Single cone versus carrier-based obturation using a premixed bioceramic sealer in postgraduate master cohort: a 36 months retrospective evaluation

Aim To evaluate 36-month clinical outcome and occurrence of sealer apical extrusion events of teeth obturated with a premixed CaSi based sealer associated with a single cone technique or carrier-based technique. Methodology In this retrospective cohort study, consecutive healthy patients were treated by a postgraduate master cohort. Teeth were shaped with NiTi rotary or reciprocating instruments, irrigated with 5% NaOCl and 10% EDTA, final irrigation with sterile water. Root canals were obturated with a premixed bioceramic-based sealer (NeoSealer Flo, Avalon Biomed, Houston, TX, USA) using either a warm carrier-based technique (Thermafil, Dentsply, Konstanz, Germany) or a cold single-cone technique. Patients were included in a recall program and teeth were examined at 3, 6, 24 and 36 months. Clinical and radiographic data were obtained and the following parameters were evaluated: preoperative Periapical Index (PAI) score and signs/symptoms, PAI score at follow-up. Teeth were considered 'healthy' (PAI <= 2, no signs/symptoms) or with "endodontic lesion" (PAI >= 3, signs/symptoms present, retreated). Two calibrated examiners assessed outcomes blinded to preoperative status. Chi-square test evaluated the outcome between these two obturation techniques. Sealer Apical extrusion typologies and radiographic modifications were analysed through a computerized methodology on periapical radiographs. Results A total of 53 root canal treatments (48 subjects, mean age 45.4 +/- 12.1 years) with a minimum 36 months follow-up were analysed. Of these, 29 were filled with single cone technique, while 24 were obturated with a carrier-based technique. At 36-month evaluation, healing rate was 88% and 93% with regards to carrier-based or single cone technique with no statistical differences (P>0.050). Apical extrusion was observed in 18/24 teeth of patients filled with carrier-based technique (75%) and 14/29 in teeth with cold technique (48.2%). Mean extrusion size was 1.49 mm. Significantly higher extrusion (in mm) was observed in teeth with PAI >= 3 and in Carrier-based group. Radiographic modification of apically extruded sealer was observed in 5 of 32 extruded cases (15.6%). Conclusions Clinical outcome shows a high rate of survived and healed teeth with both type of obturation techniques. Apical extrusion of the sealer can be frequent when using carrier-based technique or in presence of large diameters and periapical radiolucencies.