Department of Oral Medicine, School of Dentistry, Federal University of Goias, Goiania, Goias, Brazil.
Clin Oral Implants Res. 2014 Feb;25(2):e47-53. doi: 10.1111/clr.12046. Epub 2012 Oct 29.
To investigate in vivo the correlation between the bone microarchitecture of implant bone sites, bone tissue classification subjectively assessed in radiographs and primary implant stability.
Periapical and panoramic radiographs were obtained from 32 partially edentulous patients. Three surgeons classified bone quality at implant sites using two different methods: assessments in periapical and panoramic radiographs (PP) and according to the classification proposed by Lekholm and Zarb (L&Z). During the implant insertion, bone biopsies were taken, and three-dimensional parameters were measured by microcomputed tomography (microCT). Insertion torque value (ITV) and initial implant stability quotient (ISQ) were recorded at the moment of the implantation. ISQ was also recorded at the uncovering stage of a traditional implant protocol.
Bone types 2 and 3 were the most prevalent classifications according to PP (54.3%) and L&Z (58.7%). The mean and standard deviation values of primary stability variables were 38.7(16.7) for ITV, 75.3 (7.7) for initial ISQ and 79.3 (6.8) for uncovering ISQ. Several microCT original and factor variables were found to correlate with bone tissue classifications and primary stability variables. L&Z correlated with architecture (r = 0.31; P < 0.05), density (r = -0.43; P < 0.01) and bulk (r = -0.35; P < 0.05), whereas ITV correlated with architecture (r = -0.40; P < 0.01) and density (r = 0.51; P < 0.01). Multiple linear regression analysis revealed that density and bulk explained 32% of the variability of L&Z bone classification, while density and architecture explained 42% of the variability of ITV.
This study demonstrates the first step in validating L&Z classification. MicroCT provides objective and detailed quantitative data on bone microarchitecture. Intraosseous implant stability is mainly determined by the density of the bone. ITVs could be a good indicator of primary implant stability, whereas ISQs measurements have some limitations and should not be used alone.
研究种植体骨部位的骨微观结构与骨组织分类（在放射片中主观评估）和初始种植体稳定性之间的体内相关性。
从 32 名部分缺牙患者中获取根尖和全景放射片。三名外科医生使用两种不同的方法评估种植体部位的骨质量：根尖和全景放射片中的评估（PP）和 Lekholm 和 Zarb（L&Z）提出的分类。在植入过程中，进行了骨活检，并通过微计算机断层扫描（microCT）测量了三维参数。记录植入时的插入扭矩值（ITV）和初始种植体稳定性系数（ISQ）。在传统种植体方案的暴露阶段也记录了 ISQ。
根据 PP（54.3%）和 L&Z（58.7%），最常见的骨分类为 2 型和 3 型。初始稳定性变量的平均值和标准差分别为 ITV 的 38.7（16.7）、初始 ISQ 的 75.3（7.7）和暴露 ISQ 的 79.3（6.8）。发现几个 microCT 原始和因子变量与骨组织分类和初始稳定性变量相关。L&Z 与结构（r = 0.31；P < 0.05）、密度（r = -0.43；P < 0.01）和体积（r = -0.35；P < 0.05）相关，而 ITV 与结构（r = -0.40；P < 0.01）和密度（r = 0.51；P < 0.01）相关。多元线性回归分析表明，密度和体积解释了 L&Z 骨分类变化的 32%，而密度和结构解释了 ITV 变化的 42%。
本研究验证了 L&Z 分类的第一步。microCT 提供了骨微观结构的客观、详细的定量数据。骨内种植体稳定性主要由骨密度决定。ITV 可能是初始种植体稳定性的良好指标，而 ISQ 测量存在一些局限性，不应单独使用。
