Periodontal regeneration has been a clinical reality for at least 2 decades. Recent meta-analyses of randomized controlled clinical trials indicated that at least two periodontal regenerative approaches, the application of barrier membranes and the application of enamel matrix proteins, provide significant additional benefits for the treatment of intrabony defects as compared to access flap alone. The magnitude of the observed benefits was 1.1 to 1.3 mm of additional clinical attachment level (CAL) gain. Furthermore, the outcomes of regenerative periodontal surgery include significant reductions of residual probing depths. A critical issue to properly understand the significance of periodontal regeneration is the longevity of the observed outcomes. Some initial reports have indicated that the regenerated attachment could be maintained for periods up to 5 years. Further investigations indicated that regenerated attachment was no more susceptible to periodontal breakdown than procedures expected to heal with repair rather than regeneration. Patient based factors such as cigarette smoking, lack of compliance with a periodontal recall system, and carrying allele 2 for specific polymorphisms in the interleukin(IL)-1 gene complex have been associated with reduced longevity of the regenerative outcomes.

The purpose of this investigation was to assess: 1) the long-term survival of GTR treated sites in terms of CAL stability and tooth loss; and 2) the associationbetween survival and patient variables.