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, ΔE, WI) 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.