Pre-operative use of dexamethasone does not reduce incidence or intensity of bleaching-induced tooth sensitivity. A triple-blind, parallel-design, randomized clinical trial

Assessment of the effect of experimental gel of pregabalin associated with 35% hydrogen peroxide bleaching on bovine dental enamel: an in vitro study

To assess the effect of bleaching with gel of pregabalin associated with 35% hydrogen peroxide on the mechanical and chemical properties and ultramorphology of dental enamel. Thirty-six (36) specimens of bovine dental incisors were obtained and divided into three groups (n = 12), namely: CG = bleaching with 35% hydrogen peroxide; KFG = bleaching with 5% potassium nitrate and 2% sodium fluoride gel + 35% hydrogen peroxide; and PGG = bleaching with experimental gel of pregabalin + 35% hydrogen peroxide. The specimens were assessed with respect to Knoop microhardness, surface roughness, and colour change, before and after bleaching. They were also assessed using scanning electron microscopy and energy-dispersive spectroscopy after treatments. All groups exhibited an increase in surface roughness and a reduction in Knoop microhardness after the protocols. There was colour change in all groups, with no difference between them. In addition, there were changes in enamel morphology and non-significant loss of calcium and phosphorus. The experimental gel of pregabalin did not influence the action of 35% hydrogen peroxide, yielding results similar to those of the other groups assessed in all the parameters. Therefore, the gel of pregabalin can be an alternative for topical application on the surfaces of the teeth in association with bleaching treatments.

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.

Post-Operative Sensitivity and Color Change Due to In-Office Bleaching With the Prior Use of Different Desensitizing Agents: A Systematic Review

Bleaching agents can cause certain surface alterations on the enamel, such as depressions, surface porosity, and surface irregularities; this makes the dentin more susceptible to post-operative tooth sensitivity (PoS). In addition, the presence of flawed or leaky restorations, gingival recession, or defects in the cementoenamel junction can also cause severe tooth sensitivity post tooth bleaching.Hence, the current study aimed to perform a systematic review to determine the efficacy of various desensitizing agents (DA) in managing post-operative tooth sensitivity and color alteration when applied before in-office bleaching procedures. Randomized clinical trials were searched to conduct an SR where the post-operative tooth sensitivity was evaluated after in-office bleaching with various desensitizing agents used before the procedure. Post-operative pain assessment was measured using the Visual Analogue Scale (VAS). Outcomes were evaluated up to an hour and 24 hours post the procedure. Out of 163 articles, only 13 titles were selected that met the eligibility criteria. Eight hundred and forty-one adult patients with vital pulp status were included. The participants receiving prior desensitizing agent applications reported significantly lower pain scores in the VAS reports. The most significant reduction of post-operative sensitivity was observed in the immediate (up to an hour) and 24 hours after the in-office bleaching. The popular desensitizing agent that could manage post-operative tooth sensitivity (TS) is 5% potassium nitrate and 2% sodium fluoride used before the in-office bleaching procedure. 

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.

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.

Combination of strontium chloride and photobiomodulation in the control of tooth sensitivity post-bleaching: A split-mouth randomized clinical trial

Objective

This split-mouth randomized controlled clinical trial assessed the effect of 10% strontium chloride in combination with photobiomodulation (PBM) for the control of tooth sensitivity (TS) post-bleaching.

Methods

The upper/lower, right and left quadrants of fifty volunteers were randomized and allocated to four groups (n = 25): PLACEBO—placebo gel + simulation of PBM; Placebo + PBM; STRONTIUM—10% strontium chloride + simulation of PBM; and PBM + STRONTIUM—10% strontium chloride + PBM. All groups received tooth bleaching treatment with 35% hydrogen peroxide. For the PBM treatment, the laser tip was positioned in the apical and cervical regions of the teeth bleached in the respective hemi-arch. The laser system was operated in continuous mode, using 1.7 J of energy. A dose of 60 J/cm² was applied to each point for 16 seconds under 808 nm near-infrared light (100mW of power), with a point area of 0.028 cm². TS was assessed during a 21-day follow-up, using the modified visual analogue scale.

