Objectives: The aim of the present study was to test the hypothesis that use of oral hormonal contraceptives causes changes in the oral microbiota during the menstrual cycle.
Study design: Bacterial samples were collected weekly during a full menstrual cycle. Forty systemically and periodontally healthy women of childbearing age with a Community Periodontal Index of Treatment Needs (CPITN) score <= 1 using (n=20) or not using hormonal contraceptives (n=20) were studied. Seventy-three different species were analysed by checkerboard DNA-DNA hybridisation assay.
Results: Most prevalent in non-contraceptive users at the time of menstruation were Fusobacterium periodonticum, Fusobacterium nucleatum nucleatum, Leptotrichia buccalis and Gardnerella vaginalis. No differences in bacterial levels as an effect of age or an effect of menstrual cycle in noncontraceptive and contraceptive users were found. Trends of higher counts of only G. vaginalis were found at the time of menstruation in non-contraceptive users (P<0.02) compared with 3-week samples. No differences were found in comparison to other time points. At menstruation, 15.9% of the sites in women in the group not using oral hormonal contraceptives were positive (>=1.0 x 105 cells) for Prevotella intermedia, which changed to 16.1% at day 21 following the onset of menstruation. The corresponding values for P. intermedia in the group using oral hormonal contraceptives were 14.6% and 17.9% respectively.
Conclusions: No changes in subgingival bacteria as an effect of the use of hormonal contraceptives could be found. A high proportion of the women were identified with bacteria not commonly studied in subgingival samples. These results may not be similar in subjects who are not periodontally healthy.
Keywords: case control study, checkerboard DNA-DNA hybridisation, hormonal contraceptives, menstrual cycle, oral microbiota