Inclusion Criteria:  Patients between 18 - 65 years of ages Patients with healthy (ASA 1) and mild systemic disease (ASA 2) according to ASA classification Patients with no mental disorders in their medical history Patients who do not have a psychiatric disorder that they have started, and who do not use psychotherapeutic drugs. Literate and not visually impaired patients Patients presenting with single-rooted teeth with a single root canal diagnosed with asymptomatic irreversible pulpitis or single-rooted vital teeth with a single root canal requiring root canal treatment due to prosthetic reasons  Exclusion Criteria:  Patients who refuse to participate this study Patients have existing pain caused by another tooth Patients with dermatological disease in the medical histories Medically compromised patients (with immunosuppressive/systemic diseases, patients on medications) The presence of spontaneous pain, swelling, or fistula in the relevant tooth Teeth whose working length cannot be reached due to calcification and step formation in the root canal The presence of foreign material in the root canal that prevents entry (broken instrument, post) The presence of advanced periodontal disease (probing depth > 4 mm) or root fracture in the relevant tooth Patients using pain medication on the same day before treatment (within 24 hours)