Diniz Ivana Márcia Alves, Horta Ivay Diniz, Azevedo Cynthia Soares, Elmadjian Thaís Regina, Matos Adriana Bona, Simionato Maria Regina Lorenzetti, Marques Márcia Martins
Department of Restorative Dentistry, School of Dentistry, University of Sao Paulo, Av. Prof. Lineu Prestes, 2227, São Paulo 05508-000, SP, Brazil.
School of Engineering, Federal University of Minas Gerais (UFMG), Av. Antônio Carlos, 6627, Belo Horizonte 31270-901, MG, Brazil.
Photodiagnosis Photodyn Ther. 2015 Sep;12(3):511-8. doi: 10.1016/j.pdpdt.2015.04.006. Epub 2015 May 19.
Antibacterial photodynamic therapy (aPDT) is a promising adjunctive therapy to the treatment of caries lesions, mainly in the minimally invasive approach to preserve dental tissue and favor its repair. Here we analyzed both the efficacy of aPDT in reducing the bacterial load in cariogenic biofilms and the indirect effect of noxious components produced by aPDT on the viability of dental pulp cells.
The aPDT protocol was established using 0.025g/mL methylene blue (MB) and 5min pre-irradiation time. A continuous-wave diode laser (660nm, 0.04cm(2) spot size, 40mW, 60s, 60J/cm(2) and 2.4J) was used in punctual and distance modes to excite the MB. The protocol was first tested against Streptococcus mutans (U159) biofilms produced in 96-well microplates, and then evaluated on caries-like affected human dentin discs of three thicknesses. The number of colony forming units (CFU) was compared between groups. Discs were then assembled in metallic inserts to produce an artificial pulp chamber and allow investigation of the indirect effects of aPDT on dental pulp cells by the 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT) assay. Data were analyzed using Student's t test or one-way analysis of variance (ANOVA) followed by the Tukey's test at a significance level of 5%.
Bacterial load reduction was observed in biofilms produced both in the microplates (p<0.05) and on the caries-like affected dentin discs (81.01% or mean reduction of log21.010±0.1548; p=0.0029). The cell viability of aPDT and control group was similar (p>0.05).
aPDT may be considered a promise adjunctive therapy for deep carious lesions.
抗菌光动力疗法（aPDT）是一种很有前景的治疗龋损的辅助疗法，主要用于微创治疗以保留牙体组织并促进其修复。在此，我们分析了aPDT降低致龋生物膜中细菌载量的疗效以及aPDT产生的有害成分对牙髓细胞活力的间接影响。
使用0.025g/mL亚甲蓝（MB）和5分钟预照射时间建立aPDT方案。使用连续波二极管激光器（660nm，光斑尺寸0.04cm²，40mW，60秒，60J/cm²和2.4J）以点状和距离模式激发MB。该方案首先针对在96孔微孔板中产生的变形链球菌（U159）生物膜进行测试，然后在三种厚度的类龋损人牙本质圆盘上进行评估。比较各组之间的菌落形成单位（CFU）数量。然后将圆盘组装在金属插入物中以制造人工牙髓腔，并通过3-（4,5-二甲基噻唑-2-基）-二苯基四氮唑溴盐（MTT）试验研究aPDT对牙髓细胞的间接影响。使用学生t检验或单因素方差分析（ANOVA），然后进行Tukey检验，显著性水平为5%，对数据进行分析。
在微孔板中产生的生物膜（p<0.05）以及类龋损牙本质圆盘上均观察到细菌载量降低（81.01%或平均降低log21.010±0.1548；p = 0.0029）。aPDT组和对照组的细胞活力相似（p>0.05）。
aPDT可被认为是治疗深龋损的一种有前景的辅助疗法。
