Dental anxiety frequently impedes effective dental care in pediatric patients. This study aimed to compare the efficacy and safety of two doses (0.3 mg/kg and 0.6 mg/kg) of oral midazolam for sedation and amnesia in preschool children undergoing dental procedures. Methods: This prospective, double-blind, randomized controlled trial included 80 children aged 3-6 years with dental anxiety. Participants were randomly assigned to receive oral midazolam at either 0.3 mg/kg or 0.6 mg/kg. Sedation efficacy, onset time, procedure duration, cooperation level (Houpt Behavior Rating Scale), recovery time, amnesia at 12 hours, 24 hours, and one week, as well as adverse events, were recorded and analyzed

Dental anxiety is common among preschool-aged children, with prevalence rates ranging from 36.5% to 70%. Untreated anxiety often leads to delayed dental care, increased dental caries, and worsened oral health, negatively impacting children and their families. Behavioral management techniques, such as positive reinforcement, are typically employed but may be insufficient for severely anxious patients. Pharmacological sedation, especially with midazolam-a short-acting benzodiazepine-is commonly used to enhance cooperation by providing sedation, anxiety relief, and amnesia. Oral midazolam administration is widely preferred for children due to its non-invasive nature, despite slower onset and variable bioavailability. Current guidelines recommend oral midazolam doses between 0.25 and 1 mg/kg; however, optimal dosing balancing effectiveness and safety remains unclear.

Recognizing this gap, this randomized controlled trial aims to compare two oral midazolam doses (0.3 mg/kg versus 0.6 mg/kg) in preschool children aged 3-6 years who exhibit dental anxiety. Conducted from June to December 2024 at the National Hospital of Odonto-Stomatology in Hanoi, Vietnam, this prospective, double-blind study enrolls 80 pediatric patients who meet strict inclusion and exclusion criteria. Children included have significant dental anxiety, assessed as "negative" or "definitely negative" based on the Frankl Behavior Rating Scale, normal body weight, and an ASA (American Society of Anesthesiologists) physical status of I or II. Patients with systemic diseases, cognitive impairments, severe respiratory conditions, liver or kidney dysfunction, mental disorders (e.g., autism, ADHD), or allergies to sedatives are excluded from participation.

Participants are randomly assigned using block randomization into two groups receiving either 0.3 mg/kg or 0.6 mg/kg oral midazolam. Blinding ensures dentists performing procedures and data collectors remain unaware of dosing specifics to minimize bias. Sedation effectiveness is measured using the Ramsay Sedation Scale (RSS), with successful sedation defined as achieving RSS score 3 ("awake but responds to commands only") within 30 minutes post-administration. Children not reaching this sedation level within the specified timeframe are excluded from further analysis.

Vital signs, including heart rate and oxygen saturation, are closely monitored throughout the procedure. Patient behavior during dental treatment is assessed using the Houpt Behavior Rating Scale, which evaluates sleepiness, movement, and crying. The study also investigates midazolam's amnesic effects through structured memory assessments conducted 12 hours, 24 hours, and one week post-procedure.

Additionally, safety assessments monitor adverse events such as respiratory depression, hypotension, excessive sedation, nausea, and vomiting during sedation and 24 hours afterward. The collected data undergo statistical analysis using SPSS software, employing independent t-tests for continuous variables (e.g., sedation onset time, treatment duration, recovery time) and chi-square or Fisher's exact tests for categorical variables (e.g., sedation success rates, amnesia outcomes). A significance threshold is established at p<0.05.

Through detailed evaluation of sedation efficacy, amnesic effect, patient safety, and procedural cooperation, this research seeks to clarify optimal midazolam dosing strategies, contributing to improved clinical practices, reduced dental anxiety, and better overall pediatric dental experiences.

Inclusion Criteria:

• Children aged 3 to 6 years.
• Diagnosed with dental anxiety classified as "definitely negative" or "negative" based on the Frankl Behavior Rating Scale.
• Normal weight range.
• Classified as ASA I or ASA II (American Society of Anesthesiologists Physical Status Classification).

Exclusion Criteria:

• Endocrine disorders, severe respiratory diseases, or heart diseases.
• Mental health conditions such as autism, ADHD, or schizophrenia.
• Abnormal brain development or cognitive impairments.
• Liver or kidney dysfunction.
• Known allergies to benzodiazepines, opiates, etomidate, propofol, ketamine, or other medications used in the study.