Effect of Nitrous Oxide-Oxygen Inhalation on Pain and Physiological Responses During Supragingival Ultrasonic Scaling: A Prospective Cohort Study.

Abstract

Background: Nitrous oxide-oxygen (N₂O-O₂) inhalation is widely utilized for anxiolysis in dentistry; however, its clinical efficacy and physiological impact during routine supragingival scaling remain insufficiently assessed.

Methods: This prospective observational cohort study enrolled 100 adult patients. Participants were allocated to either the N₂O-O₂ sedation group (n = 50) or a non-sedated control group (n = 50) based on treatment preference. Vital signs, including heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP), were monitored at baseline (T₀), intraoperatively (T₁), and postoperatively (T₂). Pain intensity was assessed immediately after supragingival ultrasonic scaling using a 0-10 Visual Analogue Scale.

Results: All 100 participants successfully completed the study. Intra-group analysis revealed that the sedation group experienced a significant reduction in HR during scaling (T₁) compared to baseline (T₀, p = 0.0004), whereas the control group remained physiologically stable with no significant HR fluctuations (p > 0.05). SBP and DBP showed no significant intra-group or inter-group variations across all time points (p > 0.05). Pain intensity was significantly lower in the sedation group compared with the control group (p < 0.001). No adverse events were recorded.

Conclusions: N₂O-O₂ inhalation sedation significantly attenuates procedural pain and stabilizes heart rate during supragingival ultrasonic scaling without compromising hemodynamic safety. These findings suggest N₂O-O₂ sedation is a safe and feasible adjunct for routine periodontal prophylaxis.