In-office dental bleaching in adolescents using 6% hydrogen peroxide with and without gingival barrier: a randomized double-blind clinical trial.

BACKGROUND: At low concentrations used for in-office bleaching gels, such as 6% HP, gingival barrier continues to be performed. If we take into account that, in the at-home bleaching technique, no barrier is indicated, it seems that the use of a gingival barrier fails to make much sense when bleaching gel in low concentration is used for in-office bleaching. OBJECTIVE: This double-blind, split-mouth, randomized clinical trial evaluated the gingival irritation (GI) of in-office bleaching using 6% hydrogen peroxide (HP) with and without a gingival barrier in adolescents, as well as color change and the impact of oral condition on quality of life. METHODOLOGY: Overall, 60 participants were randomized into which side would or would not receive the gingival barrier. In-office bleaching was performed for 50 minutes with 6% HP in three sessions. The absolute risk and intensity of GI were assessed with a visual analogue scale. Color change was assessed using a digital spectrophotometer and color guides. The impact of oral condition on quality of life was assessed using the Brazilian version of the Oral Health Impact Profile (α=0.05). RESULTS: The proportion of patients who presented GI for the "with barrier" group was 31.6% and for the "without barrier" group, 30% (p=1.0). There is an equivalence for the evaluated groups regarding GI intensity (p<0.01). Color change was detected with no statistical differences (p>0.29). There was a significant impact of oral condition on quality of life after bleaching (p<0.001). CONCLUSIONS: The use or not of the gingival barrier for in-office bleaching with 6% HP was equivalent for GI, as well as for bleaching efficacy, with improvement in the impact of oral condition on quality of life.

Effect of topical application of ibuprofen/arginine on the in-office bleaching-induced tooth sensitivity: A randomized, triple-blind controlled trial.

OBJECTIVE: The application of anti-inflammatories as topical desensitizers before dental bleaching is an approach to reduce bleaching-induced tooth sensitivity (TS). This randomized controlled trial compared the risk and intensity of TS and the color change resulting from in-office dental bleaching after using an experimental desensitizing gel containing ibuprofen and arginine. METHODS: Sixty-two participants with upper canine shades A2 or darker were randomly assigned to either the ibuprofen-arginine desensitizing group or the placebo group. The desensitizing gel was applied for 15 min before in-office bleaching with 35 % hydrogen peroxide gel for 50 min (2 sessions). To assess the absolute risk and intensity of TS, visual (0-10) and numeric rating (0-5) scales were used, and group comparisons were made using the McNemar test, Wilcoxon test, and paired Student t-test (α = 0.05). Color change was evaluated using Vita Classical, Vita Bleachedguide (ΔSGU), and Vita EasyShade (ΔEab, ΔE00, and ΔWID) before and one month after the bleaching procedure. Group comparisons for color change were done using a paired t-test (α = 0.05). RESULTS: The odds ratio for TS was 0.14 [95 % CI 0.02 to 0.6], meaning lower odds of TS for the desensitizing gel. A lower intensity of TS was also observed for the experimental group (p < 0.005) up to 48 h after bleaching. All color evaluation tools demonstrated effective and similar whitening for both groups (p > 0.05). CONCLUSIONS: Using the experimental desensitizing gel containing ibuprofen and arginine effectively reduced the risk and intensity of TS without compromising the bleaching efficacy. CLINICAL RELEVANCE: The topical application of ibuprofen/arginine on the in-office bleaching reduced risk and intensity of bleaching-induced tooth sensitivity.

Effect of gingival barrier brands on operator perception, cervical adaptation, and patient comfort during in-office tooth bleaching: a randomized clinical trial.

