Int J Oral Maxillofac Implants. 2019 July/August;34(4):936–946. doi: 10.11607/jomi.7224. Epub 2019 Apr 1.
The aim of this study was to compare the clinical outcomes of four-implant-supported overdentures retained by stud or bar attachments for patients with an edentulous maxilla.
From January 2008 to December 2014, patients with maxillary edentulism were enrolled in this retrospective study. The insertion of four maxillary dental implants was followed by restoration with either stud-retained or bar-retained overdentures. The characteristics of the subjects and implants were recorded. Implant survival rates, marginal bone loss, peri-implant clinical parameters, and prosthetic maintenance efforts were evaluated at the last follow-up time. Furthermore, patients were asked to complete a satisfaction questionnaire using a modified Denture Satisfaction scale at their last follow-up visit. The data were statistically analyzed, and the level of significance was set at α = .05.
A total of 132 implants were placed in 33 patients, of whom 18 were restored with four-implant-supported overdentures retained by stud attachments, and the other 15 with four-implant-supported overdentures retained by bar attachments. Thirty-one patients and 124 implants were available for the entire follow-up. During a mean follow-up period of 77 months (range: 36 to 111 months), five among 72 implants failed for three patients in the stud-retained group and two among 60 implants failed for two patients in the bar-retained group, resulting in estimated cumulative implant survival rates of 81.4% and 86.2% for the stud-retained group and the bar-retained group, respectively. Except for the modified Plaque Index (mPI, P = .035), no significant differences were indicated between the two attachment groups in terms of implant survival rate, marginal bone loss, or peri-implant clinical parameters. Peri-/inter-implant gingival hyperplasia occurred only with implants under bar attachments. Over the entire observation period, the incidence of prosthetic maintenance treatments was 2.12 per patient per study for the stud-retained group and 2.29 per patient per study for the bar-retained group. Patients in both groups reported a high degree of satisfaction.
Within the limitations of this study, no significant differences were indicated between the clinical outcomes of maxillary four-implant-supported overdentures with either stud or bar attachments, although a higher modified Plaque Index was observed for the bar-retained group. Furthermore, prostheses with stud attachments were advantageous for their convenient cleaning and repair. Patients with compromised systemic and periodontal conditions should be treated with caution. Further clinical studies with larger sample sizes and stricter epidemiologic designs are still needed.
本研究旨在比较采用球帽或杆卡式附着体固位的上颌四种植体覆盖义齿的临床效果。
回顾性研究对象为 2008 年 1 月至 2014 年 12 月期间就诊的上颌无牙颌患者。患者上颌植入 4 枚种植体后，分别采用球帽或杆卡式附着体固位的覆盖义齿修复。记录患者和种植体的特征。末次随访时，评价种植体存留率、边缘骨吸收、种植体周临床参数和修复体维护情况。此外，患者在末次随访时采用改良义齿满意度量表完成满意度问卷调查。采用统计学方法分析数据，检验水准设为 α=0.05。
共纳入 33 例患者（132 枚种植体），其中 18 例患者采用球帽式附着体固位的上颌四种植体覆盖义齿修复，15 例患者采用杆卡式附着体固位的上颌四种植体覆盖义齿修复。31 例患者（124 枚种植体）完成了全部随访。平均随访 77 个月（36~111 个月），球帽式附着体组的 3 例患者中有 5 枚种植体和杆卡式附着体组的 2 例患者中有 2 枚种植体发生失败，两组种植体的累积存留率分别为 81.4%和 86.2%。除改良菌斑指数（mPI）外（P=0.035），两组在种植体存留率、边缘骨吸收或种植体周临床参数方面均无显著差异。杆卡式附着体组仅发生 2 例种植体周围/种植体间牙龈增生。在整个观察期间，球帽式附着体组和杆卡式附着体组的患者每例每年分别需进行 2.12 次和 2.29 次修复体维护治疗。两组患者均报告高度满意。
在本研究的限制范围内，采用球帽或杆卡式附着体固位的上颌四种植体覆盖义齿的临床效果无显著差异，但杆卡式附着体组的改良菌斑指数较高。此外，球帽式附着体固位的覆盖义齿具有便于清洁和修复的优点。对于合并系统性或牙周疾病的患者应谨慎治疗。仍需开展样本量更大、设计更严格的临床研究。
