A root canal filling per se does not have a significant negative effect on the marginal periodontium

Aim: To evaluate the periodontal status of single-rooted endodontically treated teeth (ET), correcting for patient- and tooth-related factors. Methods: Clinical parameters (BoP,PD,CAL) of 240 ET and 240 contralateral vital teeth (VT), before and after non-surgical periodontal treatment, were extracted retrospectively from the journals of 175 patients. Possible patientrelated (age, gender, smoking status) and tooth-related (interproximal restoration, root canal filling’s extent, post, tooth type) confounders were tested. Results: At baseline, frequency of BoP at an interproximal site at ET versus VT was 70.4% versus 65.0%, respectively. The frequency of teeth with interproximal PD ≥5 mm and CAL ≥5 mm was 47.9% versus 42.9% and 54.6% versus 49.6% at ET and VT, respectively. Interproximal PD and CAL at ET versus VT were 3.86 versus 3.61 mm and 4.11 versus 3.95 mm. After correcting for tooth-related factors, no significant differences were observed between ET and VT. An improper restoration had a significant (p < 0.001) negative effect on BoP [OR 3.49 (95%CI: 1.95–6.27)], PD [36.81% (95%CI: 18.52–57.92)] and CAL [27.01% (95% CI: 12.67–43.18)]. No significant differences between ET and VT were observed regarding clinical outcome of non-surgical periodontal therapy. Conclusions: Presence of a root canal filling per se does not have a significant negative influence on the marginal periodontium, when correcting for the quality of the interproximal restoration