Background: Severe gingival overgrowth (GO) is induced in patients taking cyclosporin A (CsA) following organ transplantation. Determining which patient will develop GO is still not possible. The purpose of this study was to establish an association between CsA and gingival overgrowth in heart transplant patients taking into account periodontal and microbiological conditions.

Methods: Thirty patients (10 female, 20 male; range: 13 to 67 years; mean age: 44.89) undergoing CsA treatment were evaluated using the gingival index (GI), plaque index (PI), probing depth (PD), and clinical attachment level (CAL). Subgingival samples collected from the deepest site of each quadrant and saliva samples were submitted to microbial analysis. All patients had at least 12 teeth. Exclusion criteria were the use of antibiotics and/or having undergone periodontal treatment 6 months prior to the study. Patients were divided in two groups: with gingival (GO+) and without gingival overgrowth (GO−).

Results: There were no statistically significant differences between the GO+ and GO− groups when CsA dosage, time since transplant, GI, PI, PD, and CAL were compared. Microbiological examination of the subgingival samples detected the following microorganisms: Actinobacillus actinomycetemcomitans (23%), Porphyromonas gingivalis (36%), Prevotella intermedia (93%), Fusobacterium sp. (66%), Campylobacter rectus (30%), Micromonas micros (66%), enteric rods (0%), and yeasts (30%). A positive association between M. micros and the GO+ group was found (P <0.001). Yeasts were detected in 30% of the subgingival and saliva samples.

Conclusions: Clinical parameters were not sufficient to determine which patients would develop GO. However, colonization by M. micros might play a role in the etiology of GO. J Periodontol 2004; 75:918–924.