Abstract
INTRODUCTION: Teeth whitening is one of the most frequently requested cosmetic dental procedures. However, concerns about the long-term impact of various whitening methods on enamel microhardness and patient satisfaction remain. This study aimed to evaluate the effects of three commonly used whitening techniques-professional in-office bleaching, at-home bleaching, and over-the-counter (OTC) products-on enamel microhardness and patient satisfaction over time. METHODS: A total of 90 participants were divided into three groups: 30 received in-office bleaching, 30 performed at-home bleaching, and 30 used OTC whitening products. Enamel microhardness was measured before and after treatment using a Vickers microhardness tester. Patient satisfaction was assessed via a standardized questionnaire at two intervals: immediately post-treatment and three months later. RESULTS: Significant differences were found between the groups regarding enamel microhardness, with in-office bleaching causing the greatest reduction (P < 0.05). At-home bleaching showed a moderate decrease, while OTC products had the least impact on microhardness. In contrast, patient satisfaction was highest in the in-office bleaching group, followed by at-home and OTC groups. CONCLUSION: Although in-office bleaching led to a significant reduction in enamel microhardness, it was associated with the highest patient satisfaction. This highlights the need for clinicians to balance efficacy and enamel preservation when recommending whitening treatments.