Post-operative Pain and Apical Healing After Root Canal (re)Treatment With Laser-activated Irrigation Versus Sonic or no Activation
Apical Periodontitis · Post Operative Pain, Acute
What this study involves
The registry says this study is recruiting. Individual locations may have different availability.
- Study type
- Interventional
- Phase
- Not applicable
- Age range
- 18 years - Not specified
- Sex eligible
- All sexes
- Healthy volunteers
- Not accepted
- Participants
- 183 Estimated
These are starting points, not an eligibility decision. The research team must review the full requirements.
About the research
When a tooth's nerve dies, inflammation can develop at the tip of the tooth's root. Root canal treatment is carried out to allow this inflammation to heal. Sometimes, inflammation persists in a tooth that has already undergone root canal treatment. In such cases, the root canals may be re-treated to allow the inflammation to heal.
During root canal treatment, the root canals inside the tooth are cleaned and then filled. Various instruments are used to clear the root canal along its entire length, so that the entire canal can be disinfected using antiseptic products. To allow these products to work more effectively, they can be activated. This activation can be achieved, amongst other methods, using vibrations caused by a plastic tip vibrating at a sonic frequency within the liquid. Another method of activation involves the use of a laser, which delivers pulsed energy. This creates shock waves in the liquid. Previous research has shown that root canals can be cleaned more effectively through the use of activation techniques.
This study aims to investigate whether the inflammation present at the root tip heals more effectively following the use of activation methods for the disinfectant. The use of the laser is compared with that of the sonic vibration instrument, and with a group in which the disinfectant is not activated. The effect of the activation method on post-treatment pain is also investigated.
Who may be able to participate?
The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.
Inclusion criteria:
- Patients older than 18 years
- Mature permanent tooth
- Pulpal diagnosis: pulp necrosis, previously initiated treatment, root filled
- Apical diagnosis: asymptomatic apical periodontitis
- Pre-operative pain of 0 on the Visual Analogue Scale (VAS)
Exclusion criteria:
- Permanent teeth with immature roots or open apices
- Teeth not eligible for orthograde (re)treatment
- Teeth with acute pain
- Teeth with periodontal pockets ≥ 5 mm
- Teeth with persistent intracanal drainage
- Non-restorable teeth
- Pregnant women
- Patients who took drugs with possible influence on the pain sensation within 12 hours before treatment
- Patients with pain from one or multiple teeth
- Patients with contra-indications for the use of NSAID
- Patients with a known or suspected malignancy
- Patients with a history of chemotherapy within five years
- Patients with a history of radiation therapy in the head and neck region
- Patients with a history of metabolic bone diseases
Treatment, groups and participation
The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.
- Assignment
- Random assignment
- Masking
- Double masked
conventional needle irrigation
Not reported in this registry record.
Other: conventional needle irrigation
sonically activated irrigation
Not reported in this registry record.
Device: sonically activated irrigation
laser activated irrigation
Not reported in this registry record.
Device: laser activated irrigation
sonically activated irrigation DEVICE
The irrigant is activated after mechanical preparation with a plastic Eddy-tip (f = 6000 Hz) inserted up to 1 - 3 mm short of the working length. Three 20 s activation cycles are performed per canal, with 2 mL irrigation in each root canal between the cycles.
laser activated irrigation DEVICE
The irrigant is activated after mechanical preparation with a pulsed Er:YAG laser (Fotona Fidelis III, PIPS, E = 20 mJ, f = 20 Hz, t = 50 μs). These settings result in a power of 0.4 W. Due to the high absorption of the Er:YAG wavelength in the irrigant, mechanical effects occur (cavitation), rather than thermal effects. As a result, the risk of thermal damage is negligible. The tip of the laser is kept at the canal orifice, but not inserted into the root canal. During activation, irrigant is continuously added to the pulp chamber, so the root canals and pulp chamber are consistently immersed in irrigating solution. Three 20 s activating cycles per orifice are executed, with intermittent flushing of the root canal with 2 mL irrigant.
conventional needle irrigation OTHER
The root canals are irrigated with 3% NaOCl, using a 27G notched needle, adapted to a 3 mL syringe and inserted up to 2 - 3 mm short of working length. Two millilitres of irrigant are used between the different instruments.
What researchers are measuring
Outcome measures describe what is being studied. They are not proof that a treatment works.
Primary measures
post-operative pain
Time frame: Post-operative pain is scored immediately after the treatment and 6 hours, 24 hours, 48 hours, 72 hours and 96 hours after treatment.
The post-operative pain immediately after completion of treatment is scored on the Visual Analogue Scale (VAS), with a score between 0 (no pain) and 10 (worst pain imaginable). Patients are asked to fill out a pain diary 6 hours, 24 hours, 48 hours, 72 hours and 96 hours after treatment with a pain score on the VAS.
tooth survival
Time frame: up to 2 years post-treatment
presence of the treated tooth inside the mouth
apical healing
Time frame: up to 2 years post-treatment
The pre-operative and recall periapical radiographs are compared for the periapical index (PAI). On the radiographs, the apical periodontitis lesion is outlined and the surface of the lesion is calculated using software. The surface of the apical periodontitis lesion on the follow-up radiograph is compared to the pre-operative radiograph. Teeth are categorized into the following three outcome categories based on analysing the change in the PAI:
- Strict radiographic success (healed teeth): absence of clinical signs or symptoms, and PAI-score of 1 or 2 at follow-up.
- Loose radiographic success (healing teeth): absence of clinical signs or symptoms, and a lower PAI-score (or smaller surface of the lesion) compared to the pre-operative radiograph.
- Failure (non-healing): clinical signs or symptoms (including pain, swelling, sinus tract), or asymptomatic with an unchanged PAI-score (or surface of the lesion), or increase in PAI-score (or surface of the lesion) at follow-up.
Review the complete result tables and limitations in the official record.
Open official results ↗Research locations (2)
The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.
2 locations
Endo PointAntwerp, BelgiumRecruiting
UZ GentGhent, BelgiumRecruiting
Study team and timeline
- Lead sponsor
- University Ghent
- Study start
- Nov 4, 2026 Actual
- Primary completion
- 2029-08 Estimated
- Study completion
- 2029-08 Estimated
- First posted
- Oct 20, 2026 Actual
- Last updated
- Nov 10, 2026 Actual
Official study contacts
Official study title
Post-operative Pain and Apical Healing After Root Canal (re)Treatment With Laser-activated Irrigation Versus Sonic or no Activation: a Multi-centre Randomised Controlled Clinical Trial
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Source: ClinicalTrials.gov API v2. Information is submitted by sponsors and investigators. NLM does not approve the safety or science of all listed studies. Registry disclaimer.
Retrieved: Nov 12, 2026 · Last registry update: Nov 10, 2026