Fan
- Hangzhou 6D Dental Technologies Co., Ltd, Hangzhou, 310001, People's Republic of China
| | - Huazhen Yu
- School of Mathematical Sciences, Zhejiang University, Hangzhou, 310012, People's Republic of China
| | - Zhijian Xie
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China.
| | - Yiqun Zhou
- School of Stomatology, Zhejiang Provincial Clinical Research Center for Oral Diseases, Stomatology HospitalZhejiang University School of MedicineKey Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Hangzhou, 310006, People's Republic of China.
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Uysal S, Akcicek G, Yalcin ED, Tuncel B, Dural S. The influence of voxel size and artifact reduction on the detection of vertical root fracture in endodontically treated teeth. Acta Odontol Scand 2021; 79:354-358. [PMID: 33337942 DOI: 10.1080/00016357.2020.1859611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the effect of voxel size and artefact reduction (AR) on the identification of vertical root fractures (VRFs) in endodontically treated teeth. METHODS A total of a hundred sound, extracted human mandibular single-rooted premolars were decoronated, after which root canal preparation was performed, canals were filled with gutta percha by single cone technique. Randomly selected fifty specimens were fractured, repositioned and glued together. The teeth were examined with cone beam computed tomography (CBCT) in five different voxel sizes (0.125, 0.200, 0.250, 0.300, and 0.400 voxels). Two scans were performed for each tooth, one with AR and one without AR. Two radiologists evaluated the CBCT scans. RESULTS All voxel dimensions were successful in detecting VRFs in CBCT scans. But as the voxel size increased, the percentage of detecting VRFs decreased. High accuracy, sensitivity, specificity and predictive values were found for VRF detection on CBCT scans. Accuracy and sensitivity values decreased (from 100 to 82) while voxel dimensions increased (from 0.125 to 0.400). High-resolution images (0.125, 0.200, and 0.250 voxels) caused an increase in sensitivity for detection of VRFs. AR did not affect the accuracy, sensitivity, specificity and predictive values for VRF detection on CBCT scans. CONCLUSIONS High-resolution CBCT images resulted in an increase in sensitivity and specificity for detection of VRFs compared with lower-resolution CBCT images. The use of AR did not further improve its diagnostic potential.
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Affiliation(s)
- Serdar Uysal
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
| | - Gokcen Akcicek
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
| | - Eda Didem Yalcin
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Gaziantep University, Gaziantep, Turkey
| | - Behram Tuncel
- Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
| | - Sema Dural
- Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
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Terrabuio BR, Carvalho CG, Peralta-Mamani M, Santos PSDS, Rubira-Bullen IRF, Rubira CMF. Cone-beam computed tomography artifacts in the presence of dental implants and associated factors: an integrative review. Imaging Sci Dent 2021; 51:93-106. [PMID: 34235055 PMCID: PMC8219451 DOI: 10.5624/isd.20200320] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/18/2021] [Accepted: 01/27/2021] [Indexed: 12/16/2022] Open
Abstract
Purpose This study was conducted to review the literature regarding the types of cone-beam computed tomography (CBCT) artifacts around dental implants and the factors that influence their formation. Materials and Methods A search strategy was carried out in the PubMed, Embase, and Scopus databases to identify published between 2010 and 2020, and 9 studies were selected. The implants included 306 titanium, titanium-zirconium, and zirconia implants, as well as 5 titanium cylinders. Results The artifacts around the implants were the beam-hardening artifact, the streaking artifact, and band-like radiolucent areas. Some factors that influenced the formation of artifacts were the implant material, bone type, evaluated regions, distance, type of CBCT, field of view (FOV) size, milliamperage, peak kilovoltage (kVp), and voxel size. The beam-hardening artifact was the most widely reported, and it was minimized in protocols with a smaller FOV, larger voxels, and higher kVp. Conclusion The risk and benefit of these protocols in individuals with dental implants must be considered, and clinical examinations and complementary radiographs play an essential role in implantology.
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Affiliation(s)
- Bianca Rodrigues Terrabuio
- Department of Surgery, Stomatology, Pathology, and Radiology, Bauru School of Dentistry, University of São Paulo, SP, Brazil
| | - Caroline Gomes Carvalho
- Department of Surgery, Stomatology, Pathology, and Radiology, Bauru School of Dentistry, University of São Paulo, SP, Brazil
| | - Mariela Peralta-Mamani
- Department of Surgery, Stomatology, Pathology, and Radiology, Bauru School of Dentistry, University of São Paulo, SP, Brazil
| | - Paulo Sérgio da Silva Santos
- Department of Surgery, Stomatology, Pathology, and Radiology, Bauru School of Dentistry, University of São Paulo, SP, Brazil
| | | | - Cássia Maria Fischer Rubira
- Department of Surgery, Stomatology, Pathology, and Radiology, Bauru School of Dentistry, University of São Paulo, SP, Brazil
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Park SW, Yoon RG, Lee H, Lee HJ, Choi YD, Lee DH. Impacts of Thresholds of Gray Value for Cone-Beam Computed Tomography 3D Reconstruction on the Accuracy of Image Matching with Optical Scan. Int J Environ Res Public Health 2020; 17:ijerph17176375. [PMID: 32882986 PMCID: PMC7503962 DOI: 10.3390/ijerph17176375] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 12/11/2022]
Abstract
In cone-beam computed tomography (CBCT), the minimum threshold of the gray value of segmentation is set to convert the CBCT images to the 3D mesh reconstruction model. This study aimed to assess the accuracy of image registration of optical scans to 3D CBCT reconstructions created by different thresholds of grey values of segmentation in partial edentulous jaw conditions. CBCT of a dentate jaw was reconstructed to 3D mesh models using three different thresholds of gray value (-500, 500, and 1500), and three partially edentulous models with different numbers of remaining teeth (4, 8, and 12) were made from each 3D reconstruction model. To merge CBCT and optical scan data, optical scan images were registered to respective 3D reconstruction CBCT images using a point-based best-fit algorithm. The accuracy of image registration was assessed by measuring the positional deviation between the matched 3D images. The Kruskal-Wallis test and a post hoc Mann-Whitney U test with Bonferroni correction were used to compare the results between groups (α = 0.05). The correlations between the experimental factors were calculated using the two-way analysis of variance test. The positional deviations were lowest with the threshold of 500, followed by the threshold of 1500, and then -500. A significant interaction was found between the threshold of gray values and the number of remaining teeth on the registration accuracy. The most significant deviation was observed in the arch model with four teeth reconstructed with a gray-value threshold of -500. The threshold for the gray value of CBCT segmentation affects the accuracy of image registration of optical scans to the 3D reconstruction model of CBCT. The appropriate gray value that can visualize the anatomical structure should be set, especially when few teeth remain in the dental arch.
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Affiliation(s)
- Se-Won Park
- Department of Prosthodontics, School of Dentistry, Institute for Translational Research in Dentistry, Kyungpook National University, Daegu 41940, Korea; (S.-W.P.); (Y.-D.C.)
| | - Ra Gyoung Yoon
- Department of Radiology, Nowon Eulji Medical Center, Eulji University, Seoul 01830, Korea;
| | - Hyunwoo Lee
- Department of Dental Clinic, National Medical Center, Seoul 04564, Korea;
| | - Heon-Jin Lee
- Department of Microbiology and Immunology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea;
| | - Yong-Do Choi
- Department of Prosthodontics, School of Dentistry, Institute for Translational Research in Dentistry, Kyungpook National University, Daegu 41940, Korea; (S.-W.P.); (Y.-D.C.)
| | - Du-Hyeong Lee
- Department of Prosthodontics, School of Dentistry, Institute for Translational Research in Dentistry, Kyungpook National University, Daegu 41940, Korea; (S.-W.P.); (Y.-D.C.)
- Correspondence: ; Tel.: +82-53-600-7676
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Rossignol J, Turtos RM, Gundacker S, Gaudreault D, Auffray E, Lecoq P, Bérubé-Lauzière Y, Fontaine R. Time-of-flight computed tomography - proof of principle. Phys Med Biol 2020; 65:085013. [PMID: 32084652 DOI: 10.1088/1361-6560/ab78bf] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Computed tomography has greatly improved over the last decade, especially through x-ray dose exposure reduction while maintaining image quality. Herein, a new concept is proposed to improve the contrast-to-noise ratio (CNR) by including the time-of-flight (TOF) information of individual photons to obtain further insight on the photon's trajectory and to reject scatter contribution. The proof of the concept relies on both simulation and experimental measurements in a cone-beam computed tomography arrangement. Results show a statistical difference between the TOF of scattered and primary photons exploitable in TOF computed tomography. For a large volume of the size of a human abdomen, a scatter reduction from 296% to 4% is achieved in our simulation setup with perfect timing measurements which yields a 110% better CNR, or a dose reduction by a factor of four. Cup artifacts are also reduced from 24.7% to 0.8%, and attenuation inaccuracies are improved from -26.3% to -0.8%. With 100 ps and 10 ps FWHM timing jitters, respectively 75% and 95% of the scatter contribution can be removed with marginal gains below 10 ps. Experimental measurements confirm the feasibility of measuring statistical differences between the TOF of scattered and primary photons.