BACKGROUND: Light-cured resins are widely used as gingival barriers to protect the gums from highly concentrated peroxides used in tooth bleaching. The impact of barrier brand on clinical outcomes is typically considered negligible. However, there is limited evidence on the effects of different brands on operator experience, barrier adaptation, and patient comfort. OBJECTIVE: This clinical trial assessed the impact of four commercial gingival barrier brands (Opaldam, Topdam, Lysadam, and Maxdam) on operator perception, adaptation quality, and patient comfort. METHODS: Twenty-one undergraduate students placed gingival barriers in a randomized sequence using blinded syringes. Photographs of the barriers were taken from frontal and incisal perspectives. After bleaching procedures, operators rated handling features and safety using Likert scale forms. Two experienced evaluators independently assessed barrier adaptation quality on a scale from 1 (perfect) to 5 (unacceptable). The absolute risk of barrier-induced discomfort was recorded. Data were analyzed using Friedman and Chi-square tests (α = 0.05). RESULTS: Opaldam and Topdam received the highest scores in most handling features, except for removal, which was similar among all brands. No significant difference was observed in barrier adaptation quality between the evaluated brands. Discomforts were mainly reported in the upper dental arch, with Maxdam having the highest absolute risk (35% for this arch and 24% overall). CONCLUSIONS: This study suggests that gingival barrier brands can influence operator perception and patient comfort. Opaldam and Topdam were preferred by operators, but all brands demonstrated comparable adaptation quality. CLINICAL TRIAL REGISTRATION: The study was nested in a randomized clinical trial registered in the Brazilian Clinical Trials Registry under identification number RBR-9gtr9sc.

Evaluation of Different Protocols with 4% Hydrogen Peroxide in Bleaching Efficacy and Tooth Sensitivity - A Single-blind, Randomized Clinical Trial.

OBJECTIVES: To compare the bleaching efficacy and tooth sensitivity (TS) of 4% hydrogen peroxide (HP) in adults using a continuous or fractioned protocol. METHODS AND MATERIALS: A single-blind randomized controlled trial with a parallel design was conducted. Eighty-six patients with upper canines A2 or darker were submitted to bleaching with 4% HP gel for three weeks after random allocation into the fractioned protocol (two 30-minute daily applications) or continuous protocol (single one-hour application). We evaluated the color change at baseline, weekly, and 30 days after the bleaching using Vita Classical and Vita Bleachedguide using the units of shade guides (SGU) and by spectrophotometer using CIELab 1976 (ΔEab) and CIEDE 2000 formulas (ΔE00), as well as Whiteness Index (ΔWID). We assessed the absolute risk of TS with a visual analog scale (VAS) and numeric rating scale (NRS). Color changes in each recall were compared with the Student t-test. The risk of TS was evaluated by the Chi-square test, and the intensity by Mann-Whitney test (NRS) and Student t-test (VAS). RESULTS: The mean difference for the ΔSGU Vita Classical (0.5; 95% CI: -0.5 to 1.5), ΔSGU Vita Bleachedguide (-0.4; 95% CI: -1.5 to 0.7), ΔEab (1.4; 95% CI: -0.1 to 2.9), ΔE00 (0.6; 95% CI: -0.4 to 1.6), and ΔWID (-3.2; 95% CI: -7.3 to 0.9) after three weeks of bleaching was not clinically or statistically significant (p>0.10). The absolute risk of TS was 44% (95% CI: 30-58%) and 46% (95% CI: 32-61%) in the fractioned and continuous protocols, respectively (RR=1.0; 95% CI: 0.6 to 1.5; p>0.91). CONCLUSION: A fractioned bleaching protocol with 4% HP (30 minutes twice daily) did not increase the whitening degree nor affect the risk and intensity of TS when compared with the one-hour continuous protocol.

Effect of an experimental desensitizing gel on bleaching-induced tooth sensitivity after in-office bleaching-a double-blind, randomized controlled trial.

OBJECTIVES: To evaluate the risk and intensity of tooth sensitivity (TS), and the efficacy of in-office bleaching after applying an experimental desensitizing gel composed of 10% calcium gluconate, 0.1% dexamethasone acetate, 10% potassium nitrate, and 5% glutaraldehyde. MATERIAL AND METHODS: In a split-mouth, double-blind, placebo-controlled study, 50 participants had their upper hemiarches randomized into experimental and placebo groups. Desensitizing and placebo gels were applied for 10 min before in-office bleaching (35% hydrogen peroxide, 1 × 50 min; two bleaching sessions; 1-week interval). TS was recorded immediately after bleaching, 1, 24, and 48 h after each session, with a 0-10 visual analogue scale (VAS) and a five-point numerical rating scale (NRS). The color was recorded in all groups at baseline, 1 week after each session, and 1 month after the end of bleaching using shade guide units (ΔSGUs) and a spectrophotometer (ΔEab, ΔE00, and ΔWID). RESULTS: Most participants (96%) felt some discomfort during treatment regardless of the study group. The odds ratio for pain was 0.65 (95% CI 0.1 to 4.1; p = 1.0). The intensity of TS did not differ between groups (p > 0.31), and it was only 0.34 VAS units lower in the experimental group. A significant color change occurred in both groups regardless of the group. CONCLUSIONS: The desensitizing experimental gel applied before in-office bleaching did not reduce the risk and the intensity of TS and did not affect color change. CLINICAL RELEVANCE: Although the experimental desensitizing agent with varying mechanisms of action did not jeopardize the color change, it did not reduce the risk or intensity of in-office bleaching. CLINICAL TRIAL REGISTRATION NUMBER: RBR-7T7D4D.

