Evaluation of reservoirs in bleaching trays for at-home bleaching: a split-mouth single-blind randomized controlled equivalence trial

Clinical Performance of At-Home Dental Bleaching in Younger and Older Adults: A Non-Randomized, Double-Blind Trial

OBJECTIVE

This non-randomized, parallel, double-blind controlled trial evaluated the equivalence of bleaching efficacy 1-month post-bleaching after at-home bleaching among younger (15-24 years) and older participants (45-78 years). The secondary outcomes: intensity and risk of tooth sensitivity (TS), gingival irritation (GI), and esthetic self-perception were compared.

METHODS

130 participants (65 per group) underwent bleaching with 10% carbamide peroxide for 2h daily/21 days. Color change was assessed using the spectrophotometer (ΔEab, ΔE00, ΔWID), and shade guides (ΔSGUs). The intensity and risk of TS and GI were recorded using a 0-10 VAS. The Orofacial Esthetic Scale (OES) was applied for both groups.

RESULTS

Non-equivalent bleaching outcomes were observed between the groups across all instruments (p>0.05); younger participants showed significantly greater efficacy (p<0.05). The TS risk was around 64% for all participants, with no statistical difference between groups (p>0.05; RR=0.9; 95%CI 0.7 to 1.2). Older participants had significantly 30% lower risk of GI (RR=0.7; 95%CI 0.5 to 2). No statistical difference for TS intensity was observed (p>0.4) but found for GI (p=0.02) favoring older participants. Significant improvements were observed for all OES items after bleaching (p<0.05).

CONCLUSION

Younger individuals experienced greater whitening effects from at-home bleaching treatments compared to older adults. However, both age groups reported similar rates of tooth sensitivity and gum irritation. Regardless of age, the treatment improved aesthetic self-perception.

CLINICAL SIGNIFICANCE

Greater whitening efficacy was observed in younger participants with comparable adverse effects across groups, and the procedure positively impacted self-perception in both age groups.

Clinical decision-making in tooth bleaching based on current evidence: A narrative review

OBJECTIVE

This review consolidates current knowledge on dentist-supervised tooth bleaching for vital teeth, drawing from systematic reviews, meta-analyses, and randomized clinical trials (RCTs) that followed CONSORT guidelines.

DATA RESOURCES

MeSH and free terms like "tooth bleaching," "tooth whitening," "randomized clinical trial," and "systematic review" were used in PubMed, Scopus, and Web of Science databases STUDY SELECTION: Out of 839 articles, 444 were selected for full-text review, excluding case reports, non-randomized trials, literature reviews and those not directly related to tooth bleaching or RCTs not following CONSORT 2010. The remaining 203 studies were used to compare the dentist-supervised at-home and in-office clinical protocols, assessing factors such as color change, tooth sensitivity, and gingival irritation. In vitro studies were cited to support and explain basic concepts of different clinical decisions CONCLUSIONS: Daily at-home bleaching with 10 % carbamide peroxide or lower-concentration hydrogen peroxide over three to four weeks is effective. In-office bleaching with high-concentration hydrogen peroxide exhibits variations in protocols based on the HP concentration and gel's pH. Emerging technologies like violet LEDs and photobiomodulation with infrared lasers show promise in enhancing efficacy and reducing sensitivity, respectively, though more research is needed. The review underscores the importance of ongoing research into desensitization strategies to manage sensitivity related to bleaching.

CLINICAL SIGNIFICANCE

Tooth bleaching is central to dental aesthetics, offering a range of options that can challenge clinicians. Adverse effects, particularly sensitivity, highlight the need for practice supported in protocols clinically tested and effective desensitization approaches.

Impact of the in-office bleaching gels pH on tooth sensitivity in combined bleaching techniques: a randomized clinical trial

OBJECTIVES

This randomized, parallel, single-blind clinical trial evaluated tooth sensitivity (TS), efficacy, gingival irritation (GI), aesthetic self-perception, and psychosocial impact of combined bleaching using in-office bleaching agents with different pHs.

