Safety and efficacy of a high-adhesion whitening strip under extended wear regimen.

OBJECTIVES: This randomized, parallel group, single centre clinical trial was conducted to evaluate the safety and compare the whitening efficacy for an extended wear of an experimental 9.5% H2O2 high-adhesion whitening strip, relative to a marketed 10% H2O2 control strip. METHODS: Twenty-nine eligible adult volunteers were randomly assigned to either a treatment series with an experimental 9.5% H2O2 high-adhesion whitening strip at home for 2h, once a day, for 8 days; or a marketed 10% H2O2 whitening strip for 30 min, on a similar daily regimen. Tooth color/whitening progression was recorded under standardized lighting conditions at baseline, day 3, day 5, and day 9, via digital imaging. Outcomes were reported using the CIELAB system. Usage safety was also assessed at each follow-up visit. Whitening efficacy for each group was investigated using a paired-difference t-test. The treatment groups were compared among each other using the analysis of covariance, with the baseline value and age as the covariates. RESULTS: Both treatment groups demonstrated statistically significant mean color improvement from baseline for b* (yellow ness) and L* (lightness) at each post-baseline visit. In addition, the 2-h high-adhesion strips demonstrated significantly greater improvement in b* and L* relative to the 30-min strip group at each follow-up visit. CONCLUSIONS: The 2-h regimen for the 9.5% H2O2 high-adhesion whitening strip was more efficient for tooth whitening than the 30-min regimen of 10% H2O2 whitening strip. Both treatments were well tolerated and the use of the test products during the study time frame was considered safe. CLINICAL RELEVANCE: Extending the daily wear time of whitening strips can improve the efficacy of the treatment and ultimately shorten the length of the treatment without any significant adverse effects.

Evaluation of bleaching efficacy and erosion potential of four different over-the-counter bleaching products.

PURPOSE: To evaluate the bleaching efficacy and erosion potential of various over-the-counter bleaching products following a test method specified in ISO 28399. METHODS: Specimens were prepared from bovine molars, stained in tea solution, embedded and randomly assigned to six groups of 10 enamel and dentin specimens each. Color was assessed at baseline, 1 day and 1 month post-bleaching with the Vita Bleachedguide 3D Master shade guide. Surface roughness changes (deltaRa), determined by baseline and post-treatment values were measured with a profilometer. The negative (NC) and positive control (PC) was treated with grade 3 water and 1.0% citric acid, respectively. Over-the-counter products were used according to manufacturer's instructions. Brite Teeth Pro (BT), Natural White 5-Minute Whitening (NW), Luster Premium White (LP), and Crest 3D Whitestrips (WS) represented a brush-on-paint system, tray system, light-activated system and adhesive-strip system, respectively. Kruskal-Wallis procedure was used to compare surface roughness changes among groups. Color change was assessed with Friedman-test and stratified by hard tissue type with alpha= 0.05. RESULTS: WS was the only group demonstrating color changes in enamel and dentin (P< 0.05). There were no differences in deltaRa for enamel and dentin among NC, BT, LP, and WS. NW showed increase in deltaRa in dentin (P< 0.05), while PC demonstrated an increase in deltaRa regardless of hard tissue type (P< 0.05).

The effectiveness of low-intensity red laser for activating a bleaching gel and its effect in temperature of the bleaching gel and the dental pulp.

STATEMENT OF THE PROBLEM: The effectiveness of low-intensity red laser for activating a bleaching gel and its effect in pulp temperature was not investigated in dental literature. PURPOSE: The objective of this study was to assess the effectiveness of low-intensity red laser for activating a bleaching gel, as well as its effect in temperature of the bleaching gel and the dental pulp. MATERIALS AND METHODS: Forty extracted bovine teeth were immersed in a solution of coffee 14 days for darkening. The initial colors were recorded by spectrophotometric analysis. The specimens were randomly distributed into two groups (N = 20): the control, which did not receive light and the experimental group that received light from an appliance fitted with three red light-emitting laser diodes (λ = 660 nm). A green-colored, 35% H(2) O(2) -based bleaching gel was applied for 30 minutes, and changed three times. After bleaching, the colors were again measured to obtain the L*a*b* values. Color variation was calculated (ΔE) and the data submitted to the non-paired t-test (5%). To assess temperature, 10 human incisors were prepared, in which one thermocouple was placed on the bleaching gel applied on the surface of the teeth and another inside the pulp chamber. RESULTS: There was a significant difference between the groups (p = 0.016), and the experimental group presented a significantly higher mean variation (7.21 ± 2.76) in comparison with the control group (5.37 ± 1.76). There was an increase in pulp temperature, but it was not sufficient to cause damage to the pulp. CONCLUSION: Bleaching gel activation with low-intensity red laser was capable of increasing the effectiveness of bleaching treatment and did not increase pulp temperature to levels deleterious to the pulp.

