Effect of personality characteristics on perception of tooth whitening outcome in young adults in long-term: a randomised, double-blind, placebo controlled trial.

Background: Tooth whitening is a popular cosmetic procedure; however, its perceived effectiveness and long-term psychosocial impact remain underexplored. This study investigated perceptions of tooth color change and the associated psychological and social effects over a one-year period, with particular attention to the role of individual personality traits.

Methods: Fifty participants aged 19 to 28 were randomly assigned to either an experimental group or a control group. The experimental group received a light-activated whitening gel, while the control group received an inactive gel. Evaluations were conducted at baseline, one week post-treatment, and one year post-treatment. Tooth color was measured using spectrophotometry. Standardized questionnaires were employed to assess psychosocial effects and personality traits. Data were analyzed using analysis of variance with Bonferroni post hoc tests and independent samples t-tests.

Results: The experimental group showed a significantly greater improvement in tooth color shortly after treatment compared to the control group. Although this improvement diminished over time, it remained above baseline levels at the one-year follow-up. In the short term, participants in the experimental group reported reduced psychological and social concerns, while the control group reported a decrease in psychological impact only. After one year, the experimental group experienced a return of psychosocial concerns, whereas the control group continued to report improvements. Personality traits influenced these outcomes: lower neuroticism and higher perfectionism were associated with enhanced short-term benefits, while higher conscientiousness was linked to more sustained long-term improvements.

Conclusions: Participants demonstrated limited ability to accurately perceive improvements in tooth color, often noticing relapse over time. The psychosocial impact of tooth whitening was influenced by personality traits, highlighting the importance of a personalized approach in cosmetic dental treatments. Practitioners should consider individual psychological profiles when managing patient expectations.

Trial registration: This clinical trial was prospectively registered with ClinicalTrials.gov (Identifier NCT03380702) on December 21, 2017.