This study will include 72 participants who apply to the Department of Endodontics, Faculty of Dentistry, Dicle University, with the need for root canal treatment, and who meet the inclusion and exclusion criteria specified. Root canal treatment will be applied only to the single-rooted and single-canal teeth of these patients in the lower jaw. Patients will be informed before the procedure, and an informed consent form will be signed. Block anesthesia (4% articaine hydrochloride containing 1:100,000 adrenaline) will be applied to the lower jaw, the relevant tooth will be isolated with a rubber dam, caries, and existing restorations will be removed with high-speed diamond burs under water cooling, and the access cavity will be prepared. The root canal length will be determined using an apex locator and a size 8 or 10 K-file and confirmed radiographically. Initial root canal shaping will be done with a size 20 K file, followed by a nickel-titanium file system Reciproc R25 in the "RECIPROC ALL" mode with a working length. Additional instrumentation will be done with R40 files according to the initial apical diameter. A total of 15 ml of 2.5% sodium hypochlorite (NaOCl), the worldwide gold standard root canal irrigation solution, will be used with a 30-gauge irrigation needle (TruNatomy, Dentsply Sirona). In all irrigation procedures, the irrigation needle will be placed 2 mm shorter than the canal's working length and applied with moderate pressure to prevent irrigation accidents. Finally, final irrigation will be performed with 5 ml 17% EDTA (a chelator commonly used during root canal treatment), 5 ml 2.5% NaOCl, and 2 ml distilled water, respectively. During the final irrigation process, irrigation activation will be performed for 30 seconds with a sonic irrigation activation device. Finally, the root canals will be dried with paper points. Then, the patients will be randomly divided into three treatment groups according to the root canal sealer used (n=24).
Group 1: AH Plus Root Canal Sealer (Dentsply Sirona, Ballaigues, Switzerland) Group 2: TotalFill BC Sealer (FKG Dentaire, La Chaux-des-Fonds, Switzerland) Group 3: Bio-C Sealer (Angelus, PR, Brazil).
The determined root canal sealer will be sent to the canals. Then, all canals will be filled using the hot vertical condensation technique. All treatments will be completed in a single session with the upper restorations. Patients will be given the VAS Pain Assessment Scale and asked to mark their individual pain levels between 0 and 10 at 6, 24, 48, 72 hours and 7 days after root canal treatment. At the end of the 7th day, patients will be called for a check-up and VAS questionnaires will be collected. Data will be collected in an excel table and analyzed.
Sample Size Calculation Sample size was calculated using the G\*Power V. 3.1.9.6 program. Considering the pain values in the literature, it was decided to plan the study with a total of 60 cases, 20 in each group, with 95% confidence (1-α), 95% test power (1-β), f=0.412 effect size.\* Considering the possible case losses as 20%, the final number of cases for each group will be 24.
Statistically Analysis Statistical analyses will be performed using the IBM SPSS Statistics for Windows, Version 25.0. (IBM Corp. Released 2017, Armonk, USA) package program. The package program has a license. Descriptive statistics will be given with percentage, frequency, mean ± standard deviation. Gender and age distributions according to groups were evaluated with Chi Square Analysis. Kruskal Wallis H test or ANOVA will be used to compare postoperative pain and according to VAS scores between three groups. Friedman Two-Way Variance Analysis will be used to evaluate VAS scores at all time points for each group. In case of significance, Dunn Test will be used by applying Bonferroni Correction in pairwise comparison of time points within groups. Significance level will be taken as α= 0.05.
