Plasma deactivation of oral bacteria seeded on hydroxyapatite disks as tooth enamel analogue.
Plasma deactivation of oral bacteria seeded on hydroxyapatite disks as tooth enamel analogue.
复制标题
DOI：
--
复制
发表时间：
2014-04
影响因子：
1.4
通讯作者：
A. Blumhagen;Prashant Singh;A. Mustapha;Meng Chen;Yong Wang;Qingsong Yu
中科院分区：
文献类型：
--
作者：
A. Blumhagen;Prashant Singh;A. Mustapha;Meng Chen;Yong Wang;Qingsong Yu
目的研究等离子体对牙釉质模拟物口腔细菌灭活的影响。方法采用非热常压氩等离子体刷对两种革兰氏阳性口腔细菌嗜酸乳杆菌（L. acidophilus）和变形链球菌（S. mutans）进行处理。将细菌播种在羟基磷灰石（HA）圆盘上，作为牙釉质模拟物，初始细菌播种浓度为3种：低接种浓度为2.1 × 10(8)至2.4 × 10(8) cfu/mL，中接种浓度为9.8 × 10(8)至2.4 × 10(9) cfu/mL，高接种浓度为1.7 × 10（10）至3.5 × 10(10) cfu/mL。根据等离子体暴露时间和等离子体中氧的添加量来检查细菌在等离子体暴露后的存活率。用扫描电镜观察等离子体暴露后细菌形态的变化。结果实验数据表明，当细菌在HA表面的初始播种密度小于嗜酸乳杆菌6.9 × 10(6) cfu/cm2和变形链球菌1.7 × 10(7) cfu/cm2时，13 s血浆暴露时间完全杀死所有细菌，这是由于初始播种接种浓度在2.1 × 10(8) ~ 2.4 × 10(8) cfu/mL之间。然而，在较高的初始细菌播种密度和较高的初始播种接种浓度下，细菌暴露在血浆中，对嗜酸乳杆菌和变形链球菌分别只导致约1.5至2 log和约2至2.5 log的减少。还注意到，在氩等离子体电刷中添加氧气并不影响等离子体的失活效果。扫描电镜图像显示，等离子体失活主要发生在顶层细菌，而由此产生的细菌碎片的阴影效应降低了底层细菌的等离子体失活。
PURPOSE To study the plasma treatment effects on deactivation of oral bacteria seeded on a tooth enamel analogue. METHODS A non-thermal atmospheric pressure argon plasma brush was used to treat two different Gram-positive oral bacteria including Lactobacillus acidophilus (L. acidophilus) and Streptococcus mutans (S. mutans). The bacteria were seeded on hydroxyapatite (HA) disks used as tooth enamel analogue with three initial bacterial seeding concentrations: a low inoculum concentration between 2.1 x 10(8) and 2.4 x 10(8) cfu/mL, a medium inoculum concentration between 9.8x10(8) and 2.4 x 10(9) cfu/mL, and a high inoculum concentration between 1.7 x 10(10) and 3.5 x 10(10) cfu/mL. The bacterial survivability upon plasma exposure was examined in terms of plasma exposure time and oxygen addition into the plasmas. SEM was performed to examine bacterial morphological changes after plasma exposure. RESULTS The experimental data indicated that a 13-second plasma exposure time completely killed all the bacteria when initial bacterial seeding density on HA surfaces was less than 6.9 x 10(6) cfu/cm2 for L. acidophilus and 1.7 x 10(7) cfu/cm2 for S. mutans, which resulted from low initial seeding inoculum concentration between 2.1 x 10(8) and 2.4 x 10(8) cfu/mL. Plasma exposure of the bacteria at higher initial bacterial seeding density obtained with high initial seeding inoculum concentration, however, only resulted in approximately 1.5 to 2 log reduction and approximately 2 to 2.5 log reduction for L. acidophilus and S. mutans, respectively. It was also noted that oxygen addition into the argon plasma brush did not affect the plasma deactivation effectiveness. SEM images showed that plasma deactivation mainly occurred with the top layer bacteria, while shadowing effects from the resulting bacterial debris reduced the plasma deactivation of the underlying bacteria.