Checchi Vittorio, Felice Pietro, Zucchelli Giovanni, Barausse Carlo, Piattelli Maurizio, Pistilli Roberto, Grandi Giovanni, Esposito Marco
Eur J Oral Implantol. 2017;10(3):263-278.
To compare the effectiveness of 6.0 to 8.0 mm-wide diameter implants, placed immediately after tooth extraction, with conventional 4.0 or 5.0 mm diameter implants placed in a preserved socket after a 4-month period of healing in the molar region.
Just after extraction of one or two molar teeth, and with no vertical loss of the buccal bone in relation to the palatal wall, 100 patients requiring immediate post-extractive implants were randomly allocated to immediate placement of one or two 6.0 to 8.0 mm-wide diameter implants (immediate group; 50 patients) or for socket preservation using a porcine bone substitute covered by a resorbable collagen barrier (delayed group; 50 patients), according to a parallel group design in one centre. Bone-to-implant gaps were filled with autogenous bone retrieved with a trephine drill used to prepare the implant sites for the immediate wide diameter post-extractive implants. Four months after socket preservation, one to two 4.0 or 5.0 mm-wide delayed implants were placed. Implants were loaded 4 months after placement with fixed provisional restorations in acrylic, and replaced after 4 months by fixed, definitive, metal-ceramic restorations. Patients were followed to 1 year after loading. Outcome measures were: implant failures, complications, aesthetics assessed using the pink esthetic score (PES), peri-implant marginal bone level changes, patient satisfaction, number of appointments and surgical interventions recorded, when possible, by blinded assessors.
Three patients dropped out 1 year after loading from the immediate group vs six from the delayed group. Five implants out of 47 failed in the immediate group (10.6%) vs two out 44 (4.6%) in the delayed group, the difference being not statistically significant (difference in proportion = 6.0%, 95% CI: -8.8% to 20.8%, P = 0.436). In the immediate group 10 patients were affected by 10 complications, while in the delayed group four patients were affected by four complications. The difference was not statistically significant (difference in proportion = 12%, 95% CI: -2% to 26%, P = 0.084). At delivery of the definitive prostheses, 4 months after loading, the mean total PES score was 9.65 ± 1.62 and 10.44 ± 1.47 in the immediate and delayed groups, respectively. At 1 year after loading, the mean total PES score was 9.71 ± 2.71 and 10.86 ± 1.37 in the immediate and delayed groups, respectively. The Total PES score was statistically significantly better at delayed implants both at 4 months (mean difference = 0.79; 95% CI: 0.05 to 1.53; P = 0.03) and at 1 year (mean difference = 1.15; 95% CI: 0.13 to 2.17; P = 0.02). Marginal bone levels at implant insertion (after bone grafting) were 0.04 mm for immediate and 0.11 mm for delayed implants, which was statistically significantly different (mean difference = 0.07; 95% CI: 0.02 to 0.12; P < 0.0001). One year after loading, patients in the immediate group lost on average 1.06 mm and those from the delayed group 0.63 mm, the difference being statistically significant (mean difference = 0.43 mm; 95% CI: 0.15 to 0.61; P < 0.0001). All patients were fully or partially satisfied both for function and aesthetics, and would undergo the same procedure again both at 4 months and 1 year after loading. Patients from the immediate group required on average 7.48 ± 1.45 visits to the clinician and 2.14 ± 0.49 surgical interventions and to have their definitive prostheses delivered vs 10.30 ± 0.99 visits and 3.08 ± 0.40 surgical interventions for the delayed group, the difference being statistically significant (P < 0.001 for visits, and P < 0.001 for surgical interventions).
Preliminary 1 year follow-up data suggest that immediate placement of 6.0 to 8.0 mm wide diameter implants in molar extraction sockets yielded inferior aesthetic outcomes than ridge preservation and delayed placement of conventional 4.0 to 5.0 mm diameter implants.
比较在磨牙区拔牙后即刻植入直径6.0至8.0毫米种植体与在拔牙窝保存4个月后植入传统直径4.0或5.0毫米种植体的效果。
在拔除一或两颗磨牙后，且颊侧骨相对于腭侧壁无垂直性骨量丧失的情况下，根据单中心平行组设计，将100例需要拔牙后即刻种植的患者随机分配至即刻植入一或两颗直径6.0至8.0毫米种植体组（即刻组；50例患者），或使用可吸收胶原屏障覆盖的猪骨替代物进行拔牙窝保存组（延迟组；50例患者）。用于制备即刻植入宽直径拔牙后种植体植入位点的环钻取出的自体骨填充骨与种植体之间的间隙。拔牙窝保存4个月后，植入一至两颗直径4.0或5.0毫米的延迟种植体。种植体植入后4个月用丙烯酸树脂固定临时修复体加载，4个月后更换为固定的、最终的金属烤瓷修复体。对患者进行加载后1年的随访。观察指标包括：种植体失败、并发症、使用粉色美学评分（PES）评估美学效果、种植体周围边缘骨水平变化、患者满意度、记录的就诊次数和手术干预次数（如有可能，由盲法评估者进行记录）。
加载后1年，即刻组有3例患者退出，延迟组有6例患者退出。即刻组47颗种植体中有5颗失败（10.6%），延迟组44颗中有2颗失败（4.6%），差异无统计学意义（比例差异 = 6.0%，95%可信区间：-8.8%至20.8%，P = 0.436）。即刻组有10例患者出现10种并发症，延迟组有4例患者出现4种并发症。差异无统计学意义（比例差异 = 12%，95%可信区间：-2%至26%，P = 0.084）。在加载后4个月最终修复体交付时，即刻组和延迟组的平均总PES评分分别为9.65±1.62和10.44±1.47。加载后1年，即刻组和延迟组的平均总PES评分分别为9.71±2.71和10.86±1.37。延迟种植体在4个月（平均差异 = 0.79；95%可信区间：0.05至1.53；P = 0.03）和1年（平均差异 = 1.15；95%可信区间：0.13至2.17；P = 0.02）时的总PES评分在统计学上均显著更好。种植体植入时（骨移植后）的边缘骨水平，即刻种植体为0.04毫米，延迟种植体为0.11毫米，差异有统计学意义（平均差异 = 0.07；95%可信区间：0.02至0.12；P < 0.0001）。加载后1年，即刻组患者平均骨丧失1.06毫米，延迟组患者平均骨丧失0.63毫米，差异有统计学意义（平均差异 = 0.43毫米；95%可信区间：0.15至0.61；P < 0.0001）。所有患者对功能和美学均完全或部分满意，并且在加载后4个月和1年都愿意再次接受相同的治疗。即刻组患者平均需要就诊7.48±1.45次，进行2.14±0.49次手术干预并交付最终修复体，而延迟组患者平均需要就诊10.30±0.99次，进行3.08±0.40次手术干预，差异有统计学意义（就诊次数P < 0.001，手术干预次数P < 0.001）。
初步的1年随访数据表明，在磨牙拔牙窝即刻植入直径6.0至8.0毫米的种植体，其美学效果不如牙槽嵴保存并延迟植入传统直径4.0至5.0毫米的种植体。
