Objectives: This study was performed to evaluate the occlusion of monetite paste on dentine tubule and provide a new potential method for treating dentine hypersensitivity.
Methods: Calcium oxide, strontium chloride, and polyethylene glycol phosphate were mixed in a certain proportion and ground in a planetary ball mill. The reaction was carried out by adjusting the pH to obtain monetite and hydroxyapatite paste. The morphological characteristics of the paste were observed through scanning electron microscope (SEM). The structure and composition were analyzed through X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FTIR). The extracted third molar was selected to undergo demineralization to establish the in vitro study model of dentin hypersensitivity. The samples were randomly divided into four groups: blank control group (treated with distilled water), casein peptide phosphate-amorphic calcium phosphate (CPP-ACP) group, monetite paste group, and hydroxyapatite paste group. Each group was used to scrub the dentin surface with the corresponding materials for 7 days. The morphological characteristics of the dentin surface and section were observed through SEM, the microhardness of the dentin before and after mineralization was analyzed with a microhardness tester, and the composition of the deposits on the surface of the mineralized samples was examined through XRD.
Results: XRD and FTIR showed that the composition of the paste was mainly monetite, and the composition of hydroxyapatite paste was mainly composed of hydroxyapatite. SEM revealed that the size of the crystal particles of the synthesized paste was tens to hundreds of nanometers. Monetite and hydroxyapatite paste could produce a thicker mineralization layer on the dentin surface, and the mineralization of the dentin tubules of monetite was deeper than that of hydroxyapatite paste. The microhardness of the monetite paste group was significantly less than those of the hydroxyapatite paste groups (P<0.05).
Conclusions: Monetite paste could effectively block the exposed dentin tubules and be used for treating dentin hypersensitivity.
目的: 体外评价三斜磷钙石糊剂对牙本质小管的封闭作用，为牙本质敏感症的治疗提供新的手段。方法: 将氧化钙、氯化锶、聚乙二醇、磷酸按一定的比例共混，置于行星球磨机中球磨进行反应，调节pH值分别获得三斜磷钙石糊剂和羟磷灰石糊剂。扫描电子显微镜（SEM）观察糊剂的形态，X射线衍射（XRD）和傅里叶变换红外光谱仪（FTIR）分析糊剂的结构和成分。选择拔除的人第三磨牙进行脱矿处理，构建牙本质敏感症体外研究模型。样本随机分为4组：空白对照组（使用蒸馏水处理）、酪蛋白磷酸肽-无定形磷酸钙（CPP-ACP）组、三斜磷钙石糊剂组、羟磷灰石糊剂组。采用各组分别对应的再矿化剂涂刷样本表面7 d。SEM观察牙本质表面及断面形态，显微硬度计分析矿化前后牙本质显微硬度，XRD分析矿化后样品表面沉积物。结果: XRD和FTIR结果显示合成的三斜磷钙石糊剂成分主要为三斜磷钙石，羟磷灰石糊剂成分主要为羟磷灰石；SEM结果显示合成的糊剂晶体颗粒大小数十到数百纳米的微纳结构。三斜磷钙石糊剂组和羟磷灰石糊剂组均能在牙本质表面生成较厚的矿化层，三斜磷钙石糊剂组在牙本质小管内矿化深度较羟磷灰石糊剂组深。羟磷灰石糊剂组的显微硬度大于三斜磷钙石糊剂组，差异存在统计学意义（P<0.05）。结论: 三斜磷钙石能有效地封堵暴露的牙本质小管，有望应用于牙本质敏感症的治疗。.
Keywords: casein peptide phosphate-amorphic calcium phosphate; dentinal hypersensitivity; hydroxyapatite; monetite.