Does Virtual Reality Exposure Therapy Affect Children's Dental Anxiety, Pain, and Behaviour? A Randomized, Placebo-Controlled Cross-Over Trial

This randomized, two-armed, placebo-controlled, cross-over, controlled trial adhered to the principles of the Declaration of Helsinki, good clinical practice guidelines, and applicable regulatory requirements. Ethics approval was obtained from the Health Ethics Committee of Sivas Cumhuriyet University (Sivas, Turkey; ID: 2018-02/08). All parents or guardians of children were educated about the study before enrollment and provided informed written consent to participate. The trial adhered to the Consolidated Standards of Reporting Trials (CONSORT) guidelines.

The parameters used to calculate the sample size included a 95% confidence interval (CI), 80% statistical power, and a standard deviation of 1.90; accordingly, at least 64 subjects were required. This number was adjusted to 76 subjects to compensate for a projected loss of approximately 20% during follow-up. Thus, 76 healthy subjects between 7 and 11 years of age were included in the study. Participants who fulfilled the following criteria were included: systemically and mentally healthy; required restorative treatment for first mandibular permanent molar tooth with dentin caries in each mandibular quadrant with a bilateral inferior alveolar nerve block; absence of co-operative disability; and Frankl Scale score 2 or 3 during first dental examination. Patients with systemic or mental illnesses, reduced audiovisual capabilities, acute dental pain or trauma, those with previous painful or negative dental experience, and those who were extremely uncooperative were excluded.

The present randomized, two-armed, within-subject, cross-over, controlled trial included patients who applied to Department of Pediatric Dentistry, Cumhuriyet University, for routine dental treatment.The study comprised three visits: V0, baseline dental examination and inclusion; V1, first restorative treatment session; and V2, second restorative treatment session for symmetrical teeth. The initial oral and radiographic examination and Frankl Behaviour Scale scoring of all patients were performed by one experienced and pre-calibrated researcher. A dental assistant not participating in the study used a random-order generator (http://www.random.org) to randomize patients to the experimental group according to block randomization.

Eligible participants were treated in two different appointments: protective glasses only, without distraction (APC); or with the treatment condition (VRET). All procedures were performed by a single experienced and calibrated paediatric dentist (BB).

Participants were randomly assigned by a computer algorithm to receive VR with the first or second sequential dental treatment session and with protective glasses for the other treatment session. The investigators were blinded to treatment sequence until before the first dental treatment was to begin. Before VRET, the VR headset was shown to the patients, who were permitted to handle it. This enabled the patient to recognize the device and be familiar with it before treatment. Before starting treatment, the VR headset was placed on each patient's head, and the patient was asked whether the device caused pain or discomfort, and the patient's consent was confirmed. In the APC group, each patient was informed about the dental procedure and was provided with protective glasses. All patients were told that they were wearing these glasses to ensure a pain- and stress-free treatment, and that the dentist would devote additional attention to the treatment. This aimed to provide the patient with feeling like being in an experimental session. The reason for choosing an APC group with the routine protective glasses without distraction was to mitigate possible Hawthorne effects.