The goal of this clinical trial is to compare two root canal obturation techniques for endodontic treatment in patients aged 15 to 56 years with irreversible pulpitis. The main questions it aims to answer are:

1. Does continuous wave condensation differ from the single-cone technique in obturation time?
2. Does continuous wave condensation differ from the single-cone technique in obturation quality, postoperative pain, and 6-month treatment success? Researchers will compare continuous wave condensation with single-cone obturation to see whether one technique provides better sealing quality, shorter treatment time, less postoperative pain, or higher clinical success.

Participants will:

• Receive endodontic treatment for teeth diagnosed with irreversible pulpitis.
• Undergo root canal preparation with Reciproc Blue R25.
• Have canals obturated using either continuous wave condensation or the single-cone technique.
• Be evaluated for obturation time, radiographic quality immediately after treatment, postoperative pain at 4, 24, 48, and 72 hours, and clinical-radiographic outcome at 6 months.

Background and Rationale: Irreversible pulpitis requires endodontic treatment to eliminate infection, prevent reinfection, and preserve tooth function. Effective three-dimensional obturation of the root canal system (RCS) is critical for long-term success. The single-cone (SC) technique offers procedural simplicity and reduced chair time but may compromise adaptation to complex canal anatomy. Continuous wave condensation (CWC) uses thermoplasticized gutta-percha to improve sealing of lateral canals and isthmuses. Despite widespread clinical use, comparative clinical data on obturation time, radiographic quality, postoperative pain, and short-term outcomes remain limited, particularly in irreversible pulpitis cases without periapical pathology.

Study Design:

This single-center, superiority, parallel-group randomized clinical trial compared CWC and SC obturation techniques in 60 teeth from 54 patients. Randomization occurred at the tooth level (1:1 allocation) using sequentially numbered opaque sealed envelopes. Operators (two calibrated endodontists) were unblinded due to technique differences; radiographic and clinical assessors remained blinded.

Interventions:

All teeth underwent standardized single-visit treatment under local anesthesia:

Root Canal Preparation (both groups): (1) Access cavity preparation, (2) Working length determination (apex locator + radiograph), (3) Cleaning/shaping with Reciproc Blue R25 reciprocating files (VDW, Germany) using step-down technique, (4) Final irrigation: 3% NaOCl (5 mL per canal), EDTA (17%, 3 min), saline rinse

• CWC Group (EQ-V system, Meta Biomed, South Korea): (1) Master cone fit verified radiographically. (2) EQ-V cutting tip positioned 4-6 mm short of working length; cone tip trimmed 0.5-1 mm. (3) Master cone + sealer inserted: Heated plugger activated (230°C) to apical 4-6 mm compaction --> Hand plugger vertical condensation --> Thermoplasticized gutta-percha backfill --> Post-obturation radiograph
• SC Group: (1) Master cone fit verified radiographically. (2) Cone coated with sealer, seated to working length. (3) Excess gutta-percha is heat-trimmed at the orifice. (4) Post-obturation radiograph

Sealer: AH Plus (Dentsply Sirona) in both groups. Obturation time is measured from cone insertion to radiograph completion.

Outcome Assessments:

• Primary: 6-month success (European Society of Endodontology criteria: no symptoms + normal/reduced PDL space)

• Secondaries:

  • Obturation time (stopwatch, seconds)
  • Radiographic quality (length: adequate/short/long; voids; sealer extrusion; accessory canal filling)
  • Pain (NRS 0-10 at 4, 24, 48, 72 hours)

Assessor: Independent blinded evaluator (NTNV)

Follow-up: Patients are recalled at 6 months (±2 weeks) for clinical exam and radiograph. Success determined by absence of pain/swelling/sinus tract + radiographic healing.

Statistical Considerations:

Sample size calculated for 80% power (α=0.05, P1=89.5% vs P2=77.0% canal filling rates). Intention-to-treat analysis. Continuous data: independent t-tests. Categorical: chi-square/Fisher's exact. p<0.05 significant.

Inclusion Criteria:

• Teeth diagnosed with irreversible pulpitis
• Indicated for endodontic treatment
• Patients aged 18-60 years

Exclusion Criteria:

• Periapical/furcation lesions;
• Need for periodontal surgery
• Periodontal pockets ≥ 5 mm
• Adjacent teeth undergoing endodontic treatment
• Severely fractured or non-restorable crowns
• Immature/abnormal roots
• Internal or external resorption
• Calcified/C-shaped canals
• Canal curvature >70°
• Failures during canal preparation

As this study was completed prior to institutional data sharing policy implementation at Hue University of Medicine and Pharmacy, individual participant data (IPD) sharing is undecided. De-identified patient data includes sensitive clinical records (radiographs, pain scores, demographics) from a Vietnamese university hospital population.

Sharing requires Institutional Review Board (IRB) re-approval (H2022/259), participant re-consent (not obtained at enrollment), and Vietnamese Ministry of Health data protection compliance. Technical limitations include lack of standardized electronic health record format and absence of data use agreements with international repositories.

Researchers may contact the corresponding author (ntnvy@huemed-univ.edu.vn) to discuss potential collaboration. Aggregate results are fully reported in the primary publication. IPD sharing decisions will follow institutional policy updates and applicable regulations including GDPR-equivalent Vietnamese personal data