Multiple-Visit RCT in Teeth With SAP: Interappointment Dressing or Not?

The aim of the study is to evaluate the effectiveness of calcium hydroxide as an intracanal medicament in the clinical and radiographic healing of periapical tissues in teeth diagnosed with symptomatic apical periodontitis. This evaluation will be conducted after multiple visit endodontic treatment. The follow-up sessions will be programmed from 6 to 24 months postoperatively. Postoperative pain will also be considered as a secondary outcome. Participants will be asked to rate their pain level on a numerical scale from 0 to10 before and after each session of endodontic treatment. Additionally, the use of analgesics after the procedure will be measured and the incidence of flare-ups will be evaluated. Two study groups will be formed to undergo multiple-visit endodontic treatment. The intervention group will receive intracanal medication of calcium hydroxide, while the control group will have the root canal left empty between appointments.

The first visit will include the following clinical steps . After administering local anesthesia with 4% articaine hydrochloride and epinephrine injection (with 1:200,000 adrenaline) or 2% mepivacaine for an inferior alveolar block, all decayed tissue from the tooth will be removed. The tooth will be isolated with a rubber dam, the tooth crown will be disinfected with 2% NaOCl, and an access cavity preparation will be created. The #10 C-Pilot file will be used to create a glide path. The working length will be established with an apex locator and an x-ray. The root canal will be instrumented using the sequence of NiTi rotary files Edge Endo X7. The canals will be irrigated copiously with 10ml of 2% NaOCl each time. Following instrumentation, a final rinse with 10ml of 2% NaOCl, 10ml of 17% EDTA, and 10ml of saline solution will be performed. Group 1 will receive intracanal dressing with Ca (OH)2 paste using Lentulo for a period of 7-10 days. Group 2 will be left without intracanal dressing for a period of 7-10 days. In both groups, teeth will be restored with glass ionomer cement (GIC) as a temporary restoration. The final visit will include the following clinical steps. After examining the tooth and surrounding tissues, local anesthesia will be administered as previously described. The temporary restorative material will be removed, and the tooth will be isolated with a rubber dam before accessing the root canal. In Group 1, the intracanal dressing will be removed through irrigation, and then obturated using a standardized, matched size and taper gutta-percha cone with AH-plus sealer with the single-cone obturation technique. The tooth will be then temporarily restored with glass ionomer cement (GIC), and the participant will be referred for final restoration within 7-14 days. The same protocol is followed for Group 2.

Eligibility Criteria:
Inclusion Criteria:

* ASA grade: I or II
* Age: ≥18 years
* Permanent teeth
* Pulp diagnosis: necrosis or previously treated
* Diagnosis of periapical tissues: symptomatic apical periodontitis
* Teeth sensitive to percussion and/or palpation
* Initial PAI: 3-5
* Signed Patient Consent Statement for participation in clinical research

Exclusion Criteria:

* Subjects that do not meet the inclusion criteria
* Pregnant women
* Patients who receive corticosteroids and/or have received antibiotics within the previous three months
* Patients who report pain in a different area than that of the tooth under investigation
* Teeth that cannot be isolated with a rubber dam
* Teeth with extensive hard tissue destruction that is not restorable
* Teeth with an anatomic peculiarity of the root canal (internal resorption, perforation, displacement of root canal course due to previous endodontic treatment)
* Teeth in which the formation of the apex has not been completed
* Fractured teeth with periodontal involvement
* Teeth with periodontal pocket depth ≥ 4mm or teeth with bone loss at the bifurcation of the roots due to periodontitis
* Teeth with loss of periodontal attachment ≥ 5 mm
* Teeth with embedded exudate in the session planned for root canal obturation.
* Teeth that after completion of the endodontic treatment show underocclusion \&amp;gt;2mm or hyperobstruction \&amp;gt;1mm from the radiographic apex.
* Teeth in which permanent restoration has not been completed over time less than one month after endodontic treatment.