Perioperative use of an anti-inflammatory drug on tooth sensitivity caused by in-office bleaching: a randomized, triple-blind clinical trial

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.

Preemptive use of ibuprofen and desensitizer decreases immediate tooth sensitivity after in-office bleaching: A triple-blind, randomized, placebo-controlled clinical trial

BACKGROUND

The authors evaluated the synergistic analgesic effect of preemptive administration of 400 mg of ibuprofen (IBU) and potassium fluoride 2% (KF2), both in isolation or combination, on the painful perception of tooth sensitivity after tooth bleaching.

METHODS

Fifteen patients participated in this triple-blind, randomized, placebo-controlled clinical trial. The study used a crossover design for drug administration and a split-mouth design for desensitizer agent. Four paired groups were formed: IBU plus KF2 (IBU + KF2); IBU (IBU + placebo KF); KF2 (placebo IBU + KF2), and placebo (placebo IBU + placebo KF). The outcome measure was the perception of tooth sensitivity, assessed using a visual analog scale. Data were collected at 4 different times: immediately after tooth bleaching (baseline) and after 6, 30, and 54 hours. Statistical analysis was performed using the Friedman test and relative risk.

RESULTS

IBU plus KF2 was found to be more effective in reducing tooth sensitivity immediately after bleaching (baseline) compared with the placebo group (P < .05). The risk of experiencing moderate or severe tooth sensitivity was approximately 4 times higher in the placebo group than in the IBU plus KF2 group (relative risk, 4.00; 95% CI, 1.01 to 15.81; P = .025).

CONCLUSIONS

The combined use of 400 mg of IBU and KF2 appears to be beneficial in managing postbleaching tooth sensitivity. It provides a superior analgesic effect compared with placebo.

PRACTICAL IMPLICATIONS

The preemptive administration of IBU plus KF2 reduces tooth sensitivity after tooth whitening when compared with placebo. This clinical trial was registered in the Brazilian Clinical Trials Registry Platform. The registration number is U1111-1249-8191.

Effect of a Toothpaste for Sensitive Teeth on the Sensitivity and Effectiveness of In-office Dental Bleaching: A Randomized Clinical Trial

OBJECTIVES

The present study aimed to evaluate the desensitizing effect of toothpaste for sensitive teeth on patient tooth sensitivity and on bleaching efficacy of the 38% hydrogen peroxide bleaching agent used for in-office bleaching compared to a regular toothpaste in a randomized clinical trial.

METHODS AND MATERIALS

Forty-eight patients having maxillary right central incisors with darkness greater than A1 were selected for the present double-blind randomized clinical trial. Patients were randomly allocated into two groups: the placebo group, which used regular toothpaste, and the experimental group, which used sensitivity toothpaste. The intervention consisted of applying toothpaste with the aid of an individual tray for a period of 4 minutes daily, starting one week before the first bleaching session and interrupting use immediately after the second session. After allocation to one of the groups, individuals received in-office dental bleaching with a 40-minute application of 38% hydrogen peroxide for two sessions with an interval of one week. The incidence and intensity of sensitivity were assessed using a visual analogue scale and a numeric analogue scale. Sensitivity was measured immediately before each session, 1 hour, 24 hours, and 48 hours after each bleaching session and four weeks after the second bleaching session. Tooth shade was evaluated using a spectrophotometer and by comparison with the VITA Classical Shade Guide (Vita Zahnfabrik, Bad Säckingen, Germany). Tooth shade was evaluated before the first bleaching session, one week after the first bleaching session, one week after the second bleaching session and four weeks after the second bleaching session. Participants and professionals who performed the bleaching, shade, and sensitivity assessments were blinded to the group of patients they were treating or assessing. For the incidence of hypersensitivity, the results were evaluated by comparing the groups at different evaluation times with the Mann-Whitney test for comparison between groups, the Friedman test for repeated measures, and the Tukey test for comparison of times. Shade change on the guide was analyzed using the Mann-Whitney test for comparison between groups and the Wilcoxon test for comparison between times. Shade change by the spectrophotometer was analyzed using the t-test for comparison between groups and the paired t-test for comparison between times. All analyses were performed with a significance level of 5%.

RESULTS

There was no difference in the pattern of dental hypersensitivity between groups. For all shade measures, there was no difference between the bleaching results, and no statistically significant difference was observed between the study groups.

CONCLUSION

The use of arginine-based desensitizing toothpaste did not interfere with the bleaching ability of hydrogen peroxide and was not effective in reducing the sensitivity caused by in-office tooth bleaching.

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 (ΔE_ab, ΔE₀₀, and ΔWI_D).

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.

Blinded, Parallel and Randomized Clinical Evaluation of In-office Dental Bleaching with Violet LED (405-410 nm)

This clinical study evaluated the effect of bleaching performed with violet LED light (405-410 nm), either combined with hydrogen peroxide (HP) gel, or not, on color change, dental sensitivity, participants' satisfaction and impact on their quality of life. A hundred participants were divided into one of the groups (n = 25): G1 - 35% HP (4 sessions, 1x/week); G2 - violet LED (4 sessions, 1x/week); G3 - violet LED (4 sessions, 2x/week); G4 - hybrid technique (violet LED + 35% HP; 4 sessions, 1x/week). Color evaluation was performed with colorimetric tests (objective and subjective), before, 14 days and 3 months after completion. Additionally, satisfaction with treatment, impact on quality of life (OHIP-14) and dental sensitivity were recorded. The data were submitted to statistical analysis, considering a significance level of 5%, with the exception of the data from the questionnaire on satisfaction (descriptive analysis). Two-way ANOVA and Tukey tests showed that there was no difference between color variation resulting from techniques used in G1 and G4; those used in G2 and G3 did not differ and were less effective for bleaching than those of the other groups, in both subjective and objective evaluations. Regarding tooth sensitivity, subjects in G2 and G3 experienced no sensitivity, ​​while those in G4 showed lower sensitivity values than those in G1. With respect to quality of life, only subjects in G1 and G2 showed a significant positive impact. Among the evaluated techniques, the hybrid type seemed to be a good alternative, showing effective bleaching with less tooth sensitivity.

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.

Topical application of Otosporin® before in-office bleaching: a split mouth, triple-blind, multicenter randomized clinical trial

OBJECTIVES

To evaluate if the topical application of Otosporin® before in-office bleaching with a 35% hydrogen peroxide (HP) gel reduces the risk and intensity of tooth sensitivity (TS), as well as the bleaching effectiveness.