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Affiliation(s)
- J Rossignol
- Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, Sherbrooke, Québec, Canada. Département de Génie Électrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, Québec, Canada
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Candemil AP, Salmon B, Freitas DQ, Haiter-Neto F, Oliveira ML. Distribution of metal artifacts arising from the exomass in small field-of-view cone beam computed tomography scans. Oral Surg Oral Med Oral Pathol Oral Radiol 2020; 130:116-125. [PMID: 32057753 DOI: 10.1016/j.oooo.2020.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 12/11/2019] [Accepted: 01/10/2020] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To evaluate the distribution of metal artifacts from the exomass in small field-of-view (FOV) cone beam computed tomography (CBCT) scans. STUDY DESIGN An image phantom was scanned by using 3 CBCT units. Metal objects were positioned in the exomass, and additional CBCT scans were obtained. Mean gray values were obtained from 16 homogeneous areas and the standard deviation was calculated to quantify gray level inhomogeneity according to distinct zones of the FOV: total area and outer, inner, right, left, and mid-zones. The discrepancy between each zone and the total area was calculated to compare different CBCT units. Mean gray, gray level inhomogeneity, and discrepancy values were separately assessed by using analysis of variance (ANOVA) and Tukey's test (α = 0.05). RESULTS Overall, the mean gray values were significantly lower in the inner zone, and the gray level inhomogeneity values were significantly higher in the inner and mid-zones irrespective of the presence of metal objects in the exomass. The 3 CBCT units presented significantly different discrepancy values in most conditions. CONCLUSIONS The distribution of metal artifacts from the exomass follows the inherent gray value dispersion of CBCT images, with greater inhomogeneity in the inner zone of the FOV. This is exacerbated when metal objects are in the exomass.
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Affiliation(s)
- Amanda P Candemil
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba (São Paulo), Brazil.
| | - Benjamin Salmon
- Université de Paris, Orofacial Pathologies, Imaging and Biotherapies EA2496 Lab, Montrouge, France; Dental Medicine Department, AP-HP, Bretonneau Hospital, Paris, France
| | - Deborah Queiroz Freitas
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba (São Paulo), Brazil
| | - Francisco Haiter-Neto
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba (São Paulo), Brazil
| | - Matheus Lima Oliveira
- Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba (São Paulo), Brazil
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Stamatakis HC, Steegman R, Dusseldorp J, Ren Y. Head positioning in a cone beam computed tomography unit and the effect on accuracy of the three-dimensional surface mode. Eur J Oral Sci 2018; 127:72-80. [DOI: 10.1111/eos.12582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Harry C. Stamatakis
- Department of Orthodontics; University of Groningen; University Medical Centre Groningen; Groningen the Netherlands
| | - Ralph Steegman
- Department of Orthodontics; University of Groningen; University Medical Centre Groningen; Groningen the Netherlands
| | - Joost Dusseldorp
- Department of Orthodontics; University of Groningen; University Medical Centre Groningen; Groningen the Netherlands
| | - Yijin Ren
- Department of Orthodontics, W. J. Kolff Institute of Biomedical Engineering and Materials Science; University of Groningen; University Medical Centre Groningen; Groningen the Netherlands
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Liu J, Chen HY, DoDo H, Yousef H, Firestone AR, Chaudhry J, Johnston WM, Lee DJ, Emam HA, Kim DG. Efficacy of Cone-Beam Computed Tomography in Evaluating Bone Quality for Optimum Implant Treatment Planning. IMPLANT DENT 2018; 26:405-411. [PMID: 28125517 DOI: 10.1097/id.0000000000000542] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE This study examined (1) if cone-beam computed tomography (CBCT) can determine relative differences in bone mineral density distribution using clinical images of patients' mandibular bone and (2) if the relative differences can be used to detect the effects of sex and age on bone mineral density distribution. MATERIALS AND METHODS Sixty-six clinical CBCT images from patients (36 females and 30 males) of 3 age groups (40, 50, and 60 years) were identified. Alveolar (AB) and basal cortical bone (CB) regions were digitally isolated. A histogram of gray levels, which are proportional to degrees of bone mineralization, was obtained from each region. Mean, variability (SD and coefficient of variation), and percentage differences of gray level parameters between AB and basal CBs were computed. RESULTS Significant sex differences in gray level variability were observed within the postmenopausal age group (P < 0.042). CONCLUSION These findings suggest that clinical CBCT images can be a valuable tool in providing information on bone quality, which is an important criterion for optimum planning for dental implant placement.
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Affiliation(s)
- Jie Liu
- *Private Practice, Former Resident, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. †Undergraduate Student, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. ‡Predoctoral Student, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. §Master Student, Clinical and Translational Science, College of Medicine, Ohio State University, Columbus, OH. ¶Associate Professor, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, OH. ‖Clinical Associate Professor, Department of Oral Pathology, Medicine and Radiology, School of Dentistry, Indiana University, Indianapolis, IN. #Professor Emeritus, Division of General Practice and Materials Science, College of Dentistry, Ohio State University, Columbus, OH. **Assistant Professor, Division of Restorative Sciences and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH. ††Division of Oral and Maxillofacial Surgery, College of Dentistry, The Ohio State University, Columbus, OH
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Shokri A, Ramezani L, Bidgoli M, Akbarzadeh M, Ghazikhanlu-Sani K, Fallahi-Sichani H. Effect of field-of-view size on gray values derived from cone-beam computed tomography compared with the Hounsfield unit values from multidetector computed tomography scans. Imaging Sci Dent 2018; 48:31-39. [PMID: 29581947 PMCID: PMC5863017 DOI: 10.5624/isd.2018.48.1.31] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 01/15/2018] [Accepted: 01/30/2018] [Indexed: 11/18/2022] Open
Abstract
Purpose This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. Materials and Methods A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol. Results In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes (P<.05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. Conclusion The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.
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Affiliation(s)
- Abbas Shokri
- Dental Implant Research Center, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Leila Ramezani
- Dental Implant Research Center, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohsen Bidgoli
- Department of Periodontics, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mahdi Akbarzadeh
- Molecular Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Karim Ghazikhanlu-Sani
- Department of Radiology, Faculty of Para Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamed Fallahi-Sichani
- Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
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Lindfors N, Lund H, Johansson H, Ekestubbe A. Influence of patient position and other inherent factors on image quality in two different cone beam computed tomography (CBCT) devices. Eur J Radiol Open 2017; 4:132-7. [PMID: 29159206 DOI: 10.1016/j.ejro.2017.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/20/2017] [Indexed: 11/23/2022] Open
Abstract
Patient head position can affect the image quality in CBCT-examinations. CNR values can be used to evaluate image quality. Inherent factors influence effective dose variations between CBCT-devices.
Objectives The aim of this in vitro study was to evaluate how a deviation from the horizontal plane, affects the image quality in two different CBCT-devices. Methods A phantom head SK150 (RANDO, The Phantom Laboratory, Salem, NY, USA) was examined in two CBCT-units: Accuitomo 80 and Veraviewepocs 3D R100 (J. Morita Mfg. Corp. Kyoto, Japan). The phantom head was placed with the hard palate parallel to the horizontal plane and tilted 20 ° backwards. Exposures were performed with different field of views (FOVs), voxel sizes, slice thicknesses and exposure settings. Effective dose was calculated using PCXMC 2.0 (STUK, Helsinki, Finland). Image quality was assessed using contrast-to-noise-ratio (CNR). Region of interest (ROI) was set at three different levels of the mandibular bone and soft tissue, uni- and bilaterally in small and large FOVs, respectively. CNR values were calculated by CT-value and standard deviation for each ROI. Factor analysis was used to analyze the material. Results Tilting the phantom head backwards rendered significantly higher mean CNR values regardless of FOV. The effective dose was lower in small than in large FOVs and varied to a larger extent between CBCT-devices in large FOVs. Conclusions Head position can affect the image quality. Tilting the head backward improved image quality in the mandibular region. However, if influenced by other variables e.g. motion artifacts in a clinical situation, remains to be further investigated. Advances in knowledge Image quality assessed using CNR values to investigate the influence of different patient positions and FOVs.
