In vitro assessment of the effectiveness of whitening dentifrices for the removal of extrinsic tooth stains

Abstract

This in vitro study evaluated the effectiveness of whitening dentifrices for the removal of extrinsic tooth stains. Twenty dental blocks (4 x 4 mm), including enamel and dentine, removed from freshly extracted bovine incisors, were randomly divided into 4 groups: G1 -distilled water, G2 -Colgate, G3 -Crest Extra Whitening and G4 -Rapid White. In all specimens, the dentin was covered with colorless nail polish, and the enamel was left exposed. Next, the specimens were immersed in a solution of black tea, which was changed every 24 h, for a period of 6 days. After this period, a photo-reflectance reading was taken (Time 1) with a spectrometer. The stained specimens were then submitted to linear brushing movements (5,000 cycles) using brushes (Oral B-Soft) coupled to an automatic toothbrushing machine, under a static axial load of 200 g and with a speed of 4 movements/second, at 37°C, with the dentifrice or water being injected every 60 s. When toothbrushing ended, a second photo-reflectance reading was taken (Time 2). The results were submitted to two-criteria analysis of variance (ANOVA) and to the Tukey test (α = 0.05). When the two times for a same group were compared, Time 2 presented the highest reflectance values with statistical difference only for G3 and G4. Among the dentifrices tested, only the Rapid White group differed from the control group, presenting the highest reflectance values. Only the whitening dentifrice Rapid White was effective for the removal of extrinsic stains.

Evaluation of surface roughness of a nanofill resin composite after simulated brushing and immersion in mouthrinses, alcohol and water

“…Brushes with soft bristles and rounded edges (TEK ® , Johnson & Johnson ® , São Paulo, Brazil) were fixed to the apparatus and kept alongside the samples, using slurry of Colgate ® Total 12 Clean Mint dentifrice with distilled water in a ratio of 1:3 by weight 20 . Simulated brushing was performed with a linear movement, speed of 4.5 cycles per second, a cycle understood as being the complete back-and-forth movement of the toothbrush.…”

“…Simulated brushing was performed with a linear movement, speed of 4.5 cycles per second, a cycle understood as being the complete back-and-forth movement of the toothbrush. Each experimental group (1) Listerine ® Vanilla Mint, (2) Plax ® without alcohol, (3) Oral B ® alcohol-free, (4) alcohol 96, and (5) distilled water, was subjected to 02 intercalated time periods of 5,000 brushing cycles equal to a total of 10,000 cycles (representing the total time of 1 year of brushing) each time period performed in 40 minutes 20 . At the end of each cycle, the samples were washed under running water to remove the toothpaste.…”

Over-the-counter whitening agents: a concise review

“…9 Their stain-removal ability is related to the large quantity of abrasives in their formulation, which remove superficial extrinsic stains. 10 The active components of tooth whitening dentifrices include enzymes that break down the organic molecules of biological film. Additionally, abrasives such as alumina, dicalcium phosphate dihydrate and silica are also present in the formulation to promote stain-removal.…”

“…11 A number of studies have been published to measure changes in tooth color after regular whitening toothpaste use. [10][11][12] Generally, when whitening dentifrices are compared to non-whitening toothpastes the results have demonstrated that their use can remove and/or prevent extrinsic tooth stains. 1,10,13,14 Although whitening toothpastes can prevent ex-trinsic tooth stains, the whitening effect obtained seems not to be clinically significant.…”

“…[10][11][12] Generally, when whitening dentifrices are compared to non-whitening toothpastes the results have demonstrated that their use can remove and/or prevent extrinsic tooth stains. 1,10,13,14 Although whitening toothpastes can prevent ex-trinsic tooth stains, the whitening effect obtained seems not to be clinically significant. A study that compared the efficacy and safety of three OTC bleaching products (1% hydrogen peroxide dentifrice, 18% carbamide peroxide paint-on gel, and 5% carbamide peroxide tray system) showed that the group treated with the tray system experienced the greatest color improvement.…”