MATERIALS AND METHODS

Twenty participants were selected for this split mouth, triple-blind, multicenter randomized clinical trial. Before each bleaching session, the placebo was applied in the patient's hemi-arch and the other half received the Otosporin®, according to the randomization procedure. Both products were applied topically for 10 min. The 35% HP was applied in two sessions with a 1-week interval. The risk and intensity of TS were assessed using the Numerical Scale (NRS) and the Visual Analog Scale (VAS). The bleaching effectiveness were evaluated with the visual scales and with a digital spectrophotometer. The absolute risk of TS was compared by McNemar's test. To compare the intensity of TS, the Wilcoxon signed-rank test was used to evaluate the NRS, while the paired t test was used to evaluate VAS. Bleaching effectiveness (ΔSGUs and ΔE_ab, ΔE₀₀, and ΔWI_D) was compared between groups using the paired t-test (α = 0.05).

RESULTS

No significant difference at risk (p = 1.0) and intensity of TS (p > 0.59; VAS and p = 1.00 for NRS) was detected between groups. For both groups, a significant bleaching was observed after 30 days of evaluation (p < 0.39).

CONCLUSIONS

The previous application of Otosporin® in the in-office bleaching did not reduce the risk and intensity of TS and did not affect the effectiveness of the bleaching.

CLINICAL RELEVANCE

The application of Otosporin® before in-office bleaching with 35% HP was not able to reduce the risk and intensity of TS.

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.

Clinical evaluation of in-office tooth whitening with violet LED (405 nm): A double-blind randomized controlled clinical trial

BACKGROUND

Although there is little evidence showing the effectiveness of violet LED on in-office tooth whitening, there are some studies which have reported satisfactory results. This double-blind randomized controlled clinical trial aimed to evaluate the effect of a violet light emission diode (LED) (405 nm) system, used in-office, on tooth whitening, sensitivity, use of medication after whitening and quality of life.

METHODS

Eight patients were randomized into 4 groups (n = 20): G1 - violet LED, G2 - 35% carbamide peroxide (CP) and violet LED, G3 only CP 35% and G4 35% hydrogen peroxide (HP). The color was measured using a spectrophotometer at the following times: baseline, 15 and 180days. The colorimetric changes were analyzed using measurements from the CieLab System ΔE (ΔL, Δa and Δb) and the WID (Whiteness Index for Dentistry) for the 4 groups. Tooth sensitivity was recorded via a visual analog scale (VAS). Additionally, the Psychosocial Impact of Dental. Aesthetics Questionnaire (PIDAQ) was used to evaluate quality of life.

RESULTS

For the analysis of ΔL, G4 and G2 presented more brightness than G1 and G3 (p<0.05), implying that G2 is at least as good as G4 (p>0.05). For measure of Δa, G4 presented better results, standing out from the other groups. (p<0.05). For Δb, both G4 and G2 showed a greater tendency for blue color than groups G1 and G3 (p <0.05). When analyzing ∆E at the 180-day follow up, G4 produced the highest ∆E, while G3 showed the lowest ∆E. The other 2 whitening groups produced intermediate ∆E values. For ∆W, G1 and G3 significantly differed from G2 and G3. When analyzing the 180-day follow up, G2 produced the highest ∆W, while G3 showed the lowest ∆W. The other two whitening treatments produced intermediate ∆W values. As for sensitivity, only G4 patients showed dental sensitivity within 24 h of the bleaching, with pain ceasing after 48 h. For G4, 33% of the patients needed to take analgesics within the first 24 h after the first 3 whitening sessions. For PIDAQ, there was no overall decrease in score over time for any of the groups and there was no difference between them (p>0.05).

CONCLUSION

Our results showed that violet LED was not able to whiten teeth at the same intensity, when used alone, as it was when associated with 35% CP, contrary to our initial hypothesis. However, given that pain was not consistently reported in G2, one could suggest that treatment with LED + 35% CP is quite similar to that of 35% HP when used for tooth whitening, but with better pain outcomes. All treatments suggested an improvement in quality of life.Clinical Trial Registry: This trial is registered at ClinicalTrials.gov; the registration number is NCT03192852 https://clinicaltrials.gov/ct2/show/NCT03192852.

Effect of topical application of nanoencapsulated eugenol on dental sensitivity reduction after in-office dental bleaching: a randomized, triple-blind clinical trial

PURPOSE

This randomized, split-mouth, triple-blind clinical study evaluated the effect of application of nanoencapsulated eugenol (NE) on the absolute risk and intensity of tooth sensitivity (TS) resulting from in-office bleaching.

METHODS

Fifty-six patients received a NE in one hemiarch and a placebo gel in the other hemiarch, determined by random sequence, before in-office bleaching. A visual analogue scale (VAS) (0-10) and a numeric rating scale (NRS) (0-4) were used to record TS during bleaching and 1 and 48 h after bleaching. The tooth color was performed from baseline to 2 weeks after bleaching with shade guides (ΔSGU) and a spectrophotometer (∆E_ab , ∆E_00, and WI_D ). The TS was assessed through the McNemar test (α = 0.05) and by the Wilcoxon signed-rank test (NRS) and paired t-test (VAS). The paired test-t was employed to compare the color changes (ΔSGU and ΔE_ab , ∆E_00, and WI_D ). The significance level was 5%.

RESULTS

No statistically significant difference was found in the absolute risk or intensity of TS between both groups (p > 0.05). A significant color change was observed in both groups (p > 0.05).

CONCLUSION

Administration of the gel containing NE before the in-office dental bleaching did not reduce the TS and did not interfere in the bleaching effect.

CLINICAL RELEVANCE STATEMENT

The use of desensitizing gel containing NE did not reduce in-office bleaching-induced tooth sensitivity.

Prior Application of 10% Potassium Nitrate to Reduce Postbleaching Sensitivity: A Randomized Triple-Blind Clinical Trial

OBJECTIVE

To evaluate if the topical application of 10% potassium nitrate applied before in-office bleaching is effective to reduce the risk and intensity of tooth sensitivity (TS), as well as to evaluate if its application can jeopardize color change.

