Tehran University of Medical Sciences, Tehran, Iran.
Nuclear Science and Technology Research Institute, Tehran, Iran.
Folia Med (Plovdiv). 2020 Dec 31;62(4):817-824. doi: 10.3897/folmed.62.e50200.
Microbial biofilm accumulation around orthodontic brackets and composite is a common complication of fixed orth-odontic treatment. This study assessed the antibacterial effects of orthodontic primer containing chitosan nanoparticles (CNPs) against the multispecies biofilm of cariogenic bacteria in а rat model.
Transbond XT orthodontic primer containing 0%, 1%, 5%, and 10% CNPs was experimentally prepared. The Wistar rats were randomly divided into four groups (n=7) of control (0% CNPs), 1%, 5% and 10% CNPs. The oral cavities of the rats were infected with cariogenic bacteria. After anesthetizing the rats, 1 drop (10 µL) of primer with different concentrations of CNPs was applied to their central incisor and light-cured for 20 seconds. Transbond XT orthodontic adhesive (2 × 2 mm) was applied on the primer. Another drop (10 µL) of primer was applied and light-cured for 40 seconds. The number of Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus acidophilus colonies in the saliva of rats was quantified at 24 hours, 4 days and 7 days.
Adding 1% (p=0.005), 5% (p<0.001) and 10% (p<0.001) of CNPs to orthodontic primer significantly reduced the S. mutans colony count at 24 hours compared with the control group. At 24 hours, the mean S. sanguinis colony counts in the 5% (p=0.04) and 10% (p=0.02) CNP groups were significantly lower than that in the control group. Also, at 4 and 7 days, the mean colony counts in the 5% and 10% CNP groups were significantly lower than that in the control group (p<0.05). At 24 hours and 4 days, the mean L. acidophilus colony count in the 10% CNP group was significantly lower than that in the control group (p<0.05). At 7 days, rats with failed adhesive showed a significantly higher count of all three bacteria compared with rats with adhesive (p<0.05).
The addition of 5% CNPs to orthodontic primer significantly decreased the colony count of cariogenic bacteria in rats.
正畸托槽和复合树脂周围微生物生物膜的积累是固定正畸治疗的常见并发症。本研究评估了含有壳聚糖纳米粒子（CNPs）的正畸底漆对致龋细菌多物种生物膜的抗菌作用在大鼠模型中。
实验制备了含有 0%、1%、5%和 10%CNPs 的 Transbond XT 正畸底漆。将 Wistar 大鼠随机分为四组（n=7），分别为对照组（0%CNPs）、1%、5%和 10%CNPs。大鼠口腔感染致龋菌。在麻醉大鼠后，将不同浓度的含有 CNPs 的底漆滴（10µL）滴在其中切牙上，并光固化 20 秒。将 Transbond XT 正畸胶（2×2mm）涂在底漆上。再滴（10µL）底漆，光固化 40 秒。在 24 小时、4 天和 7 天测量大鼠唾液中变形链球菌、血链球菌和嗜酸乳杆菌的菌落数量。
与对照组相比，正畸底漆中添加 1%（p=0.005）、5%（p<0.001）和 10%（p<0.001）CNPs 可显著降低 24 小时变形链球菌菌落数。在 24 小时时，5%（p=0.04）和 10%（p=0.02）CNP 组的平均血链球菌菌落计数明显低于对照组。此外，在 4 天和 7 天，5%和 10%CNP 组的平均菌落计数明显低于对照组（p<0.05）。在 24 小时和 4 天，10%CNP 组的嗜酸乳杆菌平均菌落计数明显低于对照组（p<0.05）。在 7 天，与具有粘合力的大鼠相比，粘合力失败的大鼠的所有三种细菌的菌落计数明显更高（p<0.05）。
正畸底漆中添加 5%CNPs 可显著降低致龋菌在大鼠中的菌落计数。
