School of Dentistry, The University of Queensland, Herston, Queensland, Australia.
School of Dentistry and Oral Health, Griffith University, Southport, Queensland, Australia.
Photodiagnosis Photodyn Ther. 2022 Jun;38:102791. doi: 10.1016/j.pdpdt.2022.102791. Epub 2022 Mar 2.
Laser-fluorescence diagnostic technology for real-time clinical assessment of residual bacteria could help assist in determining the endpoints for root canal debridement. Sodium hypochlorite (NaOCl) can however quench fluorescence and lead to false low reading. This study aims to evaluate various antioxidant for their ability to recover quenched fluorescence in dentine treated with NaOCl.
Human dentine fluorescence was measured using 655 nm laser at baseline and again after a 2 min application of 4% NaOCl. The putative recovery agents were then applied, and the fluorescence measured after 5, 10, 20, 30 and 60 min. Recovery from quenching was also assessed using laser confocal scanning microscopy (CLSM) with a bound tetracycline fluorophore using 488 nm excitation.
A 5 min application of vitamin E oil or buffered 2% lignocaine solution (1:80,000 adrenaline) was effective in regaining quenched fluorescence within the following 5 mins. Distilled water, sodium thiosulfate, unbuffered 2% lignocaine with 1:80000 adrenaline and phosphate buffered saline were less effective, and of equal performance. Ascorbic acid and butylated hydroxyanisole were not effective and had deleterious effects on the levels of dentine fluorescence. CLSM provided confirmation of recovery from quenched fluorescence using vitamin E oil.
Based on these findings, reversal agents should be employed when assessing the fluorescence of dentine that has been exposed to NaOCl or other quenching agents.
用于实时临床评估残留细菌的激光荧光诊断技术可以帮助确定根管清创的终点。然而，次氯酸钠 (NaOCl) 会猝灭荧光并导致读数偏低。本研究旨在评估各种抗氧化剂恢复用 NaOCl 处理后的牙本质中猝灭荧光的能力。
使用 655nm 激光在基线和 4% NaOCl 应用 2 分钟后再次测量人牙本质荧光。然后应用假定的恢复剂，并在 5、10、20、30 和 60 分钟后测量荧光。使用结合四环素荧光团的激光共聚焦扫描显微镜 (CLSM) 评估猝灭后的恢复情况，使用 488nm 激发。
5 分钟应用维生素 E 油或缓冲 2%利多卡因溶液（1:80000 肾上腺素）可在接下来的 5 分钟内有效恢复猝灭荧光。蒸馏水、硫代硫酸钠、无缓冲 2%利多卡因加 1:80000 肾上腺素和磷酸盐缓冲盐水效果较差，性能相同。抗坏血酸和丁基羟基茴香醚无效，且对牙本质荧光水平有有害影响。CLSM 证实了用维生素 E 油恢复猝灭荧光。
基于这些发现，在用 NaOCl 或其他猝灭剂处理后的牙本质荧光评估中应使用逆转剂。