MATERIALS AND METHODS

160 participants were randomized into two groups (n = 80) with 35% hydrogen peroxide in-office bleaching gels: Whiteness HP Maxx (acidic, unstable pH) and Whiteness HP Automixx Plus (neutral, stable pH). In-office bleaching was performed in one session: HP Maxx (3 applications of 15 min) and HP Automixx Plus (1 application of 50 min). Both groups then received at-home bleaching with 10% carbamide peroxide for 4 h daily for two weeks. TS and GI were assessed using Visual Analogue Scales. Color change was measured with a spectrophotometer and color guides. Aesthetic self-perception and psychosocial impact were evaluated using three scales: Orofacial Aesthetics Scale, Oral Health Impact Profile, and Psychosocial Impact Questionnaire of Dental Aesthetics.

RESULTS

The risk and intensity of TS significantly favored the neutral and stable pH gel for both in-office (p < 0.001) and combined treatments (p < 0.004). Both groups achieved significant whitening (p > 0.37). No difference in GI risk or intensity was found (p > 0.11). All aesthetic and psychosocial scales showed significant improvement post-treatment (p < 0.05).

CONCLUSION

Using a gel with neutral and stable pH during in-office bleaching reduces the risk and intensity of TS without compromising whitening efficacy.

CLINICAL RELEVANCE

Combining at-home and in-office bleaching with a neutral, stable gel reduces TS risk and intensity while ensuring optimal whitening results and patient comfort.

Different daily times for at-home bleaching with 10% carbamide peroxide: A randomized single-blind, noninferiority controlled trial

BACKGROUND

This single-blind, noninferiority trial evaluated whether 10% carbamide peroxide (CP) applied for 2 or 4 hours daily is noninferior to 8 hours.

METHODS

A total of 120 healthy adults, with teeth shade A2 or darker, were randomly allocated to 3 groups (n = 40). All participants used 10% CP gel in a bleaching tray for 2, 4, and 8 hours daily for 14 days, with the option to extend treatment if they were dissatisfied. Color change was measured using a spectrophotometer and shade guides at baseline, every 5 days, and 1 month posttreatment. Risk and intensity of tooth sensitivity (TS) were assessed daily using a 0 through 10 visual analog scale. Satisfaction was recorded via a Likert scale wherein 1 corresponded to very dissatisfied and 7 corresponded to very satisfied and the Orofacial Esthetic Scale. Noninferiority was tested for color change using the 1976 formula (ΔEab) at 1 month postbleaching (primary outcome), color change using the 2000 formula (ΔE00), Whiteness Index, and shade guide units, whereas TS and satisfaction were analyzed with χ2, analysis of variance, Kruskal-Wallis, and Friedman tests.

RESULTS

Color change in ΔEab (2 vs 8 h: mean difference, -0.6; 90% CI, -2.1 to 1.0, 4 vs 8 h: mean difference, 0.0; 90% CI, -1.6 to 1.6) and ΔE00 values for shorter durations were noninferior to 8 hours at 1 month. Whiteness Index results were inconclusive. TS risk and intensity were similar (P > .05), and patient satisfaction improved across all groups similarly (P > .05).

CONCLUSIONS

Shorter 2- and 4-hour daily bleaching with 10% CP is noninferior to the 8-hour protocol.

PRACTICAL IMPLICATIONS

Shorter periods of at-home bleaching (2 and 4 h) can be prescribed depending on the patient's availability or preferences without jeopardizing the bleaching efficacy. This clinical trial was registered at Registro Brasileiro de Ensaios Clínicos (RBR-10vvfpcm).

Effect of the reduction in the exposure time to at-home bleaching gel on color change and tooth sensitivity: A systematic review and meta-analysis

OBJECTIVE

To investigate the effect of reducing exposure time to at-home bleaching gel on color change and tooth sensitivity.

MATERIALS AND METHODS

The search was carried out using PubMed, Scopus, Web of Science, EMBASE, LILACS, Cochrane. Randomized clinical trials (RCTs) were included involving adult patients who have never undergone bleaching treatment before (P), subjected to bleaching with a reduced exposure time to the at-home bleaching agent (I) compared to those who used it for the time indicated by the manufacturer (C), to evaluate the effects on color change and tooth sensitivity (O). The Cochrane guidelines for the Risk of Bias Assessment Tool (RoB 2.0) and GRADE were used to assess risk of bias and quality of evidence, respectively.

