Clinical efficacy of a bleaching enzyme-based toothpaste. A double-blind controlled clinical trial.

OBJECTIVES: To assess the efficacy of a bleaching enzyme-based toothpaste. MATERIAL AND METHODS: A randomized clinical trial was carried out, comprising 48 participants with teeth exhibiting color A3 or higher according to the Vita Classical guide. One-half of the sample received the bleaching enzyme-based toothpaste (White Kin(®)), while the other received placebo toothpaste. Both products were supplied in identical containers and had the same composition except for the active components. The teeth color was measured with a spectrophotometer. The patients were instructed to brush their teeth three times a day during 3 min with the assigned product, during 12 weeks. The color measurements were repeated after 3, 6, 9 and 12 weeks of treatment. Color variation was based on the CIE L*a*b* coordinates, ΔE and the EW index. The relationship of these variables at different observation times were performed using a generalized estimating equations model, which evaluated the effect of treatment, time and interaction. RESULTS: The patients using the bleaching enzyme-based toothpaste showed an increase in lightness (80.14 -treatment- versus 79.25 -control group-) and a reduction in component b*. ΔE was found higher in the treatment group (p=0.064), close to statistical significance. CONCLUSIONS: The bleaching enzyme-based toothpaste could be potentially efficient in the modification in tooth color progressing from the third to ninth week of treatment, tending to stabilize after the ninth week. CLINICAL RELEVANCE: A very low carbamide peroxide concentration, with the incorporation of lactoperoxidase, tooth paste, tends to offer clinically satisfactory results, in terms of modifications in tooth color, nevertheless no significant differences were founded when compared to the control group, with an oral hygiene controlled along the study.

Therapeutic effectiveness of a new enzymatic bleaching dentifrice.

BACKGROUND: Research into bleaching focuses on new products in order to minimize undesirable effects. This study evaluated the bleaching effectiveness of a new enzymatic-activated dentifrice. MATERIALS AND METHODS: A total of 20 volunteers were bleached with a dentifrice containing 5% lactoperoxidase and 3% carbamide peroxide applied three times a day for two minutes over 21 days. Color was recorded before and after the treatment using a spectrophotometer. CIELAB differences were calculated before and after treatment using the paired t test (P < 0.05). RESULTS: Lightness was significantly higher after treatment (P < 0.001), ΔE was 5.14. The maxillary central incisors showed greater lightness than the laterals and canines, both before and after treatment, and a greater tendency towards green and blue; the same occurred in the mandibular central incisors in comparison to the canines and laterals. CONCLUSIONS: The use of brush-applied enzyme-activated carbamide peroxide at low concentrations with short exposure time is effective for whitening teeth. CLINICAL IMPLICATIONS: Enzymatic dental bleaching is able to increase the efficiency of low concentration peroxides, reducing the potential risk of peroxides on oral tissues.

Reliability of two color selection devices in matching and measuring tooth color.

OBJECTIVE: The objective of this study was to investigate the intra and interdevice reliability of two tooth color measurement devices: EasyShade (ES) and SpectroShade Micro (SSM). MATERIALS AND METHODS: Tooth color was measured in six maxillary and mandibular. L*, a* and b* values and shade matches to VITA Classical and Vitapan 3D-Master shade guide systems were determined for all teeth. ΔE was assessed. Paired t-test and correlation coefficient (ICC) were used. RESULTS: Intradevices no significant differences (p > 0.05) were found between L*, a*, b*. Interdevice L* and b* were significantly higher for ES (p < 0.05), while a* was significantly higher for SSM (p < 0.05). ΔE showed no significant interdevice difference (p > 0.05). Intradevices ICC values were higher for ES but not significant (p > 0.05). DISCUSSION: The null hypotheses that they present no differences in their color measuring within devices or shade systems is accepted, but the results allow to reject the null hypotheses that they present no differences in their color measuring or shade systems between devices. CONCLUSION: Both EasyShade (ES) and SpectroShade Micro (SSM) show excellent repeatability and so they can be used in office to evaluate tooth color or to assess color changes after treatment. CLINICAL SIGNIFICANCE: Dental color can be diagnosed using dental spectrophotometers, allowing to detect in an objective way therapeutic dental color changes.

