PDF(Pubmed)
Abstract：
BACKGROUND: Retrieval of cement-retained implant-supported restorations is intriguing in cases of screw loosening. Detecting the estimated size of the screw access hole (SAH) could decrease destruction to the prosthesis and preserve the crown.
OBJECTIVE: To precisely localize loose implant screws through cemented crowns to reduce crown damage after screw loosening.
METHODS: In this in vitro study, 60 cement-retained implants supported 30 zirconia-based, and 30 ceramics fused to metal (CFM) lower molar crowns were invented, and each was subdivided into three subgroups (10 each). In group I (AI/BI) (control), SAH was created with the aid of orthopantomography (OPG). In contrast, in group II (zirconia-crown), SAH was created with the aid of CBCT + 3D printed surgical guide with a 2 mm metal sleeve in subgroups IIA/IIIA and CBCT + MAR was used to develop SAH in subgroups IIB/IIIB. SEM and Micro-CT scanned the SAH openings to determine the diameter of the hole, cracking, chipping, and chipping volume.
RESULTS: Regarding the effect of plane CBCT and CBCT + MAR on prepared crowns, a highly significant association between group I with group II (p = 0.001) and group III (p = 0.002) was detected. Regarding the cracking of SAH, significant differences between the zirconium crown and CFM restoration (p = 0.009) were found, while for the chipping, no significant association was seen between groups (p = 0.19).
CONCLUSIONS: CBCT, either as a plane CBCT or with MAR, significantly improved the accuracy of drilling the screw channel and decreased injury to the existing restoration and abutment, aiding in better localization of SAH in loosened implant abutment screws.
OBJECTIVE: To precisely localize loose implant screws through cemented crowns to reduce crown damage after screw loosening.
METHODS: In this in vitro study, 60 cement-retained implants supported 30 zirconia-based, and 30 ceramics fused to metal (CFM) lower molar crowns were invented, and each was subdivided into three subgroups (10 each). In group I (AI/BI) (control), SAH was created with the aid of orthopantomography (OPG). In contrast, in group II (zirconia-crown), SAH was created with the aid of CBCT + 3D printed surgical guide with a 2 mm metal sleeve in subgroups IIA/IIIA and CBCT + MAR was used to develop SAH in subgroups IIB/IIIB. SEM and Micro-CT scanned the SAH openings to determine the diameter of the hole, cracking, chipping, and chipping volume.
RESULTS: Regarding the effect of plane CBCT and CBCT + MAR on prepared crowns, a highly significant association between group I with group II (p = 0.001) and group III (p = 0.002) was detected. Regarding the cracking of SAH, significant differences between the zirconium crown and CFM restoration (p = 0.009) were found, while for the chipping, no significant association was seen between groups (p = 0.19).
CONCLUSIONS: CBCT, either as a plane CBCT or with MAR, significantly improved the accuracy of drilling the screw channel and decreased injury to the existing restoration and abutment, aiding in better localization of SAH in loosened implant abutment screws.
摘要：
背景：在螺钉松动的情况下，回收水泥保留的植入物支持的修复体很有趣。检测螺钉进入孔（SAH）的估计尺寸可以减少对假体的破坏并保留牙冠。
目的：通过胶结牙冠精确定位松动的种植体螺钉，以减少螺钉松动后牙冠的损伤。
方法：在这项体外研究中，60个水泥保留植入物支持30个氧化锆基，并发明了30个陶瓷与金属（CFM）下磨牙冠，每个被细分为三个子组（每个10个）。在I组（AI/BI）（对照组）中，SAH是在骨科造影术（OPG）的帮助下创建的。相比之下,在第II组（氧化锆冠）中，SAH是在IIA/IIIA亚组中在具有2mm金属套管的CBCT+3D打印手术导向器的帮助下创建的,并且CBCT+MAR用于在IIB/IIIB亚组中开发SAH。SEM和Micro-CT扫描SAH开口以确定孔的直径,cracking,削片,和碎裂的音量。
结果：关于平面CBCT和CBCT+MAR对预备冠的影响，检测到I组与II组(p=0.001)和III组(p=0.002)之间存在高度显著的相关性.关于SAH的开裂,发现锆冠和CFM修复之间存在显着差异（p=0.009），而对于削片，组间无显著关联(p=0.19).
结论：CBCT，作为飞机CBCT或MAR，显著提高了螺钉通道的钻孔精度，减少了对现有修复体和基台的损伤，帮助SAH在松动的种植体基台螺钉中更好地定位。
目的：通过胶结牙冠精确定位松动的种植体螺钉，以减少螺钉松动后牙冠的损伤。
方法：在这项体外研究中，60个水泥保留植入物支持30个氧化锆基，并发明了30个陶瓷与金属（CFM）下磨牙冠，每个被细分为三个子组（每个10个）。在I组（AI/BI）（对照组）中，SAH是在骨科造影术（OPG）的帮助下创建的。相比之下,在第II组（氧化锆冠）中，SAH是在IIA/IIIA亚组中在具有2mm金属套管的CBCT+3D打印手术导向器的帮助下创建的,并且CBCT+MAR用于在IIB/IIIB亚组中开发SAH。SEM和Micro-CT扫描SAH开口以确定孔的直径,cracking,削片,和碎裂的音量。
结果：关于平面CBCT和CBCT+MAR对预备冠的影响，检测到I组与II组(p=0.001)和III组(p=0.002)之间存在高度显著的相关性.关于SAH的开裂,发现锆冠和CFM修复之间存在显着差异（p=0.009），而对于削片，组间无显著关联(p=0.19).
结论：CBCT，作为飞机CBCT或MAR，显著提高了螺钉通道的钻孔精度，减少了对现有修复体和基台的损伤，帮助SAH在松动的种植体基台螺钉中更好地定位。