Results

In the intragroup assessment, the Friedman test indicated that PBM + STRONTIUM promoted the greatest reduction in TS after the second week of treatment (p ≤ 0.05). The Wilcoxon-Mann-Whitney test indicated that the groups Placebo + PBM, STRONTIUM, and STRONTIUM + PBM did not differ statistically (p ≥ 0.05) in the first and third weeks of treatment The group PLACEBO exhibited the greatest TS in the first three days after each bleaching session.

Conclusion

The combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, the combination of 10% strontium chloride with PBM was effective in reducing post-bleaching TS; however, it did not differ from the individual use of Placebo + PBM or STRONTIUM groups assessed after 21 days of follow-up.

The combined use of systemic analgesic/anti-inflammatory drugs and a bioactive topical desensitizer for reduced in-office bleaching sensitivity without jeopardizing the hydrogen peroxide efficacy: a randomized, triple blinded, split-mouth clinical trial

OBJECTIVE

To evaluate the effect of combined systemic administration of paracetamol 500 mg/codeine phosphate 30 mg (PACO) and postoperative topical application of a bioactive desensitizer on in-office bleaching sensitivity and tooth color change.

MATERIALS AND METHODS

A randomized, triple-blind, split-mouth clinical trial was conducted. Forty volunteers ingested PACO (n = 20) or placebo (PLA) (n = 20). Their left/right hemiarches received topical application of a bioactive desensitizer [Nano-P™(NP)] and prophylactic paste (PAS), generating four treatment approaches: PACO/NP, PACO/PAS, PLA/NP, and PLA/PAS. Two bleaching sessions (35% hydrogen peroxide) were performed, and the PAS/NP were applied after the procedure. Sensitivity was obtained since the first bleaching session up to 7 days post-bleaching. The color change was evaluated using CIEDE2000 and whiteness index parameters up to 7 days post-bleaching. Data were analyzed using one- and two-way ANOVA/Tukey post hoc tests (p < 0.05).

RESULTS

The PLA/PAS showed a sensitivity average of at least two times higher than the PACO/NP. The treatment approaches promoted statistically similar bleaching patterns (p > 0.05).

CONCLUSION

The combined approach of systemic administration of PACO and postoperative topical application of NP reduced the level of in-office bleaching sensitivity without jeopardizing hydrogen peroxide efficacy.

CLINICAL RELEVANCE

Professionals can adopt the combined approach of systemic administration of analgesic/anti-inflammatory drugs and topical application of a bioactive desensitizer for decreased bleaching sensitivity caused by 35% hydrogen peroxide in-office.

In vitro analysis of the pH stability of dental bleaching gels during in-office procedures

Background

Previous studies have shown that acidic bleaching gels could lead to worse collateral effects during an in-office bleaching procedure, while neutral or basic products leads towards a better experience. Considering this fact, the main purpose of this study was to evaluate the pH behavior of 6 in-office bleaching gels, compared to the information provided by their manufacturers.

Material and Methods

Thirty enamel discs of bovine teeth were prepared, the initial colors of which were measured by a spectrophotometer and then divided into 6 groups. A pH meter was used to measure the pH every 30 seconds until the end of each procedure, when a new color evaluation was then made. The Tukey test was used for statistical analysis of the results.

Results

There was no difference in the color variation (ΔE) between the groups (p> 0.05). In two groups, the pH variation (ΔpH) showed neutral stability, with initial and final pH averages of 7.04 and 7.11 (p = 0.08) and 7.21 and 7.19 (p = 0.55), respectively; in another, there was alkaline stability, with an initial and final pH average of 8.54 and 8.37 (p = 0.14). In the other three brands, however, the results showed acidification, with initial and final pH averages of 6.14 and 5.22 (p = 0.001), 6.05 and 5.16 (p = 0.001) and 7.14 and 5.83 (p = 0.001), respectively.

Conclusions

In 3 of the evaluated gels, a discrepancy existed between the manufacturer’s information and the data obtained, which could lead, considering previous studies discussed throughout this article, to unexpected collateral effects on the patients, especially dental sensitivity. Thus, clinicians and researchers should be aware about pH stability studies of in-office bleaching gels for better predictability and safety on their clinical usage.

