A 5-year prospective study on regenerative periodontal therapy of infrabony defects using minimally invasive surgery and a collagen-enriched bovine-derived xenograft.

RPT failed in 24% of the patients after 5 years. Regression analyses demonstrated a significant impact of plaque and patients' compliance on the long-term outcome. Only patients with perfect oral hygiene and excellent compliance should be considered for RPT. Patients should not be treated too soon following initial therapy, since compliance can only be reliably assessed after sufficient follow-up.