Nibali L, et al. - In this retrospective study, researchers evaluated the progression of periodontal disease and tooth loss in a cohort of patients with degree III furcation involvement (FI) treated with tunnelling by two periodontists in a private practice setting in the UK and in a hospital setting in Sweden. This investigation was carried out on 102 consecutive surgically-created tunnelled molars in 62 periodontitis patients and followed up at least 5 years later. Data reported that overall tooth loss for tunnelled molars was 29.4%. Multivariate analysis showed statistically significant connections with tooth loss for ‘irregular supportive periodontal therapy (SPT)' and age. Tooth loss occurred only in the Swedish sample, not regularly undergoing SPT. Following tunnelling surgery, a high rate of tooth loss was observed, primarily in patients not undergoing regular support therapy. Clinical studies should be performed to compare tunnelling with other treatment options for advanced FI in SPT patients.