Ribeiro Jeter Bochnia, Foggiato Augusto Alberto, Fernandes Douglas Silva, Câmara João Victor Frazão, Ribeiro Amanda de Oliveira Pinto, França Fabiana Mantovani Gomes
School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Center for Health Sciences - Dentistry, State University of Northern Paraná, Jacarezinho, PR, Brazil.
Photodiagnosis Photodyn Ther. 2025 Aug;54:104669. doi: 10.1016/j.pdpdt.2025.104669. Epub 2025 Jun 13.
Photodynamic therapy is a two-stage treatment that combines light energy with a photosensitizer, and enhances the treatment against bacterial infections. In this context, the present study evaluated a newly patented device, called an ultrasonic photodynamic inactivation device (UPID), which performs microbial inactivation using photodynamic therapy for both prosthetic braces (PBs) and prototyped surgical guides (PSGs).
Photodynamic inactivation was analyzed by contaminating the instruments with bacterial suspensions (3 × 10 CFU/mL) of 100 µM/L methylene blue solution for 20 min, followed by irradiation (0.30 J/cm) with red light-emitting diode (660 nm) for 20 min, on three types of microorganisms: Candida albicans ATCC 10,231, Staphylococcus aureus ATCC 25,923 and Escherichia coli ATCC 25,922. The PSGs included a group with irradiation for 30 min (0.45 J/cm), and a control group with 0.2 % peracetic acid, evaluated at both 20-minute time points. Microbial inhibition was assessed by counting the number of colony-forming units (CFU), and by the data evaluated using the Shapiro-Wilk, Mann-Whitney-U, and Kruskal-Wallis tests, at a 5 % significance level.
All experimental treatments showed significant reduction in log CFU/mL. The UPID promoted a significant microbial reduction (p < 0.001), compared with the positive control. In addition, peracetic acid was more effective than PDT for the PSG (p < 0.001). However, after 20 min, both treatments protected the surface material against bacterial growth.
The device proved effective for microbial inhibition of PB and PSG, thus proposing a new technique for the non-toxic disinfection of biomedical devices.
光动力疗法是一种将光能与光敏剂相结合的两阶段治疗方法，可增强对细菌感染的治疗效果。在此背景下，本研究评估了一种新获得专利的设备，即超声光动力灭活设备（UPID），该设备使用光动力疗法对义齿矫治器（PBs）和原型手术导板（PSGs）进行微生物灭活。
通过用100 μM/L亚甲蓝溶液的细菌悬液（3×10 CFU/mL）污染器械20分钟，然后用红色发光二极管（660 nm）照射（0.30 J/cm）20分钟，对三种微生物进行光动力灭活分析：白色念珠菌ATCC 10231、金黄色葡萄球菌ATCC 25923和大肠杆菌ATCC 25922。PSGs包括一个照射30分钟（0.45 J/cm）的组和一个用0.2%过氧乙酸处理的对照组，在两个20分钟时间点进行评估。通过计算菌落形成单位（CFU）数量以及使用Shapiro-Wilk、Mann-Whitney-U和Kruskal-Wallis检验评估的数据，在5%显著性水平下评估微生物抑制情况。
所有实验处理均显示log CFU/mL显著降低。与阳性对照相比，UPID促进了显著的微生物减少（p < 0.001）。此外，对于PSG，过氧乙酸比光动力疗法更有效（p < 0.001）。然而，20分钟后，两种处理均能保护表面材料免受细菌生长。
该设备被证明对PB和PSG的微生物抑制有效，从而提出了一种用于生物医学设备无毒消毒的新技术。
