Hakami Zaki, Alshehri Abdulkarim Hussain
Division of Orthodontics, Department of Preventive Dental Sciences, College of Dentistry, Jazan University, Jazan, Saudi Arabia.
Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan, Saudi Arabia.
Photodiagnosis Photodyn Ther. 2022 Sep;39:102951. doi: 10.1016/j.pdpdt.2022.102951. Epub 2022 Jun 8.
Vacuum-formed retainers (VFRs) are widely used in dental practices because of their superior esthetics. However, simultaneous maintenance of their hygiene, mechanical and optical properties is challenging. This study aimed to evaluate and compare the disinfection efficacy of antimicrobial photodynamic therapy (aPDT), chlorhexidine (CHX), sodium hypochlorite (NaOCl) and water over VFRs specimens, along with their effect on flexural strength and color stability.
Fabricated VFRs of thicknesses 1 mm and 2 mm were contaminated with S. mutans and C. albicans. Brain Heart Infusion agar was used to seed Streptococcus Mutans whereas Candida Albicans was seeded in Sabourand Dextrose Agar. The contaminated retainers were divided into four groups and decontaminated using four different treatment protocols: aPDT, CHX, NaOCl and water, with 10 specimens per group. Microbial viability following decontamination, was assayed using MTT. To assess the color stability, pre and post decontamination color difference of 10 specimens was recorded using a spectrophotometer by blinding technique. The flexural strength of 10 specimens was measured using a universal testing machine by a standardized 3-point flexural strength (FS) test.
aPDT showed the highest reduction in the viability of S. mutans (28%) and C. albicans (20%) species in 1 mm thickness group while the second highest reduction following disinfection with CHX (40%) in followed by NaOCl disinfection (50%). On comparison between 1 mm and 2 mm, a statistically significant difference was noted for S. mutans in aPDT (p = 0.033) and NaOCl (p = 0.028) groups, and for C. albicans, a significant difference was noted within NaOCl (p = 0.001) and CHX (p = 0.043) groups. For FS, a statistically significant difference (p < 0.05) was observed between aPDT and the rest of the groups, whereas there was no statistically significant difference in the flexural strength between the CHX, NaOCl and water groups (p > 0.05) in both 1 mm and 2 mm specimens. Between 1 mm and 2 mm specimens, no statistically significant difference in the mean color difference was noted after any disinfection protocol (p > 0.05).
Antimicrobial photodynamic therapy showed a remarkable reduction in candidal and bacterial viability over VFRs. aPDT treated VFR specimens showed increased flexural strength and a higher color difference post treatment compared to other reagents.
真空成型保持器（VFRs）因其出色的美观性而在牙科实践中广泛使用。然而，同时保持其卫生、机械和光学性能具有挑战性。本研究旨在评估和比较抗菌光动力疗法（aPDT）、洗必泰（CHX）、次氯酸钠（NaOCl）和水对VFRs标本的消毒效果，以及它们对弯曲强度和颜色稳定性的影响。
制作厚度为1毫米和2毫米的VFRs，并使其被变形链球菌和白色念珠菌污染。脑心浸液琼脂用于接种变形链球菌，而白色念珠菌接种于沙氏葡萄糖琼脂中。将受污染的保持器分为四组，采用四种不同的处理方案进行去污：aPDT、CHX、NaOCl和水，每组10个标本。去污后的微生物活力采用MTT法测定。为评估颜色稳定性，使用分光光度计通过盲法记录10个标本去污前后的颜色差异。使用万能试验机通过标准化的三点弯曲强度（FS）试验测量10个标本的弯曲强度。
在1毫米厚度组中，aPDT对变形链球菌（28%）和白色念珠菌（20%）的活力降低率最高，而CHX消毒后降低率次之（40%），其次是NaOCl消毒（50%）。在1毫米和2毫米组之间比较时，aPDT组（p = 0.033）和NaOCl组（p = 0.028）的变形链球菌有统计学显著差异，对于白色念珠菌，NaOCl组（p = 0.001）和CHX组（p = 0.043）有显著差异。对于FS，aPDT组与其他组之间观察到统计学显著差异（p < 0.05），而在1毫米和2毫米标本中，CHX、NaOCl和水组之间的弯曲强度无统计学显著差异（p > 0.05）。在1毫米和2毫米标本之间，任何消毒方案后平均颜色差异均无统计学显著差异（p > 0.05）。
抗菌光动力疗法对VFRs上的念珠菌和细菌活力有显著降低作用。与其他试剂相比，aPDT处理的VFR标本处理后弯曲强度增加，颜色差异更大。
