OBJECTIVETo investigate the effect of putative periodontopathogenic bacteria on the development of drug-induced gingival overgrowth (GO) in renal transplant recipients.

METHODSA total of 57 patients undergoing cyclosporine treatment were divided into two groups according to GO index: with gingival overgrowth (group A) and without gingival overgrowth (group B). Demographic, pharmacologic and periodontal data were analyzed. The real-time polymerase chain reaction (PCR) method was used to detect and quantify five putative periodontopathogenic bacteria, including Porphyromonas gingivalis (Pg), Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia (Pi), Treponema denticola (Td) and Tannerella forsythia (Tf) in subgingival samples. Moreover, the relationship between the bacterial amount and the severity of GO was analyzed.

RESULTSGroup A presented a significantly higher plaque index, sulcus bleeding index and probing depth than group B (P < 0.01). The occurrences of Pg, Td, and Tf in the group A (96%, 82% and 89%) were significantly increased compared with those in the group B (69%, 55% and 66%, P < 0. 05), respectively. The prevalence of Pg, Td, and Tf in the group A (79%) was markedly higher than that in the group B (38%, P < 0.01). The bacterial amount of Pg, Td, Tf and Pi were enhanced along with the severity of GO. However, the bacterial amount of Aa had no difference between two groups.

CONCLUSIONSPg, Td, and Tf may have a significant relationship with the development of GO.