RESULTS

Using at-home bleaching gel for the period recommended by the manufacturer resulted in significantly higher ΔEab and ΔWID values and better subjective color change (ΔSGU-Classical), regardless of the evaluation time. Regarding the post-bleaching evaluation, no significant differences were found for ΔE00 immediately after bleaching or ΔSGU (Bleached) at any time. Reducing the time of use significantly decreased tooth sensitivity events.

CONCLUSIONS

Reducing exposure time to at-home bleaching gel reduces tooth sensitivity events; however, most of the parameters that assess color change indicate using at-home bleaching gel for the time recommended by the manufacturer.

CLINICAL SIGNIFICANCE

Reducing exposure time to at-home bleaching gel should be applied with caution in clinical practice. Although the evidence suggests a reduction in tooth sensitivity events, bleaching effectiveness was significantly higher after using the bleaching gel for the time indicated by the manufacturer.

Efficacy of a buccal and lingual at-home bleaching protocol-A randomized, split-mouth, single-blind controlled trial

OBJECTIVE

To compare the color change, the risk and intensity of tooth sensitivity (TS), and gingival irritation (GI) of at-home bleaching applied on the buccal surface only or the buccal and lingual surfaces.

MATERIALS AND METHODS

Sixty patients with canines A2 or darker were selected and their superior arches were randomized in two groups: at-home bleaching on the buccal-only or on the buccal and lingual surfaces, with 7.5% hydrogen peroxide, for 1 h daily/2 weeks. The color change was evaluated at baseline, 7, 14 days, and 1 month after bleaching using shade guides scales (ΔSGU) and a spectrophotometer (ΔEAB, ΔE00, and ΔWID). Risk and intensity of TS and GI were recorded daily using visual analogic scale (0-10). Patient satisfaction was evaluated with the orofacial esthetics. Paired t-test, McNemar's, and Wilcoxon signed-rank test were used for data analysis (α = 5%).

RESULTS

Neither the color change nor the risk/intensity of TS was statistically different between groups (p > 0.05). Patient satisfaction increased after bleaching for both groups (p < 0.05).

CONCLUSION

The addition of one contact surface does not result in an increased whitening degree compared to bleaching applied solely on the buccal surface.

CLINICAL SIGNIFICANCE

Understanding the influence of surfaces interacting with the bleaching agent is crucial for comprehending the bleaching mechanism and avoiding unnecessary material expenses. Notably, employing the buccal-only technique is sufficient to achieve the desired efficacy.

Whitening toothpastes with hydrogen peroxide concentrations vs. at-home bleaching

OBJECTIVES

To evaluate the effect of whitening toothpastes with different hydrogen peroxide (HP) concentrations on HP permeability, color change, and physicochemical properties, compared to at-home bleaching treatment.

MATERIALS AND METHODS

Forty-nine premolars were randomized into seven groups (n = 7): untreated (control); at-home bleaching with 10% carbamide peroxide gel (AH; 10% CP) with 14 and 28 applications of 180 min each (AH [14 × 180 min] and AH [28 × 180 min]); three whitening toothpastes (3% HP; 4% HP and 5% HP) and 10% CP brushed 28 times for 90 s each (TB [28 × 90 s]). HP permeability was measured using a UV-VIS spectrophotometer and color change by a digital spectrophotometer (ΔEab, ΔE00, and ΔWID). Initial concentration, pH, and viscosity were measured through titration, digital pH meter, and rheometer, respectively. Statistical analysis included one-way ANOVA, Tukey's test, and Dunnett's test (α = 0.05).

RESULTS

4% HP group showed acidic pH, the lowest viscosity and the highest HP concentration into the pulp chamber (p < 0.05). The 10% CP groups had lower HP in the pulp chamber and greater color change than other groups (p < 0.05), except the 5% HP group in ΔEab and ΔE00. For ΔWID, the 10% CP AH groups showed greater whitening than other groups (p < 0.05).

CONCLUSIONS

Whitening toothpaste with up to 5% HP resulted in higher HP permeability and less color change compared to 10% CP. Higher HP commercial concentrations in toothpaste increased whitening effect; however, acidic pH toothpastes exhibited greater HP permeability.

CLINICAL RELEVANCE

Whitening toothpastes with high hydrogen peroxide concentrations were less effective than at-home bleaching, resulting in less color change and greater permeability of hydrogen peroxide, potentially increasing the risk of tooth sensitivity.