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Rabelo KA, Cavalcanti YW, de Oliveira Pinto MG, Sousa Melo SL, Campos PSF, de Andrade Freitas Oliveira LS, de Melo DP. Quantitative assessment of image artifacts from root filling materials on CBCT scans made using several exposure parameters. Imaging Sci Dent 2017; 47:189-197. [PMID: 28989902 PMCID: PMC5620464 DOI: 10.5624/isd.2017.47.3.189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 06/03/2017] [Accepted: 06/07/2017] [Indexed: 02/01/2023] Open
Abstract
Purpose To quantify artifacts from different root filling materials in cone-beam computed tomography (CBCT) images acquired using different exposure parameters. Materials and Methods Fifteen single-rooted teeth were scanned using 8 different exposure protocols with 3 different filling materials and once without filling material as a control group. Artifact quantification was performed by a trained observer who made measurements in the central axial slice of all acquired images in a fixed region of interest using ImageJ. Hyperdense artifacts, hypodense artifacts, and the remaining tooth area were identified, and the percentages of hyperdense and hypodense artifacts, remaining tooth area, and tooth area affected by the artifacts were calculated. Artifacts were analyzed qualitatively by 2 observers using the following scores: absence (0), moderate presence (1), and high presence (2) for hypodense halos, hypodense lines, and hyperdense lines. Two-way ANOVA and the post-hoc Tukey test were used for quantitative and qualitative artifact analysis. The Dunnet test was also used for qualitative analysis. The significance level was set at P<.05. Results There were no significant interactions among the exposure parameters in the quantitative or qualitative analysis. Significant differences were observed among the studied filling materials in all quantitative analyses. In the qualitative analyses, all materials differed from the control group in terms of hypodense and hyperdense lines (P<.05). Fiberglass posts did not differ statistically from the control group in terms of hypodense halos (P>.05). Conclusion Different exposure parameters did not affect the objective or subjective observations of artifacts in CBCT images; however, the filling materials used in endodontic restorations did affect both types of assessments.
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Affiliation(s)
| | | | | | | | | | | | - Daniela Pita de Melo
- Department of Oral Diagnosis, State University of Paraíba, Campina Grande, Brazil
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de Oliveira MVL, Santos AC, Paulo G, Campos PSF, Santos J. Application of a newly developed software program for image quality assessment in cone-beam computed tomography. Imaging Sci Dent 2017; 47:75-86. [PMID: 28680843 PMCID: PMC5489672 DOI: 10.5624/isd.2017.47.2.75] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/01/2017] [Accepted: 04/24/2017] [Indexed: 11/18/2022] Open
Abstract
PURPOSE The purpose of this study was to apply a newly developed free software program, at low cost and with minimal time, to evaluate the quality of dental and maxillofacial cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS A polymethyl methacrylate (PMMA) phantom, CQP-IFBA, was scanned in 3 CBCT units with 7 protocols. A macro program was developed, using the free software ImageJ, to automatically evaluate the image quality parameters. The image quality evaluation was based on 8 parameters: uniformity, the signal-to-noise ratio (SNR), noise, the contrast-to-noise ratio (CNR), spatial resolution, the artifact index, geometric accuracy, and low-contrast resolution. RESULTS The image uniformity and noise depended on the protocol that was applied. Regarding the CNR, high-density structures were more sensitive to the effect of scanning parameters. There were no significant differences between SNR and CNR in centered and peripheral objects. The geometric accuracy assessment showed that all the distance measurements were lower than the real values. Low-contrast resolution was influenced by the scanning parameters, and the 1-mm rod present in the phantom was not depicted in any of the 3 CBCT units. Smaller voxel sizes presented higher spatial resolution. There were no significant differences among the protocols regarding artifact presence. CONCLUSION This software package provided a fast, low-cost, and feasible method for the evaluation of image quality parameters in CBCT.
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Affiliation(s)
- Marcus Vinicius Linhares de Oliveira
- Department of Health Technology and Biology, Federal Institute of Bahia, Salvador, BA, Brazil.,Department of Interactive Processes of Organs and Systems, Institute of Health Sciences, Federal University of Bahia, Salvador, BA, Brazil
| | - António Carvalho Santos
- Department of Complementary Sciences, Coimbra Health School, Polytechnic Institute of Coimbra, Portugal
| | - Graciano Paulo
- Department of Medical Imaging and Radiotherapy, Coimbra Health School, Polytechnic Institute of Coimbra, Portugal
| | - Paulo Sergio Flores Campos
- Department of Interactive Processes of Organs and Systems, Institute of Health Sciences, Federal University of Bahia, Salvador, BA, Brazil
| | - Joana Santos
- Department of Medical Imaging and Radiotherapy, Coimbra Health School, Polytechnic Institute of Coimbra, Portugal
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de Oliveira MVL, Wenzel A, Campos PSF, Spin-Neto R. Quality assurance phantoms for cone beam computed tomography: a systematic literature review. Dentomaxillofac Radiol 2017; 46:20160329. [PMID: 28045345 DOI: 10.1259/dmfr.20160329] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVES To undertake a systematic review on quality assurance (QA) phantoms for CBCT imaging, including studies on the development and application of phantoms. METHODS The MEDLINE (PubMed) bibliographic database was searched until May 2016 for studies evaluating the development and use of phantoms in CBCT image QA. The search strategy was restricted to English language publications using the following combined terms: (Cone Beam CT) OR (Cone Beam Computed Tomography) OR (Cone-Beam Computed Tomography) OR (CBCT) AND (quality OR phantom). It was assessed which of the six image quality parameters stated by the European Commission could be evaluated with each phantom and which of them actually were. RESULTS The search strategy yielded 37 studies, which had developed and used (25 studies) or only used (12 studies) a phantom in CBCT image QA. According to the literature, in 7 phantoms, it is possible to evaluate 4 or more image quality parameters while in 11 phantoms, merely 1 parameter can be evaluated. Only two phantoms permit the evaluation of the six image quality parameters stated by the European Commission. The parameters, which can most often be evaluated using a phantom, are image density values, spatial resolution and geometric accuracy. The SEDENTEXCT phantom was used most frequently. In two studies, all quality parameters suggested by the European Commission were evaluated. CONCLUSIONS QA phantoms rarely allow all image quality parameters stated by the European Commission to be evaluated. Furthermore, alternative phantoms, which allow all image quality parameters to be evaluated in a single exposure, even for a small field of view, should be developed.
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Affiliation(s)
- Marcus V L de Oliveira
- 1 Department of Health Technology and Biology, Federal Institute of Bahia, Salvador, Brazil.,2 Institute of Health Sciences, Department of Interactive, Processes of Organs and Systems, Federal University of Bahia, Salvador, Brazil
| | - Ann Wenzel
- 3 Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - Paulo S F Campos
- 2 Institute of Health Sciences, Department of Interactive, Processes of Organs and Systems, Federal University of Bahia, Salvador, Brazil
| | - Rubens Spin-Neto
- 3 Oral Radiology, Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
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Smeets R, Schöllchen M, Gauer T, Aarabi G, Assaf AT, Rendenbach C, Beck-Broichsitter B, Semmusch J, Sedlacik J, Heiland M, Fiehler J, Siemonsen S. Artefacts in multimodal imaging of titanium, zirconium and binary titanium-zirconium alloy dental implants: an in vitro study. Dentomaxillofac Radiol 2016; 46:20160267. [PMID: 27910719 DOI: 10.1259/dmfr.20160267] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To analyze and evaluate imaging artefacts induced by zirconium, titanium and titanium-zirconium alloy dental implants. METHODS Zirconium, titanium and titanium-zirconium alloy implants were embedded in gelatin and MRI, CT and CBCT were performed. Standard protocols were used for each modality. For MRI, line-distance profiles were plotted to quantify the accuracy of size determination. For CT and CBCT, six shells surrounding the implant were defined every 0.5 cm from the implant surface and histogram parameters were determined for each shell. RESULTS While titanium and titanium-zirconium alloy induced extensive signal voids in MRI owing to strong susceptibility, zirconium implants were clearly definable with only minor distortion artefacts. For titanium and titanium-zirconium alloy, the MR signal was attenuated up to 14.1 mm from the implant. In CT, titanium and titanium-zirconium alloy resulted in less streak artefacts in comparison with zirconium. In CBCT, titanium-zirconium alloy induced more severe artefacts than zirconium and titanium. CONCLUSIONS MRI allows for an excellent image contrast and limited artefacts in patients with zirconium implants. CT and CBCT examinations are less affected by artefacts from titanium and titanium-zirconium alloy implants compared with MRI. The knowledge about differences of artefacts through different implant materials and image modalities might help support clinical decisions for the choice of implant material or imaging device in the clinical setting.
