Subgingival Oxygen Levels and Smoking

Bacterial colonization of the gingival crevice is critical to the development and progression of periodontal disease. The crevicular environment plays an important role in determining the nature of the bacterial infection. Since most pathogenic periodontal microorganisms thrive in oxygen-poor environments and smoking could potentially influence oxygen availability in the oral cavity and within the crevice, Hanioka et al of Osaka University, Japan, studied oxygen levels in the periodontal tissues and crevices of smokers and non-smokers.

Patients with mild to moderate periodontitis were studied. Included were 27 smokers (mean age 51.2 years) and 34 non-smokers (mean age 45.4 years). Oxygen present in the periodontitum was determined by the oxygen tension in the crevice and the oxygen saturation in the adjacent periodontal tissues. Clinical measures included probing depth, gingival inflammation and supragingival plaque accumulation. The deepest palatal site anterior to the molars was selected for study in each patient.

Gingival inflammation, probing depth and oxygen saturation of the tissues were similar in the 2 groups. Plaque accumulation was greater in smokers versus non-smokers; this difference approached but did not reach statistical significance (p = 0.08).

Oxygen tension in the crevice was lower in the smokers than non-smokers (p < 0.0001). There was also a strong relationship between oxygen tension and probing depth; as the probing depth increased, oxygen tension in the crevice decreased.

This study demonstrated reduced oxygen tension in gingival crevices of smokers versus non-smokers. This finding suggests that the crevices of smokers may favor colonization by pathogenic bacteria that thrive in environments poor in oxygen. Further, the reduced oxygen tension may be associated with impaired wound healing in the periodontal tissues of smokers.     

Hanioka T, Tanaka M, Takaya K, et al.

• Association of Smoking and Periodontal Disease
• Smoking as a Risk Factor for Periodontitis
• Smoking and Periodontal Bacteria
• Bone Mineral Density, Smoking and Alveolar Bone Loss