Int J Oral Implantol (Berl). 2019;12(4):449-466.
To compare the 3-year outcomes of immediately loaded and one-stage conventionally loaded variable-thread tapered implants in the posterior maxilla.
This study was designed as a split-mouth randomised controlled trial. Twenty-six patients attending the postgraduate Periodontics Department at the Lebanese University, and missing teeth bilaterally in the posterior maxilla were randomised. All patients received three to four implants in each of the posterior sextants. The implants on one side were immediately loaded with a provisional resin fixed partial denture on definitive multi-unit abutments regardless of their primary stability. The implants in the contralateral side received definitive multi-unit abutments according to the one-stage unloaded protocol. Three to 3.5 months following implant placement, the implants were restored with metal-ceramic fixed prostheses. Outcome measures were implant and prosthesis failure rates, complications, and peri-implant bone level changes up to 3 years following delivery of the definitive prosthesis. The clinical outcomes and radiographic measurements were performed by a single outcome assessor blinded to the type of interventions.
Two patients dropped out prior to the delivery of definitive prostheses. The results were analysed using a per-protocol analysis and included 24 patients. Four implants supporting a four-unit immediately loaded prosthesis failed in one patient, 3 months following definitive prosthesis. In the same patient, the three contralateral conventionally loaded implants failed 14 months after definitive prosthesis. There were no significant differences in the proportions of implant and prosthesis failures at 3 years (difference = 0%; 95% CI 0.0% to 14.2%; P = 0.999). Peri-implantitis was diagnosed at two adjacent conventionally loaded implants in one patient at the 3-year examination. In the immediately loaded group, four early minor prosthetic complications occurred during the provisionalisation phase. Following delivery of the definitive prostheses, one minor ceramic fracture was observed in each of the implant groups. The difference in the rate of complications between the two interventions was not statistically significant at 3 years (difference = 13%; 95% CI 3.4% to 27.7%; P = 0.453). The 3-year peri-implant marginal bone level changes were evaluated in 23 patients (77 immediately loaded and 76 conventionally loaded implants). On average, patients lost 0.79 (0.62) mm at the immediately loaded and 0.91 (0.82) mm at the conventionally loaded implants, the difference being statistically not significant (difference = 0.12 mm; 95% CI -0.31 to 0.55 mm; P = 0.590). The 3-year marginal bone level changes were not significantly different between smokers (n = 12) and non-smokers (n = 11) (difference = 0.19 mm; 95% CI -0.24 to 0.62 mm; P = 0.382).
Immediate loading of three- to four-unit fixed partial prostheses supported by variable-thread implants in the posterior maxilla can achieve similar 3-year results to one-stage conventionally loaded implants.
比较在后牙区即刻负载和一期常规负载变螺纹种植体的 3 年临床效果。
这是一项随机对照的分牙区研究。26 名来自黎巴嫩大学牙周病科的患者,双侧后牙区缺失,随机分组。所有患者在每侧后牙区植入 3 到 4 颗种植体。一侧的种植体立即加载临时树脂固定修复体于最终多单位基台,无论其初始稳定性如何。对侧的种植体按照一期非负载方案,加载最终的多单位基台。种植体植入 3 至 3.5 个月后,用金属烤瓷固定修复体修复。在最终修复体交付后长达 3 年的时间里,评估种植体和修复体的失败率、并发症以及种植体周围骨水平的变化。临床结果和影像学测量由一名对干预类型不知情的单一结果评估者进行。
两名患者在交付最终修复体之前退出。使用方案预设分析对结果进行了分析,共纳入 24 名患者。一名患者在最终修复体 3 个月后,四颗四单位即刻负载修复体中的四颗种植体支持的修复体失败。在同一名患者中,三个对侧常规负载种植体在最终修复体 14 个月后失败。在 3 年时,种植体和修复体失败的比例没有显著差异(差异=0%;95%CI 0.0%至 14.2%;P=0.999)。在一名患者的 3 年检查中,诊断出两个相邻的常规负载种植体有牙周炎。在即刻负载组中,在临时修复阶段有 4 例早期轻微的修复体并发症。在交付最终修复体后,在每个种植体组中观察到 1 例轻微的陶瓷裂。两种干预措施的并发症发生率在 3 年时无统计学差异(差异=13%;95%CI 3.4%至 27.7%;P=0.453)。在 23 名患者(即刻负载 77 名,常规负载 76 名)中评估了 3 年的种植体周围边缘骨水平变化。平均而言,即刻负载组患者的骨损失为 0.79(0.62)mm,常规负载组为 0.91(0.82)mm,差异无统计学意义(差异=0.12mm;95%CI -0.31 至 0.55mm;P=0.590)。吸烟者(n=12)和非吸烟者(n=11)的 3 年边缘骨水平变化无显著差异(差异=0.19mm;95%CI -0.24 至 0.62mm;P=0.382)。
在后牙区使用变螺纹种植体支持的三到四单位固定修复体即刻负载可获得与一期常规负载种植体相似的 3 年临床效果。