Detection rate of Actinobacillus actinomycetemcomitans on the permanent 1st molars of primary school children in Taiwan by polymerase chain reaction

Background, aims: Actinobacillus actinomycetemcomitans (Aa) has been implic ated as the putative micro-organism for localized juvenile periodontitis (L JP), The most distinct clinical features of LJP include severe angular bony defects of the mesial sides of permanent first molars and the onset of dis ease during puberty. Currently, no large-scale studies have been performed which address the change in detection rates of Aa on the mesial sides of pe rmanent Ist molars following eruption and up to puberty. Method: In this study, subgingival plaque samples were taken from the mesia l pockets of 2 randomly selected permanent Ist molars from 328 primary scho ol children and 50 adult staff, and analyzed by polymerase chain reaction ( PCR) to detect Aa, Results: The results showed a 5.5% prevalence rate of Aa which increased af ter the eruption of Ist molars and peaked near puberty. There were no signi ficant differences in the detection rates of Aa among different groups in t erms of gender, plaque index (PII), and gingival index (GI), however, the h igher detection rates of Au were significantly associated with increased pr obing depths at p<0.05. Conclusion: PCR analysis of the subgingival plaques demonstrated a prevalen ce of Ao which peaked near puberty, suggesting that Aa may be important for LJP in Taiwan.