MATERIALS AND METHODS

A randomized, split-mouth triple-blind clinical trial was conducted on 43 young patients with incisors A2 or darker. Half of the patient's upper arch received either the application of a 10% potassium nitrate or placebo gel for 10 min in a university setting. In-office bleaching was performed in three 15-min applications in two clinical sessions (1-week interval) using 35% hydrogen peroxide. Risk and intensity of TS was recorded with a 0-4 Numeric Rating Scale and a 0-10 Visual Analogue Scale during bleaching, 1 hour, 24 hours, and 48 hours after bleaching. Color was evaluated before and 1 month after bleaching with shade guides (Vita Classical and Vita Bleachedguide) and a spectrophotometer. The risk of TS (McNemar's test) and intensity of TS (Wilcoxon signed-rank for Numeric Rating Scale and paired t-test for Visual Analogue Scale) were statistically evaluated. Color change was compared using paired t-test. Significant level was set at 5%.

RESULTS

No significant difference was observed in the absolute risks of TS between groups (RR = 1.11; 95% CI 0.97 to 1.27; P = .12), which exceeded 87% for both groups. Similarly, no difference in TS intensities was detected (P > .05). Significant whitening was observed with all color measurement instruments with no difference between groups (P > .05).

CONCLUSION

The topical application of 10% potassium nitrate, before in-office bleaching, did not reduce the risk and intensity of TS and did not jeopardize color change.

Clinical Effects of Desensitizing Prefilled Disposable Trays in In-office Bleaching: A Randomized Single-blind Clinical Trial

Objectives:

This study aimed to evaluate the desensitizing effect of a prefilled disposable tray containing potassium nitrate and fluoride on the self-reported tooth sensitivity (TS) and the bleaching efficacy of 40% hydrogen peroxide bleaching agent used for in-office bleaching in comparison with potassium nitrate and fluoride gel applied in a conventional-delivered tray system in an equivalence clinical trial.

Methods and Materials:

Seventy-eight patients, with a right maxillary canine darker than A3, were selected for this single-blind (evaluators), randomized clinical trial. Teeth were bleached in two sessions with a one-week interval in between. Before in-office bleaching, the prefilled disposable tray or conventional tray containing potassium nitrate and fluoride was used for 15 minutes. Subsequently, the bleaching agent was applied in two 20-minute applications (per the manufacturer's directions) in each session. The color change was evaluated by subjective (Vita Classical and Vita Bleachedguide) and objective (Easyshade Advance Spectrophotometer) methods at baseline and 30 days after the first bleaching session. TS was recorded for up to 48 hours using a 0-10 visual analog scale. The absolute risk was evaluated by chi-square test, while the intensity of TS was evaluated by McNemar test (α=0.05). Color change in shade guide units and ΔE was analyzed by Student t-test for independent samples (α=0.05).

Results:

Significant whitening was observed in both groups after 30 days of clinical evaluation. The use of different methods of desensitizer in a tray did not influence the absolute risk and intensity of TS (p&gt;0.05), although a tendency of lower risk of TS with the prefilled disposable tray containing potassium nitrate and fluoride was observed.

Conclusion:

The use of a prefilled disposable tray containing potassium nitrate and fluoride before the application of the in-office bleaching product did not affect the whitening degree and decreased self-reported TS when compared with a conventional-delivered tray system.

Effect of Analgesic Drugs on Tooth Sensitivity Induced by In-office Dental Bleaching: A Systematic Review and Meta-analysis

OBJECTIVE

This systematic review evaluates the effect of preemptive analgesia on tooth sensitivity induced by in-office tooth bleaching.

METHODS

The review was structured based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. The methods were recorded at PROSPERO (CRD42018095440). Randomized clinical trials, studies published in English, and studies in which the efficacy of preemptive analgesia with analgesic and anti-inflammatory medications prior to in-office tooth bleaching was compared with that of placebo were included. PubMed/MEDLINE, Scopus, Web of Science, and Cochrane Library were used for searching. The electronic search provided 373 articles, and seven of them were selected based on the inclusion criteria.

RESULTS

Immediately after time point, a significant reduction of dental sensitivity was observed in the drug group compared to the control group (p=0.02; mean difference [MD]: -0.90; confidence interval [CI]: -1.63 to -0.16), while there was no significant difference at up to one-hour (p=0.22; MD: -0.42; CI: -1.09 to -0.25), at 1-24-hour (p=0.88; MD: -0.05; CI: -0.61 to 0.72), or 24-48-hour (p=0.69; MD: 0.05; CI: -0.21 to 0.32) time points. The incidence of sensitivity during the procedure was not statistically different between the groups (p=0.64; MD: 0.91; CI: 0.92 to 1.15). The nonsteroidal anti-inflammatory drug group showed a statistically significant reduction (p=0.04; MD: -0.69; CI: -1.36 to -0.03) in tooth sensitivity compared with the other groups.

CONCLUSIONS

This systematic review and meta-analysis demonstrated that the medications analyzed did not interfere with the incidence of sensitivity symptoms. Regarding the intensity, no difference was observed between the drug and placebo groups at the up to one-hour, 1-24-hour, or 24-48-hour time points, and there was a statistically significant difference at the zero-hour time point in favor of the drug group. However, based on the variables that influenced this result, it should be considered with prudence because a small difference was observed.

The effect of oral anti-inflammatory drugs on reducing tooth sensitivity due to in-office dental bleaching: A systematic review and meta-analysis

BACKGROUND

The authors' aim was to evaluate the effectiveness of anti-inflammatory drugs on tooth sensitivity (TS) during and after in-office dental bleaching procedures.

TYPES OF STUDIES REVIEWED

The authors selected randomized controlled trials in which the investigators compared anti-inflammatory drugs with a placebo to evaluate in-office dental bleaching TS. The authors performed an electronic search by using PubMed, ScienceDirect, and Embase. In addition, the authors searched other Web sites, such as ClinicalTrials.gov, to identify ongoing studies.

RESULTS

The authors included 7 randomized controlled trials (324 adults) in the review. According to the extracted data, the authors performed the meta-analysis by using risk ratios and their 95% confidence intervals or by using the mean difference with a 95% confidence interval. The authors used the Cochrane Collaboration's tool to assess study quality. After the evaluation, the authors considered 6 studies to be high quality and a single study to be low quality. The overall results of the evaluation process revealed the absence of a clinically significant effect of anti-inflammatory drugs.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The results of this analytic process indicated that anti-inflammatory drugs have no clinically significant effect on the TS that occurs due to in-office bleaching. Readers must analyze these results carefully given the limitations of this review, such as the small samples size and the heterogeneity among the studies in some stages of the evaluation process. The results of this analytical study highlight the need for more clinical studies to reach a significant conclusion because TS is one of the most important reasons for the cessation of bleaching treatment.

