• bone replacement graft;
  • guided tissue regeneration;
  • intrabony defects;
  • periodontal regeneration;
  • randomized controlled clinical trial


Aim: This prospective multicenter randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of a guided tissue regeneration (GTR)/bone replacement material.

Materials and Methods: One hundred and twenty-four patients with advanced chronic periodontitis were recruited in 10 centers in seven countries. All patients had at least one intrabony defect of geqslant R: gt-or-equal, slanted3 mm. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CALs), probing pocket depths (PPDs), recession, full-mouth plaque scores and full-mouth bleeding scores (FMBS) were assessed.

Results: One year after treatment, the test defects gained 3.3±1.7 mm of CAL, while the control defects yielded a significantly lower CAL gain of 2.5±1.5 mm. Pocket reduction was also significantly higher in the test group (3.7±1.8 mm) when compared with the controls (3.2±1.5 mm). A multivariate analysis indicated that the treatment, the clinical centers, baseline PPD and baseline FMBS significantly influenced CAL gains. Odds ratios (ORs) of achieving above-median CAL gains were significantly improved by the test procedure (OR=2.6, 95% CI 1.2–5.4) and by starting with deeper PPD (OR=1.7, 1.3–2.2) but were decreased by receiving treatment at the worst-performing clinical center (OR=0.9, 0.76–0.99).

Conclusions: The results of this trial indicated that regenerative periodontal surgery with a GTR/bone replacement material offers an additional benefit in terms of CAL gains, PPD reductions and predictability of outcomes with respect to papilla preservation flaps alone.