In vitro evaluation of the efficacy of two bleaching procedures

Objective: In vitro comparison of the efficacy of two bleaching procedures, one based on carbamide peroxide (CP)and the other on hydrogen peroxide (HP), simulating clinical conditions.Study Design: Two groups of 20 teeth in each group were selected. Group A: 22% CP, one hour a day for 21 consecutivedays. Group B: 37.5% HP, in 2 treatment sessions with an one week interval between each session. At eachsession the product was applied three successive times for eight minutes. Colour was recorded before treatment,when it was finished and one week after finishing it, with the Vita EasyShade spectrophotometer. CIEL*a*b* andΔE were established at each moment in the study. Intra-group data was compared using the paired t-test and intergroupdata with the independent groups t-test. Scores from the Vita Classical guide provided with the device wererecorded and the colour improvement percentage was calculated.Results: In both groups significant whitening was achieved by the end of treatment. Lightness remained significantlyhigh when treatment was finished and one week after in both groups. The percentage of bleaching wassignificantly higher in group A.Conclusions: Both 22% CP and 37.5% HP were effective for bleaching teeth. Bleaching effect was greater in CPgroup (AU)

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In vitro evaluation of the efficacy of two bleaching procedures.

OBJECTIVE: In vitro comparison of the efficacy of two bleaching procedures, one based on carbamide peroxide (CP) and the other on hydrogen peroxide (HP), simulating clinical conditions. STUDY DESIGN: Two groups of 20 teeth in each group were selected. Group A: 22% CP, one hour a day for 21 consecutive days. Group B: 37.5% HP, in 2 treatment sessions with an one week interval between each session. At each session the product was applied three successive times for eight minutes. Colour was recorded before treatment, when it was finished and one week after finishing it, with the Vita EasyShade spectrophotometer. CIEL*a*b* and ΔE were established at each moment in the study. Intra-group data was compared using the paired t-test and inter-group data with the independent groups t-test. Scores from the Vita Classical guide provided with the device were recorded and the colour improvement percentage was calculated. RESULTS: In both groups significant whitening was achieved by the end of treatment. Lightness remained significantly high when treatment was finished and one week after in both groups. The percentage of bleaching was significantly higher in group A. CONCLUSIONS: Both 22% CP and 37.5% HP were effective for bleaching teeth. Bleaching effect was greater in CP group.

Toothguide Training Box for dental color choice training.

The purpose of this study was to evaluate the use of the Toothguide Training Box (TTB) for training dental students in color identification. The seventy-four volunteers who took part in the study attended a seminar on the Vita 3D Master Guide (MG) and the TTB system as well as a demonstration of the equipment before training began. At the end of the training they took the TTB final test. In addition, the participants were asked to recognize ten MG shade tabs in a blind manner before and after TTB training. The training times and percentages of correct answers were compared using the paired t-test. Variations in scores with training times and percentages of correct answers before and after training were compared using the ANOVA test. Training times between thirty-one and thirty-eight minutes provided a significantly higher mean score than training times of over thirty-eight minutes (p=0.036). The percentage of correct answers obtained with the MG before and after training shows a positive correlation. High TTB scores are associated with a greater number of correct answers in MG shade tab selection.

The use of atomic force microscopy in determining the stiffness and adhesion force of human dentin after exposure to bleaching agents.

INTRODUCTION: Oxidant bleaching agents may induce several alterations on mineralized teeth tissues. Our aim is to study, at the ultrastructural level, mechanical modifications induced on dentin after exposure to different bleaching agents. METHODS: Nanoindentation performed with atomic force microscopy was used to measure changes in dentin stiffness as well as the adhesion force between the tip and the tissue both in intertubular and peritubular dentin. For each specimen, dentin localization, and bleaching agent, 100 independent nanoindentations were performed. Carbamide peroxide (30%) and hydrogen peroxide (35%) were used as bleaching agents. RESULTS: A significant reduction of both stiffness and adhesion force was found for both carbamide and hydrogen peroxide in peritubular and intertubular dentin. CONCLUSIONS: The use of bleaching agents led to a significant reduction in dentin local (at the nanoscale) mechanical properties.