Perrotti Vittoria, Aprile Guiseppe, Degidi Marco, Piattelli Adriano, Iezzi Giovanna
Dental School, University of Chieti-Pescara, Chieti, Italy.
Int J Periodontics Restorative Dent. 2011 Nov-Dec;31(6):633-9.
Surface roughness is important for implant osseointegration. It has mostly been assessed by amplitude and height descriptors. Fractal analysis is derived from fractal geometry and is used to describe the organization of objects found in nature, quantifying their shape complexity with a value. Fractal dimension (Df?) is an index of the space-filling properties of an object and can be used as a parameter that describes the organization of surface roughness. The greater the Df value, the more chaotic the surface topography. The aim of this study was to assess the Df of implants with three different surface topographies to evaluate whether a novel method to measure roughness of implant surface topography could be developed. Forty-five disk-shaped samples (10 x 2 mm) with three different surface topographies were analyzed by scanning electron microscopy: group A, machined surface; group B, sandblasted and acid-etched surface; and group C, sandblasted, acid-etched, and neutralized surface. Images at 20,000x and 50,000x magnification were processed for quantitative analysis of Df using the box-counting method. Df values were correlated to the image magnification. At 20,000x magnification, Df for groups A, B, and C was 1.81, 1.67, and 1.59, respectively. At 50,000x magnification, Df was lower for all examined groups; more specifically, Df was 1.77, 1.59, and 1.42 for groups A, B, and C, respectively. Statistically significant differences were found between groups A and C at both magnifications. Df is used widely and successfully as a measurement to characterize anatomical structures and physiologic and pathologic processes. Df not only provides an index of roughness size values, but also a measure of roughness spatial organization; therefore, it could be a promising method to differentiate between rough surfaces capable of supporting osseointegration.
表面粗糙度对种植体骨结合很重要。它主要通过幅度和高度描述符来评估。分形分析源自分形几何，用于描述自然界中物体的组织情况，用一个值量化其形状复杂性。分形维数（Df）是物体空间填充特性的指标，可用作描述表面粗糙度组织情况的参数。Df值越大，表面形貌越不规则。本研究的目的是评估具有三种不同表面形貌的种植体的Df，以评估是否可以开发一种测量种植体表面形貌粗糙度的新方法。通过扫描电子显微镜分析了45个具有三种不同表面形貌的盘状样本（10×2毫米）：A组，机械加工表面；B组，喷砂和酸蚀表面；C组，喷砂、酸蚀和中和表面。使用盒计数法对放大20000倍和50000倍的图像进行处理，以定量分析Df。Df值与图像放大倍数相关。在20000倍放大倍数下，A组、B组和C组的Df分别为1.81、1.67和1.59。在50000倍放大倍数下，所有检查组的Df都较低；更具体地说，A组、B组和C组的Df分别为1.77、1.59和1.42。在两种放大倍数下，A组和C组之间均发现有统计学显著差异。Df作为一种测量方法被广泛且成功地用于表征解剖结构以及生理和病理过程。Df不仅提供粗糙度尺寸值的指标，还提供粗糙度空间组织的度量；因此，它可能是区分能够支持骨结合的粗糙表面的一种有前景的方法。