Effect of anti-inflammatory and analgesic drugs for the prevention of bleaching-induced tooth sensitivity: A systematic review and meta-analysis

BACKGROUND

In-office dental bleaching results in a high risk of tooth sensitivity caused by the inflammatory process of the pulpal tissue. In this systematic review, the authors aimed to evaluate the effect of administering anti-inflammatory and analgesic drugs for the prevention of tooth sensitivity associated with in-office dental bleaching.

TYPES OF STUDIES REVIEWED

The authors searched the databases MEDLINE via PubMed, Scopus, Web of Science, and Cochrane Library for clinical trials. They searched in ClinicalTrials.gov for unpublished trials. The authors included only randomized clinical trials comparing anti-inflammatory and analgesic drugs with a placebo and evaluating tooth sensitivity after in-office bleaching. They imposed no restrictions regarding publication dates or languages.

RESULTS

The authors identified 5,050 studies after the removal of duplicates. They qualitatively and quantitatively analyzed the 11 studies remaining after the title and abstract screening. Nine studies showed a low risk of bias. The authors found no effect of the drugs on the risk (9 studies evaluated this outcome). Using a visual analog scale, the authors identified a similar level of sensitivity evaluated up to 1 hour (10 studies evaluated this outcome) and 24 hours (8 studies evaluated this outcome). They observed similar results using the numeric rate scale (8 and 6 studies used this tool, up to 1 hour and 24 hours respectively). The Grading of Recommendations Assessment, Development, and Evaluation approach showed a high level of evidence for all outcomes.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The high level of evidence available does not support the administration of anti-inflammatory and analgesic drugs to prevent tooth sensitivity caused by in-office dental bleaching.

Tooth Sensitivity After Dental Bleaching With a Desensitizer-containing and a Desensitizer-free Bleaching Gel: A Systematic Review and Meta-analysis

Objectives:

A systematic review and meta-analysis were performed to evaluate the risk and intensity of tooth sensitivity (TS) after dental bleaching with a desensitizer-containing and a desensitizer-free bleaching gel in adult patients. Color change and risk of gingival sensitivity was also evaluated.

Methods:

A comprehensive search was performed MEDLINE via PubMed, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database (LILACS), Brazilian Library in Dentistry (BBO), EMBASE and Cochrane Library, and System for Information on Grey Literature in Europe (SIGLE) without restrictions to identify randomized clinical trials. Abstracts from the annual conference of the International Association for Dental Research (1990–2016), unpublished and ongoing trials registries, dissertations, and theses were also searched. The quality of the evidence was rated using the Grading of Recommendations: Assessment, Development and Evaluation (GRADE) approach.

Data:

After duplicates were removed, 1352 articles were identified. After title and abstract screening, only 47 studies remained for qualitative evaluation. Most of the studies had unclear risk of bias. No difference between groups were observed for the risk ratio of TS (risk ratio = 0.99; 95% confidence interval [CI] = 0.74–1.33); intensity of TS (standardized difference in means [SMD] = 0.04; 95% CI = 0.79–0.70); color change in shade guide units (SMD – 0.04; 95% CI = 0.50–0.42); color change in ΔE* (SMD = 0.41 (95% CI = 0.07–0.89); and risk ratio of gingival irritation (SMD = 1.05; 95% CI = 0.81–1.36). Except for the risk of TS, graded as moderate quality of evidence, all other outcomes were rated as low and very low quality.

Conclusions:

Incorporating desensitizers in the bleaching gel did not reduce the risk of TS, and the quality of this evidence was considered moderate. On the other hand, the intensity of TS, color change, and risk of gingival irritation was similar between groups, but the quality of the evidence for these outcomes was graded as low or very low, thus reducing the level of confidence in these outcomes.

Combination of Acetaminophen/Codeine Analgesics Does Not Avoid Bleaching-Induced Tooth Sensitivity: A Randomized, Triple-Blind Two-Center Clinical Trial

Bleaching-induced tooth sensitivity (TS) is highly prevalent.

OBJECTIVE

This study aimed to determine if the combination of opioids and nonopioids analgesics (Tylex) may provide a better analgesic effect.

METHOD

A triple-blind, parallel, randomized two-center clinical trial was conducted with 105 healthy patients who received either a placebo or a combination of acetaminophen/codeine. The first dose of Tylex 30 mg (acetaminophen 500 mg/codeine 30 mg) or placebo was administered one hour before the in-office bleaching (35% hydrogen peroxide), and extra doses were administered every six hours for 48 hours. The TS was recorded using a visual analog scale of 0 to 10 and a numeric rating scale of 0 to 4 in different periods: during bleaching, one hour up to 24 hours, and 24 hours up to 48 hours postbleaching. The color was measured before and one month after dental bleaching with a visual shade guide (Vita Classical), Vita Bleachedguide 3D-MASTER, and the spectrophotometer Vita Easyshade. The absolute risk of TS was evaluated using the Fisher exact test. Data of TS intensity with numeric rating scale of the two groups were compared with the Mann-Whitney U-test and the Friedman test, while data from the visual analog scale were evaluated by two-way repeated measures analysis of variance and the Tukey test for pairwise comparison. The color changes between groups were compared using the Student t-test (α=0.05).

RESULTS

No significant differences between the groups were observed in the risk and intensity of TS. The overall absolute risk of TS was approximately 96%. No significant differences between groups were observed in terms of color change ( p>0.05) for any scale.

CONCLUSION

The use of an acetaminophen/codeine combination prior to in-office bleaching does not reduce the risk and intensity of bleaching-induced TS.

High-concentration carbamide peroxide can reduce the sensitivity caused by in-office tooth bleaching: a single-blinded randomized controlled trial

Objectives

A single-blinded, randomized, parallel clinical trial evaluated the use of 37% carbamide peroxide (CP) on bleaching effectiveness and tooth sensitivity reported by patients undergoing in-office tooth bleaching, in comparison with the results of using 35% hydrogen peroxide.

