Effect of a novel pH-responsive tertiary amine monomer dodecylmethylaminoethyl methacrylate modified resin adhesive on biofilm formation of Streptococcus mutans and Lactobacillus caseiin vitro
10.3760/cma.j.cn112144-20231018-00206
- VernacularTitle:pH响应性新型叔胺单体改性树脂粘接剂对变异链球菌和干酪乳杆菌体外双菌种生物膜形成的影响
- Author:
Jiaxin ZHANG
1
;
Bolei LI
;
Xuedong ZHOU
;
Lei CHENG
Author Information
1. 四川大学华西口腔医院牙体牙髓病科 口腔疾病防治全国重点实验室 国家口腔医学中心 国家口腔疾病临床医学研究中心，成都 610041
- Keywords:
Dental caries;
Streptococcus mutans;
Lactobacillus casei;
Biofilms;
Tertiary amine monomer;
Antibacterial effect;
Secondary caries;
pH response
- From:
Chinese Journal of Stomatology
2024;59(1):45-53
- CountryChina
- Language:Chinese
-
Abstract:
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.
