Clinical performance of low-concentration bleaching gels with hyaluronic acid and NF_TiO2 nanoparticles activated by violet LED: A randomized clinical trial

Resumo (EN)

Objectives: To evaluate the bleaching efficacy, tooth sensitivity (TS), pulpal oxygen saturation (SaO2), and patient satisfaction following in-office bleaching using experimental gels containing hyaluronic acid (HA) or carbomer 940 (CAR), co-doped TiO2 nanoparticles with nitrogen and fluoride (NP; NF_TiO₂), and 6 % hydrogen peroxide (HP), activated by violet LED.

Methods: Seventy-two participants were randomly assigned to three groups (n = 24): HP35 (commercial bleaching gel), HA-NP-HP6+LED, and CAR-NP-HP6+LED. Bleaching was performed in three weekly sessions (1 × 30 min; 1-week interval). TS (VAS) and SaO2 were recorded before and after each session, with TS reassessed seven days post-treatment. Tooth color was evaluated at baseline, 14 days, and 6 months post-treatment. The parameters ΔEab, ΔE00, ΔWID, and ΔSGU were calculated. Patient satisfaction was assessed using a subjective scale. Statistical analysis was performed using one-way ANOVA with Tukey post hoc and non-parametric tests (α = 0.05).

Results: The HP35 group showed significantly higher bleaching efficacy after 14 days. However, at the 6-month evaluation, the experimental gels exhibited similar performance. TS was significantly lower in the experimental groups (p < 0.05), while SaO2 levels remained stable across all groups. All participants (100 %) reported satisfaction with the outcomes.

Conclusions: Low-concentration bleaching gels containing 6 % hydrogen peroxide and NF_TiO₂ nanoparticles showed comparable efficacy to a 35 % hydrogen peroxide gel after 6 months, with less tooth sensitivity and no adverse effects on pulp oxygen saturation. Patient satisfaction was high across all groups, supporting the clinical viability of these safer experimental gels.

Clinical relevance: Low-concentration gels enhanced with NF_TiO₂ nanoparticles and activated by violet LED may provide an effective and patient-centered bleaching option, maintaining long-term results while minimizing sensitivity.