Key words:Tooth bleaching, Bleaching agents, Hydrogen-ion concentration, Dentin sensitivity, Hydrogen peroxide.

Short-term effects of stain-causing beverages on tooth bleaching: A randomized controlled clinical trial

OBJECTIVES

To evaluate the short-term effects of stain-causing beverages on the effectiveness of in-office tooth bleaching.

METHODS

Participants were recruited and randomly divided into 3 groups based on beverages used for rinsing during and after the bleaching procedure: group N (tap water, control group), group C (coffee), and group T (tea). Participants were instructed to rinse with the respective solutions for 30 s, 4 times daily for 4 weeks. All participants received two in-office bleaching treatment sessions with 40 % hydrogen peroxide (Opalescence BOOST PF 40 %, Ultradent); the sessions were separated by a 1-week interval. Tooth colour was assessed using a spectrophotometer (Easyshade, Vita ZahnFabrik) before the bleaching procedure (T0), immediately after the first session of bleaching (T1), immediately after the second session of bleaching (T2), as well as one week (T3) and three weeks after (T4) the end of bleaching. Tooth sensitivity (TS) was ranked using a numerical rating scale (NRS) and a visual analogue scale (VAS) at different time points.

RESULTS

No significant difference in the whiteness index (W), △E, △a* and △b* values among the 3 groups was observed at any time interval (P for all > 0.05). At T4, the △L* value in group C was significantly lower than that in groups T and N (P = 0.022 and P = 0.001, respectively), though no significant difference in △L* values was observed among the 3 groups at T1 (P = 0.402), T2 (P = 0.643) and T3 (P = 0.177). Additionally, no significant difference was found in the TS values among the 3 groups at any of the evaluation time points (P for all > 0.05).

CONCLUSIONS

Exposure to coffee or tea during the bleaching treatment period did not affect the effectiveness of the treatment. However, exposure to coffee after the bleaching treatment did affect the effectiveness of the treatment. Exposure to stain-causing beverages did not affect the bleaching-induced TS (ClinicalTrials.gov Identifier: NCT03933527).

CLINICAL SIGNIFICANCE

The consumption of coffee or tea during tooth bleaching may not interfere with the colour change produced by the treatment. However, clinicians should advise their patients to refrain from, at least to some extent, consuming coffee after the bleaching procedure to maintain the effectiveness of the treatment.

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.

Evaluation of post-bleaching hypersensitivity using desensitizing agent before and /or after in-office bleaching: A randomized clinical trial

Background: Dental bleaching has become one of the most demanded aesthetic procedures as it is very simple and gives fast results that satisfy the patient’s wishes. However, unfortunately, it has the annoying side effect of tooth sensitivity. This clinical trial was designed to evaluate the efficacy of using a desensitizing agent, which was applied during in-office bleaching with 30% HP (hydrogen peroxide). Methods: 36 participants were divided into four groups (N = 9). According to the intended intervention as follows: Group I:—Application of Relief ®Amorphous Calcium Phosphate (ACP) before in-office bleaching; Group II—Application of Relief ®ACP before and after in-office bleaching; Group III—Application of Relief ®ACP after in-office bleaching; and Group IV: placebo was applied before and after in-office bleaching.  Then, three hydrogen peroxide bleaching applications for a total of 45 minutes were performed. The primary outcome variable was hypersensitivity, assessed with (VAS) scale immediately and 24h, 1 week and 1 month after the procedure; while the secondary outcome was teeth shade assessed using the VITAPAN ® classical shade guide. Results: Statistical analysis was done using Kolmogorov-Smirnov, Shapiro-Wilk tests, Kruskal-Wallis test and Dunn’s test. Immediately after bleaching, there was statistically significant distinction in the median pain score between the groups. After 1 day, the ACP gel before and after bleaching group showed the lowest median score, while, the control group confirmed the highest median score. After 2 days, no statistically sizable difference was observed between all groups. The group receiving ACP gel before and after showed the highest change in median of classical shade guide scores while, (ACP gel after) and control group; showed the lowest change. Conclusion: The application of the desensitizing agent prior to and after in–office bleaching was successful in lowering post-bleaching hypersensitivity. Trail Registration: Clinical trial.gov NCT02942082 21/10/2016

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.