Effect of Various Vital Bleaching Systems on Clinical Outcomes and Patient Satisfaction

Objective To evaluate the clinical behavior of different bleaching products - the hydrogen peroxide (H2O2), carbamide peroxide (CP), and titanium dioxide bleaching systems. Methods Three bleaching systems with different concentrations (H2O2 15%, 38%, CP 15%, 35%, and titanium dioxide 20% H2O2) were used. Sixty participants with discolored teeth were enrolled and equally divided into six groups. Each group was rendered the assigned bleaching protocol against the control group, which received plain dentifrice polishing. Each case was evaluated immediately, two weeks, three months, six months, and one year after the bleaching treatment. The clinical evaluation was made for color change by (shade guide and digital images with L*a*b* parameters), tooth sensitivity, gingival irritation, and participants' satisfaction. Results All bleaching systems showed color improvement after bleaching regimens with significant effect showed by in-office titanium dioxide 20% H2O2 followed by 38% H2O2 with Δ=10.26 and Δ=6.52, respectively, when compared to other bleaching techniques. Higher sensitivity was recorded in group III with 50% of the participants reporting postoperative sensitivity. Higher gingival irritation was recorded in group IV (15% CP) where 60% of the patients reported gingival irritation. Thirty-five of the 60 participants (58.5%) recorded that the treatment whitened their teeth "moderately" and "a lot" while seven participants recorded "a slight" difference. There was a highly significant difference in participants' satisfaction between all bleaching groups (p < 0.05). Conclusion It is evident that there is a development of dental sensitivity and gingival irritation irrespective of the bleaching system used. The color assessment showed that the desired result can be achieved with variable levels of patient satisfaction with excellent overall results with the titanium dioxide system.

At-home bleaching with carbamide peroxide with concentrations below 10%: bleaching efficacy and permeability in the pulp chamber

OBJECTIVES

To evaluate the bleaching efficacy and permeability of hydrogen peroxide (HP) in the pulp chamber of human teeth bleached with lower concentrations of carbamide peroxide gel (4%, 5% and 7% CP).

MATERIALS AND METHODS

Bleaching gels with lower concentrations were formulated and a commercial standard gel, 10% CP, was used as a reference. Fifty-six human premolars were randomly divided into four groups. Applications of the bleaching gel were made for 3 h for 21 days. The bleaching efficacy was evaluated by digital spectrophotometry on 1, 7, 14 and 21 days, with analysis in the ∆Eab, ∆E00 and WID color spaces. The concentration of HP in the pulp chamber was measured in the same periods by UV-Vis spectrophotometry (µg/mL). Two-way repeated analysis of variance (ANOVA) examined bleaching efficacy and HP permeability, followed by Tukey's post-hoc test (α = 0.05).

RESULTS

All groups showed significant color changes, with no statistical differences after the second and third week of bleaching (p > 0.05). The 'time' factor was statistically different (p < 0.05), increasing the bleaching efficacy throughout the treatment. The 4% CP group had lower HP levels in the pulp chamber (p < 0.05).

CONCLUSIONS

The results seem promising, revealing that low concentration gels are as effective as 10% CP with the benefit of reducing the amount of HP in the pulp chamber.

CLINICAL RELEVANCE

Low concentration 4% PC and 5% PC maintains bleaching efficacy, reduces the penetration of HP peroxide into the pulp chamber, and may reduce tooth sensitivity.

Evaluation of at-home bleaching protocol with application on different surfaces: bleaching efficacy and hydrogen peroxide permeability

Objectives

This study aimed to evaluate the bleaching efficacy and hydrogen peroxide permeability in the pulp chamber by the at-home bleaching gel in protocols applied on different dental surfaces.

Materials and Methods

Forty premolars were randomly into 4 groups: control group no bleaching, only application on the buccal surface (OB), only application on the lingual surface (OL) and application in buccal and lingual surfaces, simultaneously (BL). At-home bleaching gel (White Class 7.5%) was used for the procedure. The bleaching efficacy was evaluated with a digital spectrophotometer (color change in CIELAB [ΔE ab] and CIEDE 2000 [ΔE 00] systems and Whitening Index for Dentistry [ΔWID]). The hydrogen peroxide permeability in the pulp chamber (µg/mL) was assessed using UV-Vis spectrophotometry and data were analyzed for a 1-way analysis of variance and Tukey's test (α = 0.05).