Material and Methods

Forty patients were allocated to receive two sessions of in-office tooth bleaching using either 35% hydrogen peroxide (HP) or 37% CP. Each patient’s sensitivity level was evaluated during and up to 24 h after bleaching. The effectiveness of the bleaching procedures was evaluated with a spectrophotometer one week after each session and 30 days after the last session. The impact of tooth bleaching on the patients’ perceptions regarding smile changes, in addition to the bleaching procedures and their results, were also recorded. Absolute and relative sensitivity risks were calculated. Data on sensitivity level were analyzed using the Mann-Whitney or T-test, and data from the color evaluation were subjected to 2-way repeated measures ANOVA.

Results

The use of CP reduced the risk and level of tooth sensitivity to values close to zero, whereas the difference between the bleaching agents disappeared after 24 h. An increased bleaching effect was observed for HP, mainly due to an improved reduction of redness and yellowness. Participants perceived improved tooth bleaching for HP and reduced sensitivity for CP, but no differences regarding the comfort of the techniques were noted.

Conclusions

In our study, 37% CP resulted in reduced tooth sensitivity but decreased the tooth bleaching effectiveness. However, both bleaching agents resulted in high levels of patient satisfaction.

Effect of an experimental desensitizing agent on reduction of bleaching-induced tooth sensitivity: A triple-blind randomized clinical trial

BACKGROUND

In this randomized study, split-mouth, triple-blind clinical trial, the authors evaluated the efficacy of a desensitizing gel that contained 5% potassium nitrate and 5% glutaraldehyde applied before in-office bleaching with 35% hydrogen peroxide (HP).

METHODS

Treatment with the desensitizing or placebo control gels was randomly assigned to one-half of the maxillary teeth of 42 patients in a split-mouth design. The desensitizing gels were applied and maintained in contact with the tooth enamel for 10 minutes, followed by 2 HP bleaching sessions separated by 1 week. The primary outcome variable was pain intensity assessed with a numeric rating scale and a visual analog scale. Color was evaluated by means of a digital spectrophotometer and a value-oriented shade guide.

RESULTS

The difference in risk of developing tooth sensitivity between the desensitizing gel group (31.7%, 95% confidence interval [CI], 19.6 to 46.9) and the control group (70.7%; 95% CI, 55.5 to 82.3%) was statistically significant (P < .0001), as well as the difference in pain intensity in the first 24 hours (P < .001). No statistically significant difference was found in color change between teeth that received the desensitizing gel and those that received the placebo gel.

CONCLUSIONS

Application of desensitizing gel that contained 5% potassium nitrate and 5% glutaraldehyde before HP whitening reduced the risk and severity of dental sensitivity, without altering the effectiveness of whitening.

PRACTICAL IMPLICATIONS

A single application of desensitizing gel that contained 5% potassium nitrate and 5% glutaraldehyde can reduce tooth sensitivity after dental bleaching systems.

Preventive Use of a Resin-based Desensitizer Containing Glutaraldehyde on Tooth Sensitivity Caused by In-office Bleaching: A Randomized, Single-blind Clinical Trial

OBJECTIVE

To evaluate the risk and intensity of bleaching-induced tooth sensitivity (TS) after in-office bleaching following topical application of a resin-based glutaraldehyde desensitizer.

METHODS

Thirty-three patients were randomly assigned to the experimental (Gluma Desensitizer Liquid, Heraeus Kulzer, Hanau, Germany) and placebo groups. The placebo or Gluma Desensitizer Liquid was applied for one minute prior to application of an in-office bleaching gel. Bleaching was performed with 35% hydrogen peroxide gel (three applications × 15 minutes each) over two sessions, one week apart. The color of the anterior teeth was evaluated before and 21 days after treatment using the VITA Classical shade guide, Bleachedguide 3D, and Easyshade spectrophotometer. TS during and after the bleaching was recorded according to the visual analog (VAS) and numerical rating (NRS) scales. All data were submitted to statistical analysis (α=0.05).

RESULTS

There was no significant difference in absolute risk or intensity of TS between the two groups (risk and VAS, p=0.93 and 0.31, respectively; NRS, p≥0.45). At the end of the bleaching protocol, tooth whitening was observed in both groups, as evident from color change in shade guide units (ΔSGU, 4.1-7.1; both guides) and overall color change (ΔE, 7.4-9.3 units); however, there were no significant differences in whitening between the two groups ( p>0.11).

CONCLUSION

Gluma Desensitizer Liquid was not able to reduce the risk or intensity of TS. Bleaching efficacy was not affected by application of the desensitizer.

Effect of topical application of dipyrone on dental sensitivity reduction after in-office dental bleaching: A randomized, triple-blind multicenter clinical trial

BACKGROUND

Tooth sensitivity commonly occurs during and immediately after dental bleaching. The authors conducted a trial to compare tooth sensitivity after in-office bleaching after the use of either a topical dipyrone or placebo gel.

METHODS

A split-mouth, triple-blind, randomized, multicenter clinical trial was conducted among 120 healthy adults having teeth that were shade A2 or darker. The facial tooth surfaces of the right or left sides of the maxillary arch of each patient were randomly assigned to receive either topical dipyrone or placebo gel before 2 in-office bleaching sessions (35% hydrogen peroxide) separated by 2 weeks. Visual analog and numerical rating scales were used to record tooth sensitivity during and up to 48 hours after bleaching. Tooth color change from baseline to 1 month after bleaching was measured with shade guide and spectrophotometer measures. The primary outcome variable was absolute risk of tooth sensitivity. An intention-to-treat analysis was used to analyze data from all patients who were randomly assigned to receive the dipyrone and placebo gels.

RESULTS

No statically significant difference was found in the absolute risk of tooth sensitivity between the dipyrone and placebo gels (83% and 90%, respectively, P = .09; relative risk, 0.92; 95% confidence interval, 0.8 to 1.0). A whitening effect was observed in both groups with no statistically significant difference (P > .05) between them. No adverse effects were observed.

CONCLUSION

Topical use of dipyrone gel before tooth bleaching, at the levels used in this study, did not reduce the risk or intensity of bleaching-induced tooth sensitivity.

PRACTICAL IMPLICATIONS

Topical application of dipyrone gel does not reduce bleaching-induced tooth sensitivity.

Preemptive use of etodolac on tooth sensitivity after in-office bleaching: a randomized clinical trial

Purpose

This study determined the effectiveness of the preemptive administration of etodolac on risk and intensity of tooth sensitivity and the bleaching effect caused by in-office bleaching using 35% hydrogen peroxide.

