摘要
目的探索pH响应性新型叔胺单体(DMAEM)改性树脂粘接剂(DMAEM@RA)防治继发龋的应用前景。方法按粘接剂改性的方法,向树脂粘接剂中添加5%DMAEM,改性合成DMAEM@RA。以变异链球菌(Sm)和干酪乳杆菌(Lc)双菌种生物膜为研究模型,分别在树脂粘接剂(对照组)和DMAEM@RA(DMAEM@RA组)上进行培养。分别设置pH值为7.4、6.0、5.5和5.0的培养体系。通过定量PCR分析菌量,通过扫描电镜和胞外多糖染色分析DMAEM@RA对双菌种生物膜表型、菌量及胞外多糖的影响。实时荧光定量PCR研究DMAEM@RA对Sm致龋毒力基因的影响。结果DMAEM@RA在酸性条件下可显著降低Sm和Lc的菌量,特别是Lc。pH=5.0时,DMAEM@RA组共培养Sm菌量对数值[lg(CFU/ml)](7.58±0.01)显著低于对照组(7.87±0.03)(t=14.32,P<0.001),Lc菌量对数值[lg(CFU/ml)](7.29±0.04)亦显著低于对照组(7.93±0.15)(t=6.93,P=0.002)。扫描电镜下也可观察到DMAEM@RA组菌量减少,同时有细胞碎片出现。此外,DMAEM@RA可在酸性条件下显著减少双菌种生物膜的胞外多糖生物量,pH=5.0时DMAEM@RA组胞外多糖生物量值[(25.13±3.14)mm^(3)/mm^(2)]显著低于对照组[(42.66±7.46)mm^(3)/mm^(2)](t=3.75,P=0.020)。DMAEM@RA可在酸性条件下显著上调Sm的gtfB、gtfC基因表达,pH=5.0时gtfB、gtfC基因分别显著上调(14.64±0.44)和(2.99±0.20)倍(t=-42.74,P<0.001;t=-13.55,P<0.001)。结论DMAEM@RA在酸性条件下有较好的抑菌作用,具有防治继发龋发生发展的良好潜力。
Objective To explore the application prospect of a new pH-responsive tertiary amine monomer dodecylmethylaminoethyl methacrylate(DMAEM)modified resin adhesive(DMAEM@RA)in the prevention and treatment of secondary caries.Methods Five percents DMAEM was added to the resin adhesive to synthesize DMAEM@RA for modifying.Streptococcus mutans(Sm)and Lactobacillus casei(Lc)biofilms were cultured on resin adhesive and DMAEM@RA,respectively.The culture systems were set up at pH=7.4,6.0,5.5,and 5.0.The antimicrobial activity of DMAEM@RA was evaluated by quantitative PCR.The effects of DMAEM@RA on biofilm thickness,bacterial amount,and extracellular polysaccharides were studied by scanning electron microscope(SEM)and extracellular polysaccharide staining.Real-time fluorescence quantitative PCR was used to study the effect of DMAEM@RA on the expression levels of cariogenic genes in Sm.Results DMAEM@RA could significantly reduce the amount of Sm and Lc under acidic conditions,especially Lc.At pH=5.0,the logarithm value of co-cultured Sm bacteria[lg(CFU/ml)]in DMAEM@RA group(7.58±0.01)was significantly lower than that in control group(7.87±0.03)(t=14.32,P<0.001),and the logarithm value of Lc bacteria[lg(CFU/ml)](7.29±0.04)was also significantly lower than that in control group(7.93±0.15)(t=6.93,P=0.002).SEM observed that the bacteria decreased and the cell fragments appeared in DMAEM@RA group.In addition,DMAEM@RA significantly reduced the biomass of extracellular polysaccharides in the dual-species biofilm under acidic conditions.At pH=5.0,the biomass of extracellular polysaccharides in DMAEM@RA group[(25.13±3.14)mm^(3)/mm^(2)]was significantly lower than that in the control group[(42.66±7.46)mm^(3)/mm^(2)](t=3.75,P=0.020).DMAEM@RA could significantly up-regulate the expressions of gtfB and gtfC genes in Sm under acidic conditions.At pH=5.0,gtfB and gtfC genes were significantly up-regulated by(14.64±0.44)times and(2.99±0.20)times,respectively(t=-42.74,P<0.001;t=-13.55,P<0.001).Conclusions The DMAEM@RA has a good antibacterial effect under acidic conditions,demonstrating that it has a good potential to prevent the occurrence and development of secondary caries.
作者
张嘉欣
李博磊
周学东
程磊
Zhang Jiaxin;Li Bolei;Zhou Xuedong;Cheng Lei(Department of Cariology and Endodontics,West China Hospital of Stomatology,Sichuan University&State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases,Chengdu 610041,China)
出处
《中华口腔医学杂志》
CAS
CSCD
北大核心
2024年第1期45-53,共9页
Chinese Journal of Stomatology
基金
国家自然科学基金(82071106)。
关键词
龋齿
链球菌
变异
干酪乳杆菌
生物膜
叔胺单体
抗菌作用
继发龋
PH响应
Dental caries
Streptococcus mutans
Lactobacillus casei
Biofilms
Tertiary amine monomer
Antibacterial effect
Secondary caries
pH response
作者简介
通信作者:程磊,Email:chengleidentist@163.com,电话:028-85501439。
