Mechanical reduction of bacteria
All hard and soft deposits are removed from the tooth and root surfaces by means of subgingival scaling and root planing (SRP). The aim of this is to reduce the amount of plaque below a critical threshold. It should be noted that supragingival cleaning is not suitable on its own for periodontal therapy. Only subgingival instrumentation leads to a fundamental change in the microbial flora, resulting in regression of the inflammation. The success of this measure depends largely on the effectiveness of plaque removal, however. If any live bacteria remain in niches, reinfection occurs rapidly. Experts therefore recommend that SRP should be performed according to the “full-mouth disinfection” principle. Ideally, this will involve the anti-infective measures, including subgingival curettage of all quadrants, being carried out in a single session. This is the best possible way of preventing recolonization of areas that have already been cleaned. Alternatively, subgingival cleaning can also be carried out on 2 consecutive days.