Use of infrared photobiomodulation with low-level laser therapy for reduction of bleaching-induced tooth sensitivity after in-office bleaching: a double-blind, randomized controlled trial.

The purpose of this study is to evaluate the use of infrared photobiomodulation with low-level laser therapy (PBM) to reduce bleaching-induced tooth sensitivity (TS) after in-office bleaching. Eighty-three participants were randomized in blocks into two groups. In the experimental group, the patients received an application after each session of in-office bleaching (35% hydrogen peroxide, 1 × 50 min; 2 sessions with 1-week interval), while the laser application was simulated in the control group. The PBM system was operated in continuous mode, using 3 J of energy. A dose of 100 J/cm2 was applied for 30 s with 808 nm (100 mW of power) in the middle third of the crown. The risk and intensity of TS were recorded immediately after bleaching, 1 h, 24 h, and 48 h after each bleaching session, with a visual scale analog (0-10) and a five-point numerical scale (0-4). The color was recorded at the beginning, weekly, and 1 month after the end of the bleaching (VITA Classical, VITA Bleachedguide, and digital spectrophotometer). The risk of TS was 98% (95% CI 88 to 99%) for the laser group and 95% (95% CI 83 to 99%) for the control (RR = 1.03; 95% CI 0.94 to 1.12; p = 1.0). Similarly, no difference in the intensity of TS was detected for both pain scales (p > 0.65). Improvement in color change, regardless of the group, was observed (p > 0.15). The application of an PBM did not reduce the risk and intensity of TS when applied after the procedure using the parameters recommended by the manufacturer.Trial registration number and date of registration: RBR-4HCVSG-04/06/2019.

Does simultaneous versus individual-arch at-home dental bleaching regimen influence patient satisfaction? A randomized clinical trial.

OBJECTIVE: Our randomized, parallel and single-blinded clinical trial evaluated patient level of discomfort during at-home bleaching testing the equivalence between two different protocols for the use of bleaching trays (simultaneous vs. single arch), as well as tooth sensitivity (TS), gingival irritation, (GI) and bleaching efficacy (BE). MATERIALS AND METHODS: We randomized 100 patients into: simultaneous (n = 50) and single arch (n = 50). At-home bleaching was performed with 10% hydrogen peroxide (HP) for 2 weeks for simultaneous group and 4 weeks for single arch group. We assessed patient level of discomfort using 9-item questionnaire. The TS and GI, as well as BE using spectrophotometer and color guide were assessed using the visual analog scale (0-10). Data from level of discomfort and BE were evaluated by Student's t test. The TS and GI were compared using the relative risk and confidence interval (α = 0.05). RESULTS: Only tray adaptation showed a significant effect after the second week (p < 0.002). There was equivalence between groups for level of discomfort (p < 0.01). We found no significant intergroup differences for the risk of TS or GI, nor for intensity. We observed no significant differences between them regarding bleaching efficacy (p > 0.21). CONCLUSIONS: A simultaneous-use protocol for customized at-home dental bleaching trays proved to be equivalent to using single arch for patient level of discomfort and bleaching efficacy, with no significant increase in adverse effects. CLINICAL SIGNIFICANCE: Clinicians may decide whether to use a simultaneous or single arch protocol for tray usage; however, bleaching was achieved more quickly when the trays were worn simultaneously.

Gingival irritation in patients submitted to at-home bleaching with different cutouts of the bleaching tray: a randomized, single-blind clinical trial.

