Dental Compression Analysis Using Confined Compression and Imagining

总结 我们的初步数据表明，在酯酶中老化修复性牙科复合材料 人工唾液（AS）中的酶导致直径强度相对于 样品老化水有或没有酸。基于这些数据，本研究将利用 牙本质环包含一个复合标本，以结构完整的牙本质-粘附和 粘合剂-复合材料界面经受具有两个模型口腔的模拟口腔环境， 细菌（致龋S.变异链球菌和S. sanguinis）和在酯酶存在下孵育 AS培养基中的酶。此外，将对样本进行轴向和径向循环试验， 加载在该牙本质粘合剂复合材料环内以模拟I类修复。实验 将使我们能够确定是否致龋孵育 条件和/或生物膜生长和葡糖酰转移酶（gtfB，生物膜中的关键酶）的表达。 致龋生物膜中细胞外基质形成的产生）显著影响 试样的结构完整性。包括酯酶将使我们能够测试是否 这些酶降解并降低牙本质-粘合剂-复合物结合的强度， 已经展示了复合材料。静态测试将确定水的作用 地球化学条件（无论是非生物或生物诱导）发挥攻击的结构 测试样本的完整性和动态循环压缩将使我们能够确定 模拟咀嚼力对更真实的体内模型应力的影响。 将分析从界面和散装复合材料中浸出的降解产物， 通过电感耦合等离子体质谱法（ICP-MS）定量表征， 复合物的无机组分（例如Zr、Si和Ti），并通过液相色谱/ 聚合物降解产物的串联MS（LC-MS/MS）。显微和纳米成像分析 牙本质-粘合剂-复合物体积（界面、孔隙和裂缝）应有助于澄清 导致牙科复合材料修复临床失败的事件序列。是 预计将在细菌之间观察到显着差异 与对照标本相比，AS环境中的孵育物与酯酶 （未循环，在AS中老化120天）。看来，牙科复合材料的行为受到 在这两种环境中的多轴载荷至今尚未在文献中报道。 牙科复合材料在口腔中经受极端的化学和机械条件， 环境，这有助于材料在体内的降解和最终失效。

SUMMARY Our preliminary data indicated that aging a restorative dental composite in an esterase enzyme in artificial saliva (AS) resulted in a significant decrease in diametral strength relative to specimens aged water with or without an acid. Building on this data, this research will utilize a dentin ring containing a composite specimen to the structural integrity of dentin-adhesive and adhesive-composite interfaces subjected to simulated oral environments with two model oral bacteria (cariogenic S. mutans and S. sanguinis) and incubation in the presence of esterase enzyme in AS media. In addition, the specimens will be subjected to axial and radial cyclic loading within this dentin-adhesive-composite ring to simulate a class I restoration. Experiments with the two Streptococcus strains will allow us to determine whether cariogenic incubation conditions and/or biofilm growth and expression of glucsoyltransferases (gtfB, a key enzyme in the production of extracellular matrix formation in cariogenic biofilms) significantly impact the structural integrity of the test specimens. Inclusion of esterases will allow us to test whether these enzymes degrade and reduce the strength of dentin-adhesive-composite bonds, as we have shown previously with composites. Static tests will determine the role aqueous geochemical conditions (either abiotic or biotically-induced) play in attacking the structural integrity of the test specimens, and dynamically cycled compression will allow us to determine the impact of simulated forces from mastication to more realistically model stress in vivo. Analysis of the degradation products leaching from the interfaces and bulk composite will be quantitatively characterized by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for inorganic components of the composite (e.g. Zr, Si, and Ti), and by liquid chromatography/ tandem MS (LC-MS/MS) for polymer degradation products. Micro- and nano-imaging analysis of the dentin-adhesive-composite volumes (interfaces, pores, and cracks) should aid in clarification of the sequence of events leading to clinical failure of dental composite restorations. It is anticipated that significant differences will be observed between and among the bacteria incubations versus the esterase enzyme in AS environments with respect to control specimens (uncycled and aged 120 d in AS). It appears that behavior of dental composites subjected to multiaxial loading in these two environments has not been reported on in the literature to date. Dental composites are subjected to extreme chemical and mechanical conditions in the oral environment, which contribute to the degradation and ultimate failure of the material in vivo.