Londhe S M, Gowda E Mahesh, Mandlik V B, Shashidhar M P
Commandant and Command Dental Adviser (Southern Command), Pune 411040, India.
Consultant (Prosthodontics), Command Military Dental Centre (Southern Command), Pune 411040, India.
Med J Armed Forces India. 2020 Jan;76(1):37-40. doi: 10.1016/j.mjafi.2018.06.011. Epub 2018 Oct 10.
Implant restorations are considered an ideal treatment option for replacement of missing teeth in partially edentulous patients. Abutment screw loosening is one of the frequently observed technical complications of implant-supported prosthesis. This study aimed to determine the prevalence and factors associated with the abutment screw loosening in cement-retained single-implant crowns.
Enrolment criteria included partially edentulous patients who have been rehabilitated with one or more cement-retained single-implant crowns with minimum postcementation period of 1 year. They were recalled and evaluated for the presence or absence of screw loosening both clinically and radiographically. They were further evaluated for the presence or absence of factors associated with screw loosening such as parafunctional habits, wider occlusal table, steep cuspal inclines, non-axial loading and cantilevering of the pontic.
Twenty-six cement-retained single-implant crowns out of 280 showed screw loosening, making the overall prevalence rate of 10.77%. Among the factors evaluated, parafunctional habits were associated with three cases, wider occlusal table in four, steep cuspal inclines in three, non-axial loading in nine and cantilevering of the pontic in three cases. Exact reasons could not be ascertained in four cases.
Abutment screw loosening seems to be a significant prosthetic complication of cement-retained single-implant crowns. Factors evaluated significantly affect the functional durability of the prosthesis. These factors should be considered while restoring to enhance the longevity of such restorations.
种植体修复被认为是部分牙列缺损患者缺失牙替代的理想治疗选择。基台螺丝松动是种植体支持修复体常见的技术并发症之一。本研究旨在确定粘结固位单颗种植体牙冠基台螺丝松动的患病率及相关因素。
纳入标准包括部分牙列缺损患者，这些患者已通过一颗或多颗粘结固位单颗种植体牙冠进行修复，且粘结后最短观察期为1年。对他们进行复诊，通过临床和影像学评估螺丝是否松动。进一步评估与螺丝松动相关的因素，如副功能习惯、较宽的咬合面、陡峭的牙尖斜面、非轴向负荷和桥体悬臂。
280颗粘结固位单颗种植体牙冠中有26颗出现螺丝松动，总体患病率为10.77%。在评估的因素中，副功能习惯与3例相关，较宽的咬合面与4例相关，陡峭的牙尖斜面与3例相关，非轴向负荷与9例相关，桥体悬臂与3例相关。4例无法确定确切原因。
基台螺丝松动似乎是粘结固位单颗种植体牙冠的一种重要修复并发症。评估的因素显著影响修复体的功能耐久性。在修复时应考虑这些因素，以提高此类修复体的使用寿命。
