Bhalla Karan, Kalha Anmol S
Department of Orthodontics and Dentofacial Orthopedics, ITS Dental College, Hospital and Research Centre, Greater Noida, Delhi (NCR), India.
Orthodontics (Chic.). 2013;14(1):e10-21. doi: 10.11607/ortho.759.
This prospective clinical trial aims at correlating miniscrew implant (MSI) micro/macro architecture, the method of placement, and biologic markers in peri-MSI crevicular fluid (PMICF) as indicators of bone response. A comparative evaluation of surface morphology of the MSIs before placement and after retrieval defines a correlation between the architecture of the MSIs and the bone- implant contact ratio.
Two types of MSIs (hybrid and cylindric) were placed in ten patients using a split-mouth technique with the aid of a restricted random number table. Each of the MSIs was placed in the intraradicular area between the second premolar and first molar in the attached gingiva, 4 mm from the cementoenamel junction. The MSIs were immediately loaded, and PMICF was collected on days 0, 7, 14, 21, 28, and 42 and evaluated using a standard laboratory protocol. Surface morphology before placement and after retrieval of the MSI was observed using scanning electron microscopy (SEM) at a magnification of ×11, ×40, and ×1,000.
Alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels observed were lower in the hybrid MSI in comparison to the cylindric MSI. For both MSIs, ALP and AST levels showed a trend of significant increase at days 0, 7, and 14 and then a significant decrease on days 21, 28, and 42. Observations from SEM showed an oxide layer over the entire surface of the bone-expanding hybrid MSI; this layer was observed only at the tip of the cylindric MSI.
Levels of both the diagnostic tissue destruction biologic markers ALP and AST are significantly higher in cylindric MSIs compared with hybrid MSIs, indicating a correlation to the type and method of placement of the MSI. The inflammatory markers show a definitive trend, with an elevation until day 14 and a decline after that, indicating an active inflammatory process until day 14 that could be correlated to tissue trauma. Observations from the SEM show a greater oxide layer formation in the hybrid MSI, which could imply a better bone-MSI contact ratio.
这项前瞻性临床试验旨在关联微型螺钉种植体（MSI）的微观/宏观结构、植入方法以及种植体周围龈沟液（PMICF）中的生物标志物，以此作为骨反应的指标。对植入前和取出后的MSI表面形态进行比较评估，以确定MSI结构与骨-种植体接触率之间的相关性。
借助受限随机数表，采用分口技术将两种类型的MSI（混合型和圆柱形）植入10例患者体内。每个MSI均植入附着龈中第二前磨牙和第一磨牙之间的根内区域，距牙骨质釉质界4毫米处。MSI即刻加载，并在第0、7、14、21、28和42天收集PMICF，采用标准实验室方案进行评估。使用扫描电子显微镜（SEM）在放大倍数为×11、×40和×1000的条件下观察植入前和取出后的MSI表面形态。
与圆柱形MSI相比，混合型MSI中观察到的碱性磷酸酶（ALP）和天冬氨酸转氨酶（AST）水平较低。对于两种MSI，ALP和AST水平在第0、7和14天均呈现显著上升趋势，然后在第21、28和42天显著下降。SEM观察显示，骨扩张型混合型MSI的整个表面有一层氧化层；而这种氧化层仅在圆柱形MSI的尖端观察到。
与混合型MSI相比，圆柱形MSI中诊断组织破坏的生物标志物ALP和AST的水平显著更高，这表明与MSI的类型和植入方法存在相关性。炎症标志物呈现出明确的趋势，在第14天之前升高，之后下降，表明直到第14天存在活跃的炎症过程，这可能与组织创伤有关。SEM观察显示，混合型MSI中形成了更厚的氧化层，这可能意味着骨与MSI之间有更好的接触率。
