Becker William, Sennerby Lars, Bedrossian Edwin, Becker Burton E, Lucchini Jean Pierre
Private practice, Tucson, AZ 85715, USA.
J Periodontol. 2005 Mar;76(3):391-7. doi: 10.1902/jop.2005.76.3.391.
Studies indicate that implants placed at the time of extraction have high success rates. Implants must be stable at the time of insertion. Presently there are no data indicating the degree of implant stability when implants are placed at the time of extraction. This study evaluated changes in stability of implants from implant placement to abutment connection utilizing resonance frequency analysis (RFA). The unit of measurement was the international stability quotient (ISQ).
Prior to treatment, patients were given medical history and dental evaluations. Periapical and panogram radiographs were taken. Fifty-two patients requiring extraction of one or two teeth and implant placement immediately after extraction were enrolled in this study. Under conscious sedation and local anesthesia or local anesthesia alone, teeth were atraumatically removed and the extraction sockets were debrided. A total of 73 dental implants (57 in the maxilla, 16 in the mandible) were placed. Using a one-stage approach, all implants were placed within the patient's alveolar envelope and were never placed directly into extraction sockets. All implants were placed into contained extraction sites. Bone augmentation procedures were not performed. After implant insertion, the RFA electronic transducer was attached to the head of the implant with the retaining screw. The device was attached to a computer designed to register RFA scores in ISQ units. RFA measurements were taken at implant placement and abutment connection. Bone qualities, quantity, implant length and width as well as site of placement were recorded.
The average interval between implant insertion and abutment connection was 5.6 months (SD 2.05). Two implants were lost between implant insertion and 1 year. At 2 to 3 years, the cumulative survival was 97.2%. Resonance frequency measurements at implant placement showed a mean primary stability of 62.0 (SE 1.1; range 43 to 83 ISQ) and a mean secondary stability after 1 year of 64.0 (SE 1.2; range 40 to 98 ISQ) for all implants. The increase was marginally significant (generalized estimating equation z-statistic = 1.79; P value = 0.07).
Implants placed at the time of extraction and inserted into native bone and not directly into extractions sockets have a high degree of initial stability as evidenced by RFA measurements. Implants with initial high ISQ levels revealed a slight drop in levels over time, while implants with levels lower than 60 had increases in levels between implant insertion and abutment connection. At 2 to 3 years the cumulative survival rate was 97.2%.
研究表明，拔牙时同期植入种植体成功率较高。种植体植入时必须稳定。目前尚无数据表明拔牙时植入种植体的稳定程度。本研究利用共振频率分析（RFA）评估从种植体植入到基台连接过程中种植体稳定性的变化。测量单位为国际稳定性商数（ISQ）。
治疗前，对患者进行病史和口腔检查。拍摄根尖片和全景片。本研究纳入52例需要拔除一颗或两颗牙齿并在拔牙后立即植入种植体的患者。在清醒镇静和局部麻醉或仅局部麻醉下，牙齿被无创拔除，拔牙窝进行清创。共植入73颗牙种植体（上颌57颗，下颌16颗）。采用一期植入法，所有种植体均植入患者牙槽窝内，从未直接植入拔牙窝。所有种植体均植入封闭的拔牙位点。未进行骨增量手术。种植体植入后，将RFA电子传感器通过固位螺钉连接到种植体头部。该装置连接到一台设计用于记录ISQ单位RFA分数的计算机上。在种植体植入时和基台连接时进行RFA测量。记录骨质量、骨量、种植体长径、种植体宽度以及种植位点。
种植体植入与基台连接之间的平均间隔时间为5.6个月（标准差2.05）。在种植体植入至1年期间，有2颗种植体脱落。在2至3年时，累积存留率为97.2%。所有种植体在植入时的共振频率测量显示，平均初始稳定性为62.0（标准误1.1；范围43至83 ISQ），1年后的平均二次稳定性为64.0（标准误1.2；范围40至98 ISQ）。增加幅度略有显著性（广义估计方程z统计量=1.79；P值=0.07）。
拔牙时植入且植入天然骨而非直接植入拔牙窝的种植体具有较高的初始稳定性，这由RFA测量结果证明。初始ISQ水平较高的种植体随着时间推移水平略有下降，而初始水平低于60的种植体在种植体植入至基台连接期间水平有所升高。在2至3年时，累积存留率为97.2%。
