Establishment of effective personal oral hygiene is a widely accepted prerequisite for therapy andprevention of periodontal disease. Long-term clinical studies have, however, to date not been ableto deliver definitive proof of a preventive periodontal effect of good oral hygiene beyond gingivitisreduction. Data derived from more recent studies have fundamentally challenged the validity of thecentral role of oral hygiene in periodontal prevention. Contrary to former concepts, the driving forcebehind the development of pro-inflammatory dental plaques is not a lack of oral hygiene, but rathera malfunction or overreaction of the oral immune system. Good oral hygiene can only, to a very lim-ited extent, alleviate the effects of such immunological deficiencies on the integrity of the periodon-tium, and it is therefore essential in periodontal patients to supplement it with regularly performedprofessional preventive measures.
Keywords: biofilm, gingivitis, immune system, oral hygiene, periodontitis