Evaluation of the effect of tooth vitality on regenerative outcomes in infrabony defects

Background, aims. This investigation was designed to evaluate the null hypothesis of no differences in GTR outcomes in intrabony defects at vital and successfully root-canal-treated teeth. Method: 208 consecutive patients with one intrabony defect each were enrolled. Based on tooth vitality, the treated population was divided at baseline into 2 groups: one with 41 non-vital teeth and the other with 167 vital teeth. The 2 groups were similar in terms of patient and defect characteristics. Results: A slight unbalance in terms of depth of the intrabony component was observed in the non-vital group compared to the vital group (6.9 +/-2.1 nm versus 6.2 +/-2.3 mm, p=0.08). All defects were treated with GTR therapy. At 1 year, the non-vital and the vital groups showed a clinical attachment level (CAL) gain of 4.9 +/-2.2 mm and of 4.2 +/-2 mm, respectively. The difference was statistically significant (p=0.03). To correct for the baseline unbalance in defect depth, data were expressed as a % of clinical attachment level gains with respect to the original intrabony depth of the defect. % CAL gains were 72.8 +/- 42.2% and 73 +/- 26.4% for vital and non-vital teeth, respectively: the difference was not statistically significant (p=0.48). Average residual pocket depths were 2.8 +/-1 mm in the vital and 2.8 +/-0.9 mm in the non-vital group. Tooth vitality was assessed at baseline, at 1-year and at follow-up (5.4 +/-2.8 years after surgery): all teeth vital at baseline were still vital at follow-up with the exception of 2 teeth that received endodontic treatment for reconstructive reasons and for caries. At follow-up visit, the difference in CAL with respect to 1-year measurements was -0.9 +/-0.8 mm in the vital group and -0.7 +/-0.8 mm in the non-vital group, indicating stability of the regenerated attachment at the majority of sites. Conclusions: Data from this study demonstrate that root canal treatment does not negatively affect the healing response of deep intrabony defects treated with GTR therapy; furthermore GTR therapy in deep intrabony defects does not negatively influence tooth vitality.