Background & Aims: Gingival enlargement is a known side effect and one of the most cumbersome complications of Cyclosporine A (CsA). It affects patient's life style due to the effects of this immunosuppressor on esthetics and function of masticatory tract. Since there was not enough available data in this regard in Iran, this study was conducted to determine the prevalence and risk factors of CsA-induced gingival enlargement.

Materials & Methods: A total of 200 patients (mean age 39.7±13.2) who met the inclusion criteria of the study were selected from 1320 renal transplanted patients of Imam Khomeyni General Hospital. All subjects were dentate and took CsA for at least 12 months prior to the study. Factors such as age, gender, CsA dose, plasma concentration duration of CsA, plaque, and gingival indices were evaluated to gingival enlargement.

Results: Thirty-five percent of the subjects showed various degrees of gingival enlargement. Multiple regression analysis revealed an independent association between gingival enlargement and either plasmatic concentration of CsA or plaque index (p<0.05). The other variables failed to show a significant relationship to gingival enlargement.

Conclusion: The prevalence of CsA induced gingival enlargement is slightly greater than the mean prevalence. Changing the drug and oral hygiene reinforcement may lower the prevalence or the intensity.