Astrand P, Engquist B, Dahlgren S, Engquist E, Feldmann H, Gröndahl K
Department of Oral and Maxillofacial Surgery, University Hospital, SE-58185, Linköping, Sweden.
Clin Implant Dent Relat Res. 1999;1(1):17-26. doi: 10.1111/j.1708-8208.1999.tb00087.x.
Endosseous dental implants are used frequently, and many implant systems are available. The scientific documentation of the implant system presents a great variation, and it is often difficult to compare studies of different systems.
The aim of this study was to compare two Swedish implant systems (Astra Tech and Brånemark System implants), in a prospective randomized study.
Sixty-six patients were equally distributed between the two implant systems; 184 Astra Tech and 187 Brånemark System implants were used. The patients have been followed annually with clinical and radiographic examinations. The results after 1 year are reported.
The abutment procedure was found to be easier and less time-consuming with Astra Tech than with Brånemark implants. The operation times in minutes (mean +/- SEM) were for the respective implant 35 +/- 4.0 and 51 +/- 4.8 in the maxilla and 32 +/- 3.8 and 43 +/- 2.4 in the mandible. The differences in both cases were significant: p < .02 and p < .05, respectively. The failure rate for Astra Tech implants was 0.5% and for Brånemark implants 4.3%. The difference was significant (p < .05); however, taking into account that five of the eight implant losses in the Brånemark implant group occurred in one patient, an intraindividual correlation cannot be excluded. Therefore, this result should be interpreted with caution. The marginal bone level changes were examined already from the fixture installation. The major bone loss was found between fixture installation and baseline. This bone loss was several times greater than the bone loss between the baseline and the 1-year follow-up. The total bone loss during the observation period did not differ significantly between the systems, but they had different resorption patterns. The bone loss in the upper jaw between baseline and 1-year follow-up was 0.22 +/- 0.14 and 0.03 +/- 0.09 mm for the Astra Tech and Brånemark implants, respectively. In the lower jaw, the loss was -0.31 for both systems. The frequency of plaque accumulation and bleeding on probing did not differ between the implant systems.
Abutment connection with Astra Tech implants was simpler than the corresponding surgery with Brånemark System implants and the survival rate of Astra Tech implants was higher than that of Brånemark system implants.
骨内牙种植体使用频繁，且有多种种植系统可供选择。种植系统的科学文献存在很大差异，不同系统的研究往往难以比较。
本前瞻性随机研究旨在比较两种瑞典种植系统（Astra Tech和Brånemark系统种植体）。
66例患者平均分配至两种种植系统；分别使用了184枚Astra Tech种植体和187枚Brånemark系统种植体。每年对患者进行临床和影像学检查，并报告1年后的结果。
发现Astra Tech种植体的基台连接过程比Brånemark种植体更容易且耗时更少。上颌中，各种植体的手术时间（分钟，均值±标准误）分别为35±4.0和51±4.8；下颌中分别为32±3.8和43±2.4。两种情况的差异均具有显著性：分别为p<0.02和p<0.05。Astra Tech种植体的失败率为0.5%，Brånemark种植体为4.3%。差异具有显著性（p<0.05）；然而，考虑到Brånemark种植体组8例种植体丢失中有5例发生在1例患者身上，不能排除个体内相关性。因此，该结果应谨慎解读。从种植体植入时就开始检查边缘骨水平变化。发现主要的骨吸收发生在种植体植入至基线期。该阶段的骨吸收比基线至1年随访期的骨吸收大几倍。观察期内，两种系统的总骨吸收无显著差异，但吸收模式不同。Astra Tech和Brånemark种植体在上颌基线至1年随访期的骨吸收分别为0.22±0.14和0.03±0.09mm。在下颌，两种系统的骨吸收均为-0.31。种植系统之间菌斑堆积频率和探诊出血情况无差异。
Astra Tech种植体的基台连接比Brånemark系统种植体的相应手术更简单，且Astra Tech种植体的生存率高于Brånemark系统种植体。
