Twenty-Five-Year Follow-Up of Individuals With Intact Periodontium and Differing Susceptibility to Experimentally Induced Gingival Inflammation

Aim: To evaluate the periodontal condition of individuals with different susceptibility to dental biofilm–induced gingivitis 25 years after their classification as high responders (HR) or low responders (LR) to plaque. Methods: Forty-eight systemically and periodontally healthy young adults who participated in a 21-day experimental gingivitis trial in 2000–2001 and exhibited either markedly pronounced (HR, n = 24) or milder (LR, n = 24) gingival inflammation despite similar supragingival plaque exposure were invited to a follow-up visit, during which a periodontal diagnosis was established. Results: Nine LR and eight HR individuals accepted to participate. Among the LR participants, six (67%) were diagnosed as periodontally healthy or with gingivitis, whereas 100% of HR participants were diagnosed with periodontitis (p = 0.009). Compared to LR, HR individuals presented higher bleeding on probing score (39.5% ± 13.8% vs. 15.0% ± 10.1%; p = 0.003) as well as a higher proportion of visibly inflamed sites (p < 0.001). Intergroup differences could not be explained by other variables, including full-mouth plaque score, oral hygiene habits or adherence to supportive care. Conclusions: This study, based on a very limited sample size and therefore hypothesis-generating rather than confirmatory, suggests that susceptibility to biofilm-induced gingivitis may help identify individuals at different risks of periodontitis.