الفهرس 
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Abstract
The importance of medical imaging has expanded significantly beyond conventional, diagnostic visualization during the past ten years as a result of improvements in image analysis and graphics processing capacity. Since volume quantification and conversion to 3D model printouts (e.g., anatomical models, surgical cutting guides, and implants) are the newest technologies on the market, three-dimensional (3D) medical images have become a hot topic in research. Multi-slice computed tomography (MSCT) scanners are now considered to provide the finest images for this particular request. However, the usage of cone beam computed tomography (CBCT) scanners for such specialized jobs in the oral and maxillofacial disciplines is growing.
One of the crucial factors affecting the volumetric assessment of 3D models is voxel size. It was shown that as voxel sizes increased during scanning, the volume measurements of structures tended to grow. This could be attributable to scatter and the partial-volume effect.
This study used the following materials and techniques to investigate how different voxel sizes affected volume segmentation of the pulp area prepared for the upper anterior teeth: 60 maxillary anterior teeth underwent endodontic preparation before having their CBCT pictures taken.
The pulp spaces that had actually been formed physically served as the gold standard. Rapid gentle addition Rubber Impression to build a replica, material was pumped into a pulp space that had been prepared. The volume of the replica represented the physical volume (VP) of the pulp space that had been created.
Each block of four teeth was mounted separately using silicon impression putty. Following that, the blocks were put within a thin plastic cylinder filled with water to represent soft tissue (phantom). On the chin rest of the CBCT device, the phantom was placed. The block was centered in the narrowest field-of-view FOV (H D) of 50 mm, which was used to image the teeth.
The CBCT was utilized to scan the teeth in three distinct voxel sizes: (1) endodontic mode (75 m), (2) high-dose mode (150 m), and (3) low-dose mode (400 m). After that, the prepared pulp area was assessed using a semi-automated segmentation technique by the Materialise Mimics software. This study proved that a small voxel size (75 m) is the most reliable parameter to segment the prepared pulp space of upper anterior teeth. The accuracy of the segmented volume declined as the voxel size was raised during scanning.
Conclusion
The most accurate voxel size in volumetric analysis of prepared pulp space of maxillary anterior teeth is Endodontic mode (75 μm)
The segmented volume increases in size with increasing voxel size from (75 μm) to (150 μm), in accordance with physical volume due to surface surrounding artifact.
Low dose mode (400 m) is the least accurate voxel size in volumetric analysis of prepared pulp space of maxillary anterior teeth, in accordance with physical volume due to missing data.
Small voxel size for large object segmentation is preferable to large voxel size for tiny object segmentation. It might be because the distinction between gray colors in large items makes it simpler to segment and distinguish between others.