The furcation tunnel preparation-A prospective 5-year follow-up study.

AIM: The aim of this study was to prospectively follow furcation tunnelled molars over a 5-year period of supportive periodontal therapy (SPT) and to identify factors associated with tooth loss. MATERIALS AND METHODS: A total of 32 patients with 42 furcation tunnelled molars (all class III prior tunnelling) were recruited upon commencing SPT following active periodontal therapy. Clinical registrations, bacterial samples and standardised radiographs were taken at baseline, year 1 (no radiographs), 2 and 5. Total viable counts, total streptococci, Streptococcus sanguinis and mutans streptococci (MS) were identified through culture, a panel of periodontal pathogens through the checkerboard technique. RESULTS: After 5 years, 29 molars (69%) were still in function. Of the lost molars, eight were upper and five lower molars. Recurrent periodontal disease and caries were reasons for tooth loss. A multilevel regression analysis showed that a smoking habit, bleeding on probing and the presence of MS in furcations were associated with an increased risk of tooth loss. CONCLUSIONS: Furcation tunnelled molars can in most cases be kept over a period of 5 years of SPT. A smoking habit, baseline bleeding scores and the presence of MS in the furcation were risk indicators for loss.