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Affiliation(s)
- Ralf Smeets
- 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maximilian Schöllchen
- 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tobias Gauer
- 2 Department of Radiotherapy and Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ghazal Aarabi
- 3 Department of Prosthetic Dentistry, Center for Dental and Oral Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexandre T Assaf
- 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carsten Rendenbach
- 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Benedicta Beck-Broichsitter
- 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan Semmusch
- 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan Sedlacik
- 4 Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Max Heiland
- 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jens Fiehler
- 4 Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Susanne Siemonsen
- 4 Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Elsaltani MH, Farid MM, Eldin Ashmawy MS. Detection of Simulated Vertical Root Fractures: Which Cone-beam Computed Tomographic System Is the Most Accurate? J Endod 2016; 42:972-7. [DOI: 10.1016/j.joen.2016.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 03/09/2016] [Accepted: 03/13/2016] [Indexed: 12/25/2022]
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18
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Taylor C. Evaluation of the effects of positioning and configuration on contrast-to-noise ratio in the quality control of a 3D Accuitomo 170 dental CBCT system. Dentomaxillofac Radiol 2016; 45:20150430. [PMID: 27008106 DOI: 10.1259/dmfr.20150430] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES This study evaluated the effect of phantom positioning and the configuration of phantom inserts on the measurement of contrast-to-noise ratio (CNR) in dental CBCT. The work aimed to make pragmatic suggestions for the remedial tolerances for CNR measurements in the routine quality control (QC) of a three-dimensional Accuitomo 170 dental CBCT system (J Morita, Kyoto, Japan). METHODS Images of the SEDENTEXCT (safety and efficacy of a new and emerging dental X-ray modality) IQ (image quality) dental CBCT phantom (Leeds Test Objects Ltd, Boroughbridge, UK) were acquired and measurements of CNR were obtained in three configurations of inserts and in six phantom orientations for one of the configurations. Five consecutive images were acquired in each case, to assess the reproducibility of measurements. RESULTS Reproducibility of measurements ranged from 1.8% to 4.6%. For the CNR measurements in the three phantom configurations, the ratio of the measured CNR to the minimum value was 2.1 ± 0.2 times the minimum value for Delrin(®) (DuPont UK Ltd, Stevenage, UK). For aluminium, there was no significant variation between configurations and for the other three materials, the ratio ranged from 20% to 50%. Significant variations in CNR with phantom position were observed, with differences between the maximum and minimum values ranging from 10% to 60%. Absolute differences in CNR from the minimum value ranged from <0.1 to 2.1 with phantom configuration and from 1.2 to 4.5 with phantom position. CONCLUSIONS The effects of phantom configuration and positioning on CNR measurements for dental CBCT QC were investigated and possible remedial tolerances suggested.
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Affiliation(s)
- Catherine Taylor
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
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Cotrim S, Nardotto J, Abreu L, Silva A, Galera P, Santana M. Estudo anatômico do trajeto do canal mandibular em felinos (Felis catus domesticus). ARQ BRAS MED VET ZOO 2015. [DOI: 10.1590/1678-4162-8325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Objetivou-se descrever, por meio de tomografia computadorizada, o trajeto do canal mandibular (CM) em 20 gatos sem raça definida, com ausência de alterações na cavidade oral, provenientes do Centro de Controle de Zoonoses do Distrito Federal. Foram realizados cortes tomográficos com 2mm de espessura, acompanhando todo o trajeto do CM, tendo como referência a região do forame mandibular, as raízes distais e mesiais dos dentes pré-molares e molares e o forame mentoniano, obtendo-se medidas desde o CM até as faces vestibular, lingual, ventral e alveolar (profundidade) do corpo da mandíbula, bem como seu diâmetro. Pôde constatar que o CM manteve-se no aspecto lingual do corpo da mandíbula desde o forame mandibular até a raiz mesial do 1º pré-molar, onde se deslocou para a face vestibular, emergindo no forame mentoniano. Com relação à profundidade, seu trajeto sofreu declive a partir do forame mandibular até a região da raiz mesial do 1º molar, onde alcançou seu ponto mais profundo para prosseguir em suave ascensão até o forame mentoniano. Os dados apresentados contribuem para o estudo anatômico da mandíbula de gatos, bem como auxiliam no melhor planejamento e execução de procedimentos cirúrgicos na mandíbula dessa espécie.
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Affiliation(s)
| | | | - L.G. Abreu
- SCAN Medicina Veterinária Diagnóstica, Brasil
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Rostetter C, Metzler P, Schenkel JS, Seifert B, Luebbers HT. Comparison of in vivo cone-beam and multidetector computed tomographic scans by three-dimensional merging software. Br J Oral Maxillofac Surg 2015; 53:1021-6. [DOI: 10.1016/j.bjoms.2015.09.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 09/27/2015] [Indexed: 12/17/2022]
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Abouei E, Lee S, Ford NL. Quantitative performance characterization of image quality and radiation dose for a CS 9300 dental cone beam computed tomography machine. J Med Imaging (Bellingham) 2015; 2:044002. [PMID: 26587550 DOI: 10.1117/1.jmi.2.4.044002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/16/2015] [Indexed: 11/14/2022] Open
Abstract
This paper aims to characterize the radiation dose and image quality (IQ) performance of a dental cone beam computed tomography (CBCT) unit over a range of fields of view (FOV). IQ and dose were measured using a Carestream 9300 dental CBCT. Phantoms were positioned in the FOV to imitate clinical positioning. IQ was assessed by scanning a SEDENTEXCT IQ phantom, and images were analyzed in ImageJ. Dose index 1 was obtained using a thimble ionization chamber and SEDENTEXCT DI phantom. Mean gray values agreed within 93.5% to 99.7% across the images, with pixel-to-pixel fluctuations of 6% to 12.5%, with poorer uniformity and increased noise for child protocols. CNR was fairly constant across FOVs, with higher CNR for larger patient settings. The measured limiting spatial resolution agreed well with 10% MTF and bar pattern measurements. Dose was reduced for smaller patient settings within a given FOV; however, smaller FOVs obtained with different acquisition settings did not necessarily result in reduced dose. The use of patient-specific acquisition settings decreased the radiation dose for smaller patients, with minimal impact on the IQ. The full set of IQ and dose measurements is reported to allow dental professionals to compare the different FOV settings for clinical use.
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Affiliation(s)
- Elham Abouei
- University of British Columbia , Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1, Canada
| | - Sierra Lee
- University of British Columbia , Department of Oral Biological and Medical Sciences, 2199 Webrook Mall, Vancouver, B.C. V6T 1Z3, Canada
| | - Nancy L Ford
- University of British Columbia , Department of Physics and Astronomy, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1, Canada ; University of British Columbia , Department of Oral Biological and Medical Sciences, 2199 Webrook Mall, Vancouver, B.C. V6T 1Z3, Canada
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Abstract
CBCT is a widely applied imaging modality in dentistry. It enables the visualization of high-contrast structures of the oral region (bone, teeth, air cavities) at a high resolution. CBCT is now commonly used for the assessment of bone quality, primarily for pre-operative implant planning. Traditionally, bone quality parameters and classifications were primarily based on bone density, which could be estimated through the use of Hounsfield units derived from multidetector CT (MDCT) data sets. However, there are crucial differences between MDCT and CBCT, which complicates the use of quantitative gray values (GVs) for the latter. From experimental as well as clinical research, it can be seen that great variability of GVs can exist on CBCT images owing to various reasons that are inherently associated with this technique (i.e. the limited field size, relatively high amount of scattered radiation and limitations of currently applied reconstruction algorithms). Although attempts have been made to correct for GV variability, it can be postulated that the quantitative use of GVs in CBCT should be generally avoided at this time. In addition, recent research and clinical findings have shifted the paradigm of bone quality from a density-based analysis to a structural evaluation of the bone. The ever-improving image quality of CBCT allows it to display trabecular bone patterns, indicating that it may be possible to apply structural analysis methods that are commonly used in micro-CT and histology.
