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The study of the new dentin lying method by CO_2 laser irradiation and hydroxyapatite paste

CO_2激光照射和羟基磷灰石糊剂修复牙本质新方法的研究

基本信息

批准号：
09671974
负责人：
GOMI Akira
金额：
$ 1.34万
依托单位：
Aichi-Gakuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

The purpose of this study was k find out a possibility of sealing the dentin tubuli using CO_2 laser and hydroxyapatite paste.Hydinxyapatite paste (mixed paste of CaHPO_4 2H_2O, CaCO_3, and H_2O) was applied to the prepared smooth dentin surfaces, which made of extracted human teeth, and irradiated by CO_2 laser under conditions of 3W Rep. 10/1000 and 100/1000 second. Next, these samples were cut in vertically, then investigated and analyzed by scanning electron microscope (SEM) and Fourier transform infrared (FT-IR).In every sample, the layer in which has the structure that sealed dentin tubuli was observed by SEM, and also the rich band of Calcium and phosphorus was found by FT-IR.The ingredients of internal dentin tubuli were, however, not determined.As a practical study, cervical cavities were prepared to expose dentin on upper first premolars which were intended to extract for orthodontal treatment, with patients' permission. Then the hydroxyapatite paste was applied to cavities and irradiated by CO_2 laser under conditions of 3W Rep. 100/1000 second. After extracted, they were investigated by SEM and pathological samples which had treated with hematoxylin-eosin staining.The results of SEM investigation, the micrographs which were the same as extracted human teeth were observed. And results of pathological investigation, normal dentinoblasts and pulpal tissue were observed.By this study, it was suggested that the irradiation of CO_2 laser with hydroxyapatite paste can seal the dentin tubuli without pulpal damage and carbonized layer.

为探讨CO_2激光和羟基磷灰石糊剂封闭牙本质小管的可能性，将羟基磷灰石糊剂（CaHPO_4·2H_2O、CaCO_3和H_2O的混合糊剂）涂敷在离体牙的光滑牙本质表面上，用CO_2激光在3 W、10/1000和100/1000秒的条件下照射。然后，将这些标本垂直切开，用扫描电镜（SEM）和傅立叶变换红外光谱（FT-IR）进行观察和分析，在每个标本中，扫描电镜观察到封闭牙本质小管的结构层，傅立叶变换红外光谱观察到钙和磷的富集带，但没有确定牙本质小管的成分。在患者允许的情况下，准备颈部空腔以暴露上部第一前磨牙上的牙本质，所述牙本质打算被提取以进行正畸治疗。然后将羟基磷灰石糊剂涂于洞内，用CO_2激光在3 W重复频率100/1000秒的条件下照射。取离体牙进行扫描电镜（SEM）和HE染色，观察与离体牙相同的显微图像。结果表明，CO_2激光照射羟基磷灰石糊剂能封闭牙本质小管，且不损伤牙髓，不产生覆盖层。