Clinical evaluation of the effectiveness of different bleaching therapies in vital teeth.

The aims of this in vivo study were to compare the effectiveness and color stability of at-home and in-office bleaching techniques and to evaluate whether the use of light sources can alter bleaching results. According to preestablished criteria, 40 patients were selected and randomly divided into four groups according to bleaching treatment: (1) at-home bleaching with 10% carbamide peroxide, (2) in-office bleaching with 35% hydrogen peroxide (HP) without a light source, (3) in-office bleaching with 35% HP with quartz-tungsten-halogen light, and (4) in-office bleaching with 35% HP with a light-emitting diode/laser. Tooth shade was evaluated using the VITA Classical Shade Guide before bleaching as well as after the first and third weeks of bleaching. Tooth shade was evaluated again using the same guide 1 and 6 months after the completion of treatment. The shade guide was arranged to yield scores that were used for statistical comparison. Statistical analysis using the Kruskal-Wallis test showed no significant differences among the groups for any time point (P > .01). There was no color rebound in any of the groups. The bleaching techniques tested were equally effective. Light sources are unnecessary to bleach teeth.

Tooth colour change with Ozicure Oxygen Activator: a comparative in vitro tooth bleaching study.

INTRODUCTION: This in vitro study compared a new tooth bleaching product, Ozicure Oxygen Activator (O3, RSA) with Opalescence Quick (Ultradent, USA) using a randomised block design to assess tooth colour change. AIM: Colour change, stability and relapse in canine, incisor and premolar teeth was assessed following three bleach treatments and subsequent tooth colour assessment. METHODS: Ninety nine teeth (canines, incisors and premolars), which were caries free, had no surface defects and were within the colour range 1M2 and 5M3 were selected. Teeth were randomly divided into the three experimental groups: Opalescence Quick, Ozicure Oxygen Activator and control. The three experimental groups received three treatments of one hour each over three consecutive days. Tooth colour was assessed using the Vitapan 3D Master Tooth Guide (VITA, Germany). A General Linear Models test for analysis of variance for a fractional design with significance set at P < 0.05 was used to test for significance. RESULTS: Both bleaching methods significantly lightened the teeth (P < 0.0001). Tooth colour change was mainly after the first hour of tooth bleaching. The tooth type was significant in tooth colour change (P = 0.0416). Tooth colour relapse and resistance to colour change were observed. CONCLUSIONS: Ozicure Oxygen Activator bleached teeth in a manner and to an extent similar to Opalescence Quick.

Effect of light units on tooth bleaching with visible-light activating titanium dioxide photocatalyst.

This study evaluated the influence of different light sources on the efficiency of an office bleaching agent containing visible-light activating titanium dioxide photocatalyst (VL-TiO(2)) using an artificial discoloration tooth model. Extracted bovine teeth were stained by black tea. The CIE L*a*b* values were measured before and after nine consecutive treatments by the VL-TiO(2)-containing bleaching agent (TiON in Office, GC, Tokyo, Japan). A halogen light unit (CB; CoBee, GC) or an LED unit (G-light, GC) with two modes (blue and violet: GL-BV, blue: GL-B) were used to activate the bleaching agent in three groups (n=8). Brightness (ΔL) and color difference (ΔE) increased as bleaching repeated in all groups. Two-way ANOVA showed that both number of treatments and light sources significantly affected ΔE (p<0.05). GL-BV showed better bleaching effect than GL-B. In measurement of irradiation spectra, CB showed a wide spectrum (380-530 nm), GL-B had a sharp peak at 470 nm and GL-BV showed an additional peak at 405 nm. It was concluded that the light source influenced the efficiency of the tooth bleaching with VL-TiO(2).