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Affiliation(s)
- R Pauwels
- 1 Department of Radiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
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Kühl S, Zürcher S, Zitzmann NU, Filippi A, Payer M, Dagassan-Berndt D. Detection of peri-implant bone defects with different radiographic techniques - a human cadaver study. Clin Oral Implants Res 2015; 27:529-34. [PMID: 26059443 DOI: 10.1111/clr.12619] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2015] [Indexed: 01/03/2023]
Abstract
OBJECTIVES Two- and three-dimensional radiographic techniques are available to determine peri-implantitis-related bone loss around dental implants. PURPOSE To compare the performance of detecting different peri-implant bone defects in intraoral radiography (IR), panoramic radiography (PR), Cone Beam Computer Tomography (CBCT) and Computer Tomography (CT). MATERIAL AND METHODS Six implants were inserted under ideal conditions into the lower jaw of an edentulous human cadaver. IR, PR, CBCT and CT were performed. Two-wall, three-wall and four-wall defects with 1 mm depth were artificially created around two of the implants (one anterior and one posterior), and radiographies were repeated. The identical set-up was used for 3-mm-deep bone defects. All images were presented to seven observers. Sensitivity (SN) and specificity (SP) were determined for each modality, defect type and depths, and likelihood ratios were calculated. RESULTS The highest sensitivity was found with IR and CBCT for 1 mm (0.67; 0.68) and 3-mm defects (0.81; 0.79). The highest specificity was found with IR for both defect depths (0.51). The best classification of defect type revealed PR for both 1-mm and 3-mm-deep defects. Both likelihood ratios (LR+ and LR-) were best for IR with 1-mm (1.37 and 0.65) and with 3-mm defects (1.65 and 0.37). CONCLUSIONS IR should still be recommended as favourable method evaluating bone loss around dental implants, while CT demonstrated the lowest performance in detecting peri-implant bone defects.
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Affiliation(s)
- Sebastian Kühl
- Department of Oral Surgery, Oral Radiology and Oral Medicine, School of Dental Medicine University of Basel, Basel, Switzerland
| | - Silvia Zürcher
- Department of Oral Surgery, Oral Radiology and Oral Medicine, School of Dental Medicine University of Basel, Basel, Switzerland
| | - Nicola U Zitzmann
- Clinic for Periodontology, Endodontics and Cariology, University of Basel, Basel, Switzerland
| | - Andreas Filippi
- Department of Oral Surgery, Oral Radiology and Oral Medicine, School of Dental Medicine University of Basel, Basel, Switzerland
| | - Michael Payer
- Department of Oral Surgery and Radiology, Medical University of Graz, Graz, Austria
| | - Dorothea Dagassan-Berndt
- Department of Oral Surgery, Oral Radiology and Oral Medicine, School of Dental Medicine University of Basel, Basel, Switzerland
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Nishikawa K, Kousuge Y, Sano T. Is application of a quantitative CT technique helpful for quantitative measurement of bone density using dental cone-beam CT? Oral Radiol 2015. [DOI: 10.1007/s11282-015-0202-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rodrigues AF, da Silva Campos MJ, Chaoubah A, Fraga MR, Farinazzo Vitral RW. Use of Gray Values in CBCT and MSCT Images for Determination of Density: Influence of Variation of FOV Size. IMPLANT DENT 2015; Publish Ahead of Print. [DOI: 10.1097/id.0000000000000179] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Plachtovics M, Goczan J, Nagy K. The effect of calibration and detector temperature on the reconstructed cone beam computed tomography image quality: a study for the workflow of the iCAT Classic equipment. Oral Surg Oral Med Oral Pathol Oral Radiol 2014; 119:473-80. [PMID: 25687195 DOI: 10.1016/j.oooo.2014.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 12/02/2014] [Accepted: 12/09/2014] [Indexed: 12/01/2022]
Abstract
OBJECTIVE The image quality of the reconstructed dental cone beam computed tomography (CBCT) acquisition is strongly dependent on the characteristics of the applied detector. Some flat panel detector (FPD) types require a warming-up period (WUP) to achieve a steady-state temperature; and some of them, those that have a cesium iodide detector, may require a calibration process (CP) after each WUP. STUDY DESIGN Quality-assurance phantom was used for the evaluation of image quality, including spatial accuracy and density response with and without WUP and CP using iCAT Classic equipment. RESULTS The correlation between the measured gray values and the multidetector computed tomography (MDCT) values deviated slightly from linearity (defined by the 45-degree line). There was no detectable difference in the spatial accuracy of the four different scanning modes. CONCLUSIONS Although the WUP is important to reach the required steady-state temperature, the CP has a greater effect on the image quality.
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Affiliation(s)
- Mark Plachtovics
- Research Associate, Faculty of Dentistry, University of Szeged, Tisza Lajos krt 64, Szeged, 6720, Hungary.
| | - Janos Goczan
- Research Associate, Resolution Specialist Treatment Centre, Becket House, Hendford, Yeovil, BA20 1 TE, UK
| | - Katalin Nagy
- Professor, Faculty of Dentistry, University of Szeged, Tisza Lajos krt 64, Szeged, 6720, Hungary
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Kuusisto N, Vallittu PK, Lassila LVJ, Huumonen S. Evaluation of intensity of artefacts in CBCT by radio-opacity of composite simulation models of implants in vitro. Dentomaxillofac Radiol 2014; 44:20140157. [PMID: 25283364 DOI: 10.1259/dmfr.20140157] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim was to compare the intensity of artefacts in CBCT images caused by different percentages of radio-opacifying material in composite simulation models of implants. Titanium and zirconia models of implants were used as a reference for the evaluation of the intensity of artefacts. METHODS Seven different percentages of radio-opacifying BaAlSiO2 fillers were added to composite resin to fabricate seven step wedges and simulation models of implants. Titanium and zirconia simulation models of implants were also fabricated. Aluminium step wedge was used as a reference for the measurement of grey values in intraoral radiographs. Step wedges were exposed with a Planmeca Intra X-ray machine (Planmeca Oy, Helsinki, Finland). All composite, titanium and zirconia simulation models of implants were exposed with a SCANORA(®) 3D dental X-ray machine (Soredex, Tuusula, Finland). Images and grey values were analysed with ImageJ software (National Institutes of Health, Bethesda, MD). To demonstrate possible artefacts between all the simulation models of implants, the images were also visually compared with each other using ImageJ software. RESULTS Artefacts were clearly present in CBCT images caused by titanium and zirconia and when the composite material consisted at least 20% BaAlSiO2. The intensity of artefacts increased when the radio-opacity of the composite material increased. CONCLUSIONS Materials containing less radio-opacity produce less pronounced artefacts. The cut-off point for artefacts is at 20% radio-opaque filling material in composite material.
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Affiliation(s)
- N Kuusisto
- 1 Department of Oral Pathology and Radiology, Institute of Dentistry, University of Turku, Turku, Finland
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Crawford B, Kim DG, Moon ES, Johnson E, Fields HW, Palomo JM, Johnston WM. Cervical vertebral bone mineral density changes in adolescents during orthodontic treatment. Am J Orthod Dentofacial Orthop 2014; 146:183-9. [PMID: 25085301 DOI: 10.1016/j.ajodo.2014.04.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 04/01/2014] [Accepted: 04/01/2014] [Indexed: 10/25/2022]
Abstract
INTRODUCTION The cervical vertebral maturation (CVM) stages have been used to estimate facial growth status. In this study, we examined whether cone-beam computed tomography images can be used to detect changes of CVM-related parameters and bone mineral density distribution in adolescents during orthodontic treatment. METHODS Eighty-two cone-beam computed tomography images were obtained from 41 patients before (14.47 ± 1.42 years) and after (16.15 ± 1.38 years) orthodontic treatment. Two cervical vertebral bodies (C2 and C3) were digitally isolated from each image, and their volumes, means, and standard deviations of gray-level histograms were measured. The CVM stages and mandibular lengths were also estimated after converting the cone-beam computed tomography images. RESULTS Significant changes for the examined variables were detected during the observation period (P ≤0.018) except for C3 vertebral body volume (P = 0.210). The changes of CVM stage had significant positive correlations with those of vertebral body volume (P ≤0.021). The change of the standard deviation of bone mineral density (variability) showed significant correlations with those of vertebral body volume and mandibular length for C2 (P ≤0.029). CONCLUSIONS The means and variability of the gray levels account for bone mineral density and active remodeling, respectively. Our results indicate that bone mineral density distribution and the volume of the cervical vertebral body changed because of active bone remodeling during maturation.
