Hashem Mohamed
Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Photodiagnosis Photodyn Ther. 2021 Mar;33:102145. doi: 10.1016/j.pdpdt.2020.102145. Epub 2020 Dec 20.
To assess the micro-tensile bond strength (μ-TBS), degree of conversion, and antimicrobial capacity of modified dentin adhesive using riboflavin photoinitiators.
Three groups of adhesives (control; 0.1 % riboflavin-PDT and 0.5 % riboflavin PDT) were prepared and tested on 70 sound molar teeth. Fourier-transformed infrared spectroscopy (FTIR) was performed for riboflavin and riboflavin-modified adhesives to calculate the degree of conversion. Contact angle measurement was performed by dropping a 5 μL droplet of the adhesives onto polished dentin disk. For μ-TBS testing, the dentin beams were fixed on a micro-tensile tester and were loaded in tension at a cross-head speed of 1 mm per min until fracture. The viability of Streptococcus mutans biofilm was tested using MTT assay.
The spectrum at 1728 cm-1 indicates CO stretching frequency of riboflavin. The groups control and 0.1 % riboflavin PDT showed the highest degree of conversion followed by lowest degree of conversion of 0.5 % riboflavin adhesive after PDT. The control adhesive exhibited the highest contact angle over the dentin surface compared to the riboflavin-modified adhesive groups (p < 0.05). The lowest contact angle was observed for 0.1 % riboflavin that showed increased permeability of the adhesive onto the dentin surface (p < 0.05). The variables of immediate bonding (F = 12.328, p = 0.000) and ageing in artificial saliva (F = 41.559, p = 0.000) significantly affected the bond strength. For aged μ-TBS testing, the scores for 0.1 % riboflavin PDT was significantly higher as compared to the 0.5 % riboflavin PDT samples. The MTT resulted in a lower S. mutans viability for 0.5 % riboflavin PDT compared to 0.1 % riboflavin PDT and control adhesive (p < 0.05), irrespective of any time point, that is, after 24 h and 30 days ageing.
The addition of riboflavin as photosensitizer in dentin adhesive demonstrated higher bond strength, excellent antimicrobial capability, and degree of conversion following PDT. The addition of riboflavin in dentin adhesive for PDT could be used as a potential restorative material in adhesive dentistry.
评估使用核黄素光引发剂的改性牙本质黏结剂的微拉伸黏结强度（μ-TBS）、转化率和抗菌能力。
制备三组黏结剂（对照组；0.1%核黄素-PDT和0.5%核黄素-PDT），并在70颗完好的磨牙上进行测试。对核黄素和核黄素改性黏结剂进行傅里叶变换红外光谱（FTIR）分析以计算转化率。通过将5μL黏结剂液滴滴到抛光的牙本质盘上来进行接触角测量。对于μ-TBS测试，将牙本质梁固定在微拉伸测试仪上，并以每分钟1mm的十字头速度进行拉伸加载直至断裂。使用MTT法测试变形链球菌生物膜的活力。
1728cm-1处的光谱表明核黄素的CO伸缩频率。对照组和0.1%核黄素-PDT组显示出最高的转化率，其次是0.5%核黄素黏结剂在光动力疗法（PDT）后的最低转化率。与核黄素改性黏结剂组相比，对照黏结剂在牙本质表面表现出最高的接触角（p<0.05）。观察到0.1%核黄素的接触角最低，表明该黏结剂在牙本质表面的渗透性增加（p<0.05）。即时黏结（F=12.328，p=0.000）和在人工唾液中老化（F=41.559，p=0.000）的变量显著影响黏结强度。对于老化后的μ-TBS测试，0.1%核黄素-PDT组的得分显著高于0.5%核黄素-PDT组的样本。无论在任何时间点，即老化24小时和30天后，MTT结果显示0.5%核黄素-PDT组的变形链球菌活力低于0.1%核黄素-PDT组和对照黏结剂（p<0.05）。
在牙本质黏结剂中添加核黄素作为光敏剂，在PDT后表现出更高的黏结强度、优异的抗菌能力和转化率。在用于PDT的牙本质黏结剂中添加核黄素可作为口腔黏结修复的潜在材料。