Results

All groups submitted to bleaching procedure showed bleaching efficacy when measured with ΔE ab and ΔE 00 (p > 0.05). Therefore, when analyzed by ΔWID, a higher bleaching efficacy were observed for the application on the groups OB and BL (p = 0.00003). Similar hydrogen peroxide permeability was found in the pulp chambers of the teeth undergoing different protocols (p > 0.05).

Conclusions

The application of bleaching gel exclusively on the OB is sufficient to achieve bleaching efficacy, when compared to BL. Although the OL protocol demonstrated lower bleaching efficacy based on the ΔWID values, it may still be of interest and relevant in certain clinical scenarios based on individual needs, requiring clinical trials to better understand its specificities.

The influence of smoking on the effectiveness of at-home bleaching: A prospective clinical study

OBJECTIVES

To evaluate the effect of smoking on tooth whitening and color change after at-home bleaching.

MATERIALS AND METHODS

This prospective clinical study evaluated two groups of participants: NS-non-smokers (n = 24) and S-smokers (n = 16). All subjects were treated with at-home bleaching using 22% carbamide peroxide (CP) for 1 h/day for 14 days. Color coordinates (L*-luminosity, a*-red-green axis and b*-yellow-blue axis) were obtained before bleaching (D0-baseline), 1 day (D1), 15 days (D15), and 1 month (D30) after bleaching. The whiteness index (WID ) and CIEDE2000 color differences (ΔE00 ) were calculated for S and NS. Color changes between S and NS subjects for specific teeth (CI-Central Incisors, LI-Lateral Incisors, and C-Canines) were analyzed using the Mann-Whitney test (α = 0.05).

RESULTS

There was no significant difference in WID between S and NS subjects at baseline. NS participants showed higher WID than S at D1, D15, and D30 (p < 0.05). NS showed higher ΔWID for CI and C between D0 and the other evaluation times (D1, D15, and D30) compared to S. Smokers showed higher darkening of CI than NS in ΔWID D30-D1 (p < 0.05). Color changes showed similar overall behavior for ΔWID . For all evaluation times, ΔWID and ΔE00 values were below the corresponding acceptability thresholds.

CONCLUSION

At-home bleaching was effective on smokers and nonsmokers. Smoking negatively affected color stability after bleaching. ΔE00 and ΔWID were acceptable for both groups.

CLINICAL SIGNIFICANCE

Although smoking negatively affected color stability after bleaching, the observed changes were clinically acceptable.

One-year clinical observation of the effect of internal bleaching on pulpless discolored teeth

OBJECTIVES

This study aimed to observe the color rebound and rebound rates of non-pulp discolored teeth within 1 year after routine internal bleaching to guide clinical practice and prompt prognosis.

METHODS

In this work, the efficacy of bleaching was observed in 20 patients. The color of discolored teeth was measured by using a computerized colorimeter before bleaching; immediately after bleaching; and at the 1st, 3rd, 6th, 9th, and 12th months after bleaching. The L*, a*, and b* values of the color of cervical, mesial, and incisal parts of the teeth were obtained, and the color change amounts ΔE*, ΔL*, Δa*, and Δb* were calculated. The overall rebound rate (P*) and the color rebound velocity (V*) were also analyzed over time.

RESULTS

In 20 patients following treatment, the average ΔE* of tooth color change was 14.99. After bleaching, the neck and middle of the teeth ΔE* and ΔL* decreased in the 1st, 3rd, 6th, 9th, and 12th months, and the differences were statistically significant. Meanwhile, from the 9th month after bleaching, the rebound speed was lower than that in the 1st month, and the difference was statistically significant. The incisal end of the tooth ΔE* and ΔL* decreased in the 6th, 9th, and 12th months after bleaching, and the differences were statistically significant. No significant difference was found in the rebound speed between time points. However, this rate settled after the 9th month, with an average color rebound rate of 30.11% in 20 patients.

CONCLUSIONS

The results indicated that internal bleaching could cause a noticeable color change on pulpless teeth. The color rebound after bleaching was mainly caused by lightness (L*), which gradually decreased with time, and it was slightly related to a* and b*. The color of the teeth after internal bleaching rebounded to a certain extent with time, but the color rebound speed became stable from the 9th month. Clinically, secondary internal bleaching can be considered at this time according to whether the colors of the affected tooth and the adjacent tooth are coordinated and depending on the patient's needs.