OBJECTIVES: This split-mouth randomized, single-blind clinical trial evaluated the gingival irritation (GI) of at-home bleaching with individual trays of different cutouts, as well as the tooth sensitivity (TS) and color change. MATERIALS AND METHODS: One hundred and twenty patients were randomized as to which side would receive the type of bleaching tray cutout: scalloped (in the gingival margin) and nonscalloped (extended from the gingival margin). The at-home bleaching was performed for 30 min with 10% hydrogen peroxide (HP) for 2 weeks. The absolute risk and intensity of GI and TS were assessed with a visual analog scale. Color change was assessed using a digital spectrophotometer and a color guide (α = 0.05). RESULTS: The proportion of patients who experienced GI was 57.5% (odds ratio 95% CI = 1.1 [0.7 to 1.8]), with no significant difference between groups (p = 0.66). The proportion of patients who experienced TS was 64.1% (odds ratio 95% CI = 1.0 [0.6 to 1.6]), with no significant difference between groups (p = 1.0). There is equivalence of scalloped and noscalloped groups for GI intensity (p < 0.01). Significant whitening was detected for both groups. Although some differences were observed between groups (CIELab and CIEDE00; p < 0.02), these were below of the considered clinically noticeable. CONCLUSIONS: The different cutouts of trays proved to be equivalent when regarding gengival irritation and tooth sensitivity when 10% HP for at-home bleaching was used. Significant color change was observed in both groups. However, significant differences detected between groups are not considered clinically noticeable. TRIAL REGISTRATION: Brazilian Clinical Trials Registry (RBR-2s34685). CLINICAL RELEVANCE: Scalloped or not, the individual trays for at-home bleaching could be considered a clinician's decision.

LED photobiomodulation effect on the bleaching-induced sensitivity with hydrogen peroxide 35%-a controlled randomized clinical trial.

OBJECTIVES: The aim of this study was to evaluate the effect of a protocol of photobiomodulation (PBM) with light-emitting diodes (LED) on the clinical risk of bleaching-induced sensitivity. MATERIALS AND METHODS: Sixty-four volunteers were selected and randomly divided in two groups, placebo (PG) and LED (LG). The LG received PBM irradiation and tooth bleaching, while the PG received tooth bleaching and simulation of the irradiation. The occurrence of painful sensitivity was recorded during the dental bleaching; immediately after bleaching; and 24, 48, and 72 h after tooth bleaching. At the same measurement times, data were collected on the intensity of sensitivity (VAS and NRS scale) and teeth affected by bleaching-induced sensitivity. A questionnaire sought to measure how the painful sensitivity influenced basic daily activities. Tooth color measures were performed using subjective and objective methods. RESULTS: LED irradiation decreased the occurrence of sensitivity at all studied evaluation times as well as its intensity, with the exception of the 72-h data when both groups presented no difference. Teeth affected by bleaching-induced sensitivity were significantly greater in the PG. Color measurements presented no differences between the groups in the recently after and later measures. CONCLUSIONS: PBM with LED decreases sensitivity risk and sensibility intensity during and after office bleaching and causes no influence on the shade degree of whitening achieved. The decrease in tooth sensitivity provided more comfort and less suffering while drinking. CLINICAL RELEVANCE: LED irradiation is a promising intervention in the control of bleaching-induced sensitivity. TRIAL REGISTRATION: RBR-7hpfwj. Sensitivity intensity measured by the VAS scale (0-10) in the first whitening session (Graphic A) and second whitening session (Graphic B). Significance level set at ≤ 5%. *Mann-Whiteney U test. Columns followed by the same letter are significant different (ap < 0.001; bp < 0.001; cp < 0.001; dp =0.013; ep < 0.001; fp < 0.001; gp < 0.001; hp = 0.002).

Does the Bleaching Gel Application Site Interfere With the Whitening Result? A Randomized Clinical Trial.

