Department of Reconstructive Dentistry and Gerodontology, University of Bern, Bern, Switzerland.
Department of Prosthodontics, Preclinical Education and Dental Materials Science, University of Bonn, Bonn, Switzerland.
Clin Oral Implants Res. 2020 Jun;31(6):549-556. doi: 10.1111/clr.13591. Epub 2020 Mar 9.
To report on the clinical outcomes of one-piece mini dental implants (MDIs) retaining mandibular implant overdentures (IODs), including marginal bone-level alterations (ΔMBLs), clinical peri-implant parameters, and technical- and biological complications during a 5-year follow-up. The null hypothesis was that ΔMBLs would be equal in subjects older than 65 years relative to younger subjects.
Four 1.8-mm diameter one-piece MDIs with ball attachments were placed in the interforaminal region of 20 edentulous subjects. The existing complete dentures were converted to IODs. Standardized radiographs of each implant were taken at implant placement (baseline) and during the five-year follow-up. ΔMBLs and potential influencing factors were evaluated, and peri-implant parameters, and biological and technical complications were recorded.
The implant and prosthetic survival rates were both 100%. IODs fractured in seven participants. The overall mean ΔMBL after 5 years was -1.18 mm (standard deviation: 0.79 mm). ΔMBLs per month were most pronounced within the first 3 months after implant placement. ΔMBLs were not influenced by the implant location, the presence of keratinized mucosa, or gender. However, ΔMBLs were significantly smaller in subjects older than 65 years (p = .007).
One-piece MDIs retaining mandibular IODs with O-ring attachments are a predictable treatment option, providing stable peri-implant bone and soft tissue conditions over a mid-term follow-up. Incorporating a metal reinforcement can prevent denture fracturing when converting a complete denture into an IOD. The presence of keratinized mucosa does not necessarily lead to decreased bone-level changes. Advanced age might be beneficial in terms of peri-implant bone stability.
报告一体式微型牙科种植体（MDIs）保留下颌种植覆盖义齿（IOD）的临床结果，包括边缘骨水平变化（ΔMBLs）、临床种植体周围参数以及 5 年随访期间的技术和生物学并发症。零假设是，年龄大于 65 岁的患者与年轻患者相比，ΔMBLs 相等。
将 4 个直径为 1.8 毫米的一体式 MDIs 与球附着体一起放置在 20 名无牙颌患者的眶下区域。将现有的全口义齿转换为 IOD。在植入物放置（基线）和 5 年随访期间，对每个植入物进行标准化的 X 光拍摄。评估 ΔMBLs 和潜在影响因素，并记录种植体周围参数、生物学和技术并发症。
种植体和修复体的存活率均为 100%。7 名参与者的 IOD 断裂。5 年后的总体平均 ΔMBL 为-1.18 毫米（标准差：0.79 毫米）。植入物放置后前 3 个月内，ΔMBLs 每月变化最明显。ΔMBLs 不受植入物位置、角化黏膜的存在或性别影响。然而，年龄大于 65 岁的患者的 ΔMBLs 明显较小（p=0.007）。
一体式微型牙科种植体（MDIs）保留带有 O 型环附着体的下颌 IOD 是一种可预测的治疗选择，在中期随访期间提供稳定的种植体周围骨和软组织状况。在将全口义齿转换为 IOD 时，加入金属加固物可以防止义齿断裂。角化黏膜的存在不一定会导致骨水平变化减少。在种植体周围骨稳定性方面，年龄较大可能有益。
