Objectives: To investigate effects of nicotine on biofilm formation of Streptococcus mutans isolates from oral washes of smoker and non-smoker human subjects.

Materials and methods: This study was conducted using 60 S. mutans isolates with three S. mutans isolates collected from oral washes of ten smoking subjects and ten from non-smoking subjects. Biofilm was formed by culturing each S. mutans strain (10 μl) in 190 μl of TSB supplemented with 1% sucrose (TSBS) containing 0, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0, and 32.0 mg/ml of nicotine for 24 h in 5% CO₂ at 37°C in 96 well microtiter plates. The absorbance values of biofilm were measured at 490 nm in a microplate spectrophotometer.

Results: There was a significant effect (p-value < 0.05) of nicotine concentrations and smoking on the growth of biofilm, planktonic cells, and total absorbance, for all strains of S. mutans. Isolates from smokers had significantly more biofilm at 0–16 mg/ml of nicotine compared to those from non-smokers (p-value < 0.0001).

Conclusion: S. mutans smoker isolates are more affected by high nicotine concentrations than non-smoker isolates.

Clinical Relevance: The use of nicotine products increases the growth of S. mutans and may place tobacco users at risk for dental decay.

目的：研究尼古丁对吸烟者和非吸烟者口腔洗液中分离出的变形链球菌生物膜形成的影响。

材料和方法：本研究使用 60 株 变形链球菌分离株和从 10 名吸烟受试者和 10 名非吸烟受试者的口腔洗液中收集的3 株变形链球菌分离株进行。通过在 190 μl 补充有 1% 蔗糖 (TSBS) 的 TSB 中培养每种变形链球菌菌株 (10 μl) 来形成生物膜，其中含有 0、0.25、0.5、1.0、2.0、4.0、8.0、16.0 和 32.0 mg/ ml在 96 孔微量滴定板中，在 5% CO _{2中于 37°C 下对尼古丁进行 24 小时。}在微孔板分光光度计中在 490 nm 处测量生物膜的吸光度值。

结果：对于所有变形链球菌菌株，尼古丁浓度和吸烟对生物膜、浮游细胞和总吸光度的生长有显着影响（p 值 < 0.05）。与非吸烟者相比，吸烟者的分离物在 0–16 mg/ml 的尼古丁浓度下具有明显更多的生物膜（p 值 < 0.0001）。

结论：与非吸烟者分离株相比，吸烟者分离的变形链球菌更容易受到高尼古丁浓度的影响。

临床相关性：使用尼古丁产品会增加变形链球菌的生长，并可能使烟草使用者面临蛀牙的风险。