This study aimed to evaluate the effect of the bleaching gel application site on chromatic changes and postoperative sensitivity in teeth. Thirty patients were selected and allocated to three groups (n=10 per group), according to the location of the gel: GI, cervical application; GII, incisal application; and GIII, total facial. The amount and time of application of the 35% hydrogen peroxide (H2O2) gel were standardized. Color changes were analyzed by ΔE and Wid (bleaching index), using the values obtained in the readings conducted on a digital spectrophotometer in the cervical (CRs) and incisal regions (IRs) of the teeth. Spontaneous sensitivity was assessed using the questionnaire, and the stimulated sensitivity caused by the thermosensory analysis (TSA). The analysis occurred in five stages: baseline, after the first, second, and third whitening sessions (S), and 14 days after the end of the whitening, using the linear regression statistical model with mixed effects and post-test by orthogonal contrasts (p<0.05). Although the IR was momentarily favored, at the end of the treatment, the restriction of the application site provided results similar to those obtained when the gel was applied over the entire facial surface. Regarding sensitivity, only the GI showed spontaneous sensitivity. In the TSA, GIII had less influence on the threshold of the thermal sensation. It was concluded that the chromatic alteration does not depend on the gel application site. Spontaneous sensitivity is greater when the gel is concentrated in the cervical region (CR), and the teeth remain sensitized by thermal stimuli even after 14 days.

Effectiveness and adverse effects of at-home dental bleaching with 37% versus 10% carbamide peroxide: A randomized, blind clinical trial.

PURPOSE: The aim of this trial was to evaluate bleaching effectiveness, tooth sensitivity and gingival irritation of whitening patients with 10% versus 37% carbamide peroxide (CP). METHODS: Eighty patients were selected by inclusion and exclusion criteria and randomly allocated into two groups (n = 40): 37% CP and 10% CP. In both groups, patients performed whitening for 3 weeks, 4 h/day for 10% group and 30 min/day for 37% group. Color was evaluated with Vita Classical, Vita Bleachedguide 3D Master and Spectrophotometer Easyshade, at baseline, weekly and 30 days after treatment. Absolute risk and intensity of tooth sensitivity (TS) and gingival irritation (GI) were assessed with numeric rating scale (NRS) and a visual analog scale (VAS). Color changes were compared with t-test for independent samples. TS and GI were evaluated with Fisher's exact tests. Mann-Whitney test was used for NRS, and t-tests for VAS (α = 0.05). RESULTS: The 37% CP group showed faster whitening than 10% group at 1-3 weeks. However, 1 month after conclusion, both groups showed equivalent bleaching (p = 0.06). Regarding sensitivity and gingival irritation, 10% and 37% groups met no significant differences (p > 0.05). CONCLUSION: The use of 37% CP 30 min/day showed equivalent results to 10% 4 h/day. CLINICAL SIGNIFICANCE: The use of 37% carbamide peroxide 30 min/day may decrease the time of tray use in at-home protocol for whitening because it presents equivalent results to 10% carbamide peroxide 4 h/day.

Effectiveness of remineralization agents on the prevention of dental bleaching induced sensitivity: A randomized clinical trial.

OBJECTIVES: This study aims to compare the use of different remineralization agents before in-office bleaching for decreasing bleaching induced sensitivity. METHODS: A total of 64 volunteers were randomly divided into four groups. Before undergoing in-office bleaching with 38% hydrogen peroxide gel (three applications of 15 min each, one session), clinicians applied a placebo gel (control group), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), neutral sodium fluoride gel (NSF) or nano-hydroxyapatite solution (n-HAP) on all buccal surfaces of teeth. The gel was left undisturbed for 4 min. The efficacy of tooth whitening was assessed by determining the colour change using SGU. Patients recorded their tooth sensitivities on the VAS scale. Kruskal-Wallis test followed by Mann-Whitney U test was used to compare changes in tooth colour and intensity of tooth sensitivity between groups. RESULTS: Overall, there was no significant difference in shade change between the groups. Control and CPP-ACP groups showed significantly higher rates of hypersensitivity than NSF and the n-HAP group (p < 0.05). CONCLUSIONS: The use of a remineralization agent (n-HAP/NSF) before in-office bleaching did not affect the bleaching efficacy but did reduce tooth sensitivity. The before bleaching treatment use of an n-HAP solution can be suitable for reducing bleaching born sensitivity as well as commonly used NSF remineralizing gel before in-office tooth bleaching can reduce tooth sensitivity, the most common side effect associated with this procedure.

Efficacy and tooth sensitivity of at-home bleaching in patients with esthetic restorations: a randomized clinical trial.

