Subgingival Microbiome Profiles in Bulgarian Children Aged 10–14 with Gingival Inflammation and Healthy Periodontium: A Targeted PCR Study

The subgingival microbiome is a critical component of the oral microbiota and plays a central role in pediatric periodontology. This study investigated differences in periodontopathogen profiles in children with gingival inflammation compared to healthy controls using real-time PCR, with a focus on the microbial complexes defined by Socransky. A total of 73 children (ages 10-14) underwent comprehensive periodontal assessment, including assessments of general health status, the O'Leary hygiene index (HI), gingival condition, and the papillary bleeding index (PBI). Subgingival plaque samples were analyzed using real-time PCR to identify key bacterial species associated with gingival health and disease. Highly pathogenic periodontopathogens such as <i>Aggregatibacter actinomycetemcomitans</i>, <i>Porphyromonas gingivalis</i>, <i>Treponema denticola</i>, and <i>Eubacterium nodatum</i> were absent in healthy subjects. In contrast, <i>Tannerella forsythia</i> was significantly more frequently detected in children with gingival inflammation (<i>p</i> < 0.05). The most abundant species in the inflammation group were <i>Prevotella intermedia</i> and <i>Capnocytophaga gingivalis.</i> Children with gingival inflammation exhibit a distinct subgingival microbiome profile characterized by an increased presence of specific periodontopathogens, including a higher prevalence of red complex species as defined by Socransky. However, the cross-sectional nature of this study limits the ability to establish causal relationships.