根管内氢氧化钙药物的傅里叶变换拉曼光谱分析

Kwon T Y, Fujishima T, Imai Y

Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan.

Int Endod J. 2004 Jul;37(7):489-93. doi: 10.1111/j.1365-2591.2004.00831.x.

AIM

To investigate chemical changes in calcium hydroxide introduced into human root canals as a medicament using Fourier transform-(FT) Raman spectroscopy.

METHODOLOGY

Ten necrotic maxillary anterior teeth were selected in 10 patients. The teeth were divided into five treatment groups, according to the survey time. Root canal instrumentation was performed with hand instruments until the master apical file was size 40. Calcium hydroxide paste, in a 1 : 1.25 mixture by weight of powder and distilled water, was introduced directly into the root canal with a lentulo-spiral filler and then condensed with a finger plugger. The access cavity was sealed with a temporary dressing. After 2 and 4 days, then 2, 4 and 6 weeks, the calcium hydroxide paste was sampled with a K-file and then analysed using FT-Raman spectroscopy. The excitation source was an Nd : YAG laser with an excitation wavelength of 1064 nm. All spectra were taken with a laser power of 200 mW, 275-1185 scans, and 4 cm(-1) resolution. The conversion of calcium hydroxide to calcium carbonate was calculated on the basis of the spectral data obtained from the mixtures of both compounds.

RESULTS

The calcium hydroxide paste in the apical region showed weak bands at 1088 and 284 cm(-1), in addition to bands associated with calcium hydroxide. The weak bands, assigned to calcium carbonate, became stronger with time. Calcium carbonate content increased rapidly in the first 2 days and then tended to increase slowly. Approximately 11% of the calcium hydroxide at the apical portion of the canal was converted to calcium carbonate after 6 weeks. However, little alteration of the paste was noticed in the samples from the middle portion of the canal.

CONCLUSIONS

Calcium hydroxide medicament in root canals became transformed into calcium carbonate in the apical region within 2 days. Although the transformation continued with time, approximately 90% of the calcium hydroxide remained unchanged after 6 weeks.

目的

采用傅里叶变换 - 拉曼光谱法研究作为药物引入人体根管的氢氧化钙中的化学变化。

方法

选取10例患者的10颗坏死上颌前牙。根据观察时间将牙齿分为五个治疗组。用手动器械进行根管预备，直至主尖锉为40号。将按粉末与蒸馏水重量比1 : 1.25混合的氢氧化钙糊剂，用螺旋输送器直接导入根管，然后用手指压器加压。用临时充填材料封闭髓腔。在2天和4天后，以及2、4和6周后，用K锉采集氢氧化钙糊剂样本，然后用傅里叶变换 - 拉曼光谱法进行分析。激发源为Nd : YAG激光，激发波长为1064 nm。所有光谱均在激光功率200 mW、扫描275 - 1185次、分辨率4 cm⁻¹的条件下采集。根据从两种化合物混合物获得的光谱数据计算氢氧化钙向碳酸钙的转化率。