de Oliveira Becci Ana Carolina, Marti Luana Mafra, Cilense Zuanon Angela Cristina, Brighenti Fernanda Lourenço, Palomari Spolidório Denise Madalena, Aparecida Giro Elisa Maria
Araraquara School of Dentistry - UNESP, Araraquara, São Paulo, Brazil.
Department of Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry - UNESP, Araraquara, São Paulo, Brazil.
Am J Dent. 2016 Oct;29(5):277-281.
This cross-over in situ experiment evaluated the microbial composition and quantified the total polysaccharides in the biofilm formed on the surface of a high viscosity glass-ionomer cement (GIC) mixed with chlorhexidine diacetate (CHX) in concentrations of 0.5%, 1% and 2%. GIC without CHX was used as control.
The volunteers (n= 8) tested each material for a 7-day period, by using a palatal acrylic device containing four round specimens, all fabricated with the same material. An increasing order of CHX concentration and a 15-day washout period between each concentration was adopted. The biofilm formed was collected and inoculated in specific culture media and thereafter, the total microorganisms, total streptococci, Streptococcus mutans and Lactobacillus spp were counted. Total polysaccharides were quantified by using a phenol-sulfuric method. Microbiologic data were analyzed by ANOVA for repeated measures and Tukey tests, and the total polysaccharide content by Friedman and Dunn's tests. Significance level was set at 5%.
Microorganism counts showed statistically significant differences among groups only for Lactobacillus (P< 0.05), that were significantly higher for group GIC+CHX 2% compared with GIC and GIC+CHX 0.5%. However, the concentration of total polysaccharides in the biofilm was lower for groups containing 1% and 2% of CHX.
The addition of chlorhexidine in the studied concentrations did not reduce the microorganism counts, but caused reduction of biofilm density.
本交叉原位实验评估了在与浓度为0.5%、1%和2%的醋酸氯己定（CHX）混合的高粘度玻璃离子水门汀（GIC）表面形成的生物膜中的微生物组成，并对总多糖进行了定量分析。未添加CHX的GIC用作对照。
志愿者（n = 8）使用含有四个圆形样本的腭部丙烯酸装置，对每种材料进行为期7天的测试，所有样本均由相同材料制成。采用CHX浓度递增顺序，并在每种浓度之间设置15天的洗脱期。收集形成的生物膜并接种到特定培养基中，然后对总微生物、总链球菌、变形链球菌和乳酸杆菌属进行计数。使用苯酚 - 硫酸法对总多糖进行定量。微生物学数据通过重复测量的方差分析和Tukey检验进行分析，总多糖含量通过Friedman和Dunn检验进行分析。显著性水平设定为5%。
微生物计数显示，仅乳酸杆菌在各组之间存在统计学显著差异（P < 0.05），与GIC组和GIC + CHX 0.5%组相比，GIC + CHX 2%组的乳酸杆菌数量显著更高。然而，含有1%和2% CHX的组中生物膜中的总多糖浓度较低。
在所研究的浓度下添加氯己定并没有减少微生物数量，但导致生物膜密度降低。
