Private practice, San Antonio, Texas; Department of Periodontics and Dental Hygiene, The University of Texas School of Dentistry, Health Science Center at Houston, Houston, Texas.
Clinical Associate Professor, Department of Periodontics and Dental Hygiene, The University of Texas School of Dentistry, Health Science Center at Houston, Houston, Texas; Private practice, Houston, Texas.
J Prosthet Dent. 2022 Sep;128(3):443-449. doi: 10.1016/j.prosdent.2021.01.004. Epub 2021 Feb 18.
Evidence to validate the routine use of angled screw-channel abutments in the anterior maxilla is sparse. If properly planned, they might provide surgical and prosthetic benefits.
The purpose of this observational study was to determine the prevalence of digitally placed implants in the anterior maxilla that would allow screw-retained implant-supported restorations with either a straight or an angled screw-channel abutment.
Two hundred cone beam computed tomography (CBCT) scans met the inclusion criteria for retrospective analysis and digital implant planning. Virtual implants were planned for randomly selected anterior maxillary teeth by using the anatomic crown and root position. Virtual abutments of varying angulation were attached to the implants to determine the ability to screw retain a restoration with either a straight or an angled screw-channel abutment.
One hundred fifty-two (76%) sites required an angled screw-channel abutment to enable screw retention. Forty-eight (24%) sites allowed screw retention with a straight abutment. The percentage of implants requiring angled or straight abutments varied significantly among anterior teeth (P<.005). One hundred nine (71.7%) angled screw-channel abutment sites required a 5-degree abutment, 41 (26.9%) required a 10-degree abutment, and 2 (1.3%) required a 15-degree abutment. Among the anterior teeth, lateral incisors presented a greater need for angled screw-channel abutments. None of the implants in the present study needed cement-retained restorations.
Angled abutments allowed for screw-retained restorations on digitally planned implants in the anterior maxilla. The required angular correction to a screw-retained restoration was ≤15 degrees. Screw-retained restorations were frequently achievable (76%) with the use of angled screw-channel abutments or with straight abutments (24%), and lateral incisors presented a greater need for angled screw-channel abutments.
缺乏验证在前上颌骨中常规使用角度螺丝通道基台的证据。如果计划得当，它们可能会提供手术和修复方面的益处。
本观察性研究的目的是确定在前上颌骨中可放置数字化种植体的比例，这些种植体允许使用直或角度螺丝通道基台进行螺丝固位的种植体支持修复。
对 200 例锥形束 CT（CBCT）扫描进行了回顾性分析和数字化种植体规划，这些扫描符合纳入标准。通过使用解剖冠和根位置，对随机选择的前上颌牙齿进行虚拟种植体规划。将不同角度的虚拟基台连接到种植体上，以确定使用直或角度螺丝通道基台固定修复体的螺丝固位能力。
152 个（76%）位点需要使用角度螺丝通道基台才能实现螺丝固位。48 个（24%）位点允许使用直基台进行螺丝固位。在前牙中，需要使用角度或直基台的种植体比例差异显著（P<.005）。109 个（71.7%）角度螺丝通道基台位点需要 5 度基台，41 个（26.9%）需要 10 度基台，2 个（1.3%）需要 15 度基台。在前牙中，侧切牙更需要角度螺丝通道基台。本研究中没有种植体需要使用粘结固位修复体。
在前上颌骨的数字化规划种植体上，角度基台允许螺丝固位修复。螺丝固位修复所需的角度校正≤15 度。使用角度螺丝通道基台或直基台（76%）通常可以实现螺丝固位修复，而使用角度螺丝通道基台（24%）的情况更为常见，侧切牙更需要使用角度螺丝通道基台。