Material and methods

Fifty patients were selected for this tripleblind, randomized, crossover, and placebo-controlled clinical trial. Etodolac (400 mg) or placebo was administrated in a single-dose 1 hour prior to the bleaching procedure. The whitening treatment with 35% hydrogen peroxide was carried out in two sessions with a 7-day interval. Tooth sensitivity was assessed before, during, and 24 hours after the procedure using the analog visual scale and the verbal rating scale. Color alteration was assessed by a bleach guide scale, 7 days after each session. Relative risk of sensitivity was calculated and adjusted by session, while overall risk was compared by the McNemar's test. Data on the sensitivity level of both scales and color shade were subjected to Friedman, Wilcoxon, and Mann-Whitney tests, respectively (α=0.05).

Results

The preemptive administration of etodolac did not affect the risk of tooth sensitivity and the level of sensitivity reported, regardless of the time of evaluation and scale used. The sequence of treatment allocation did not affect bleaching effectiveness, while the second session resulted in additional color modification. The preemptive administration of etodolac in a single dose 1 hour prior to in-office tooth bleaching did not alter tooth color, and the risk and intensity of tooth sensitivity reported by patients.

Conclusion

A single-dose preemptive administration of 400 mg of etodolac did not affect either risk of tooth sensitivity or level of sensitivity reported by patients, during or after the in-office tooth bleaching procedure.

Preemptive Use of Naproxen on Tooth Sensitivity Caused by In-Office Bleaching: A Triple-Blind, Crossover, Randomized Clinical Trial

Objectives:

A triple-blind, randomized, crossover clinical trial evaluated prior use of nonsteroidal anti-inflammatory naproxen on sensitivity reported by patients undergoing in-office tooth bleaching.

Methods and Materials:

Fifty patients were subjected to two sessions of in-office tooth bleaching with 35% hydrogen peroxide in a single application of 40 minutes for two sessions, with an interval of seven days between applications. One hour prior to the procedure, each patient randomly received a single dose of naproxen (500 mg) or placebo. The patient's sensitivity level was evaluated during and immediately after the bleaching using two scales (verbal and visual analog); the verbal scale only was repeated after 24 hours. The effectiveness of the bleaching procedures was evaluated with the Bleachedguide scale. Relative risk to sensitivity was calculated and adjusted by session, while comparison of overall risk was performed by the McNemar test. Data on the sensitivity level for both scales and shade were subjected to the Friedman, Wilcoxon, and Mann-Whitney tests (α=0.05).

Results:

The use of naproxen only decreased the absolute risk and intensity of tooth sensitivity reported immediately after the second session. On the other hand, no measurable effect was observed during or 24 hours after either session. The sequence of drug administration did not affect the bleaching effectiveness.

Conclusions:

Preemptive use of naproxen only reduced tooth sensitivity reported by patients immediately after the second session of bleaching.

Randomized clinical trials of dental bleaching - Compliance with the CONSORT Statement: a systematic review

We reviewed the literature to evaluate: a) The compliance of randomized clinical trials (RCTs) on bleaching with the CONSORT; and b) the risk of bias of these studies using the Cochrane Collaboration risk of bias tool (CCRT). We searched the Cochrane Library, PubMed and other electronic databases, to find RCTs focused on bleaching (or whitening). The articles were evaluated in compliance with CONSORT in a scale: 0 = no description, 1 = poor description and 2 = adequate description. Descriptive analyses of the number of studies by journal, follow-up period, country and quality assessments were performed with CCRT for assessing risk of bias in RCTs. 185 RCTs were included for assessment. More than 30% of the studies received score 0 or 1. Protocol, flow chart, allocation concealment and sample size were more critical items, as 80% of the studies scored 0. The overall CONSORT score for the included studies was 16.7 ± 5.4 points, which represents 52.2% of the maximum CONSORT score. A significant difference among journal, country and period of time was observed (p < 0.02). Only 7.6% of the studies were judged at "low" risk; 62.1% were classified as "unclear"; and 30.3% as "high" risk of bias. The adherence of RCTs evaluating bleaching materials and techniques to the CONSORT is still low with unclear/high risk of bias.

Clinical Evaluation of Genotoxicity of In-office Bleaching

Objective: The aim of this study was to evaluate the genotoxicity of in-office bleaching with 35% hydrogen peroxide in epithelial cells from the gingival and lip tissues.

Methods and Materials: Thirty volunteers with central incisors shade A1 or darker were selected for this study. The gingival tissue of the teeth to be bleached was isolated with a light-polymerized resin dam, and the 35% hydrogen peroxide gel was administered during three 15-minute applications over the course of the 45-minute application period. Two bleaching sessions with a one-week interval in between were performed. Exfoliated oral mucosa gingival epithelial cells and upper lip lining were collected at baseline and one month after the in-office dental bleaching. The scraped cells were placed on clean glass slides and smears were prepared. After staining with Giemsa solution, two blinded examiners performed cell and micronuclei counts under a 100× optical microscope. Tooth sensitivity was evaluated using the Visual Analogue Scale (VAS). Shade evaluation was recorded before and one month after the bleaching treatment with the value-oriented shade guide Vita Bleachedguide 3D-MASTER and the spectrophotometer Vita Easyshade. Data from the shade guide units and the micronuclei (MN) frequency were subjected to a Mann-Whitney test (α=0.05). The overall difference between before and one month after the bleaching treatment (ΔE and ΔSGU), absolute risk, and intensity of tooth sensitivity (TS) were calculated, as was the 95% confidence interval (CI).

Results: The frequency of MN was not increased after bleaching with 35% hydrogen peroxide in both study groups (p&gt;0.05). The absolute risk of TS of the participants was 93% (95% CI, 79%-98%), with a mean VAS intensity of 5.7 ± 2.9 (95% CI, 4.6-6.8). Meaningful whitening was observed after bleaching. The change in shade guide units in the Bleachedguide 3D-MASTER was 2.3 ± 1.4. In terms of ΔE, the change in color was 7.7 ± 3.5.

Conclusions: The in-office bleaching did not induce DNA damage to the gingival and lip tissue during the bleaching period. Although effective whitening was observed, most of the participants experienced TS.

A Single-Blind Randomized Trial About the Effect of Hydrogen Peroxide Concentration on Light-Activated Bleaching

Objective: To compare the bleaching efficacy and tooth sensitivity (TS) of two hydrogen peroxide (HP) concentrations (20% and 35%) used for in-office bleaching associated or not with a light-emitting diode (LED)/laser light activation.

