To compare the effectiveness of inhalation sedation with nitrous oxide/oxygen (N₂O/O₂) and cognitive behavioural therapy (CBT) in reducing dental anxiety in preschool children.

Randomised controlled clinical trial.

This study was conducted on 45 preschoolers with moderate to severe dental anxiety (determined by the Children’s Fear Survey Schedule Dental Subscale), who required pulp treatment of at least one primary mandibular molar. Baseline anxiety and cooperation levels were determined using Venham Clinical Anxiety and Cooperation Scales (VCAS and VCCS) and Venham Picture Test (VPT) at the first dental visit (dental prophylaxis and fluoride treatment). Before the second dental visit (pulp treatment), the children were randomly assigned to one of three groups—1: control, 2: N₂O/O₂ and 3: CBT. In group 1, the usual behaviour management techniques were used, in group 2, nitrous oxide/oxygen gas was used and in group 3, unrelated play, Benson’s breathing and positive self-talk and modelling were used. Anxiety and cooperation levels were determined at three periods: injection, rubber dam placement and the application of a high-speed handpiece with VCAS and VCCS and VPT. Finally, anxiety and cooperation differences between the two dental visits were compared within the three groups.

Chi square, ANOVA and Kruskal–Wallis and Mann–Whitney U tests were used.

N₂O/O₂ and CBT significantly resulted in lower anxiety and higher cooperation in the second visit (at all three periods) compared to the control, although there was no significant difference between these two treatment methods.

Both test methods were effective in reducing dental anxiety in preschoolers. Considering the adverse effects and necessity of equipment and trained personnel when using nitrous oxide and oxygen inhalation sedation, cognitive behavioural therapy is preferable because of its better applicability.