In-office Bleaching After a Desensitizing Protocol: a 4.5-Year Follow-up of a Randomized Controlled Trial

Objectives

This clinical trial aims to evaluate the bleaching efficacy and longevity of in-office bleaching after 4.5 years with or without ibuprofen/arginine desensitization.

Methods

Sixty-two patients, canines darker than A2 and in good general and oral health were selected and their hemi-arches randomized to receive an ibuprofen-arginine or placebo desensitizing gels before in-office dental bleaching. Two bleaching sessions (35% hydrogen peroxide gel; 1-week) were performed. Color change was evaluated using the Vita Classical, Vita Bleachedguide (ΔSGU), and Vita EasyShade spectrophotometer (ΔE_ab, ΔE₀₀, WI_D) before dental bleaching, one month and 4.5 years after the bleaching procedure. Data was evaluated by paired t-test (α = 0.05). Long-term dental tooth sensitivity, patient satisfaction and desire for a new bleaching procedure were evaluated.

Results

After 4.5 years, no significant difference in color change was found between the desensitizing and placebo sides (p > 0.05). A significant color rebound was observed (mean ΔSGU Classical 2.1 units, per-protocol analysis), though bleaching effects remained clinically relevant. Long-term tooth sensitivity was reported by 25.5% of participants. Patient satisfaction was moderate (mean VAS 6.7 ± 2.6), with 85.1% expressing interest in additional bleaching.

Conclusions

In-office dental bleaching showed sustained whitening effects after 4.5 years, despite a mild color rebound.

Clinical relevance

In-office bleaching maintains clinically acceptable whitening for over 4 years despite slight color rebound.