OBJECTIVES: This study aims to evaluate the color change and tooth sensitivity (TS) caused by at-home bleaching in patients with sound and with restored teeth. METHODS: Forty patients were selected according to the inclusion and exclusion criteria and divided into two groups: So (patients with six caries-free maxillary anterior teeth) and Re (patients with at least one restoration in the six maxillary anterior teeth). Both groups were bleached with 10% carbamide peroxide (CP) at-home bleaching. The color change (CIELab [ΔE*ab], CIEDE00 [ΔE00], and whiteness index [∆WID]) were assessed using a spectrophotometer at baseline, 2 weeks, and 1 and 3 months after bleaching. Patients recorded their TS using a numeric rating scale (0-4). Data of color change were submitted to Student's T-test. The absolute risk and intensity of TS were compared using Fisher's and the Mann-Whitney tests, respectively (α = 0.05). RESULTS: Higher ΔE*ab, ΔE00, and ∆WID values were observed for So in relation to Re after all recall rate (p < 0.0001). No significant differences were observed regarding of bleaching-induced TS (p > 0.9). CONCLUSIONS: At-home dental bleaching with 10% CP generated the same pattern of TS in patients with or without restorations. However, in patients with restored teeth, it produced a lower color change after 2 weeks of bleaching. CLINICAL SIGNIFICANCE: After 2 weeks of at-home bleaching, a lower whitening effect was observed in patients with anterior restorations when compared with patients with sound teeth. TRIAL REGISTRATION: ClinicalTrials.gov identifier RBR-52j6gmg.

Coadministration of ibuprofen/caffeine on bleaching-induced tooth sensitivity: A randomized clinical trial.

This clinical trial evaluated the effect of the coadministration of ibuprofen/caffeine on bleaching-induced tooth sensitivity (TS). A triple-blind, parallel-design, randomized clinical trial was conducted on 84 patients who received ibuprofen/caffeine or placebo capsules. The drugs were administered for 48 hours, starting 1 hour before the in-office bleaching. Two bleaching sessions were performed with 35% hydrogen peroxide gel with 1-week interval. TS was recorded up to 48 hours after dental bleaching with a 0-10 visual analogic scale (VAS) and a 5-point numeric rating scale (NRS). The color was evaluated with VITA Classical and VITA Bleachedguide scales (ΔSGU) and VITA Easyshade spectrophotometer (ΔE*ab and ΔE00). The absolute risk of TS in both groups was evaluated using Fischer's exact test. Comparisons of the TS intensity (NRS and VAS data) were performed by using the Mann-Whitney test and a two-way repeated measures ANOVA, respectively. The color alteration between the groups was compared with the Student's t test. The significance level was 5%. There was no statistically significant difference between the groups for the absolute risk of TS (p = 1.00) or for the intensity of TS (p > 0.05). A bleaching of approximately 7 shade guide units was observed on the Vita Classical and Vita Bleachedguide scales, with no statistical difference between the groups. It was concluded that coadministration of ibuprofen and caffeine did not reduce the absolute risk or intensity of TS and did not interfere with the efficacy of dental bleaching.

Comparison of the Effect of Agitation on Whitening and Tooth Sensitivity of In-Office Bleaching: A Randomized Clinical Trial.

OBJECTIVE: This single-blind, split-mouth, randomized trial was aimed at evaluating the bleaching efficacy (BE) and tooth sensitivity (TS) of a 20% hydrogen peroxide (HP) bleaching agent used under active or passive application. METHODS AND MATERIALS: Twenty-two patients with canines darker than C2 were selected. Teeth were bleached in two sessions, with a one-week interval between treatments. The bleaching agent was applied using active (HPactive) or passive (HPpassive) application. Each tooth in the HPactive-allocated hemiarch received bleaching gel with sonic activation after 10 and 30 minutes from the start of treatment, with rounded movements all over the buccal surface. The color changes were evaluated by subjective (Vita Classical and Vita Bleachedguide) and objective (VITA Easyshade Spectrophotometer) methods at baseline and 30 days after the second session. TS was recorded up to 48 hours after treatment using a 0-10 visual analog scale. Color change in shade guide units (SGUs) and ΔE was analyzed using a Wilcoxon test (α=0.05). The absolute risk and intensity of TS were evaluated using McNemar test and a Wilcoxon test, respectively (α=0.05). RESULTS: Significant whitening was observed in both groups after 30 days of clinical evaluation. The activation did not significantly influence BE (ΔSGU HPpassive=5.6 and HPActive=5.8; p=0.98; and ΔE HPpassive=10.6 and HPactive=10.3; p=0.83). Absolute risk of TS (HPactive=36.4% and HPpassive=31.8%; p=0.94) was similar for both groups (Fisher exact test). TS intensity (visual analogue scale) was higher during the bleaching sessions and up to 24 hours thereafter for both groups, with no differences between groups (two-way analysis of variance and Tukey). CONCLUSION: The active application of a 20% HP gel did not improve BE and TS.

