School of Dental Medicine, University of Zagreb, Gundulićeva 5, 10000, Zagreb, Croatia.
Department of Clinical and Molecular Microbiology, University Hospital Centre Zagreb, Kišpatićeva 12, 10000, Zagreb, Croatia.
Photodiagnosis Photodyn Ther. 2018 Mar;21:328-333. doi: 10.1016/j.pdpdt.2018.01.017. Epub 2018 Feb 2.
We aimed to evaluate the antimicrobial efficacy of photodynamic therapy (PDT) and light-activated disinfection (LAD) on zirconia dental implants contaminated with three bacterial species and investigate if the PDT and LAD cause implant surface alterations.
Seventy-two zirconia dental implants were contaminated with a bacterial suspension of Prevotella intermedia, Actinomyces actinomycetemcomitans, and Porphyromonas gingivalis. The implants were subsequently randomly divided into four groups (n = 12 dental implants/each) according to the decontamination protocol: Group 1 (PDT1) - PDT (660 nm, 100 mW) with toluidine blue; Group 2 (PDT2) - PDT (660 nm, 100 mW) with phenothiazine chloride dye; Group 3 (LAD) - light emitting diode (LED) with toluidine blue; and Group 4 (TB) - toluidine blue without the application of light. Implants in the positive control (PC) group were treated with a 0.2% chlorhexidine-based solution, and implants assigned to the negative control (NC) group did not undergo any treatment. Each implant was then placed in tubes containing phosphate buffered saline (PBS) and vortexed for 60 s to remove the remaining bacteria from the implant surface. After 10-fold serial dilutions, 30 μl of the suspension was plated on Brucella agar plates. After 72 h, the colony forming units (CFU) were counted. Distinctive colonies were confirmed with MALDI Biotyper. The implants were analyzed using scanning electron microscope (SEM) to evaluate the possible surface alterations due to PDT or LAD.
All study groups had significant reductions in the number of CFUs compared with the NC (p < 0.05). PDT1, the PDT2, and the LAD groups had the largest bacterial reduction with respect to each bacterial species separately and the total bacterial count, and they were more efficient compared with the TB group (p < 0.05). SEM analysis did not reveal any alterations of the implant surface after the treatment procedures.
Both PDT protocols and LAD showed high and equal effectiveness in decontamination of zirconia dental implants.
本研究旨在评估光动力疗法（PDT）和光激活消毒（LAD）对受三种细菌污染的氧化锆牙科种植体的抗菌效果，并探讨 PDT 和 LAD 是否会导致种植体表面发生变化。
将 72 个氧化锆牙科种植体用中间普氏菌、伴放线放线杆菌和牙龈卟啉单胞菌的细菌悬液污染。随后，根据去污方案将种植体随机分为四组（每组 12 个种植体）：第 1 组（PDT1）-PDT（660nm，100mW）联合甲苯胺蓝；第 2 组（PDT2）-PDT（660nm，100mW）联合吩噻嗪氯染料；第 3 组（LAD）-发光二极管（LED）联合甲苯胺蓝；第 4 组（TB）-无光照的甲苯胺蓝。阳性对照组（PC）的种植体用 0.2%氯己定溶液处理，阴性对照组（NC）的种植体不做任何处理。然后，将每个种植体放入含有磷酸盐缓冲盐水（PBS）的管中，涡旋 60s 以去除种植体表面残留的细菌。对 10 倍系列稀释液进行 30μl 悬浮液平板接种，将接种后的 Brucella 琼脂平板在 72h 后进行菌落计数。通过 MALDI Biotyper 对特征性菌落进行确认。使用扫描电子显微镜（SEM）分析种植体，以评估 PDT 或 LAD 可能导致的表面变化。
与 NC 组相比，所有研究组的 CFU 数量均显著减少（p<0.05）。PDT1、PDT2 和 LAD 组对每种细菌和总细菌计数的细菌减少量最大，与 TB 组相比，它们的效果更显著（p<0.05）。SEM 分析显示，在处理程序后，种植体表面没有任何变化。
两种 PDT 方案和 LAD 对氧化锆牙科种植体的消毒均具有高效且同等的效果。
