Department of Periodontology, Faculty of Dental Medicine, Ain Shams University, Cairo, Egypt.
J Periodontol. 2013 Dec;84(12):1730-9. doi: 10.1902/jop.2013.120701. Epub 2013 Mar 1.
The use of nanoparticles of graft materials may lead to breakthrough applications for periodontal regeneration. However, due to their small particle size, nanoparticles may be eliminated from periodontal defects by phagocytosis. In an attempt to improve nanoparticle retention in periodontal defects, the present in vivo study uses scanning electron microscopy (SEM) to evaluate the potential of micrograft particles of β-tricalcium phosphate (β-TCP) to enhance the binding and retention of nanoparticles of hydroxyapatite (nHA) on EDTA-treated and non-treated root surfaces in periodontal defects after 14 days of healing.
Sixty patients having at least two hopeless periodontally affected teeth designated for extraction were randomly divided into four treatment groups (15 patients per group). Patients in group 1 had selected periodontal intrabony defects grafted with nHA of particle size 10 to 100 nm. Patients in group 2 were treated in a similar manner but had the affected roots etched for 2 minutes with a neutral 24% EDTA gel before grafting of the associated vertical defects with nHA. Patients in group 3 had the selected intrabony defects grafted with a composite graft consisting of equal volumes of nHA and β-TCP (particle size 63 to 150 nm). Patients in group 4 were treated as in group 3 but the affected roots were etched with neutral 24% EDTA as in group 2. For each of the four groups, one tooth was extracted immediately, and the second tooth was extracted after 14 days of healing for SEM evaluation.
Fourteen days after surgery, all group 1 samples were devoid of any nanoparticles adherent to the root surfaces. Group 2 showed root surface areas 44.7% covered by a single layer of clot-blended grafted particles 14 days following graft application. After 14 days, group 3 samples appeared to retain fibrin strands devoid of grafted particles. Immediately extracted root samples of group 4 had adherent graft particles that covered a considerable area of the root surfaces (88.6%). Grafted particles appeared to cover all samples in a multilayered pattern. After 14 days, the group 4 extracted samples showed multilayered fibrin-covered nano/micro-sized graft particles adherent to the root surfaces (78.5%).
The use of a composite graft consisting of nHA and microsized β-TCP after root surface treatment with 24% EDTA may be a suitable method to improve nHA retention in periodontal defects with subsequent graft bioreactivity.
接枝材料纳米颗粒的使用可能为牙周再生带来突破性应用。然而，由于其粒径较小，纳米颗粒可能会被吞噬作用从牙周缺损中清除。为了提高牙周缺损中纳米颗粒的保留率，本体内研究采用扫描电子显微镜（SEM）评估β-磷酸三钙（β-TCP）微接枝颗粒增强 EDTA 处理和未处理根面中羟基磷灰石（nHA）纳米颗粒结合和保留的潜力，在愈合后 14 天的牙周缺损。
60 名至少有两颗牙周病晚期受影响的牙齿需要拔除的患者被随机分为四组（每组 15 名患者）。第 1 组患者将接受粒径为 10 至 100nm 的 nHA 颗粒进行牙周骨内缺损移植。第 2 组患者以类似方式治疗，但在移植相关垂直缺损的 nHA 之前，将受影响的牙根用 24%中性 EDTA 凝胶蚀刻 2 分钟。第 3 组患者将接受由 nHA 和 β-TCP（粒径 63 至 150nm）等体积组成的复合移植物进行治疗。第 4 组患者的治疗方法与第 3 组相同，但用 24%中性 EDTA 如第 2 组一样对受影响的牙根进行蚀刻。对于每组中的每颗牙齿，在 14 天的愈合后，立即拔出一颗牙，然后拔出第二颗牙，用于 SEM 评估。
术后 14 天，第 1 组的所有样本均无任何纳米颗粒附着在牙根表面。第 2 组在移植后 14 天显示出覆盖单个纤维蛋白层的簇状移植颗粒的根表面面积为 44.7%。第 3 组 14 天后的样本似乎保留了没有移植颗粒的纤维蛋白丝。第 4 组立即提取的根样本具有附着的移植颗粒，覆盖了相当大的牙根表面区域（88.6%）。移植颗粒似乎以多层模式覆盖所有样本。第 4 组 14 天后提取的样本显示出覆盖在根表面的多层纤维蛋白覆盖的纳米/微米大小的移植颗粒（78.5%）。
在 24%EDTA 处理根面后使用 nHA 和微尺寸β-TCP 的复合移植物可能是一种提高牙周缺损中 nHA 保留率的合适方法，同时具有后续移植物生物反应性。
