Aim: The objective of this study was to analyze the reassuring role of music associated with the personality traits of children during dental care. Method: The study involved a randomized crossover clinical trial with 34 children, aged from 4 to 6 years, who exhibited two carious lesions on the occlusal surfaces of the molars. The children were divided into two groups: (G1) first tooth restoration intervention session with music, second session without music; and (G2) first tooth restoration intervention session without music, second session with music. The first consultation was to perform a clinical examination, and the second and third to perform modified Atraumatic Restorative Treatment (mART). Symphony No. 40 by Mozart was played via headphones. Pulse rate (PR) was measured using a pulse oximeter. The Brazilian version of the Eysenck Personality Questionnaire-Junior (EPQ-J) was used to measure the children’s personality. For statistical analysis, descriptive, Chi-square, and Wilcoxon tests were carried out. Results: The G1 group exhibited a lower PR at the time of the intervention during the second consultation compared to the third consultation (p = 0.012). The G2 group exhibited a lower PR at the time of the intervention during the third consultation compared to the first consultation (p = 0.002). The majority of the children with a low level of extraversion presented with higher PR (p = 0.005). Conclusion: Music could reduce the PR among children during dental intervention. Children with low extraversion showed a tendency towards a higher PR without music during dental care.