Changing apical tip size and taper during one-visit root canal to improve healing and pain

Effect of Apical Third Enlargement to Different Taper and Master Apical Preparation Size on Periapical Healing and Postoperative Pain After Primary Single Sitting Non Surgical Root Canal Treatment

This trial will see if using different tip sizes and tapers during a single‑visit root canal helps healing and reduces pain in adults with asymptomatic irreversible pulpitis of a lower molar.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 270 (estimated)
• Ages: 18 Years to 65 Years
• Sex: All
• Sponsor: Postgraduate Institute of Dental Sciences Rohtak (Academic / other)
• Locations: 1 site (Rohtak)
• Trial ID: NCT07166679 on ClinicalTrials.gov

What this trial studies

This randomized clinical trial compares root canal shaping with 2%, 4%, and 6% tapers in the apical third during single‑visit non‑surgical root canal treatment of mandibular molars with radiographic periapical lesions. Eligible adults (18–65) with pulpal necrosis and a mesial root PAI score ≥3 and an initial apical binding file ≤20 will be randomized to one of the three taper groups. Primary outcomes are radiographic periapical healing and patient‑reported postoperative pain measured after treatment and during follow‑up. The trial addresses limited and mixed prior clinical evidence on whether larger apical preparations or greater tapers improve outcomes.

Who should consider this trial

Good fit: Adults 18–65 with asymptomatic pulp necrosis and a periapical radiolucency (PAI ≥3) in the mesial root of a mandibular molar and an initial apical binding file of 20 or smaller.

Not a fit: Patients who are medically compromised, pregnant or lactating, recently used antibiotics or require antibiotic prophylaxis, or have an initial apical binding file greater than 20 are excluded and unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this could help dentists choose the optimal apical taper and preparation size to improve radiographic healing and reduce postoperative pain after one‑visit root canal treatment.

How similar studies have performed: Previous clinical trials are few and mixed—some reported no benefit from larger apical sizes while others found better success with larger preparations and greater tapers, so evidence remains inconclusive.

Eligibility criteria

Inclusion Criteria:

1. 18-65 years of age of either sex
2. Asymptomatic teeth having pulpal necrosis with apical periodontitis in a mandibular molar (no response to EPT or cold test)
3. Radiographic evidence of periapical radiolucency corresponding to a periapical index (PAI) score \>/=3 in mesial root of mandibular molars

Exclusion Criteria:

1. Patients who were medically compromised
2. Patients with initial apical binding file (IABF) size more than 20
3. Pregnancy; lactation \& contraceptives.
4. Positive history of antibiotic use within the past month or required antibiotic premedication for dental treatment (including infective endocarditis or pros thetic joint prophylaxis -

Where this trial is running

Rohtak

• Pgids Rohtak — Rohtak, India (Recruiting)

Study contacts

• Principal investigator: Dr shweta MITTAL, MDS — Pdids Rohtak
• Study coordinator: Dr shweta mittal, MDS

Conditions Asymptomatic Irreversible Pulpitis