Association of Gene Expression of Porphyromonas Gingivalis with Cigarette Smoking and Periodontal Pocket Depth

Periodontal disease is a complex disease that involves many bacteria including Porphyromonas gingivalis (P. gingivalis) in its pathophysiological process. We sought to analyze and correlate levels of P. gingivalis based on smoking status and periodontal pocket depth in periodontitis subjects. This was a cross-sectional study of smokers aged 35 to 60 years with periodontitis. Clinical data (periodontal pocket depth), smoking status information (pack-years), and Gingival Crevicular Fluid (GCF) samples were collected. The gene expression of P. gingivalis in GCF was measured by quantitative real-time polymerase chain reaction (qPCR). Spearman correlation testing between P. Igingivalis in GCF and periodontal pocket depth and smoking status was completed. P. gingivalis findings in shallow pocket versus deep pocket populations (P=0.72) and nonsmokers, moderate smokers, and heavy smokers (P=0.258) showed no significant difference. No significant correlation was present between P. gingivalis proportion and periodontal pocket depth (r=0.128; P=0.552), while the correlation between P. gingivalis and smoking status was moderate but statistically insignificant (r=0.488; P=0.016). Periodontal pocket depth and smoking status are not primary factors influencing the periodontal microflora, although variable gene expression of P. gingivalis was observed between groups.