Mitic Dijana D, Milosevic Markovic Maja S, Jovanovic Igor D, Mancic Dragan D, Orhan Kaan, Jokanovic Vukoman R, Markovic Dejan Lj
School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia.
Faculty of Electronic Engineering, University of Nis, 18000 Nis, Serbia.
Biomimetics (Basel). 2025 Apr 2;10(4):216. doi: 10.3390/biomimetics10040216.
The root walls of immature permanent teeth are often weak, thin, and short, making regenerative endodontic treatment (RET) necessary. The goal of RET is to create a favorable environment for further root development. A biomimetic approach is essential for thorough disinfection, followed by the preservation and potential stimulation of stem cells from surrounding tissue to enable root regeneration and continued development. The objective of this study was to assess temperature changes on the external root surface, structural alterations in the internal root walls following irradiation with a 940 nm diode laser, and the biocompatibility of stem cells from the apical papilla (SCAPs). Irradiation was performed with varying output powers (0.5 W, 1 W, 1.5 W, and 2 W) in continuous mode for 5 s over four consecutive cycles. Thermographic measurements during irradiation, the micro-CT analysis of root samples, and mitochondrial activity of SCAPs were evaluated. The heating effect correlated directly with a higher output power and thinner root walls. A 1 W output power was found to be safe for immature teeth, particularly in the apical third of the root, while 1.5 W could be safely used for mature mandibular incisors. Diode laser irradiation at 1 W and 1.5 W significantly stimulated SCAPs' mitochondrial activity within 24 h post-irradiation, indicating a potential photobiostimulatory effect. However, no significant changes were observed at lower (0.5 W) and higher (2 W) output powers. The area of open tubular space inside the root canal was significantly reduced after irradiation, regardless of the applied power. Additionally, irradiation contributed to the demineralization of the dentin on the inner root walls. Future studies should explore the impact of irrigants used between irradiation cycles, the potential benefits of conical laser tips for more even energy distribution, and a thorough analysis of how disinfection protocols affect both the dentin structure and stem cell viability.
未成熟恒牙的根壁通常薄弱、纤细且短小，因此进行再生性牙髓治疗（RET）很有必要。RET的目标是为牙根的进一步发育创造有利环境。仿生方法对于彻底消毒至关重要，随后要保存并潜在刺激周围组织的干细胞，以实现牙根再生和持续发育。本研究的目的是评估940纳米二极管激光照射后牙根外表面的温度变化、牙根内壁的结构改变以及根尖乳头干细胞（SCAPs）的生物相容性。以连续模式在四个连续周期内用不同输出功率（0.5瓦、1瓦、1.5瓦和2瓦）照射5秒。评估了照射期间的热成像测量、牙根样本的显微CT分析以及SCAPs的线粒体活性。热效应与更高的输出功率和更薄的根壁直接相关。发现1瓦的输出功率对未成熟牙齿是安全的，特别是在牙根的根尖三分之一处，而1.5瓦可安全用于成熟的下颌切牙。1瓦和1.5瓦的二极管激光照射在照射后24小时内显著刺激了SCAPs的线粒体活性，表明存在潜在的光生物刺激作用。然而，在较低（0.5瓦）和较高（2瓦）输出功率下未观察到显著变化。无论施加的功率如何，照射后根管内开放管状空间的面积均显著减小。此外，照射导致牙根内壁牙本质脱矿。未来的研究应探讨照射周期之间使用的冲洗液的影响、锥形激光头对更均匀能量分布的潜在益处，以及对消毒方案如何影响牙本质结构和干细胞活力的全面分析。
