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NCT Number: NCT07351383

Topical Cryoanesthesia Versus Benzocaine in Pediatric Dentistry

This clinical study tested and compared two ways (cold-base technique or "cryoanesthesia" and conventional benzocaine gel) to reduce pain from dental injections in children.

Researchers worked with 28 children between 6 and 12 years old who needed injections on both sides of the lower jaw for dental treatment. Each child received cryoanesthesia on one side and 20% benzocaine gel on the other side, in different appointments, and the team measured pain, behavior, heart rate, and blood oxygen levels.

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Key information

Conditions

Local Anesthetic Infiltration Pain Perception Topical Anesthesia

Age range

6 year–12 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Pediatric Dentistry Postgraduate Program, Faculty of Denttistry

San Luis Potosí City, S.l.p., 78990, Mexico

About this study

Objective: To evaluate and compare pain perception during inferior alveolar nerve block puncture in pediatric patients using cryoanesthesia versus conventional topical benzocaine anesthesia.

Methods: A split-mouth randomized controlled clinical trial was conducted with 28 patients aged 6 to 12 years requiring bilateral inferior alveolar nerve blocks for bilateral lower arch dental treatment. Each participant received both anesthetic techniques in a randomized order on separate appointments, with treatment allocated to contralateral mandibular hemiarches. Primary and secondary outcome measures included pain intensity (Visual Analog Scale), heart rate, oxygen saturation, and behavioral response (FLACC scale).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Systemic health: No significant medical history or uncontrolled systemic disease.
  • Bilateral dental pathology requiring treatment: At least two teeth (one per mandibular hemiarch) requiring bilateral inferior alveolar nerve blocks for restorative or endodontic treatment.
  • Cooperation level: Frankl behavioral rating scale classification III or IV (positive or very positive).
  • Informed consent/Child assent: Signed informed consent from parent or legal guardian; signed assent from participant (age-appropriate).

Exclusion criteria

  • Acute dental emergency requiring immediate treatment.
  • Known hypersensitivity or allergy to benzocaine or other local anesthetics.
  • Known hypersensitivity to cold (cryophobia or cold urticaria).
  • Significant dental anxiety or phobia precluding study participation.
  • Developmental delay or behavioral disorders limiting communication or cooperation.
  • Current use of medications affecting pain perception or hemodynamic parameters.

Treatment and study plan

Local Anesthesia (lidocaine hydrochloride)

Procedure

After topical anesthesia (either technique), the clinician proceeded with conventional inferior alveolar nerve block using standardized technique:

  • Patient positioned recumbent in dental chair with mouth held open.
  • Palpation of ipsilateral mandibular condyle by clinician's non-dominant hand.
  • Cheek retracted with non-dominant hand to improve visualization.
  • Long needle (27-gauge, 32 mm) inserted at horizontal level of contralateral mandibular canine, directed toward insertion of lateral pterygoid muscle below maxillary tuberosity.
  • Needle advanced to contact medial mandibular wall (lingual surface).
  • Aspiration performed to rule out intravascular needle placement.
  • Injection of local anesthetic solution (1.8 mL of 2% lidocaine with 1:100,000 epinephrine).
  • Needle carefully withdrawn following injection completion.

Primary outcomes

  1. Pain perception

    Time frame: Baseline: At the time of the anesthetic injection (or needle puncture) at the oral mucosa.

    Pain intensity was assessed using a validated instrument:

    Wong-Baker FACES® Pain Rating Scale (Visual Analog Scale): Immediately following completion of infiltration anesthesia injection, the participant was asked to indicate the level of pain experienced using the face scale (0 = no hurt to 10 = hurts worst).

Secondary outcomes

  1. Heart Rate

    Time frame: Periprocedural: During the injection anesthetic procedure, from the anesthetic solution injection to the removal of the needle (approximately 45 seconds)

    Continuous pulse oximetry monitoring was conducted using a calibrated pulse oximeter (typical brands: Nellcor or equivalent) with appropriate pediatric finger probe or reusable sensor. Measurement unit: Pulses per minute (ppm) for heart rate (HR), which were recorded at two time points:

    • Baseline measurement: Immediately before topical anesthetic application, with the participant in a calm resting state.
    • During anesthetic infiltration: Recorded during active injection of local anesthetic solution into the infiltration site (oral mucosa).

  2. Oxygen saturation

    Time frame: Periprocedural: During the injection anesthetic procedure, from the needle puncture to the removal of the needle (approximately 45 seconds).

    Percentage of blood's hemoglobin carrying oxygen (normally 95-100%). Continuous pulse oximetry monitoring was conducted using a calibrated pulse oximeter (typical brands: Nellcor or equivalent) with appropriate pediatric finger probe or reusable sensor. Measurement units: SpO2 percentage (%), which was recorded at two time points: 1. Baseline measurement: Immediately before topical anesthetic application, with the participant in a calm resting state. And 2. During infiltration measurement: During active injection of local anesthetic solution into the infiltration site.

  3. Patient's behavioral response

    Time frame: Periprocedural: 45 seconds, from the anesthetic injection to the removal of the needle.

    Observable emotional and physiological reactions to the anesthetic injection through the FLACC (Facial expression, Legs, Activity, Cry, and Consolability) scale. Values: 0-10 (0 = relaxed, calm; 10 = severe distress).

Sponsors and collaborators

Lead sponsor

Universidad Autonoma de San Luis Potosí

Other

Registry information

Official study title

Comparison of Topical Cryoanethesia and Benzocaine in Pain Perception During Mandibular Nerve Block in Pediatric Patients: A Randomized Controlled Clinical Trial

Acronym: No acronym

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Jan 20, 2026
Registry last updated
Jan 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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