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Affiliation(s)
- Bethany Crawford
- Resident, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus
| | - Do-Gyoon Kim
- Associate professor, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus.
| | - Eun-Sang Moon
- Predoctoral student, College of Dentistry, Ohio State University, Columbus
| | - Elizabeth Johnson
- Resident, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus
| | - Henry W Fields
- Professor, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus
| | - J Martin Palomo
- Associate professor, Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, Ohio
| | - William M Johnston
- Professor, Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, Ohio State University, Columbus
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Campos MJDS, de Souza TS, Mota Júnior SL, Fraga MR, Vitral RWF. Bone mineral density in cone beam computed tomography: Only a few shades of gray. World J Radiol 2014; 6:607-12. [PMID: 25170398 PMCID: PMC4147441 DOI: 10.4329/wjr.v6.i8.607] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 03/11/2014] [Accepted: 04/25/2014] [Indexed: 02/06/2023] Open
Abstract
Cone beam computed tomography (CBCT) has often been used to determine the quality of craniofacial bone structures through the determination of mineral density, which is based on gray scales of the images obtained. However, there is no consensus regarding the accuracy of the determination of the gray scales in these exams. This study aims to provide a literature review concerning the reliability of CBCT to determine bone mineral density. The gray values obtained with CBCT show a linear relationship with the attenuation coefficients of the materials, Hounsfield Units values obtained with medical computed tomography, and density values from dual energy X-ray absorciometry. However, errors are expected when CBCT images are used to define the quality of the scanned structures because these images show inconsistencies and arbitrariness in the gray values, particularly when related to abrupt change in the density of the object, X-ray beam hardening effect, scattered radiation, projection data discontinuity-related effect, differences between CBCT devices, changes in the volume of the field of view (FOV), and changes in the relationships of size and position between the FOV and the object evaluated. A few methods of mathematical correction of the gray scales in CBCT have been proposed; however, they do not generate consistent values that are independent of the devices and their configurations or of the scanned objects. Thus, CBCT should not be considered the examination of choice for the determination of bone and soft tissue mineral density at the current stage, particularly when values obtained are to be compared to predetermined standard values. Comparisons between symmetrically positioned structures inside the FOV and in relation to the exomass of the object, as it occurs with the right and left sides of the skull, seem to be viable because the effects on the gray scale in the regions of interest are the same.
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Sancho-Puchades M, Hämmerle CHF, Benic GI. In vitro assessment of artifacts induced by titanium, titanium-zirconium and zirconium dioxide implants in cone-beam computed tomography. Clin Oral Implants Res 2014; 26:1222-8. [PMID: 25040484 DOI: 10.1111/clr.12438] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2014] [Indexed: 11/27/2022]
Abstract
AIM The aim of this study was to test whether or not the intensity of artifacts around implants in cone-beam computed tomography (CBCT) differs between titanium, titanium-zirconium and zirconium dioxide implants. MATERIALS AND METHODS Twenty models of a human mandible, each containing one implant in the single-tooth gap position 45, were cast in dental stone. Five test models were produced for each of the following implant types: titanium 4.1 mm diameter (Ti4.1 ), titanium 3.3 mm diameter (Ti3.3 ), titanium-zirconium 3.3 mm diameter (TiZr3.3 ) and zirconium dioxide 3.5-4.5 mm diameter (ZrO3.5-4.5 ) implants. For control purposes, three models without implants were produced. Each model was scanned using a CBCT device. Gray values (GV) were recorded at eight circumferential positions around the implants at 0.5 mm, 1 mm and 2 mm from the implant surface (GVT est ). GV were assessed in the corresponding volumes of interest (VOI) in the control models without implants (GVC ontrol ). Differences of gray values (ΔGV) between GVT est and GVC ontrol were calculated as percentages. One-way ANOVA and post hoc tests were applied to detect differences between implant types. RESULTS Mean ΔGV for ZrO3.5-4.5 presented the highest absolute values, generally followed by TiZr3.3 , Ti4.1 and Ti3.3 implants. The differences of ΔGV between ZrO3.5-4.5 and the remaining groups were statistically significant in the majority of the VOI (P ≤ 0.0167). ΔGV for TiZr3.3 , Ti4.1 and Ti3.3 implants did not differ significantly in the most VOI. For all implant types, ΔGV showed positive values buccally, mesio-buccally, lingually and disto-lingually, whereas negative values were detected mesially and distally. CONCLUSIONS Zirconium dioxide implants generate significantly more artifacts as compared to titanium and titanium-zirconium implants. The intensity of artifacts around zirconium dioxide implants exhibited in average the threefold in comparison with titanium implants.
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Affiliation(s)
- Manuel Sancho-Puchades
- Clinic for Fixed and Removable Prosthodontics and Material Science, Center for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, University of Zürich, Zürich, Switzerland
| | - Christoph H F Hämmerle
- Clinic for Fixed and Removable Prosthodontics and Material Science, Center for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, University of Zürich, Zürich, Switzerland
| | - Goran I Benic
- Clinic for Fixed and Removable Prosthodontics and Material Science, Center for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, University of Zürich, Zürich, Switzerland
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Bujtár P, Simonovics J, Zombori G, Fejer Z, Szucs A, Bojtos A, Batista WO, Váradi K, Sándor GK. Internal or in-scan validation: a method to assess CBCT and MSCT gray scales using a human cadaver. Oral Surg Oral Med Oral Pathol Oral Radiol 2014; 117:768-79. [DOI: 10.1016/j.oooo.2014.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 01/29/2014] [Accepted: 02/04/2014] [Indexed: 11/25/2022]
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Abstract
Mineral density distribution of bone tissue is altered by active bone modeling and remodeling due to bone complications including bone disease and implantation surgery. Clinical cone beam computed tomography (CBCT) has been examined whether it can assess oral bone mineral density (BMD) in patient. It has been indicated that CBCT has disadvantages of higher noise and lower contrast than conventional medical computed tomography (CT) systems. On the other hand, it has advantages of a relatively lower cost and radiation dose but higher spatial resolution. However, the reliability of CBCT based mineral density measurement has not yet been fully validated. Thus, the objectives of this review are to discuss 1) why assessment of BMD distribution is important and 2) whether the clinical CBCT can be used as a potential tool to measure the BMD. Brief descriptions of image artefacts associated with assessment of gray value, which has been used to account for mineral density, in CBCT images are provided. Techniques to correct local and conversion errors in obtaining the gray values in CBCT images are also introduced. This review can be used as a quick reference for users who may encounter these errors during analysis of CBCT images.
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Affiliation(s)
- Do-Gyoon Kim
- Division of Orthodontics, Ohio State University College of Dentistry, Columbus, OH, USA
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Oliveira ML, Freitas DQ, Ambrosano GMB, Haiter-Neto F. Influence of exposure factors on the variability of CBCT voxel values: a phantom study. Dentomaxillofac Radiol 2014; 43:20140128. [PMID: 24869906 DOI: 10.1259/dmfr.20140128] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To assess the influence of milliamperage and kilovolt peak (kVp) on the variability of cone beam CT (CBCT) voxel values. METHODS CBCT scans were obtained from radiographic phantoms in varying concentrations of dipotassium hydrogen phosphate solutions (200-1200 mg ml(-1)) under different protocols of milliamperage and kVp. In addition, scans were performed with and without a dental implant and exo-mass. The variability of CBCT voxel values was measured on each scan, and factorial analysis of variance and the post hoc Tukey test were performed (α = 0.05). Linear regression was performed to assess the relationship between voxel value variability and dipotassium hydrogen phosphate concentration. RESULTS milliamperage and the presence of a dental implant did not produce significant interference (p = 0.28 and 0.87, respectively) in voxel value variability. Scans at the highest kVp value presented a significant reduction (p ≤ 0.0001) in voxel value variability when only exo-mass was not present. Voxel value variability was not influenced by exo-mass in scans at the highest levels of milliamperage and kVp. The presence of exo-mass produced a significant reduction (p ≤ 0.0001) in voxel value variability in most of the scans. Higher concentrations yielded greater variations in voxel values in all scans, except for those operating at the highest levels of mAs and kVp. CONCLUSIONS mAs did not influence the variability of CBCT voxel values; higher kVp reduced such variability when only the object was smaller than the field of view.
