Insomnia and Post-Dental Surgery Pain: A Prospective Study

Study Design and Setting This is a single-center, prospective, non-profit observational cohort study conducted at the Fondazione Policlinico Universitario A. Gemelli IRCCS. The study will span a total duration of 24 months: 18 months dedicated to patient recruitment and data collection, followed by 6 months dedicated to data processing and statistical analysis.

Patient data collection will begin only after obtaining explicit written informed consent and formal protocol approval from the Institutional Ethics Committee. Participant Recruitment and Timeline

Adult patients scheduled for dental extractions who meet the inclusion criteria will be invited to participate. Eligible individuals will be excluded if they are pregnant, present relevant comorbidities, experience acute pain/infections at recruitment, or take medications that interfere with sleep or pain management. The clinical workflow consists of the following phases:

• Baseline (Pre-surgery):

Prior to the extraction procedure, participants will complete a comprehensive set of validated psychometric and sleep questionnaires. Based on these initial assessments, patients will be classified into two parallel cohorts:

• Group 1 (patients without preoperative sleep disturbances) and
• Group 2 (patients with preoperative sleep disturbances).
• Intraoperative Assessment: Immediately following the dental extraction, patients will record the level of pain perceived during the surgical procedure. 3. Postoperative Follow-up (Days 1-7): Over the subsequent 7 days, participants will maintain a standardized daily paper diary to monitor daily pain intensity and log the frequency and type of any analgesic medications consumed.
• 7-Day Follow-up Visit: At the scheduled 7-day postoperative clinical control visit, patients will return their completed paper diaries and re-submit the same set of baseline questionnaires to track changes in sleep and psychological parameters.

Evaluated Instruments and Questionnaires

To thoroughly investigate the primary and secondary endpoints, the study utilizes the following validated instruments:

• Visual Analog Scale (VAS 0-100): Used to measure changes in perceived pain intensity from baseline to day 7.
• Insomnia Severity Index (ISI): A 7-item questionnaire (score range 0-28) evaluating insomnia severity over the past two weeks.
• Pittsburgh Sleep Quality Index (PSQI): A 19-item instrument (global score range 0-21) measuring overall sleep quality over the past 4 weeks.
• Berlin Questionnaire: A specialized screening tool to identify patients at low or high risk for Obstructive Sleep Apnea Syndrome (OSAS).
• Patient Health Questionnaire-4 (PHQ-4): An ultra-brief 4-item screening scale used to assess psychological distress, split into anxiety and depressive symptoms.

Statistical Analysis Overview Sample size calculations, conservatively adjusted based on relevant literature, dictate a minimum enrollment of 90 subjects (45 per group) to achieve 80% statistical power. Continuous variables will be evaluated for normality via the Shapiro-Wilk test. Differences in pre- versus post-operative quantitative metrics will be evaluated using paired t-tests or Wilcoxon signed-rank tests, while categorical variables will be assessed via Chi-squared or Fisher's exact tests. Multivariate linear regression models, repeated measures ANOVA, and mixed-effects models for longitudinal data will be implemented to isolate independent predictors of pain variation and identify distinct trajectories across the cohorts, adjusting for confounding factors such as age, sex, and extraction type (simple vs. surgical). Analysis will be performed using SPSS software.

Inclusion criteria

• Age over or egual 18 years.
• Need for odontoiatric surgical intervention (dental extractions).
• Willingness to participate in the study by completing the proposed questionnaires.
• Good understanding of the Italian language.
• Ability to understand and sign the informed consent form.

Exclusion criteria

• Pharmacological therapy interfering with sleep or pain at the time of recruitment.
• Acute pain or ongoing infections at the time of recruitment.
• Relevant comorbidities.
• Pregnancy.
• Impossibility to complete the follow-up.