The influence of smoking habits on the salivary pH value

Objectives: Saliva plays an important role in oral homeostasis by maintaining the pH value of the oral cavity in the range between 6.1 and 7.8. A lower salivary pH presents a risk factor for various oral diseases. Nicotine from cigarettes reduces the bicarbonate buffer secretion, which leads to a decrease in the salivary pH. The objective of the current research was to estimate the influence of smoking habits on salivary pH value. Material and Methods: Sixty subjects participated in the study and were divided into two groups: Smokers and non-smokers. Each participant in the study independently filled out the questionnaire concerning their medical condition, medication, and smoking habits. From each participant, unstimulated saliva was collected under resting conditions using the simple drooling method. The paper strip was dipped into the saliva for 5 s, removed, and then, after 15 s, the color change was matched directly with the scale provided with the strip, according to the manufacturer’s instructions. Data were analyzed using the Wilcoxon two-sample and Kruskal–Wallis tests, at a significance level of P ≤ 0.05. Results: The results showed a significant decrease ( P < 0.001) in the mean salivary pH in smokers (5.97 ± 0.27) compared to non-smokers (6.92 ± 0.17), with no difference in salivary pH found between subjects smoking standard cigarettes and those smoking electronic cigarettes ( P = 0.6306). The subjects consuming tobacco for more than 35 years had a significantly lower mean salivary pH ( P = 0.0003). No significant difference was found in the salivary pH based on the daily number of smoked cigarettes ( P = 0.7338). Conclusion: Long-term smoking of cigarettes significantly reduces the salivary pH. The consumption of standard and electronic cigarettes reduces the salivary pH without a significant difference, whereas the daily number of cigarettes had no effect.