A Clinical Study of Three In-office Dental Bleaching Systems

Objective: This clinical trial evaluated shade change and color stability (ΔE) of three in-office dental bleaching systems.

Method: 80 patients were randomly divided into 4 groups (n=20): ZAP1–25% Hydrogen Peroxide (HP) + iron complex - Zoom 2 (Discus Dental) + Zoom AP Light (Discus Dental) – 1 treatment session; OPX1–38% HP-Opalescence Xtra Boost (Ultradent) – 1 treatment session; OPX2–38% HP-Opalescence Xtra Boost (Ultradent) – 2 treatment sessions; HPB2–20% HP-HP Blue (FGM) – 2 treatment sessions. Whitening treatments were performed according to manufacturers’ instructions, with three 15-minute applications per treatment session. Shades were assessed using a Vita-Easyshade Spectrophotometer immediately before the bleaching session and post treatment at 7, 14 and 30 days.

Result: Statistical analysis using ANOVA demonstrated that groups ZAP1 [ΔE_ZAP1=8.4(+-2.3)] and OPX2 [ΔE_OPX2=7.7(+-2.7)] obtained a similar bleaching result, superior to the results achieved by groups OPX1 [ΔE_OPX1=5.6(+-1.4)] and HPB2 [ΔE_HPB2=6.0(+-1.7)], (p<0.05). Color stability can be seen in the table below.

Treatment	7 days after bleaching	14 days after bleaching	30 days after bleaching
ZAP1	8.4 (+-2.3) Aa	8.2 (+-1.7) Ca	8.5 (+-3.0) Ea
OPX1	5.5 (+-1.2) Bb	5.5 (+-1.5) Db	5.9 (+-1.5) Fb
OPX2	7.8 (+-2.8) Ac	7.9 (+-2.4) Cc	7.4 (+-2.9) Ec
HPB2	6.2 (+-1.9) Bd	5.8 (+-1.7) Dd	6.0 (+-1.5) Fd

Means with different lowercase letters in the same row are statistically different (p<0.05); means with different capital letters in the same column are statistically different (p<0.05).

Conclusion: This clinical trial indicates that a single treatment session with the whitening system based on the Photo-Fenton reaction which uses HP 25% + iron complex (ZAP1) presented statistically similar results to two sessions of OPX (OPX2). These results were statistically superior to OPX1 (1 treatment session) and HPB2 (2 treatment sessions). All groups presented shade stability.