Use of calcium-containing bioactive desensitizers in dental bleaching: A systematic review and meta-analysis

BACKGROUND

Topical application of calcium-containing bioactive desensitizers (CBs) has been used to minimize bleaching-induced tooth sensitivity (TS). This study answered the research question "Is the risk of TS lower when CBs are used with dental bleaching in adults compared with bleaching without desensitizers?"

TYPES OF STUDIES REVIEWED

The authors included randomized clinical trials comparing topical CB application with a placebo or no intervention during bleaching. Searches for eligible articles were performed in MEDLINE via PubMed, Cochrane Library, Brazilian Library in Dentistry, Latin American and Caribbean Health Sciences Literature, Scopus, Web of Science, Embase, and gray literature without language and date restrictions and updated in September 2022. The risk of bias was evaluated using Risk of Bias Version 2.0. The authors conducted meta-analyses with the random-effects model. The authors assessed heterogeneity with the Cochrane Q test, I² statistics, and prediction interval. The authors used the Grading of Recommendations Assessment, Development and Evaluation approach to assess the certainty of the evidence.

RESULTS

After database screening, 22 studies remained, with most at high risk of bias. No difference in the risk of TS was detected (risk ratio, 0.95; 95% CI, 0.90 to 1.01; P = .08, low certainty). In a visual analog scale, the intensity of TS (mean difference, -0.98; 95% CI, -1.36 to -0.60; P < .0001, very low certainty) was lower for the CB group. The color change was unaffected (P > .08).

PRACTICAL IMPLICATIONS

Although topical CB dental bleaching did not reduce the risk of TS and color change, these agents slightly reduced the TS intensity, but the certainty of the evidence is very low.

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.

One-year follow-up comparing at-home bleaching systems outcomes and the impact on patient's satisfaction: Randomized clinical trial

OBJECTIVE

To compare at-home systems with reduced daily time of use (10% hydrogen peroxide [HP] gel with prefilled (PT) or customized trays (CT), and 10% carbamide peroxide [CP] gel), with the conventional nightguard vital bleaching (10% CP). Bleaching efficacy, adverse effects, and patient's satisfaction were evaluated.

METHODS

Sixty participants were randomly divided into treatments (14 days): Opalescence GO (OGO)-10%HP PT-30 min, White Class-10%HP CT-30 min, Opalescence PF-10%CP CT-2 h, and Opalescence PF-10%CP CT-8 h. Color difference (visual and spectrophotometer), tooth sensitivity (visual analogue scale), gingival condition (Löe index), enamel mineralization (laser fluorescence), and patients' satisfaction (questionnaire) were assessed. Statistical tests were applied (5%).

RESULTS

After 1 year, color difference was similar for the groups (p > 0.05). All groups showed similar sensitivity risk (p > 0.05). The intensity of sensitivity and gingival irritation was mild for all gels, but higher for OGO. Fluorescence after bleaching remained similar to those of sound enamel. All participants were satisfied with treatments.

CONCLUSIONS

All systems produced similar bleaching efficacy, which was maintained after 1 year. Patients were satisfied with bleaching outcomes. Tooth sensitivity occurred in all groups, but with overall mild intensity. No relevant gingival irritation and enamel demineralization was observed.

CLINICAL SIGNIFICANCE

Bleaching with 10% HP gels in prefilled and CTs represent efficacious alternative for tooth color change, with patients' acceptance similar to conventional 10% CP. Patients must be warned about the mild sensitivity and gingival irritation potential, mainly with PTs.

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 [∆WI_D]) 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 ∆WI_D 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.

Colorimetric evaluation after in-office tooth bleaching with violet LED: 6- and 12-month follow-ups of a randomized clinical trial

OBJECTIVES

To evaluate the long-term outcomes of in-office bleaching with violet LED light (LED) alone or combined with carbamide (CP) or hydrogen (HP) peroxides.