Lasers in dental traumatology.

AIM: Dental traumas are frequent in children. They can be complex events and sometimes real emergencies. Since very little attention is devoted to this topic in the international literature and there are no well-coded laser guidelines for these specific clinical events, our aim is to consider and present those situations in which laser-assisted therapy can offer new treatment possibilities. The authors' aim is to stimulate more extensive scientific research in this area, which might not only increase the use of these technologies, but also improve outcomes and reduce complications connected to dental trauma, particularly in children. Furthermore, laser-assisted therapies drastically reduce the need for analgesics and anti- inflammatory medications compared with conventional procedures. CONCLUSION: Using laser equipment to obtain anaesthesia is another challenge, while the use of low power setting for desensitising tissue and to obtain anaesthesia is also an open field.

Comparison of temperature increase in in vitro human tooth pulp by different light sources in the dental whitening process.

This work evaluated the increase in dental pulp temperature caused by different light sources, used in the dental whitening process, following the irradiation protocol from the light manufacturer. Human incisor, canine and premolar teeth were used. A whitening gel made of hydrogen peroxide 35% v/v and a condenser agent were applied to each tooth, on the vestibular surface, and was activated by five different light sources: photo-polymerizer with blue bandpass filtered halogen lamp (HL) (600 mW, lambda = 430-480 nm), blue light emitting diode (LED) (BL) (1 W, lambda = 470 nm), blue LED associated with infrared diode laser (BL+IL) (120 mW, lambda = 795 nm), green LED (GL) (600 mW, lambda = 530 nm) and green LED associated with infrared diode laser (GL+IL) (120 mW, lambda = 795 nm), with the equipment turned on, an exposure time of 1 min, and resting time of 30 s, repeated three times. The temperature was measured at the beginning and ending of exposure by a digital thermometer (type K thermocouple), placed inside the dental pulp chamber. Analyzing the mean temperature variation that occurred along the irradiation time, we found that the BL and BL+IL group presented the highest temperature variations, mainly in the incisor tooth. The GL and GL+IL presented the lowest temperature increase. The maximum temperature variation reached was 5.5 degrees C for the BL+IL in the incisor tooth. The HL presented a smaller temperature variation than the BL did, but it had a residual temperature when the light was off. The GL and GL+IL promoted a non-significant temperature increase, as low as 1 degrees C, even with total power equal to the that of the HL.

A study in vitro to compare home and surgery vital bleaching techniques.

The aim of this study was to compare the effectiveness of three different types of commonly used bleaching techniques using an in-vitro model. Five groups of 10 tooth specimens were prepared and allocated randomly to treatment groups. The four treatment groups tested were a home tray bleaching product, an 'in surgery' tray bleaching product and an 'in surgery power bleaching' product for use with an activating light. The bleaching agent in the latter group was also tested without light activation to assess the additional benefit of the bleaching lamp. A placebo group treated with water was also included. Colour change was assessed using a Vita shade guide and an electronic chromometer. The mean change in shade guide units ranged from 10.9 to 13.2 units, with the 'in surgery' tray bleaching system producing the largest change. For the chromometer readings the mean change in tooth colour ranged from 3.6 to 25.6 units, with the night guard vital bleaching product producing the largest change. This study has demonstrated in vitro that all the different bleaching systems tested produced comparable changes in tooth colour.

Tooth whitening: tooth color changes following treatment by peroxide and light.

