The Impact of Nitrous Oxide Sedation on Dental Fear and Anxiety Scores in Children Aged 6-10 Years (N₂O)

The Impact of Nitrous Oxide Sedation on Dental Fear and Anxiety Scores in Children Aged 6-10 Years: A Randomized Controlled Clinical Trial

Dental anxiety (DA) is highly prevalent among children undergoing dental procedures, with 50-80% experiencing fear that disrupts treatment and exacerbates oral health outcomes. While nitrous oxide (N₂O) sedation is widely used for its anxiolytic properties, evidence remains limited regarding its standardized efficacy in reducing pediatric fear and anxiety scores.

Study Overview

• Status: Completed
• Conditions: Dental Anxiety
• Intervention / Treatment: Behavioral: psychological support; Drug: Nitrous Oxide Sedation

Detailed Description

This study adopted a randomized controlled trial (RCT) design, strictly adhering to the CONSORT (Consolidated Standards of Reporting Trials) guidelines to ensure scientific rigor, reliability, and transparency.The sample size was calculated based on previous literature and preliminary pilot study results. Referring to the standard deviations of dental fear and anxiety scores in similar studies, the significance level (α) was set at 0.05, and the power (1 - β) was set at 0.85 (90% power). With an effect size of 0.4, the study anticipated significant differences in fear and anxiety scores between the experimental and control groups. Using statistical formulas and considering practical constraints, the estimated sample size required for each group was no fewer than 58 participants to ensure sufficient statistical power.

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Phase 2

Contacts and Locations

Study Locations

• China
  • Zhejiang
    • Shaoxing, Zhejiang, China, 312000
      • Shaoxing Maternity and Child Health Care Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 1.Aged 6-10 years; 2.Classified as American Society of Anesthesiologists (ASA) physical status I-II; 3.Required dental treatments such as caries filling, pulp therapy, or tooth extraction; 4.Informed consent obtained from the child's guardian.

Exclusion Criteria:

• 1.Contraindications to nitrous oxide inhalation, such as severe cardiopulmonary dysfunction, intestinal obstruction, or pneumothorax; 2.Mental illness or intellectual disability that would hinder cooperation with assessments or treatment; 3.Received dental sedation or general anesthesia within the past month;

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: control group; The control group received only conventional local anesthesia and psychological comfort measures. Preoperatively, medical staff communicated thoroughly with the child and guardian to explain the treatment process and precautions, alleviating anxiety. The child's oral and systemic health was assessed to determine treatment difficulty. During treatment, articaine (Septodont, France) were administered under strict aseptic techniques to minimize pain. Continuous psychological support was provided through gentle communication, encouraging gestures, and distraction techniques such as soothing music or storytelling to help the child relax and cooperate. Postoperatively, the child was observed for any adverse reactions before being discharged with their guardian.	Behavioral: psychological support; gentle communication, encouraging gestures, and distraction techniques such as soothing music or storytelling to help the child relax and cooperate.
Experimental: experimental group; The experimental group received nitrous oxide anesthesia using a professional dental nitrous oxide inhalation sedation system (Matrx, the United States). This system featured precise gas concentration adjustment, real-time patient vital sign monitoring, and a reliable alarm system to ensure accurate, safe, and stable nitrous oxide administration.	Drug: Nitrous Oxide Sedation; After the child was seated in the dental chair, an appropriately sized nasal mask was selected to ensure a secure fit without leakage. The child initially inhaled 100% oxygen for 3-5 minutes to adapt to the breathing pattern and eliminate nitrogen from the lungs. Nitrous oxide was then introduced at an initial concentration of 10%-15%, with adjustments made in increments of 5%-10% based on the child's anxiety level, treatment stimuli, and vital signs. Each adjustment was followed by 1-2 minutes of observation until the desired level of sedation was achieved.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
MDAS	The Modified Dental Anxiety Scale, zero is equivalent to no anxiety and 5 indicates the worst possible anxiety, participants achieved a response if they scored a performance status of 0 on a scale ranging from 0 (best outcome) to 5 (worst outcome)	From enrollment to the end of treatment at 1 week
Behavioral Observation Scale	The Frankl behavior rating scale was used to assess the children's behavior during treatment. This 4-point scale categorizes behavior , participants achieved a response if they scored a performance status of 1 on a scale ranging from 1 (best outcome) to 4 (worst outcome)	From enrollment to the end of treatment at 1 week
CFSS-DS	Children's Fear Survey Schedule-Dental Subscale, participants achieved a response if they scored a performance status of 1 on a scale ranging from 1 (best outcome) to 5 (worst outcome)	From enrollment to the end of treatment at 1 week

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
HR	heart rate	immediately after the intervention
BP	blood pressure	systolic and diastolic will be assessed immediately after the intervention
RR	respiratory rate	immediately after the intervention

Collaborators and Investigators

• Sponsor: Shaoxing Maternity and Child Health Care Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 15, 2024
• Primary Completion (Actual): August 31, 2024
• Study Completion (Actual): September 8, 2024

Study Registration Dates

• First Submitted: January 8, 2026
• First Submitted That Met QC Criteria: January 29, 2026
• First Posted (Actual): February 3, 2026

Study Record Updates

• Last Update Posted (Actual): February 3, 2026
• Last Update Submitted That Met QC Criteria: January 29, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Nitrous Oxide; Dental anxiety
• Other Study ID Numbers: 2023SKY097

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No