Experimental gingivitis during pregnancy and post-partum: clinical, endocrinological, and microbiological aspects

The purpose of this study was to assess whether an intensive oral hygiene regimen practised during pregnancy results in a clinically healthy gingival state, and to assess whether experimentally-induced gingivitis differs in severity during pregnancy as compared to post-partum. In addition, levels of black-pigmented Gram negative anaerobes at subgingival and oral mucosal sites and plasma concentrations of free estrogens and prosterone were determined. These parameters were studied during a 14-day episode of experimental gingivitis induced in the 25th week of pregnancy, and again 6 months post-partum. The subjects were selected on shallow pockets < or = 4 mm and interproximal loss of attachment not exceeding 2 mm. As a result of controlled oral hygiene, the gingival condition improved both during pregnancy and post-partum. At day 0 during pregnancy, however, gingival swelling, redness, and bleeding on probing were found to be higher than post-partum. Free plasma levels of estrogens and progesterone were found to be normal throughout the study. It was hypothesized that the increase in severity of gingival symptoms during pregnancy reflect microvascular physiologic effects of increased levels of these hormones. During pregnancy, more swelling, redness and bleeding on probing developed during experimental gingivitis than post-partum, whereas the amount of plaque was similar in both phases. This suggests that as a result of dental plaque accumulation, gingival inflammation develops superimposed on pregnancy-associated physiologic alterations. Microbiological evaluation showed that the mean proportions of Prevotella intermedia in subgingival plaque increased during experimental gingivitis performed during pregnancy, whereas no increase of this micro-organism was found post-partum.