Choi, Jung-Yoo Chesaria
(Dental Research Institute, Seoul National University School of Dentistry)
,
Choi, Cham Albert
(Department of Field Refurbishment, Optoscan)
,
Yeo, In-Sung Luke
(Department of Prosthodontics, Seoul National University School of Dentistry)
Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, ...
Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.
Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.
* AI 자동 식별 결과로 적합하지 않은 문장이 있을 수 있으니, 이용에 유의하시기 바랍니다.
가설 설정
(A) The volume of interest height is designated by the red box. (B) The height begins from the point where the implant entirely interfaces with the bone. (C) The height ends where the implant no longer interfaces with bone.
제안 방법
Each sample was scanned 3 times, using 360° round scanning on the SkyScan 1172 and 1275 and spiral scanning on the SkyScan 1275.
A previous study used synchrotron-radiated micro-CT (Bessy II, Berlin, Germany), which is expected to provide images of equal quality to spiral scanning; however, this technique is not widely accessible, as it requires considerable time and the worldwide availability of such machines is very low [6]. Furthermore, this study did not use a fresh specimen, and monochromatic energy output does not optimize the PVE, but parallel-beam geometry does. Another study using other desktop micro-CT systems aside from spiral scanning achieved images that initially appeared to be of high quality; however, when closely examined, artifacts were present, and were falsely included as bone or implant in the BIC measurements [13].
The purpose of this study was therefore to present a method for BIC assessment through spiral scanning using an advanced algorithm, a method particularly suited to analysis of screw-shaped implants. The procedure allows BIC measurements to be made from continuous scanning, rather than from intermittent image slices, and allows results to be obtained in less than 1 hour.
대상 데이터
Five Ti implants (grade 4 commercially pure Ti, diameter: 3.0 mm, length: 12 mm) were prepared; 3 were used for surface topography and 2 for in vivo surgery. A straight form with square macrothreads was designed from the top of the implant to the middle, while a tapered form with V-shaped microthreads was designed from the middle to the bottom for bone anchorage (Figure 1A).
1 Bernhardt R Kuhlisch E Schulz MC Eckelt U Stadlinger B Comparison of bone-implant contact and bone-implant volume between 2D-histological sections and 3D-SRµCT slices Eur Cell Mater 2012 23 237 247 22492016
2 Bissinger O Probst FA Wolff KD Jeschke A Weitz J Deppe H Comparative 3D micro-CT and 2D histomorphometry analysis of dental implant osseointegration in the maxilla of minipigs J Clin Periodontol 2017 44 418 427 28063250
3 Jimbo R Coelho PG Vandeweghe S Schwartz-Filho HO Hayashi M Ono D Histological and three-dimensional evaluation of osseointegration to nanostructured calcium phosphate-coated implants Acta Biomater 2011 7 4229 4234 21816237
4 Vandeweghe S Coelho PG Vanhove C Wennerberg A Jimbo R Utilizing micro-computed tomography to evaluate bone structure surrounding dental implants: a comparison with histomorphometry J Biomed Mater Res B Appl Biomater 2013 101 1259 1266 23661363
5 Becker K Stauber M Schwarz F Beißbarth T Automated 3D-2D registration of X-ray microcomputed tomography with histological sections for dental implants in bone using chamfer matching and simulated annealing Comput Med Imaging Graph 2015 44 62 68 26026659
6 Bernhardt R Scharnweber D Müller B Thurner P Schliephake H Wyss P Comparison of microfocus- and synchrotron X-ray tomography for the analysis of osteointegration around Ti6Al4V implants Eur Cell Mater 2004 7 42 51 15375777
7 Park YS Yi KY Lee IS Jung YC Correlation between microtomography and histomorphometry for assessment of implant osseointegration Clin Oral Implants Res 2005 16 156 160 15777324
8 Barrett JF Keat N Artifacts in CT: recognition and avoidance Radiographics 2004 24 1679 1691 15537976
9 Li JY Pow EH Zheng LW Ma L Kwong DL Cheung LK Quantitative analysis of titanium-induced artifacts and correlated factors during micro-CT scanning Clin Oral Implants Res 2014 25 506 510 23745988
10 Narra N Antalainen AK Zipprich H Sándor GK Wolff J Microcomputed tomography-based assessment of retrieved dental implants Int J Oral Maxillofac Implants 2015 30 308 314 25830390
11 Kilkenny C Browne WJ Cuthill IC Emerson M Altman DG Improving bioscience research reporting: the ARRIVE guidelines for reporting animal research Osteoarthritis Cartilage 2012 20 256 260 22424462
12 Salmon P Micro-CT image analysis techniques for orthopedic applications: metal implant-to-bone contact surface and porosity of biomaterials Leung KS Qin L Cheung WH A practical manual for musculoskeletal research Singapore World Scientific 2008 583 603
13 Rebaudi A Koller B Laib A Trisi P Microcomputed tomographic analysis of the peri-implant bone Int J Periodontics Restorative Dent 2004 24 316 325 15446401
AI-Helper
※ AI-Helper는 부적절한 답변을 할 수 있습니다.