Objectives

Approximately 10⁹ bacteria can be harbored within periodontal pockets (PP) along with inflammatory byproducts implicated in the pathophysiology of systemic diseases linked to periodontitis (PD). Calculation of this inflammatory burden has involved estimation of total pocket surface area using analog data from conventional periodontal probing which is unable to determine the three-dimensional (3-D) nature of PP. The goals of this study are to determine the radiopacity, biocompatibility, and antimicrobial activity of transient micro-particle fillers in vitro and demonstrate their capability for 3-D imaging of artificial PP (U.S. Patent publication number: 9814791 B2).

Methods

Relative radiopacity values of various metal oxide fillers were obtained from conventional radiography and micro-computed tomography (μCT) using in vitro models. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were used to measure the biocompatibility of calcium tungstate (CaWO₄) particles by determination of viable keratinocytes percentage (%) after exposure. After introducing an antibacterial compound (K21) to the radiopaque agent, antimicrobial tests were conducted using Porphyromonas gingivalis (P. gingivalis) and Streptococcus gordonii (S. gordonii) strains and blood agar plates.

Results

CaWO₄ micro-particle-bearing fillers exhibited an X-ray radiopacity distinct from tooth structures that enabled 3-D visualization of an artificial periodontal pocket created around a human tooth. MTT assays indicated that CaWO₄ micro-particles are highly biocompatible (increasing the viability of exposed keratinocytes). Radiopaque micro-particle fillers combined with K21 showed significant antimicrobial activity for P. gingivalis and S. gordonii.

Significance

The plausibility of visualizing PP with 3-D radiographic imaging using new radiopaque, biocompatible, transient fillers was demonstrated in vitro. Antibacterial (or other) agents added to this formula could provide beneficial therapeutic features along with the diagnostic utility.

中文翻译：

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开发不透射线，生物相容性，抗菌，微粒填充物，用于模拟牙周袋的微CT成像

目标

牙周袋（PP）内可能藏有大约10 ^9种细菌，以及与牙周炎（PD）相关的全身性疾病的病理生理学牵连的炎性副产物。这种炎性负担的计算涉及使用无法确定PP的三维（3-D）性质的常规牙周探查的模拟数据估算囊袋总表面积。这项研究的目的是确定体外瞬态微粒填料的射线不透性，生物相容性和抗菌活性，并证明其对人工PP进行3D成像的能力（美国专利公开号：9814791 B2）。

方法

各种金属氧化物填料的相对射线不透性值是使用体外模型从常规放射线照相和微计算机断层扫描（μCT）获得的。使用3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四唑溴化物（MTT）分析法，通过测定暴露后的存活角质形成细胞百分比（％），来测量钨酸钙（CaWO ₄）颗粒的生物相容性。在向不透射线的试剂中引入抗菌化合物（K21）之后，使用牙龈卟啉单胞菌（P. gingivalis）和戈登链球菌（S. gordonii）菌株和血琼脂平板进行了抗菌测试。

结果

含CaWO ₄微粒的填料表现出与牙齿结构不同的X射线不透射线性，从而可以对在人牙齿周围形成的人工牙周袋进行3-D可视化。MTT分析表明，CaWO ₄微粒具有高度的生物相容性（增加了裸露的角质形成细胞的活力）。不透射线的微粒填料与K21结合使用对牙龈卟啉单胞菌和戈登氏链球菌具有显着的抗菌活性。

意义

在体外证明了使用新的不透射线的，生物相容性的，瞬态填充剂通过3-D射线照相成像对PP进行可视化的可行性。添加到该配方中的抗菌（或其他）试剂可提供有益的治疗功能以及诊断工具。