METHODS

Volunteers of a previous short-term study were recalled for 6- and 12-month follow-ups, according to the following interventions (n = 18/group): LED, CP, LED/CP, HP, and LED/HP. The objective color (ΔE_ab, ΔE₀₀) and whiteness index (ΔWI_D) changes were calculated applying the CIELab coordinates' values obtained using a spectrophotometer. A visual shade guide determined the tooth's subjective color change (ΔSGU). Data were submitted to one-way ANOVA or Welch's ANOVA, following appropriate post hoc tests (α = 5%).

RESULTS

The LED and CP groups exhibited the lowest ΔE_ab, ΔE₀₀, and ΔSGU (p < 0.05), but the LED group displayed a significantly lower ΔWI_D. After 12 months, the LED/CP group presented a higher ΔE_ab and ΔE₀₀ than the CP group (p < 0.05). ΔE_ab, ΔE₀₀, ΔSGU, or ΔWI_D means did not differ statistically between the LED/CP and HP groups. The LED/HP group presented a higher ΔE₀₀ than the HP group, regardless of the time.

CONCLUSIONS

The bleaching efficacy of LED alone was significantly lower compared to the LED/CP and HP-containing protocols. After 12 months, the LED/CP and HP groups did not differ in bleaching efficacy. LED irradiation only increased the objective color change of bleaching gels.

CLINICAL RELEVANCE

LED alone promoted a long-term perceptible bleaching, but not compatible with that of high-concentrated HP. The bleaching outcomes of violet irradiation to 37% CP were maintained over time, with LED/CP demonstrating comparable results to HP even after 12 months.

NATIONAL CLINICAL TRIALS REGISTRY (REBEC)

RBR-5t6bd9.

One-year follow-up evaluation of reservoirs in bleaching trays for at-home bleaching

OBJECTIVE

To evaluate the color change stability and patient satisfaction after one-year of at-home bleaching with 10% carbamide peroxide (CP) in trays with or without reservoirs.

MATERIALS AND METHODS

Forty-six patients were subjected to bleaching with CP (3 h/daily; 21 days) with a bleaching tray with or without reservoirs. The color was measured one-month and one-year after the completion of bleaching using the spectrophotometer (ΔEab, Δ00 and ΔWi), and shade guide units (ΔSGU). Patients' satisfaction were assessed using a 5-point Likert Scale questionnaire. Data were submitted to paired t-test (α = 0.05).

RESULTS

No significant difference between color change after one-month and one-year was observed (VITA Classical shade guide unit and the ΔWi; p > 0.53). Significant differences were observed for the VITA Bleachedguide 3D-MASTER shade guide, ΔEab and ΔE00 (p < 0.03). The level of patient satisfaction was similar between groups (p = 1.00).

CONCLUSIONS

Bleaching tray design did not have any influence on the bleaching stability for the 10% CP (Opalescence PF, Ultradent). Patients were very satisfied with the bleaching outcomes regardless of the bleaching tray design.

CLINICAL RELEVANCE

Placement of reservoirs in bleaching trays does not increase longevity of dental bleaching. No clinically important color rebound was observed 1 year after bleaching with 10% CP.

Whitening Efficacy of 3% Carbamide Peroxide Gel Activated by Lactoperoxidase

Objective

The aim of this clinical study was to evaluate the effectiveness of a whitening toothpaste containing 3% carbamide peroxide and lactoperoxidase. Materials and methods. Participants were instructed to brush their teeth using an enzymatic-activated dentifrice following a particular procedure for three weeks. Color was recorded before and after treatment using a VITA Easyshade spectrophotometer. Differences in L^∗ (tooth color lightness), a^∗ (displacement along the red-green axis), and b^∗ (displacement along the yellow-blue axis) were measured before and after treatment using the paired t and the Wilcoxon signed-rank tests. Color changes (Δ_E) were calculated using the obtained measurements.

Results

Thirty-four volunteers were included. Δ_E was 4.03. For the set of 348 teeth, a greater tendency towards green (lower a^∗) and blue (lower b^∗) was observed (p < 0.05). There were no significant differences in lightness after treatment. Mandibular central incisors showed a greater tendency towards green (lower a^∗) and blue (lower b^∗). Bleaching effectiveness was observed in both the upper and lower central incisors and in the lateral mandibular incisors.

Conclusion

Based on these results, it may be concluded that brushing with an enzymatic-activated dentifrice is effective for whitening teeth.