Effect of Daily Usage Time of 4% Hydrogen Peroxide on the Efficacy and Bleaching-induced Tooth Sensitivity: A Single-blind Randomized Clinical Trial.

OBJECTIVE: Compare the risk/intensity of tooth sensitivity (TS) and color change of a 30-minute vs. the recommended 120-minute application time of 4% hydrogen peroxide (HP) for at-home bleaching. METHODS: A single-blind, parallel, randomized clinical trial was conducted with 92 adult patients with caries and restoration-free anterior teeth A2 or darker, randomly allocated to two groups. Bleaching trays containing 4% HP were used for three-weeks. A four-week regimen was also offered to the patients for the 30-min group after the end of the 3-week protocol. The color change was assessed with the Vita Classical (VITA Zahnfabrik, Bad Säckingen, Germany) and Vita Bleachedguide shade guides (VITA Zahnfabrik) and the Vita Easyshade spectrophotometer (VITA Zahnfabrik) at baseline, weekly, and 30 days after the bleaching. The absolute risk and the intensity of TS were assessed daily using the 0-10 visual analogue scale (VAS) and 5-point Numerical Rating Scale (NRS) scale, and patient satisfaction was recorded with a Likert 0-7 scale. Risk of TS (Fisher's test), intensity of TS in NRS scale (Mann-Whitney test), VAS scale (t-test), and a color change (t-test) were compared. RESULTS: The 30-minute group saw color change of around 1 SGU inferior to the 120-minute group in all-time assessments (p<0.05). After an extra week of bleaching, mean color change was similar (p>0.05). Patient satisfaction was high for both groups (p>0.05). CONCLUSIONS: A four-week protocol of at-home dental bleaching with 4% HP for 30 minutes/day whitened teeth similarly to the 120 minutes/day protocol, with low intensity of dental sensitivity and high patient satisfaction.

Clinical effects of the exposure to red wine during at-home bleaching.

OBJECTIVES: This clinical trial evaluated the effects of red wine exposure on the effectiveness of at-home bleaching with 10% carbamide peroxide, degree of tooth sensitivity, and levels of periodontal inflammatory markers. METHOD AND MATERIALS: Eighty participants were assigned to two groups, namely, those who drank red wine (experimental group), and those who did not drink red wine (control group). The experimental group participants rinsed their mouths with 25 mL of red wine four times a day during the bleaching period. Shade evaluation was assessed visually by using the Vita Classical and Vita Easyshade techniques. Tooth sensitivity was evaluated by the numeric and visual analog scales, and the salivary and gingival crevicular fluids were collected for assessment of nitric oxide (NO) levels, a marker of inflammation. Differences in color change were analyzed by one-way analysis of variance (ANOVA). The absolute risks of tooth sensitivity were compared by the Fisher exact test. Tooth sensitivity intensity data sets for both the visual analog scale and the numeric rating scale were compared using the Wilcoxon signed rank test (α = .05). Repeated measures and two-way ANOVA followed by the Bonferroni test were used to assess time-course and differences between groups in NO production. RESULTS: The bleaching technique was effective regardless of wine consumption (P > .05). Tooth sensitivity was classified as mild, with no differences between groups (P > .05). Red wine reduced both the gingival crevicular fluid and salivary levels of NO (P < .05). CONCLUSION: Red wine does not interfere with the effectiveness and sensitivity of at-home teeth bleaching with 10% carbamide peroxide and protects against bleaching-induced inflammation.

Evaluation of At-home Bleaching Times on Effectiveness and Sensitivity with 10% Hydrogen Peroxide: A Randomized Controlled Double-blind Clinical Trial.

