[Bacterial recolonization in the guided regeneration of the inter-radicular periodontal tissues].

The present experimental study has been undertaken in order to analyse clinically and microbiologically the formation of new periodontal attachment in class II furcation lesions in mandibular molars, comparing healing after surgical conventional therapy and after guided periodontal tissue regeneration technique using non-resorbable membranes and evaluating at the same time, with cultural anaerobic technique, the influence on healing of the bacterial recolonization of some periodontally pathogenic species. Clinical results have demonstrated that, after therapy, may occur a certain discrepancy between soft and hard tissue regeneration and that the bone tissue shows a different pattern of apposition in the horizontal and vertical direction. Microbiological data have underlined the significance of surgical instrumentation in the guided inter-radicular periodontal tissue regeneration and have confirmed the necessity of maintaining the healing sites free from the main periodontal pathogens.