Quantity, diversity and complexity of subgingival microorganisms in children with plaque-induced gingivitis

Periodontal diseases, as an important part of oral pathology, have their distinctive characteristics when affecting children and young adults. The aim of this study was to identify the subgingival microorganisms through the use of real-time polymerase chain reaction (PCR) in children at the age of puberty who have plaque-induced gingivitis. The subjects of observation were 60 children, aged between 10 and 14, who did not have any systemic diseases: 30 without gingivitis (up to 25% PBI); 30 with clinically diagnosed plaque-induced gingivitis (over 25% PBI). The clinical status of each child was registered using a custom-made medical card. Gingival sulcus samples were taken with a paper pin from six teeth for real time PCR identification based on nine control strains (a comprehensive sample). Samples were transported in standardised containers. The results showed that the average quantities of the tested microorganisms were between 1 × 102 and 1 × 105 microorganisms per sample. There was a trend towards a putative increase in the average quantities of microorganisms, except for Fusobacterium nucleatum, in children with gingivitis as compared to healthy children. There were associations with up to four microorganisms in healthy children. In children with gingivitis, there was greater diversity of microorganisms, with half of the children from this group having associations with 5–7 microorganisms. The subgingival microflora became more complex in children with gingivitis: the predominant group were microorganisms from the red complex (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia) and the frequency of microorganisms from the orange complex also increased