This randomized clinical trial aimed to evaluate postoperative pain following the use of bioceramic and epoxy resin-based root canal sealers in combination with the continuous wave of condensation technique (CWCT), addressing a clinically relevant gap in the literature.

Seventy-two patients with single-rooted teeth diagnosed with asymptomatic irreversible pulpitis and presenting without preoperative pain were randomly assigned to three groups according to the root canal sealer used. The teeth were treated using AH Plus, TotalFill BC, or Bio-C Sealer. All endodontic procedures, including post-endodontic restorations, were completed in a single visit using the continuous wave of condensation technique (CWCT), following standardized preparation and irrigation protocols.

Patients were provided with a Visual Analog Scale (VAS) form and were instructed to record their pain intensity on a scale from 0 to 10 at 6, 24, 48, and 72 hours, and 7 days after root canal treatment. Patients were recalled on day 7, and the completed VAS forms were collected.

The null hypothesis was that the type of root canal sealer would have no statistically significant effect on postoperative pain levels. The alternative hypothesis was that, regardless of sealer type, the incidence and severity of postoperative pain would be significantly higher within the first 24 hours following treatment compared with the other assessment time points.

A total of 72 participants who presented to the Department of Endodontics, Faculty of Dentistry, Dicle University, with the need for root canal treatment and met the predefined inclusion and exclusion criteria were included in this study. Root canal treatment was performed on single-rooted, single-canaled teeth. Prior to treatment, all participants were informed about the study and provided written informed consent. Following the administration of local anesthesia (2% lidocaine with 1:80,000 epinephrine), the tooth was isolated using a rubber dam, caries and existing restorations were removed with high-speed diamond burs under water cooling, and an access cavity was prepared. Pulp vitality was confirmed by observing bleeding from the canal orifice.

Working length was determined using a #15 K-file in conjunction with the integrated apex locator of the EndoRadar Pro motor and was radiographically confirmed at 0.5 mm short of the radiographic apex. Root canals were prepared using the T-Endo MUST (Dentac, Istanbul, Türkiye) reciprocating file system driven by the EndoRadar Pro motor. According to the initial apical diameter, canals were enlarged to sizes m25 (25/0.06), m40 (40/0.04), or m50 (50/0.04). A new file was used for each patient. Irrigation was performed using a 30-gauge side-vented closed-end irrigation needle positioned 2 mm short of the working length. During instrumentation, 2 mL of 2.5% sodium hypochlorite (NaOCl) was used after each file change, resulting in a total volume of approximately 20 mL per tooth. The final irrigation protocol consisted of 5 mL of 17% EDTA, 5 mL of 2.5% NaOCl, and 10 mL of distilled water. During final irrigation, both EDTA and NaOCl were activated using a sonic irrigation device with a polymer tip tip (Scope; Gtech Dizayn Dental, Yozgat, Türkiye) for a total of 1 minute, delivered in three 20-second activation cycles. The canals were subsequently dried with paper points. Patients were then randomly allocated into three groups according to the root canal sealer used (n = 24).

Group 1: AH Plus (Dentsply DeTrey, Konstanz, Germany); Group 2: TotalFill BC Sealer (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland); Group 3: Bio-C Sealer (Angelus, Londrina, Paraná, Brazil).

AH Plus was mixed according to the manufacturer's instructions and applied to the canal walls using the master gutta-percha cone. TotalFill BC Sealer and Bio-C Sealer were applied in their premixed forms by injection into the coronal third of the canal. Subsequently, all canals were obturated using the continuous wave of condensation technique (CWCT). All treatments, including post-endodontic restorations, were completed during the same visit. Patients were provided with a Visual Analog Scale (VAS) form and were instructed to record their pain intensity on a scale ranging from 0 to 10 at 6, 24, 48, and 72 hours, and 7 days after treatment. Analgesic intake was also recorded on the VAS form. Patients were recalled on the seventh day, and the completed VAS forms were collected. All data were entered into an Excel spreadsheet and analyzed.

Sample Size Calculation

Sample size calculation was performed using G*Power software version 3.1.9.6. Based on data obtained from a previous study, a minimum of 20 patients per group was required to achieve an effect size of f = 0.412, a significance level of α = 0.05, and a statistical power of 95%. Considering a potential dropout rate of 20%, the final sample size was determined as 24 patients per group, resulting in a total sample of 72 participants.

Statistical Analysis

Statistical analyses were performed using IBM SPSS Statistics version 23.0 (IBM Corp., Armonk, NY, USA). The normality of data distribution was assessed prior to analysis. Categorical variables were analyzed using Fisher's Exact Test and Monte Carlo simulation. Changes in pain incidence over time were evaluated using Cochran's Q test. Binary logistic regression analysis was performed to determine the effects of independent variables, including age, sex, jaw, tooth region, and root canal sealer type, on the presence of postoperative pain. Statistical significance was set at P < 0.05.

Inclusion Criteria:

• Patients aged 18-65 years
• Patients who agreed to participate in this study
• Patients with single-rooted, single-canal maxillary or mandibular teeth diagnosed with asymptomatic irreversible pulpitis
• Patients with asymptomatic teeth
• Patients who have not used any analgesic, anti-inflammatory, or antibiotic drugs in the last 7 days
• Patients with good oral hygiene
• Patients with a sustained positive response to cold test and electric pulp test
• Patients with healthy periapical tissues (to be confirmed by periapical radiography)

Exclusion Criteria:

• Patients who refused to participate in this study
• Patients with medical problems (patients with immunosuppressive/systemic diseases, patients on medication)
• Patients with negative responses to thermal and electrical pulp tests
• Patients with advanced periodontal disease (probing depth >4 mm)
• Patients with preoperative percussion and palpation of the involved tooth
• Open apex, presence of calcification, presence of resorption
• Patients requiring endodontic treatment of more than one tooth
• Patients with allergic sensitivity to materials and agents to be used during root canal treatment
• Patients with allergic sensitivity to local anesthetics
• Patients with systemic or allergic sensitivity to NSAIDs
• Pregnant and lactating patients
• Teeth that cannot be restored due to excessive material loss in the coronal structure

Individual participant data will not be made available.

Participants were blinded to group allocation, whereas the operator was aware of the assigned sealer. Outcome assessments were performed by an investigator blinded to group allocation.