Department of Conservative Dentistry and Endodontics, Sri Ramachandra Institute of Higher Education & Research, Chennai, Tamil Nadu, India.
Department of Conservative Dentistry and Endodontics, Sri Ramachandra Dental College and Hospital, Chennai, Tamil Nadu, India, Phone: +91 9791109099, e-mail:
J Contemp Dent Pract. 2023 Mar 1;24(3):176-180. doi: 10.5005/jp-journals-10024-3467.
This study is aimed to evaluate the combined effect of sodium hypochlorite at varied concentrations and temperatures on radicular dentin microhardness along with its surface structural changes using an FTIR spectrometer.
Mandibular premolars were cleaned and shaped up to F3 Protaper gold rotary files, after which they were subjected to five experimental conditions - group I - neutral saline as negative control, group II - 3% NaOCl solution, group III - 5% NaOCl solution, group IV - 3% intracanal-heated NaOCl solution, and group V - 5% intracanal-heated NaOCl solution. Following this, the microhardness of radicular dentin at 100 µm and 300 µm from the canal lumen and Fourier-transform infrared (FTIR) spectroscopic analysis were performed.
The results showed that intracanal-heated sodium hypochlorite group reduced root dentin microhardness at 300 µm than its nonheated counterpart. No difference in microhardness values was observed between 3% intracanal-heated and room-temperature sodium hypochlorite groups at 100 µm. Reduction in amide/phosphate ratio was noted in all the groups treated with sodium hypochlorite irrespective of temperature and concentration.
Thus, considering that the level of alteration in physical and structural changes of root dentin with or without heating is insignificant, intracanal-heated low-concentration sodium hypochlorite solutions could be used as an alternative to high-concentration sodium hypochlorite.
Intracanal-heated low-concentration sodium hypochlorite enables the clinicians to achieve maximum disinfection while keeping the structural and physical properties of the dentin similar to room-temperature sodium hypochlorite.
本研究旨在评估不同浓度和温度的次氯酸钠对根管牙本质显微硬度的联合影响，并使用傅里叶变换红外光谱仪（FTIR）评估其表面结构变化。
下颌前磨牙经清洁和塑形至 F3 Protaper 金旋转锉后，分为 5 个实验组：- 组 I - 生理盐水作为阴性对照，- 组 II - 3%次氯酸钠溶液，- 组 III - 5%次氯酸钠溶液，- 组 IV - 根管内加热 3%次氯酸钠溶液，- 组 V - 根管内加热 5%次氯酸钠溶液。然后，在距根管腔 100 µm 和 300 µm 处测量根管牙本质的显微硬度，并进行傅里叶变换红外（FTIR）光谱分析。
结果显示，根管内加热次氯酸钠组在 300 µm 处降低了牙本质的显微硬度，而其非加热组则没有差异。在 100 µm 处，3%根管内加热和室温次氯酸钠组的显微硬度值无差异。所有用次氯酸钠处理的组的酰胺/磷酸盐比值均降低。
因此，考虑到加热和不加热对根管牙本质物理和结构变化的改变程度不大，根管内加热的低浓度次氯酸钠溶液可以替代高浓度次氯酸钠溶液。
根管内加热的低浓度次氯酸钠溶液使临床医生能够在保持牙本质的结构和物理性质与室温次氯酸钠相似的情况下，达到最大的消毒效果。
