Esposito M, Grusovin M G, Martinis E, Coulthard P, Worthington H V
School of Dentistry, Department of Oral and Maxillofacial Surgery, University of Manchester, Higher Cambridge Street, Manchester, UK, M15 6FH.
Cochrane Database Syst Rev. 2007 Jul 18(3):CD006698. doi: 10.1002/14651858.CD006698.
Implants may be placed penetrating the oral mucosa (1-stage procedure) or can be completely buried under the oral mucosa (2-stage procedure) during the healing phase of the bone at the implant surface. With a 2-stage procedure the risk of having unwanted loading onto the implants is minimized, but a second minor surgical intervention is needed to connect the healing abutments and more time is needed prior to start the prosthetic phase because of the wound-healing period required in relation to the second surgical intervention.
To evaluate whether a 1-stage implant placement procedure is as effective as a 2-stage procedure.
The Cochrane Oral Health Group's Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were searched. Handsearching included several dental journals. Authors of all identified trials, an internet discussion group and 55 dental implant manufacturers were contacted to find unpublished randomised controlled trials (RCTs). The last electronic search was conducted on 15 January 2007.
All RCTs of root-form osseointegrated dental implants comparing the same 2-piece osseointegrated root-form dental implants placed according to 1- versus 2-stage procedures with a minimum follow up of 6 months after loading. Outcome measures were: prosthesis failures, implant failures, marginal bone level changes on intraoral radiographs, patient preference including aesthetics, aesthetics evaluated by dentists, and complications.
Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. Authors were contacted for missing information. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals (CI). Heterogeneity was to be investigated including both clinical and methodological factors.
Three RCTs were identified and two trials including 45 patients in total were included. On a patient, rather than per implant basis, there were no statistically significant differences.
AUTHORS' CONCLUSIONS: The number of patients included in the trials was too small to draw reliable conclusions, however it appears that the two procedures did not show clinical significant differences. If these preliminary results will be confirmed by more robust trials, a 1-stage procedure might be preferable since it avoids one minor surgical intervention and shortens the waiting time to provide the final restoration. There might be specific situations though, such as when optimal implant stability is not obtained at placement or when barriers are used in conjunction with implants, in which a 2-stage approach might be preferable.
在种植体表面骨组织的愈合阶段，种植体可以穿透口腔黏膜植入（一期手术），也可以完全埋置于口腔黏膜下（二期手术）。二期手术可将种植体承受意外负荷的风险降至最低，但需要进行第二次小型外科手术来连接愈合基台，并且由于与第二次外科手术相关的伤口愈合期，在开始修复阶段前需要更多时间。
评估一期种植体植入手术是否与二期手术同样有效。
检索了Cochrane口腔健康组试验注册库、Cochrane对照试验中央注册库、MEDLINE和EMBASE。手工检索包括几本牙科杂志。联系了所有已识别试验的作者、一个互联网讨论组和55家牙科种植体制造商，以查找未发表的随机对照试验（RCT）。最后一次电子检索于2007年1月15日进行。
所有关于根形骨结合牙科种植体的RCT，比较按照一期和二期手术植入的同一两件式骨结合根形牙科种植体，负荷后至少随访6个月。观察指标包括：修复体失败、种植体失败、口腔内X线片上的边缘骨水平变化、患者偏好（包括美观度）、牙医评估的美观度以及并发症。
两名综述作者分别独立重复进行符合条件研究的筛选、试验方法学质量评估和数据提取。联系作者获取缺失信息。结果采用随机效应模型表示，连续型结局用均值差，二分法结局用风险比，并给出95%置信区间（CI）。将对异质性进行调查，包括临床和方法学因素。
识别出三项RCT，纳入两项试验，共45例患者。基于患者而非每个种植体，未发现统计学上的显著差异。
纳入试验的患者数量过少，无法得出可靠结论，但两项手术似乎未显示出临床显著差异。如果这些初步结果能得到更有力试验的证实，一期手术可能更可取，因为它避免了一次小型外科手术并缩短了提供最终修复体的等待时间。不过，可能存在特定情况，例如植入时未获得最佳种植体稳定性或种植体联合使用屏障时，二期手术可能更可取。
