Effectiveness of a new non-hydrogen peroxide bleaching agent after single use - a double-blind placebo-controlled short-term study

Abstract

Introduction: Tooth whitening represents perhaps the most common aesthetic procedure in dentistry worldwide. The efficacy of bleaching depends on three aspects: bleaching agent, bleaching method, and tooth color.

Objective: This in vivo study aimed to examine whitening effects on frontal teeth of the upper and lower jaws using an over-the-counter (OTC) non-hydrogen peroxide bleaching agent in comparison to a placebo after one single use.

Material and methods: Forty subjects (25 female; 15 male) participated in this double-blind randomized placebo-controlled trial. The subjects were randomly allocated to two groups (n=20). The test group received the OTC product (iWhite Instant) and the placebo group received an identically composed product except for the active agents. Each subject was treated with a prefilled tray containing iWhite Instant or the placebo for 20 minutes. The tooth shade of the front teeth (upper and lower jaws) was assessed before (E_0), immediately after (E_1) and 24 h after treatment (E_2), using a shade guide (VITA classical). Statistical testing was accomplished using the Mann-Whitney U test (p<0.001). The dropout rate was 0%.

Results: There were no significant differences at E_0 between placebo and test groups regarding the tooth color. Differences in tooth color changes immediately after (ΔE1_0) and 24 h after treatment (ΔE2_0) were calculated for both groups. The mean values (standard deviations) of tooth color changes for ΔE1_0 were 2.26 (0.92) in the test group and 0.01 (0.21) in the placebo group. The color changes for ΔE2_0 showed mean values of 2.15 (1.10) in the test group and 0.07 (0.35) in the placebo group. For ΔE1_0 and ΔE2_0 significant differences were found between the groups.

Conclusion: In this short-term study, the results showed that a non-hydrogen peroxide bleaching agent has significant whitening effects immediately and 24 h after a single-use treatment.

Figure 1. Ingredients of the test and placebo bleaching gels

Figure 2. CONSORT 2010 flow diagram

Figure 3. Values of the tooth color of the bleaching product and the placebo for baseline examination, immediately and 24 h after bleaching; n.s. (not significant); *** (p<0.001)

Figure 4. Distribution of shade improvement for the iWhite Instant between baseline and immediately after bleaching (a) per teeth (b) per subjects

Figure 5. Values of the color change for bleaching and placebo groups between baseline and immediately after bleaching, between immediately and 24 h after bleaching, and between baseline and 24 h after bleaching n.s. (not significant); *** (p<0.001)