Dental Implant Research Center, Department of Oral and Maxillofacial Radiology, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran.
Dental Implant Research Center, Department of Oral and Maxillofacial Surgery, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran.
BMC Med Imaging. 2019 Apr 29;19(1):34. doi: 10.1186/s12880-019-0334-4.
This study aimed to assess the effect of exposure parameters such as milliampere (mA) and field of view (FOV) of cone beam computed tomography (CBCT) on a metal artifact of dental implants placed in different bone densities.
A total of 27 bone blocks with different densities (nine were type 1, nine were types 2 and 3, and nine were type 4) were used in this in vitro, experimental study. These blocks were placed in mandibular wax models. The blocks were scanned after drilling (hole preparation) and after implant placement using Cranex3D imaging system with a 4 × 6 cmand 6 × 8 cm FOV and 4 and 10 mA. Gray value of the bone blocks was recorded before and after placement of implants.
In general, irrespective of bone density, the amount of artifacts was lower in small FOV compared to large FOV (P < 0.05). Change of mA had no effect on metal artifacts (P > 0.05). Artifacts in type 4 bone were greater than in other bone types (P < 0.05). Difference between type 1 and types 2 and 3 was not significant (P > 0.05).
According to the results of this study, Peri-implant artifacts were seen in all bone types; the amount of artifacts in type 4 bone was higher than that in other types. Size of FOV and bone density affect the metal artifacts around dental implants; so that a smaller FOV can be used to decrease metal artifacts.
本研究旨在评估毫安（mA）和视野（FOV）等曝光参数对不同骨密度植入物金属伪影的影响。
本体外实验研究共使用了 27 块具有不同密度的骨块（9 块为 1 型，9 块为 2 型和 3 型，9 块为 4 型）。这些骨块被放置在下颌蜡模型中。在钻孔（孔准备）后和植入物放置后，使用 Cranex3D 成像系统对这些骨块进行扫描，FOV 分别为 4×6cm 和 6×8cm，mA 分别为 4 和 10mA。在植入物放置前后记录骨块的灰度值。
总的来说，无论骨密度如何，小 FOV 的伪影量均低于大 FOV（P<0.05）。mA 的变化对金属伪影没有影响（P>0.05）。4 型骨的伪影大于其他骨类型（P<0.05）。1 型与 2 型和 3 型之间的差异无统计学意义（P>0.05）。
根据本研究的结果，所有骨类型均出现种植体周围伪影；4 型骨的伪影量高于其他类型。FOV 的大小和骨密度会影响种植体周围的金属伪影；因此，较小的 FOV 可用于减少金属伪影。