OBJECTIVE: This study examined the use of color measurement to determine tooth color in a study of bleaching with peroxide and light used separately and in combination. Two measurement protocols were evaluated for their ability to reveal differences between treatments and confirm tooth shade evaluations. METHODOLOGY: Before and after treatment, 43 subjects were evaluated for tooth color using a shade guide and a chromameter. Two measurement procedures were used: one measured a single location on each tooth using a fabricated plastic stent, and the other measured nine locations across the buccal surface. Values from the two procedures were compared to each other, and to shade guide measurements. RESULTS: Tooth color, as measured by both procedures, significantly correlated with shade evaluation. Statistically significant differences between treatment groups were found more often with data from the multiple-site procedure than from the single-site procedure. Incisal-gingival color gradation on tooth surfaces was diminished as a result of whitening treatments. Chromameter measurement data showed that tooth whitening procedures reduced tooth yellowness (b) more reproducibly than they increased whiteness (L). CONCLUSION: When more sites per surface were measured, tooth color measurement by the chromameter more closely matched shade with less variability and greater statistical power. Chromameter-derived values can be used to estimate shade values to a reasonable level of accuracy. Decreasing yellowness, particularly at the gingival margin, was an important component of the tooth whitening effect. Following tooth whitening, teeth were more uniform in their color, and this may contribute substantially to the subjective patient recognition of whiter teeth.

Initial color change and color retention with a hydrogen peroxide bleaching strip.

PURPOSE: A randomized, double blind clinical trial was conducted to evaluate initial color improvement and post-treatment color retention following vital bleaching with a strip-based tooth whitening system. MATERIALS AND METHODS: After balancing for baseline color, 57 healthy adults were randomized to either whitening strips with a 5.3% hydrogen peroxide bleaching gel (Crest Whitestrips) or placebo strips without hydrogen peroxide. Maxillary and mandibular anterior teeth were treated twice daily for 30 minutes each over a 2-week period, and efficacy was measured objectively by comparing digital images of teeth collected at baseline, end-of-treatment (Week 2) and 6 months after treatment (Month 6). RESULTS: The whitening strip group experienced a highly significant (P< 0.0001) reduction in yellow of -2.0 deltab* units versus baseline and -1.95 deltab* units versus placebo, with similar results noted for the other color parameters in the study. Most of the initial color change remained at 6 months post-treatment, with the whitening strip group continuing to demonstrate highly significant (P< 0.0001) improvements in tooth color relative to baseline and placebo. Age was found to significantly contribute to initial color improvement, with younger subjects experiencing a greater initial reduction in yellowness compared to older participants, but not to post-treatment color retention. The whitening strips were well tolerated, with minor tooth sensitivity and oral irritation representing the most common findings during treatment. There were no persistent or new treatment-related adverse events during the 6-month monitoring period.

Effects of carbamide peroxides on wear resistance and color change of enamel opposing porcelain.

PURPOSE: This study evaluated the effects of a simulated 1- and 2-week night guard bleaching technique using various bleaching gel concentrations on wear resistance and color change of human enamel opposing a feldspathic porcelain substrate. MATERIALS AND METHODS: VMK 68 feldspathic porcelain was formed into 15-mm disks (n = 63) and fired according to manufacturer's recommendations. Enamel cusps were formed and shaped from extracted third molars and treated with 1 of 3 bleaching materials for 7 or 14 days. Specimens were kept at 37 degrees C in 100% humidity. The control group was subjected to identical conditions but with water replacing the bleaching gel between and during bleaching treatments. After simulated bleaching, the enamel cusp specimens were subjected to 3-body wear testing opposite a highly polished porcelain substrate. Enamel wear was evaluated using optical scanning methods, and color was measured with a small-aperture colorimeter. Data were subjected to a one-way repeated- measure analysis of variance and various post hoc statistics. RESULTS: Results indicated that the within effect of treatment time (7 or 14 days) did not significantly affect (p = 0.13) the size of the resulting enamel wear facet, whereas the between effect of bleaching concentration was significant (p = 0.01). Statistical analysis of unbleached control groups suggests that between-group differences can be explained by variations in wear rates of the 3 enamel groups, not by the concentration differences in bleaching gels. All bleaching treatments resulted in significant color changes (p = 0.04) compared to the unbleached control, but the bleach concentration did not significantly influence the magnitude of color change (p = 0.81). CONCLUSIONS: A simulated night guard vital bleaching treatment of 1 or 2 weeks had no significant effect on the wear resistance of human enamel in vitro. The increased bleaching treatment time and concentration did not significantly affect the amount of enamel color change.