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Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation.

Kang SW, Lee WJ, Choi SC, Lee SS, Heo MS, Huh KH, Kim TI, Yi WJ - Imaging Sci Dent (2015)

Bottom Line: Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images.VA and VBIC increased significantly with as the healing period increased (p<0.05).VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05).

View Article: PubMed Central - PubMed

Affiliation: Interdisciplinary Program in Radiation, Applied Life Science Major, College of Medicine, BK21, and Dental Research Institute, Seoul National University, Seoul, Korea.

ABSTRACT

Purpose: We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA).

Materials and methods: The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method.

Results: VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05).

Conclusion: It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.

No MeSH data available.


Related in: MedlinePlus

An absorbable implant consists of a titanium upper part and a polylactic acid/tricalcium phosphate (PLA-TCP) lower part.
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Figure 1: An absorbable implant consists of a titanium upper part and a polylactic acid/tricalcium phosphate (PLA-TCP) lower part.

Mentions: In this study, we used a special implant developed for stable positioning and favorable bone regeneration. The upper part of the implant was manufactured with grade IV titanium, whereas the lower part was composed of a PLA-TCP nanocomposite (Fig. 1). The upper part of the implant had a mini-implant shape with a length of 5 mm and a diameter of 3.5 mm. Hybrid nanopowders, made of a 30% mixture of PLA-TCP, were melted into the nanocomposites to form the implant substructures. Seven beagle dogs (average age, 2 years; average weight, 13 kg) were used as experimental animals. All animal experiments, including animal management and surgical procedures, were approved and performed under the guidelines of the Institutional Animal Care and Use Committee of Seoul National University. Xylazine hydrochloride (Rumpen, Bayer Korea, Seoul, Korea) mixed with ketamine (Ketalar, Yuhan, Seoul, Korea) was injected into the veins of the dogs, and the second and fourth premolars were extracted from the left and right lower jaws. The operation was followed by an eight-week healing period. Three months after the extraction, 28 implants were placed. Seven implants broken during placement were excluded from the subsequent experiment. The animals were sacrificed four, eight, or 12 weeks after implant placement. The bones, including the implants, were cut to obtain samples, which were fixed in 10% formalin solution for 48 hours. The samples were scanned at 70 kVp and 141 µA, using a Skyscan 1172 micro-CT scanner (Skyscan, Kontich, Belgium). The micro-CT image had a pixel size of 9.86 µm and 12-bit depth. A non-placed implant was also scanned for use as a control image.


Volumetric quantification of bone-implant contact using micro-computed tomography analysis based on region-based segmentation.

Kang SW, Lee WJ, Choi SC, Lee SS, Heo MS, Huh KH, Kim TI, Yi WJ - Imaging Sci Dent (2015)

An absorbable implant consists of a titanium upper part and a polylactic acid/tricalcium phosphate (PLA-TCP) lower part.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4362995&req=5

Figure 1: An absorbable implant consists of a titanium upper part and a polylactic acid/tricalcium phosphate (PLA-TCP) lower part.
Mentions: In this study, we used a special implant developed for stable positioning and favorable bone regeneration. The upper part of the implant was manufactured with grade IV titanium, whereas the lower part was composed of a PLA-TCP nanocomposite (Fig. 1). The upper part of the implant had a mini-implant shape with a length of 5 mm and a diameter of 3.5 mm. Hybrid nanopowders, made of a 30% mixture of PLA-TCP, were melted into the nanocomposites to form the implant substructures. Seven beagle dogs (average age, 2 years; average weight, 13 kg) were used as experimental animals. All animal experiments, including animal management and surgical procedures, were approved and performed under the guidelines of the Institutional Animal Care and Use Committee of Seoul National University. Xylazine hydrochloride (Rumpen, Bayer Korea, Seoul, Korea) mixed with ketamine (Ketalar, Yuhan, Seoul, Korea) was injected into the veins of the dogs, and the second and fourth premolars were extracted from the left and right lower jaws. The operation was followed by an eight-week healing period. Three months after the extraction, 28 implants were placed. Seven implants broken during placement were excluded from the subsequent experiment. The animals were sacrificed four, eight, or 12 weeks after implant placement. The bones, including the implants, were cut to obtain samples, which were fixed in 10% formalin solution for 48 hours. The samples were scanned at 70 kVp and 141 µA, using a Skyscan 1172 micro-CT scanner (Skyscan, Kontich, Belgium). The micro-CT image had a pixel size of 9.86 µm and 12-bit depth. A non-placed implant was also scanned for use as a control image.

Bottom Line: Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images.VA and VBIC increased significantly with as the healing period increased (p<0.05).VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05).

View Article: PubMed Central - PubMed

Affiliation: Interdisciplinary Program in Radiation, Applied Life Science Major, College of Medicine, BK21, and Dental Research Institute, Seoul National University, Seoul, Korea.

ABSTRACT

Purpose: We have developed a new method of segmenting the areas of absorbable implants and bone using region-based segmentation of micro-computed tomography (micro-CT) images, which allowed us to quantify volumetric bone-implant contact (VBIC) and volumetric absorption (VA).

Materials and methods: The simple threshold technique generally used in micro-CT analysis cannot be used to segment the areas of absorbable implants and bone. Instead, a region-based segmentation method, a region-labeling method, and subsequent morphological operations were successively applied to micro-CT images. The three-dimensional VBIC and VA of the absorbable implant were then calculated over the entire volume of the implant. Two-dimensional (2D) bone-implant contact (BIC) and bone area (BA) were also measured based on the conventional histomorphometric method.

Results: VA and VBIC increased significantly with as the healing period increased (p<0.05). VBIC values were significantly correlated with VA values (p<0.05) and with 2D BIC values (p<0.05).

Conclusion: It is possible to quantify VBIC and VA for absorbable implants using micro-CT analysis using a region-based segmentation method.

No MeSH data available.


Related in: MedlinePlus