Esposito Marco, Zucchelli Giovanni, Cannizzaro Gioacchino, Checchi Luigi, Barausse Carlo, Trullenque-Eriksson Anna, Felice Pietro
Eur J Oral Implantol. 2017;10(1):11-26.
To compare the clinical outcome of single implants placed immediately after tooth extraction with implants placed 6 weeks after tooth extraction (immediate-delayed placement), and with implants placed after 4-month extraction and socket healing (delayed placement).
Two-hundred and ten (210) patients requiring a single implant-supported crown to replace a tooth to be extracted were randomised to receive immediate post-extractive implants (70 patients), immediate-delayed implants at 6 weeks (70 patients), and delayed implants after 4 months of healing (70 patients) according to a parallel group design. When needed, patients of the immediate and immediate-delayed group had the socket grafted with a bone substitute and covered with a resorbable membrane at implant placement. Sockets randomised to delayed implants were grafted in the same manner if poorly preserved or in the aesthetic areas (from second upper to second upper premolars). Implants inserted with at least 25 Ncm torque were left to heal unloaded for 4 months, whereas those inserted with less than 25 Ncm were left to heal unloaded for 6 months. Temporary crowns were delivered and were to be replaced by definitive ones after 4 months. Outcome measures were crown and implant failures, complications, peri-implant marginal bone level changes, aesthetically assessed using the pink esthetic score (PES), and patient satisfaction recorded by blinded assessors. Patients were followed up to 1 year post-loading.
One year after loading, three patients dropped out from the immediate group, five from the immediate-delayed group, and six from the delayed group. Four implants (6%) failed in the immediate, four (6.2%) in the immediate-delayed, and one (1.6%) from the delayed group (P (chi-square test) = 0.369). Apart from the crowns (which failed due to implant losses), no other crown had to be remade. Six immediate, six immediate-delayed and four delayed implants were affected by one complication each (P (chi-square test) = 0.792). Mean peri-implant marginal bone loss after 1 year was -0.25 ± 0.17 mm (CI 95% -0.29; -0.20) at immediate, -0.29 ± 0.14 mm (CI 95% -0.32; -0.25) at immediate-delayed, and -0.31 ± 0.16 mm (CI 95% -0.35; -0.27) at delayed placed implants (P (Kruskal-Wallis test) = 0.015). One year after loading, the mean total aesthetic score was 12.52, 12.49 and 11.78 at the immediate, immediate-delayed and delayed groups, respectively (P (Kruskal-Wallis test) <0.001). All patients were fully satisfied both with function and aesthetics, and would undergo the same procedure again, with four exceptions (one from the immediate, one from the immediate-delayed and two from the delayed group), who were only partially satisfied with aesthetics (P = 0.785).
No statistically significant differences for failures, complications and patient satisfaction were observed when placing single implants immediately, 6 weeks or 4 months after tooth extraction; nevertheless, failures were more frequent at immediate and immediate-delayed placed implants. Bone level changes were similar between the different procedures, but aesthetics were better results at immediate and immediate-delayed implants. Conflict-of-interest statement: This trial was partially funded by Nobel Biocare Services (code: 2010-894), the manufacturer of the implants evaluated in this investigation; however, data belonged to the authors and by no means did the manufacturer interfere with the conduct of the trial or the publication of the results.
比较拔牙后即刻植入单颗种植体、拔牙后6周植入（即刻-延迟植入）以及拔牙后4个月拔牙窝愈合后植入（延迟植入）的临床效果。
210例需要单颗种植体支持的牙冠来替代待拔除牙齿的患者，根据平行组设计随机分为三组，分别接受拔牙后即刻种植（70例患者）、6周时即刻-延迟种植（70例患者）以及愈合4个月后延迟种植（70例患者）。必要时，即刻种植组和即刻-延迟种植组的患者在植入种植体时，拔牙窝用骨替代材料移植并覆盖可吸收膜。随机分配至延迟种植组的拔牙窝，如果保存不佳或位于美学区域（从右上第二前磨牙至左上第二前磨牙），则以相同方式进行移植。以至少25 Ncm扭矩植入的种植体不加载愈合4个月，而以小于25 Ncm扭矩植入的种植体不加载愈合6个月。制作临时牙冠，4个月后更换为最终牙冠。观察指标包括牙冠和种植体失败情况、并发症、种植体周围边缘骨水平变化、使用粉色美学评分（PES）进行美学评估以及由盲法评估者记录的患者满意度。患者随访至加载后1年。
加载后1年，即刻种植组有3例患者退出，即刻-延迟种植组有5例，延迟种植组有6例。即刻种植组有4颗种植体（6%）失败，即刻-延迟种植组有4颗（6.2%），延迟种植组有1颗（1.6%）（卡方检验P = 0.369）。除了因种植体丢失导致失败的牙冠外，没有其他牙冠需要重新制作。即刻种植组、即刻-延迟种植组和延迟种植组分别有6颗、6颗和4颗种植体出现一种并发症（卡方检验P = 0.792）。1年后，即刻种植组种植体周围平均边缘骨丢失为-0.25±0.17 mm（95%CI -0.29；-0.20），即刻-延迟种植组为-0.29±0.14 mm（95%CI -0.32；-0.25），延迟种植组为-0.31±0.16 mm（95%CI -0.35；-0.27）（Kruskal-Wallis检验P = 0.015）。加载后1年，即刻种植组、即刻-延迟种植组和延迟种植组的平均总美学评分分别为12.52、12.49和11.78（Kruskal-Wallis检验P<0.001）。所有患者对功能和美学均完全满意，且愿意再次接受相同治疗，但有4例除外（即刻种植组1例、即刻-延迟种植组1例、延迟种植组2例），他们仅对美学部分满意（P = 0.785）。
拔牙后即刻、6周或4个月植入单颗种植体时，在种植体失败、并发症和患者满意度方面未观察到统计学上的显著差异；然而，即刻种植和即刻-延迟种植的失败情况更为常见。不同种植方式之间骨水平变化相似，但即刻种植和即刻-延迟种植的美学效果更好。利益冲突声明：本试验部分由诺贝尔生物科技服务公司（编号：2010 - 894）资助，该公司为本研究中评估的种植体制造商；然而，数据归作者所有，制造商并未以任何方式干扰试验的进行或结果的发表。