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Affiliation(s)
- M L Oliveira
- Department of Oral Diagnosis, Division of Oral Radiology, State University of Campinas, Piracicaba Dental School, Piracicaba, Sao Paulo, Brazil
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Madrid JRP, Gomez V, Mendoza B. Demineralized bone matrix for alveolar cleft management. Craniomaxillofac Trauma Reconstr 2014; 7:251-7. [PMID: 25383144 DOI: 10.1055/s-0034-1375173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 09/22/2013] [Indexed: 10/25/2022] Open
Abstract
The aim of this article is to describe the results of the use of demineralized bone matrix putty in alveolar cleft of patients with cleft lip and palate. We performed a prospective, descriptive case series study, in which we evaluated the results of the management of alveolar clefts with demineralized bone matrix. Surgery was performed in 10 patients aged between 7 and 26 years (mean 13 years), involving a total of 13 clefts in the 10 patients. A preoperative cone beam computed tomography (CBCT) was taken to the patients in whom the width of the cleft was measured from each edge of the cleft reporting values between 5.76 and 16.93 mm (average, 11.18 mm). The densities of the clefts were measured with a CBCT, 6 months postoperative to assess bone formation. The results showed a register of gray values of 1,148 to 1,396 (mean, 1,270). The follow-up was conducted for 15 to 33 months (mean, 28.2 months). The results did not show satisfactory bone formation in the cleft of patients with the use of demineralized bone matrix.
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Affiliation(s)
- Jose Rolando Prada Madrid
- Department of Plastic and Reconstructive Surgery, Hospital Intantil Universitario San Jose and FISULAB, Bogotá, Colombia
| | - Viviana Gomez
- Department of Plastic and Reconstructive Surgery, La Fundación Santa Fé De Bogotá and Hospital Simón Bolivar, Bogotá, Colombia
| | - Bibiana Mendoza
- Department of Plastic and Reconstructive Surgery, Fundacion Universitaria de Ciencias de la Salud, Bogota, Colombia
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Plachtovics M, Bujtar P, Nagy K, Mommaerts M. High-quality image acquisition by double exposure overlap in dental cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2014; 117:760-7. [PMID: 24736110 DOI: 10.1016/j.oooo.2014.02.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 02/11/2014] [Accepted: 02/19/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE With a double exposure overlapping cone beam computed tomography (CBCT) scan technique, using CBCT acquisition radiation dose, the objective was to obtain apparent density similar to that of multidetector computed tomography (MDCT). STUDY DESIGN Factory quality-assurance phantom and water phantom were used for the evaluation of apparent density fidelity of iCAT scans in different modes. Each scan's apparent density was analyzed for identical regions using ImageJ, version 1.42q. RESULTS The iCAT Classic extended height acquisition with 4-cm central overlap and reconstruction of 2 groups of 300 projections per rotation for the water and quality-assurance CBCT phantoms resulted in improved apparent density fidelity. This apparent density accuracy was superior to that of iCAT scan at high resolution (600 projections during 1 rotation). CONCLUSIONS Using double exposure overlapping CBCT scans allows the analysis quality to be comparable with that of MDCT.
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Affiliation(s)
- Mark Plachtovics
- Research Associate, University of Szeged, Faculty of Dentistry, Szeged, Hungary.
| | - Peter Bujtar
- Research Associate, Oral and Maxillo-Facial Surgery Department, University of Oulu, Oulu, Finland
| | - Katalin Nagy
- Professor, Department of Cranio-Maxillo-Facial Surgery, European Face Centre, Vrije Universiteit Brussel, Brussels, Belgium
| | - Maurice Mommaerts
- Professor, University of Szeged, Faculty of Dentistry, Szeged, Hungary
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Gaia B, Pinheiro L, Umetsubo O, Costa F, Cavalcanti M. Validity of three-dimensional computed tomography measurements for Le Fort I osteotomy. Int J Oral Maxillofac Surg 2014; 43:197-203. [DOI: 10.1016/j.ijom.2013.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 04/17/2013] [Accepted: 06/10/2013] [Indexed: 10/26/2022]
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Ozdemir F, Tozlu M, Germec Cakan D. Quantitative evaluation of alveolar cortical bone density in adults with different vertical facial types using cone-beam computed tomography. Korean J Orthod 2014; 44:36-43. [PMID: 24511514 PMCID: PMC3915175 DOI: 10.4041/kjod.2014.44.1.36] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 06/17/2013] [Accepted: 06/28/2013] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE The purpose of this study was to quantitatively evaluate the cortical bone densities of the maxillary and mandibular alveolar processes in adults with different vertical facial types using cone-beam computed tomography (CBCT) images. METHODS CBCT images (n = 142) of adult patients (20-45 years) were classified into hypodivergent, normodivergent, and hyperdivergent groups on the basis of linear and angular S-N/Go-Me measurements. The cortical bone densities (in Hounsfield units) at maxillary and mandibular interdental sites from the distal aspect of the canine to the mesial aspect of the second molar were measured on the images. RESULTS On the maxillary buccal side, female subjects in the hyperdivergent group showed significantly decreased bone density, while in the posterior region, male subjects in the hyperdivergent group displayed significantly decreased bone density when compared with corresponding subjects in the other groups (p<0.001). Furthermore, the subjects in the hyperdivergent group had significantly lower bone densities on the mandibular buccal side than hypodivergent subjects. The maxillary palatal bone density did not differ significantly among groups, but female subjects showed significantly denser palatal cortical bone. No significant difference in bone density was found between the palatal and buccal sides in the maxillary premolar region. Overall, the palatal cortical bone was denser anteriorly and buccal cortical bone was denser posteriorly. CONCLUSION Adults with the hyperdivergent facial type tend to have less-dense buccal cortical bone in the maxillary and mandibular alveolar processes. Clinicians should be aware of the variability of cortical bone densities at mini-implant placement sites.
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Affiliation(s)
- Fulya Ozdemir
- Department of Orthodontics, Faculty of Dentistry, Yeditepe University, Istanbul, Turkey
| | - Murat Tozlu
- Department of Orthodontics, Faculty of Dentistry, Yeditepe University, Istanbul, Turkey
| | - Derya Germec Cakan
- Department of Orthodontics, Faculty of Dentistry, Yeditepe University, Istanbul, Turkey
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Neugebauer J, Stachulla G, Ritter L, Dreiseidler T, Mischkowski RA, Keeve E, Zöller JE. Computer-aided manufacturing technologies for guided implant placement. Expert Rev Med Devices 2014; 7:113-29. [DOI: 10.1586/erd.09.61] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Ibrahim N, Parsa A, Hassan B, van der Stelt P, Aartman IHA, Nambiar P. Influence of object location in different FOVs on trabecular bone microstructure measurements of human mandible: a cone beam CT study. Dentomaxillofac Radiol 2013; 43:20130329. [PMID: 24265395 DOI: 10.1259/dmfr.20130329] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The aim of this study was to assess the influence of different object locations in different fields of view (FOVs) of two cone beam CT (CBCT) systems on trabecular bone microstructure measurements of a human mandible. A block of dry human mandible was scanned at five different locations (centre, left, right, anterior and posterior) using five different FOVs of two CBCT systems (NewTom™ 5G; QR Verona, Verona, Italy and Accuitomo 170; Morita, Kyoto, Japan). Image analysis software (CTAn software v. 1.1; SkyScan, Kontich, Belgium) was used to assess the trabecular bone microstructural parameters (thickness, Tb.Th; spacing, Tb.Sp; number, Tb.N; bone volume density, BV/TV). All measurements were taken twice by one trained observer. Tb.Th, Tb.Sp and Tb.N varied significantly across different FOVs in the NewTom 5G (p < 0.001) and the Accuitomo 170 (p < 0.001). For location, a significant difference was observed only when measuring BV/TV (p = 0.03) using the NewTom 5G. The trabecular bone microstructural measurements obtained from CBCT systems are influenced by the size of FOVs. Not all trabecular bone parameters measured using different CBCT systems are affected when varying the object location within the FOVs.
