Bacterial Species in Subgingival Plaque and Oral Bone Loss in Postmenopausal Women

Background: Oral bacteria are widely recognized in the etiology of periodontal disease. We investigated the prevalence of subgingival bacterial infection with eight species, tested associations between infection and oral bone loss, and assessed potential confounding factors and effect modifiers of those associations in a large community-based cohort of postmenopausal women.

Methods: A cross-sectional study of oral health and osteoporosis in 1,256 postmenopausal women recruited from the Buffalo, New York Women's Health Initiative Observational Study was conducted. Standardized dental radiographs were used to measure alveolar crestal height (ACH). Subgingival plaque samples were taken, and the presence of eight bacterial species was assessed by indirect immunofluorescent microscopy in each participant.

Results: The most prevalent infection was Streptococcus sanguis (59.5%), followed by Prevotella intermedia (43.4%), Tannerella forsythensis (37.9%), Capnocytophaga sp. (36.9%), Eubacterium saburreum (32.7%), Campylobacter rectus (17.4%), Porphyromonas gingivalis (15.1%), and Fusobacterium nucleatum (14.2%). Infections with P. gingivalis, T. forsythensis, P. intermedia, and C. rectus were associated with an increased likelihood of having oral bone loss as measured by ACH, even after adjustment for age, smoking, and income. The body mass index (BMI) was a modifier of this association. Overweight women with T. forsythensis infection were more likely to have oral bone loss (OR = 3.37; 95% confidence interval [CI]: 2.08 to 5.46) than normal weight (OR = 1.27; 95% CI: 0.82 to 1.98) or obese (OR = 1.26, 95% CI: 0.72 to 2.20) women with T. forsythensis infection.

Conclusions: The prevalence of specific bacterial infections was determined for a large group of postmenopausal women. Those with infection were more likely to have oral bone loss. Further studies should investigate potential modifying effects of BMI and/or inflammatory factors.