The 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 pO2 measurements. Pocket depths, Plaque‐Index and Gingival‐Index were recorded. The pO2 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 pO2 of 11.6 mm Hg. No correlation was found between the pO2 and the Plaque‐Index. Higher Gingival‐Index scores tended to be associated with higher pO2 values. The pO2 in untreated periodontal pockets was low. However, it does not represent a completely anaerobic environment. Deep pockets contained less oxygen than moderately deep sites.

The predominance of anaerobic bacteria in subgingival plaque samples suggests that the pocket environment is anaerobic. In the present investigation, a small oxygen tension (PO2) electrode was inserted into the base of the pocket and the P02 was recorded. In addition, the plaque in these pockets was examined culturally and microscopically. The oxygen tension at the bottom of 36 pockets (5 to 10 mm in depth) ranged from S to 27 mmHg (1 mmHg = 133.3 Pa) with a mean value of 13.3 mmHg. Moderate pockets (5 and 6 mm) exhibited a mean PO2 of 15.7 mmHg, which was significantly higher than the 12.0 mmHg found in the deeper pockets. The deep pockets had higher percentages of spirochetes and Bacteroides intermedius, whereas the moderate pockets had elevated proportions of Actinomyces naeslundii and Streptococcus mutans. The sites with oxygen tensions equal to or less than 15 mmHg had significantly higher percentages of spirochetes, whereas the microaerophilic Capnocytophaga species were found in pockets with a P02 greater than 15 mmHg. The presence of bleeding in the pocket was associated with higher proportions of B. intermedius, Capnocytophaga sp., and A. naeslundii. These P02 readings of periodontal pockets indicated that there is a spectrum Of PO2 values which seem to define, in a general way, the microbiological composition of the pocket.on July 16, 2020 by guest http://iai.asm.org/ Downloaded from RESULTSThe PO2 at the bottom of the untreated pockets ranged from 5 to 27 mmHg, with a mean value of 13.3 mmHg. The 95% confidence limit for the mean P02 was between 12.3 and 14.2 INFECT. IMMUN.on July 16, 2020 by guest http://iai.asm.org/ Downloaded from

No abstract

We compared the microbiological and chemical composition of dental plaque from subjects with hereditary fructose intolerance who restrict their dietary sugar intake with that of control subjects who do not. The two groups showed no significant differences in chemical composition of plaque: the mean protein, carbohydrate, calcium, magnesium, and phosphate contents were similar. Dental plaque from both groups contained similar numbers of total colony-forming units per microgram of plaque protein, and Streptococcus sanguis, an indigenous nonpathogen, was isolated with equal frequency from plaque samples of both groups. However, potentially odontopathic Streptococcus mutans and Lactobacillus were isolated three to four times more frequently from plaque samples of control subjects than from plaque samples of subjects with hereditary fructose intolerance. Clearly, diet (sucrose in particular) influences the colonization and multiplication of specific cariogenic organisms in dental plaque.