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Affiliation(s)
- N Ibrahim
- Department of General and Specialized Dentistry, Section of Oral and Maxillofacial Radiology, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, Netherlands
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Parsa A, Ibrahim N, Hassan B, van der Stelt P, Wismeijer D. Influence of object location in cone beam computed tomography (NewTom 5G and 3D Accuitomo 170) on gray value measurements at an implant site. Oral Radiol 2013. [DOI: 10.1007/s11282-013-0157-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Molteni R. Prospects and challenges of rendering tissue density in Hounsfield units for cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2013; 116:105-19. [DOI: 10.1016/j.oooo.2013.04.013] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 03/11/2013] [Accepted: 04/19/2013] [Indexed: 11/30/2022]
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Abstract
Cone-beam computed tomography (CBCT) is an imaging technology that has revolutionised dental imaging in the last decade. Although of particular value to specialists performing implant treatment, it is increasingly being adopted by general dental practitioners. As the radiation dose is higher than that of conventional radiography, it is important to consider its diagnostic efficacy for the common tasks performed in general dental practice, such as caries diagnosis, endodontics and the detection of periapical pathosis. Any new imaging technique needs to have proven advantages over existing techniques before it is adopted, yet the evidence remains quite limited. Furthermore, image quality and radiation doses vary enormously between different manufacturers' equipment, so that extrapolating results of one piece of research from one CBCT machine to another is fraught with pitfalls. Radiation doses with CBCT are typically an order of magnitude higher than conventional radiography. There is scope, however, for reducing these doses by judicious adjustment of exposure factors and limiting the field of view to the smallest dimensions consistent with the clinical situation. There is still a long way to go before we understand the value of CBCT in dentistry. High quality research evidence is needed, particularly with regard to assessing whether using BCT improves patient outcomes.
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Campos MJDS, de Albuquerque EG, Pinto BCH, Húngaro HM, Gravina MA, Fraga MR, Vitral RWF. The role of orthodontic tooth movement in bone and root mineral density: a study of patients submitted and not submitted to orthodontic treatment. Med Sci Monit 2013. [PMID: 23197239 PMCID: PMC3560800 DOI: 10.12659/msm.883604] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Background Orthodontic force application to the teeth is responsible for a series of biological responses in the bone and dentin, which lead to some alterations of the mineral density of the tissues. Our objective was determine, through cone-beam computed tomography (CBCT), the mineral density of the apical third of the roots of the upper central incisors and of the periapical bone portion surrounding these teeth, in patients submitted to orthodontic treated and untreated individuals. Material/Methods 30 untreated individuals and 15 treated ones (treatment cessation at least 1 year before the study) underwent CBCT. Mineral density was assessed in the apical third of the root of the upper central incisors and in the alveolar bone in the periapical region of these teeth. In order to reduce CBCT-related mineral density variability, we standardized the cone-beam tomography device, the image-acquisition settings and the field of view positioning and size. Student’s t test was used for the analyses. Results bone mineral density (BMD) and root mineral density (RMD), in Hounsfield Units, were 674.84 and 1282.26 for the untreated group and 630.28 and 1370.29 for the treated group, respectively. The differences between the group means were statistically significant for RMD (p<0.05). Conclusions untreated individuals had a significant lower mean RMD in comparison with those submitted to orthodontic treatment.
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Oliveira ML, Tosoni GM, Lindsey DH, Mendoza K, Tetradis S, Mallya SM. Influence of anatomical location on CT numbers in cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol 2013; 115:558-64. [DOI: 10.1016/j.oooo.2013.01.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 01/03/2013] [Accepted: 01/22/2013] [Indexed: 11/21/2022]
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Peters CI, Peters OA. Cone beam computed tomography and other imaging techniques in the determination of periapical healing. ACTA ACUST UNITED AC 2013. [DOI: 10.1111/etp.12021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Pauwels R, Nackaerts O, Bellaiche N, Stamatakis H, Tsiklakis K, Walker A, Bosmans H, Bogaerts R, Jacobs R, Horner K. Variability of dental cone beam CT grey values for density estimations. Br J Radiol 2013; 86:20120135. [PMID: 23255537 DOI: 10.1259/bjr.20120135] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE The aim of this study was to investigate the use of dental cone beam CT (CBCT) grey values for density estimations by calculating the correlation with multislice CT (MSCT) values and the grey value error after recalibration. METHODS A polymethyl methacrylate (PMMA) phantom was developed containing inserts of different density: air, PMMA, hydroxyapatite (HA) 50 mg cm(-3), HA 100, HA 200 and aluminium. The phantom was scanned on 13 CBCT devices and 1 MSCT device. Correlation between CBCT grey values and CT numbers was calculated, and the average error of the CBCT values was estimated in the medium-density range after recalibration. RESULTS Pearson correlation coefficients ranged between 0.7014 and 0.9996 in the full-density range and between 0.5620 and 0.9991 in the medium-density range. The average error of CBCT voxel values in the medium-density range was between 35 and 1562. CONCLUSION Even though most CBCT devices showed a good overall correlation with CT numbers, large errors can be seen when using the grey values in a quantitative way. Although it could be possible to obtain pseudo-Hounsfield units from certain CBCTs, alternative methods of assessing bone tissue should be further investigated. ADVANCES IN KNOWLEDGE The suitability of dental CBCT for density estimations was assessed, involving a large number of devices and protocols. The possibility for grey value calibration was thoroughly investigated.
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Affiliation(s)
- R Pauwels
- Department of Oral Health Sciences, University of Leuven, Leuven, Belgium.
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Huang H, Richards M, Bedair T, Fields HW, Palomo JM, Johnston WM, Kim D. Effects of orthodontic treatment on human alveolar bone density distribution. Clin Oral Investig 2013; 17:2033-40. [DOI: 10.1007/s00784-012-0906-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 12/04/2012] [Indexed: 10/27/2022]
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Lukats O, Vízkelety T, Markella Z, Maka E, Kiss M, Dobai A, Bujtár P, Szucs A, Barabas J. Measurement of orbital volume after enucleation and orbital implantation. PLoS One 2012; 7:e50333. [PMID: 23236368 PMCID: PMC3516498 DOI: 10.1371/journal.pone.0050333] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 10/17/2012] [Indexed: 11/25/2022] Open
Abstract
Introduction This article reports experience relating to the measurement of orbital volume by means of cone beam computed tomography (CBCT) and Cranioviewer program software in patients who have undergone enucleation and orbital implantation. Patients and Methods CBCT scans were made in 30 cases, 10 of which were later excluded because of various technical problems. The study group therefore consisted of 20 patients (8 men and 12 women). The longest follow-up time was 7 years, and the shortest was 1 year. In all 20 cases, the orbital volume was measured with Cranioviewer orbital program software. Slices were made in the ventrodorsal direction at 4.8 mm intervals in the frontal plane, in both bony orbits (both that containing the orbital implant and the healthy one). Similar measurements were made in 20 patients with various dental problems. CBCT scans were recorded for the facial region of the skull, containing the orbital region. The Cranioviewer program can colour the area of the slices red, and it automatically measures the area in mm. Results In 5 of the 20 cases, the first 4 or all 5 slices revealed that the volume of the operated orbit was significantly smaller than that of the healthy orbit, in 12 cases only from 1 to 3 of the slices indicated such a significant difference, and in 3 cases no differences were observed between the orbits. In the control group of patients with various dental problems, there was no significant difference between the two healthy orbits. The accuracy of the volume measurements was assessed statistically by means of the paired samples t-test. Summary To date, no appropriate method is avaliable for exact measurement of the bony orbital volume, which would be of particular importance in orbital injury reconstruction. However, the use of CBCT scans and Cranioviewer orbital program software appears to offer a reliable method for the measurement of changes in orbital volume.
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Affiliation(s)
- Olga Lukats
- Department of Opthalmology, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
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Benic GI, Sancho-Puchades M, Jung RE, Deyhle H, Hämmerle CH. In vitroassessment of artifacts induced by titanium dental implants in cone beam computed tomography. Clin Oral Implants Res 2012; 24:378-83. [DOI: 10.1111/clr.12048] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2012] [Indexed: 02/02/2023]
Affiliation(s)
- Goran I. Benic
- Clinic of Fixed and Removable Prosthodontics and Dental Material Science; Center of Dental Medicine; University of Zurich; Zurich; Switzerland
| | - Manuel Sancho-Puchades
- Clinic of Fixed and Removable Prosthodontics and Dental Material Science; Center of Dental Medicine; University of Zurich; Zurich; Switzerland
| | - Ronald E. Jung
- Clinic of Fixed and Removable Prosthodontics and Dental Material Science; Center of Dental Medicine; University of Zurich; Zurich; Switzerland
| | - Hans Deyhle
- Biomaterials Science Center; University of Basel; Basel; Switzerland
| | - Christoph H.F. Hämmerle
- Clinic of Fixed and Removable Prosthodontics and Dental Material Science; Center of Dental Medicine; University of Zurich; Zurich; Switzerland
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