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

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.