This observational study aims to investigate the effects of sleep quality and systemic health status on pain levels following endodontic treatment in adult patients. The primary goal is to determine how obstructive sleep apnea and common systemic conditions (diabetes and hypertension) influence postoperative dental pain.

The key questions it aims to answer are:

Does the severity of Obstructive Sleep Apnea (OSA) lead to higher postoperative pain scores after root canal treatment?

How does the presence of systemic diseases, such as diabetes and hypertension, affect pain perception compared to healthy individuals and OSA patients?

Comparison Groups:

Researchers will compare outcomes across three distinct cohorts:

OSA Group: Patients diagnosed with moderate-to-severe obstructive sleep apnea via polysomnography.

Systemic Disease Group: Patients with diagnosed systemic conditions, specifically diabetes and hypertension.

Control Group: Systemically healthy individuals without sleep disorders.

Participants will:

Undergo a polysomnography (PSG) evaluation to assess their sleep status.

Receive routine, standard-of-care endodontic treatment.

Record and report their pain intensity using the Visual Analog Scale (VAS) at specific intervals after the procedure.

Study Design and Power Analysis This observational study was designed to evaluate the interaction between Obstructive Sleep Apnea (OSA) and systemic diseases on postoperative pain following endodontic treatment. A power analysis was performed using G*Power 3.1 software with parameters f=0.40, α=0.05, and 80% power. While the analysis indicated a minimum of 66 participants, a total of 75 participants were targeted to account for a potential 15% dropout rate. The study was completed with 78 participants, maintaining and enhancing the required statistical power.

Participant Selection and Grouping

Patients aged 28 to 63 were enrolled based on their clinical status and divided into three groups:

Group 1 (n=24): Patients diagnosed with moderate (AHI 15-30) or severe (AHI >30) OSA via polysomnography (PSG) in an accredited sleep laboratory, who also presented with systemic diseases (Diabetes Mellitus and/or Hypertension).

Group 2 (n=24): Patients with diagnosed systemic diseases (Diabetes Mellitus and/or Hypertension) but without OSA.

Group 3 (n=30): Systemically healthy individuals without OSA (Control Group).

Exclusion criteria included the presence of periapical lesions on preoperative radiographs, chronic analgesic use, pregnancy, and failure to complete the study protocol. To minimize bias, the research team was blinded to the OSA classification process, and the data analyst was blinded during the statistical evaluation.

Standardized Endodontic Protocol To eliminate operator variability, all treatments were performed by a single experienced endodontist in a single session. Procedures were conducted under local anesthesia (2% lidocaine with 1:80,000 epinephrine) and rubber dam isolation. Root canal preparation was standardized using the VDW.ROTATE™ system up to a size 25.06 taper. The irrigation protocol included 5.25% NaOCl, 17% EDTA, and a final rinse with distilled water. Canals were obturated using the single-cone gutta-percha technique with AH Plus sealer.

Evaluation and Statistical Analysis Preoperative pain levels and postoperative pain at the 6th hour, 24th hour, and 7th day were recorded using a 10-point Visual Analog Scale (VAS) (0: no pain, 10: severe pain). The primary outcome was the difference in postoperative VAS scores between groups, while the secondary outcome was the duration of pain. Statistical analysis was performed using SPSS version 25. Due to non-normal distribution (confirmed via Kolmogorov-Smirnov test), the Kruskal-Wallis test with Bonferroni correction and the Mann-Whitney U test were utilized. The significance level was set at p < 0.05.

Inclusion Criteria:

• Patients aged between 18 and 65 years.
• Clinical requirement for endodontic (root canal) treatment.
• Presence of a restorable tooth structure.
• Diagnosis of moderate (AHI 15-30) or severe (AHI > 30) obstructive sleep apnea (OSA) confirmed by polysomnography, for relevant groups.
• Patients with diagnosed systemic diseases (Diabetes Mellitus and/or Hypertension) or systemically healthy controls according to group allocation.

Exclusion Criteria:

• Presence of periapical lesions identified during preoperative radiographic evaluation.
• Chronic use of analgesics or long-term pain-management medications.
• Pregnancy.
• Failure to complete the established study protocol.

The study population consists of adult patients seeking endodontic treatment at the Harran University Faculty of Dentistry, Department of Endodontics. Participants are selected consecutively from individuals who have undergone polysomnography in an accredited sleep laboratory (for the OSA groups) and from patients with diagnosed systemic conditions such as diabetes and hypertension.

Individual participant data (IPD) that are completely de-identified will be shared. This includes demographic information (age and sex), Apnea-Hypopnea Index (AHI) values, systemic health status (diabetes and hypertension status), and preoperative and postoperative Visual Analog Scale (VAS) pain scores. No personally identifying information of the participants will be disclosed to protect patient privacy.

The data will be available starting 6 months after journal publication and will remain accessible for up to 3 years.

De-identified individual participant data can be requested by qualified researchers by emailing the corresponding author for academic and scientific purposes.