Oxygen Tension (pO2) in Untreated Human Periodontal Pockets

T he purpose of this study was to assess the oxygen tension in untreated human periodontal pockets and test the hypothesis that the subgingival environment is anaerobic in nature. Twenty‐six patients with advanced chronic inflammatory periodontal disease participated. A total of 111 untreated pockets, 5 to 10 mm in depth, were selected for the pO 2 measurements. Pocket depths, Plaque‐Index and Gingival‐Index were recorded. The pO 2 at the base of the 111 pockets ranged from 5 to 27 mm Hg, with an average of 13.3 mm Hg (1.8% 02). Mean pocket depth was 6.9 mm. Moderately deep pockets (5–6 mm) had a mean p02 of 15.0 mm Hg, whereas deep pockets (7–10 mm) showed a significantly lower pO 2 of 11.6 mm Hg. No correlation was found between the pO 2 and the Plaque‐Index. Higher Gingival‐Index scores tended to be associated with higher pO 2 values. The pO 2 in untreated periodontal pockets was low. However, it does not represent a completely anaerobic environment. Deep pockets contained less oxygen than moderately deep sites.