Evaluation of the Effect of Different Irrigation Activation Methods During Endodontic Retreatment

Endodontic retreatment involves removing old root canal filling material followed by cleaning, shaping, and refilling the canals. It may be associated with postoperative pain due to periapical tissue irritation and apical extrusion of debris during instrumentation.

Also, the retreatment procedure plays a critical role in enhancing periapical healing and improving long-term outcomes in failed initial treatments.

Activation of irrigants during endodontic retreatment enhances the removal of residual gutta-percha, sealers, and debris, especially in lateral canals and complex areas. It also boosts disinfectant effectiveness, improving canal cleanliness and retreatment outcomes.

Ultrasonic activation uses high frequency vibrations to enhance irrigant penetration and fluid dynamics during endodontic retreatment. It improves the removal of residual filling materials and debris more effectively than conventional irrigation. The technique promotes cavitation and acoustic streaming, boosting disinfectant effectiveness and reducing bacterial load. Overall, ultrasonic activation enhances canal cleaning and contributes to better retreatment outcomes.

XP endo Finisher R is a specialized endodontic instrument designed for retreatment to improve removal of residual root filling materials from canals that conventional files cannot fully clean, especially in oval or curved anatomies. It uses flexible MaxWire alloy that expands in the canal, increasing contact with walls and enhancing removal of remnants and debris. Studies using micro CT imaging show that XP endo Finisher R significantly reduces filling material volume compared to some conventional techniques and is effective as a supplementary step after primary retreatment files .

CBCT provides three dimensional imaging that allows more accurate assessment of periapical healing and detection of residual pathology following endodontic retreatment compared with conventional 2 D radiographs. It is more sensitive in identifying persistent apical lesions and missed anatomy that may impact retreatment success. CBCT evaluation can influence clinical decision making and treatment planning by revealing details not seen in traditional imaging.

Systematic reviews show CBCT based outcome assessments often report different success rates due to this increased diagnostic sensitivity. Overall, CBCT contributes to a more comprehensive evaluation of retreatment outcomes and helps guide management further.

Despite the increasing use of irrigation activation techniques during endodontic retreatment, limited clinical evidence exists comparing XP-endo Finisher R with ultrasonic activation regarding postoperative pain and periapical healing outcomes.

• Xp Finisher R file (Procedure), also known as Ultrasonic activation: to evaluate the incidence and severity of postoperative pain using a numeric rating scale at 24, 48, and 72 hours and periapical healing via CBCT following retreatment with two different irrigation activation techniques: 1. Xp Finisher R file activation of irrigation. 2. Ultrasonic activation of irrigation.

Primary outcomes

• Post Operative Pain [from 6 hours to 48 hours after the procedure]: Assessing the post operative pain measured by a numerical pain rating scale (NRS) where the level of pain will be recorded as follows: 0 reading represents "no pain" ; 1- 3 reading represents "mild pain" ; 4- 6 reading represents "moderate pain" and 7- 10 reading representative sever pain.

Sex: All, ages: 13 Years to 60 Years, accepts healthy volunteers

Inclusion Criteria:

* Patients with mature teeth.
* Patients with failed previous Endo treatment related by periapical periodontitis
* Single Rooted with single root canal.
* Patients should be free from any systemic disease that may affect predictable outcome.
* Patients who agree to the consent and will commit to follow-up period

Exclusion Criteria:

* Patients with immature roots.
* Patients with any systemic disease that may affect normal healing.
* Patients with swelling.
* Pregnant females.
* Patients who could/would not participate in follow-up.
* Patients with old age.
* Teeth with periodontal involvement.
* Teeth with vertical root fractures.
* Non-restorable teeth

• Wael Hussien kamel, M.D, Study chair, Professor of Endodontics Head of Endodontic Department,Faculty of Dentistry,Future University