Method: Seventy-seven patients with a right maxillary canine darker than A3 were selected for this single-blind randomized trial. The participants were distributed in four groups: bleaching with 35% HP, 35% HP + LED/laser, 20% HP, and 20% HP + LED/laser. The anterior teeth were bleached in two sessions, using a 35% or 20% HP gel with a one-week interval. Each session had three applications of 15 minutes. For the light-activated groups, the LED/laser energy (Whitening Laser Light Plus, DMC) was employed according to the manufacturer's instructions. The color change was evaluated by subjective and objective methods. Participants recorded TS with five-point verbal and visual analog scales. Color change in ΔE was evaluated by analysis of variance and Tukey tests (α=0.05) and in ΔSGU with Kruskall-Wallis and Dunn test. The absolute risk of TS and TS intensity were evaluated by Fisher exact test and Kruskall-Wallis test, respectively (α=0.05).

Results: All groups achieved the same level of whitening, except for the 20% HP group, which showed the lowest degree of whitening in the subjective analysis. The use of light did not increase the absolute risk or intensity of TS. No significant difference among groups was observed when color changes were assessed with the spectrophotometer.

Conclusion: According to the value-oriented shade guide, the use of LED/laser light activation was able to increase the degree of whitening of the 20% HP group, but this association was not useful for the 35% HP gel. The spectrophotometer, however, did not detect significant differences among groups.

Combined Bleaching Technique Using Low and High Hydrogen Peroxide In-Office Bleaching Gel

Objectives: The aim of this study was to evaluate the efficacy, color stability, risk, and intensity of tooth sensitivity (TS) of combined bleaching techniques performed with 20% or 35% hydrogen peroxide for an in-office protocol.

Methods: Thirty patients were randomly divided into two groups and submitted to a single 45-minute in-office bleaching session with 35% hydrogen peroxide or 20% hydrogen peroxide. At-home bleaching was performed with 10% carbamide peroxide for two hours daily over the course of two weeks. The color was evaluated with the value-oriented shade guide Vita Classical at different periods up to 12 months after bleaching. Patients recorded the intensity of TS using a five-point verbal scale. Color change data were submitted to a two-way repeated-measures analysis of variance and Tukey test (α=0.05). The absolute risk and intensity of TS were compared with the Fisher exact test and Mann-Whitney test, respectively (α=0.05).

Results: On average, an effective and similar whitening of three units in shade guide was observed for both groups, which remained stable for 12 months. When both protocols were compared, the one with hydrogen peroxide 35% showed a higher risk (p=0.02) and intensity of TS (p=0.04). In regard to the TS intensity, no significant difference was observed up to 48 hours after in-office bleaching (p=0.09) and during the at-home bleaching phase of the study (p=0.71).

Conclusion: The combined bleaching technique using at-home bleaching associated with in-office bleaching was effective and stable over the course of 12 months, regardless of the concentration of the hydrogen peroxide used for in-office bleaching. However, the protocol with 20% hydrogen peroxide produced lower risk and intensity of TS.

The Impact of a Customized Tray on In-Office Bleaching Tooth Sensitivity: A Randomized Clinical Trial

Objective

It was recently demonstrated that using a tray over a bleaching agent reduces its pulpal chamber penetration, which can reduce tooth sensitivity. This study evaluated the effect of the sealed technique on the presence and level of sensitivity reported by patients during and after the bleaching procedure performed in office.

Methods

Forty-six patients underwent a bleaching procedure with 35% hydrogen peroxide used in a single application of 45 minutes for two sessions with an interval of seven days. A customized tray was maintained over the bleaching agent during the entire procedure in half of the patients. The sensitivity level was evaluated during and immediately after the bleaching using verbal and visual analogue scales. The shade alteration was evaluated with a bleach guide scale. The peak sensitivity after 24 hours and the presence/level at 24 hours were also evaluated using a verbal rating scale. Relative risks were calculated for all time assessments. Data on the sensitivity level for both scales were subjected to Friedman and Mann-Whitney tests (α=0.05). Data on the shades were analyzed by two-way repeated-measures analysis of variance and Tukey's test (α=0.05).

Results

The use of a customized tray increased the relative risks to the tooth measured 24 hours after each bleaching session. The sealed technique also increased the level of tooth sensitivity only at 24 hours after the first session. No difference was observed between the bleaching techniques regarding the shade evaluation.

Conclusion

Using a tray over the bleaching agent can increase the level and risk of tooth sensitivity for the first 24 hours after in-office bleaching.

Predictive factors on the efficacy and risk/intensity of tooth sensitivity of dental bleaching: A multi regression and logistic analysis

OBJECTIVES

The aim of this study was to identify predictor factors associated with the whitening outcome and risk and intensity of bleaching-induced tooth sensitivity from pooled data of 11 clinical trials of dental bleaching performed by the same research group.

METHODS

The individual patient data of several published and ongoing studies about dental bleaching was collected and retrospectively analyzed. At the patient-level, independent variables (bleaching techniques [at-home and in-office protocols], sex, age and baseline tooth color in shade guide unit [SGU]) as well as dependent variables (color change in shade guide units (ΔSGU), color change in the CIEL*a*b* system (ΔE), risk and intensity of TS in a visual analog scale) were collected. Multivariable linear regression and multivariable logistic regression models were carried out using backward elimination whenever the p-values were higher than 0.05.

RESULTS

A significant relationship between baseline color and age on color change estimates was detected (p<0.001). Every increase of one SGU in the baseline color resulted in an increase of approximate 0.66 in the final ΔSGU and 2.48 for the ΔE. For every increase of one year in the participant's age we observed a decrease of the whitening degree of 0.07 for the final ΔSGU and 0.69 for the ΔE. The bleaching technique was shown to be a significant predictor of ΔSGU (p<0.001) but not of ΔE. In regard to TS, baseline color and bleaching technique are significant predictors (p<0.001). The risk of TS for at-home bleaching was 51% (95% CI 41.4-60.6) and for the in-office 62.9% (95% CI 56.9-67.3).

CONCLUSIONS

Younger patients with darker teeth reach a higher degree of whitening. Patient with darker teeth and submitted to at-home bleaching presents lower risk and intensity of TS.

CLINICAL SIGNIFICANCE

The baseline color of the teeth and the patient's age is directly related to the effectiveness of dental bleaching and TS.