OBJECTIVES: The aim of this randomized double-blind controlled clinical trial was to evaluate different protocols for at-home use of 10% hydrogen peroxide in whitening effectiveness and tooth sensitivity. METHODS: Seventy-two patients were selected according to the inclusion and exclusion criteria, with the upper central incisors having color A2 or darker according to the Vita Classical scale (VITA Zahnfabrik, Bad Säckingen, Germany) and randomized into two groups: 10% hydrogen peroxide applied once daily for 15 minutes (HP 15) or applied once daily for 30 minutes (HP 30). Bleaching was performed for 14 days in both groups. The color was evaluated before bleaching, during bleaching (1st and 2nd weeks), and 1 month after the bleaching treatment using the Vita Classical, Vita Bleachedguide 3D-MASTER, and Vita Easyshade spectrophotometer (VITA Zahnfabrik). Dental sensitivity was recorded by the patients using the numerical rating scale (0-4) and visual analogue scale (0-10 cm). Color data were evaluated by two-way analysis of variance (ANOVA) of repeated measures (group vs. treatment time). The Mann-Whitney test was performed to contrast the means (α=0.05). Tooth sensitivity was assessed by Fisher's exact test (p=1.00) and intensity of tooth sensitivity was evaluated by the Mann-Whitney test (α=0.05) for both scales. RESULTS: A significant whitening effect was observed after 2 weeks of bleaching for all color measurements (p=0.01), with no difference between HP 15 and HP 30 (p>0.05). Also, the absolute risk and intensity of tooth sensitivity were similar (47%; p>0.05). CONCLUSIONS: The effectiveness and tooth sensitivity of at-home bleaching carried out with 10% hydrogen peroxide applied for 15 minutes or 30 minutes are similar.

Sonic Activation of a Desensitizing Gel Prior to In-Office Bleaching.

This double-blind, randomized, and controlled clinical trial evaluated the effect of sonic activation during the application of a desensitizing agent (DA) containing 5% potassium nitrate and 2% sodium fluoride on the occurrence of tooth sensitivity (TS) associated with in-office dental bleaching. Treatment with or without sonic activation of the DA was randomly assigned to one-half of the maxillary teeth of 34 patients in a split-mouth design. On the side without sonic activation (noSA), the DA was applied and maintained in contact with the teeth for 10 minutes. On the sonic activation side (SA), the DA was activated 30 seconds per tooth. The DA application was followed by application of 35% hydrogen peroxide in two bleaching sessions separated by a one-week interval. The primary outcome was the absolute risk of TS, recorded using a numeric rating scale and a visual analog scale. Color was evaluated with a digital spectrophotometer and a value-oriented shade guide. No significant difference between treatments was observed in the absolute risk of TS, which occurred in 93% (p=1.00) of both noSA and SA groups. The TS intensity was higher in the 24-hour interval after sessions, for both treatments, without differences between them. There was no difference in the color change for the treatments, with the average change in number of shade guide units of the Vita Classical scale of 6.35 for both (p=0.87). Sonic activation of DA containing 5% potassium nitrate and 2% sodium fluoride did not reduce the absolute risk and intensity of TS associated with in-office bleaching.

Assessment of the effect of experimental bleaching agent with nano-bioactive material on postoperative sensitivity: A randomized, triple blind clinical trial.

OBJECTIVES: This clinical study aimed to evaluate the effect of incorporating bioactive nanoparticles (n-Bm) inside an in-office bleaching gel on the risk and intensity of tooth sensitivity (TS) and on bleaching effectiveness. MATERIALS AND METHODS: Sixty-six participants were selected and randomly assigned into two groups: control-only in-office gel and experimental-in-office gel with n-Bm. Teeth were bleached in two sessions (3 × 15-min). TS was recorded using a VAS and NRS. The color change was evaluated by subjective (VITA Classical and VITA Bleachedguide) and objective (Easyshade spectrophotometer) methods at baseline and 30 days after the end of treatment. The TS was evaluated by McNemar, Wilcoxon Signed Rank, and paired t test. The color changes between groups were compared using paired t test (α = 0.05). RESULTS: No significant differences between the groups were observed in the risk (control = 27% [95%IC 18-39]; experimental = 21% [95%IC 13-32]) and intensity of TS, as well as in the color change (p >0.05) for any color measurement. CONCLUSION: The inclusion of n-Bm into the bleaching agents did not affect the whitening effectiveness, as well as the risk and intensity of TS between groups. However, the results of the absolute risk of TS were low for both in-office gels used. CLINICAL SIGNIFICANCE: Despite no significant differences between groups, both experimental bleaching agents present suitable results with low values for TS.