Evaluation of reservoirs in bleaching trays for at-home bleaching: a split-mouth single-blind randomized controlled equivalence trial

Abstract

Objectives: This randomized, split-mouth, single-blinded trial assessed whether the use of reservoirs in at-home bleaching trays is equivalent to non-reservoir trays. Our choice of an equivalence trial was based on the expectation that a non-reservoir tray is sufficient to produce a color change. Secondary outcomes such as tooth sensitivity (TS) and gingival irritation (GI) were also assessed. Methodology: Forty-six patients were selected with canines shade A2 or darker. In half of the patient's arch, bleaching trays were made with reservoirs and the other half, without reservoirs. At-home bleaching was performed with carbamide peroxide (CP) 10% (3 h daily; 21 days). Color change was evaluated with a digital spectrophotometer (ΔE, ΔE00, and Whiteness Index) and shade guide units (ΔSGU) at baseline, during and one-month post-bleaching. TS and GI were assessed with a numeric scale (NRS) and a visual analog scale (VAS). Results: After one month, the equivalence of reservoir and non-reservoir groups were observed in all color instruments (p>0.05). Fifteen and sixteen patients presented pain (absolute risk: 33% and 35%, 95%, confidence interval (CI) 21-46% and 23-49%) in the reservoir and non-reservoir side, respectively. The odds ratio for pain was 0.8 (95%CI 0.2-3.0) and the p-value was non-significant (p=1.0). TS intensity was similar between both groups in any of the pain scales (p>0.05). No difference in the GI was observed (p>0.05). Conclusions: The protocol with reservoirs is equivalent in color change to the non-reservoir, although no superiority of the latter was observed in terms of reduced TS and GI with at-home 10% carbamide peroxide bleaching. Clinical Relevance: The presence of reservoirs in a bleaching tray did not improve color change or affect tooth sensitivity and gingival irritation.

Whitening Efficacy of 3% Carbamide Peroxide Gel Activated by Lactoperoxidase

“…In this context, it is accepted that variations in ∆ E of ≥2.7 units indicate color changes, while variations of ≥3.3 units are indicative of clinically obvious changes in tooth color [38]. e Δ E retained in the present study was 3 [7].…”

“…Previous literature gave S 2 � 3.28 [13]. Assuming a 95% confidence interval (Z α/2 � 1.96) [14], an 80% power (Z 1 − β � −0.842) [14], and a minimal difference to detect equal to 3 [7], the total sample size was 19 for each group.…”

“…e VITA Shade Guide has 16 tooth tabs with different color shades. Shades were arranged from highest (B1) to lowest (C4) value as follows: B1, A1, B2, D2, A2, C1, C2, D4, A3, D3, B3, A3.5, B4, C3, A4, and C4 [7].…”

“…However, an optimum result may require several applications [6]. Secondly, at-home bleaching fundamentally involves the use of a gel applied in a fitted tray [7], containing low concentrations of whitening agents (10 to 20% CP) [3]. is technique has been used for several decades and is probably the most widely used one [8].…”

One‐year follow‐up evaluation of reservoirs in bleaching trays for at‐home bleaching

“…The 1‐month follow‐up of the present RCT 13 showed equivalent color change efficacy between bleaching trays with and without reservoirs. However, the literature still lacks long‐term evaluation of the bleaching protocols, mainly for different bleaching tray designs.…”