Pre- and postoperative dexamethasone does not reduce bleaching-induced tooth sensitivity: A randomized, triple-masked clinical trial

BACKGROUND

Tooth sensitivity (TS) is the most common side effect of dental bleaching therapies. Dexamethasone has been used with tooth bleaching to reduce TS. The efficacy of dexamethasone for this purpose has not been well studied.

METHODS

The authors conducted a triple-masked, randomized, clinical trial with a parallel design involving 63 healthy participants who received either a placebo or dexamethasone. The placebo or dexamethasone (8 milligrams) was administered 1 hour before the in-office bleaching (35% hydrogen peroxide) and extra doses of 4 mg were administered every 6 hours for a total of 48 hours. TS was recorded on 2 scales: visual analog scale (0-10) and numeric rating scale (0-4) in different periods. The color evaluations were performed before and 1 month after dental bleaching with visual shade guides VITA Classical (VITA Zahnfabrik) and VITA Bleachedguide 3D-MASTER (VITA Zahnfabrik), and for a shade guide evaluation, the authors used a digital spectrophotometer, VITA Easyshade (VITA Zahnfabrik). The absolute risk of TS was evaluated by a Fisher exact test. Data of TS intensity using the NRS scale for the 2 groups were compared with Mann-Whitney and Friedman tests, whereas data from the visual analog scale were evaluated by 2-way repeated measures analysis of variance. The color changes between groups were compared using a t test (α = .05).

RESULTS

In both groups, the authors detected a high risk of TS, which was approximately 90%. No significant difference was observed in terms of TS intensity. A whitening of approximately 3 shade guide units of the VITA Classical was detected in both groups, which were statistically similar.

CONCLUSIONS

The use of dexamethasone before bleaching did not reduce the risk and intensity of bleaching-induced TS.

PRACTICAL IMPLICATIONS

The use of the steroidal anti-inflammatory agent dexamethasone was not capable of preventing TS arising from in-office dental bleaching.

Comparison of the Effects of In-office Bleaching Times on Whitening and Tooth Sensitivity: A Single Blind, Randomized Clinical Trial

OBJECTIVES

The objective of the present study was to compare the bleaching efficacy (BE) and tooth sensitivity (TS) of in-office bleaching applied under different time protocols.

METHODS AND MATERIALS

Fifty-three patients were randomly distributed into three groups: the bleaching agent was applied in one (1×15), two (2×15), or three (3×15) 15-minute applications. The labial surfaces of the anterior teeth were bleached using a 35% hydrogen peroxide gel. Two bleaching sessions with a one-week interval between were performed. The shade evaluation was performed with a visual shade guide and spectrophotometer before and 30 days after bleaching. Participants recorded TS with a five-point verbal scale. Color change was analyzed by one-way analysis of variance and Tukey tests. The absolute risk of TS and TS intensity were evaluated by the Fisher exact and Friedman/Kruskal-Wallis tests, respectively (α= 0.05).

RESULTS

Significant whitening was observed in all groups, with statistically lower BE for the 1×15 group (p<0.05). The absolute risk of TS (95% confidence interval) was lower for the 1×15 group than for the other groups (p<0.05). The TS intensity of the 3×15 group was statistically higher than that associated with the other protocols (p<0.05).

CONCLUSIONS

A single 15-minute application produced less TS but reduced BE. The protocol with 2×15 produced a degree of BE similar to that of the 3×15 group, but with reduced overall TS intensity.

Effects of the concentration and composition of in-office bleaching gels on hydrogen peroxide penetration into the pulp chamber

In tooth whitening, the hydrogen peroxide (HP) diffuses in the enamel and dentin, reaching the pulp. This in vitro study aimed to quantify the penetration of HP in the pulp chamber in teeth submitted to bleaching agents of different concentrations of HP without calcium (HP 20% [20CF], HP 35% [35CF]) and with calcium (HP 20% [20CC], HP 35% [35CC]).

METHOD

Fifty human premolars were sectioned 3 mm from the cemento-enamel junction and the pulp tissue was removed. The teeth were divided into five groups according to treatment and with a control group (n=10). An acetate buffer solution was placed in the pulp chamber of all teeth. The control group was exposed only to distilled water, while the other groups were treated with a bleaching procedure, according to the manufacturer's recommendations. After treatment, the acetate buffer solution was transferred to a glass tube in which leuco-crystal violet and peroxidase solutions were added, resulting in a blue solution. The optical density of this blue solution was determined spectrophotometrically and converted into micrograms equivalent to the HP. Data were analyzed using analysis of variance and Tukey tests (α=0.05).

RESULTS

The HP concentration did not affect the HP inside the pulp chamber, but the presence of calcium significantly reduced it (p<0.0001).

CONCLUSION

The amount of HP that reaches the pulp chamber depends on the bleaching protocol and the product employed, and it seems to be less affected by HP concentration.

Randomized Controlled Trial of Sealed In-Office Bleaching Effectiveness

Regardless of the high success rate, patients commonly report the occurrence of tooth sensitivity during the in-office bleaching procedures. Recently, it has been demonstrated that using a customized tray (called sealed in-office bleaching technique) reduces peroxide penetration. The aim of this randomized clinical study was to evaluate tooth sensitivity and bleaching efficacy of sealed bleaching, in comparison with a conventional in-office technique. Twenty patients were randomized allocated in two groups in which 35% hydrogen peroxide gel was used in a single 45-min application. For the sealed technique, a customized bleaching tray was fabricated and carefully positioned over the bleaching agent during the session. The color was recorded at a baseline, 7 and 28 days after the bleaching session, using Vita Easy Shade spectrophotometer. Tooth sensitivity was recorded during (20 and 40 min) and immediately after the treatment using a visual analogue scale. The bleaching efficacy was evaluated by repeated-measures ANOVA, while the absolute risk of tooth sensitivity and its intensity were evaluated by Fisher's exact and Mann-Whitney tests, respectively (α=0.05). No significant difference on bleaching efficacy was observed between the conventional (7.4 and 8.1 ΔE) and sealed techniques (7.8 and 8.3 ΔE) at both evaluation periods. No significant difference was observed regarding the absolute risk of tooth sensitivity (p=0.15). Sealed technique showed a significant decrease of sensitivity intensity after 40 min (p=0.03). Sealed bleaching technique was able to reduce the sensitivity intensity during the bleaching procedure, without jeopardizing the bleaching efficacy