Intensity Of Tooth Sensitivity Research Articles

Tooth sensitivity with a desensitizing-containing at-home bleaching gel—a randomized triple-blind clinical trial

ObjectivesDesensitizing agents are usually included in the composition of bleaching agents to reduce bleaching-induced tooth sensitivity (TS). This randomized clinical trial (RCT) evaluated the risk and intensity of TS and color change after at-home bleaching with a desensitizing-containing (3% potassium nitrate and 0.2% sodium fluoride) and desensitizing-free 10% carbamide peroxide (CP) gel (Whiteness Perfect, FGM). MethodsA triple-blind, within-person RCT was conducted on 60 caries-free adult patients. Each participant used the gel in a bleaching tray for 3 h daily for 21 days in both the upper and lower dental arches. The absolute risk and intensity of TS were assessed daily through the 0–10 VAS and NRS scale for 21 days. Color change was recorded using shade guides (Vita Classical and Vita Bleachedguide) and the Easyshade spectrophotometer at baseline, weekly and 30 days after the end of the bleaching. The risk and intensity of TS were evaluated by the McNemar and Wilcoxon Signed Rank tests, respectively. Color change (ΔSGU and ΔE) were evaluated by the Mann-Whitney test and a paired t-test, respectively (α = 0.05). ResultsNo difference in the TS and color change was observed (p > 0.05). ConclusionsThe incorporation of potassium nitrate and sodium fluoride in 10% carbamide peroxide at-home bleaching gel tested in this study did not reduce the TS and did not affect color change (RBR-4M6YR2).

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

This study aimed to determine if the combination of opioids and nonopioids analgesics (Tylex) may provide a better analgesic effect. 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). 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. The use of an acetaminophen/codeine combination prior to in-office bleaching does not reduce the risk and intensity of bleaching-induced TS.

Clinical Evaluation of 10% Hydrogen Peroxide on Tooth Sensitivity and Effectiveness in at Home Dental Bleaching

The purpose of this study was to evaluate the dental effect and sensitivity of at-home dental bleaching with 10% hydrogen peroxide (H2O2). Twenty volunteers with A2 or darker central incisors were selected for this study. Was used 10% H2O2 for thirty minutes twice a day, for two weeks. Shade evaluation was assessed visually by the value-oriented shade guide Vita Classical shade guide, Vita Bleachedguide 3D-MASTER and by the Easyshade spectrophotometer at baseline, during bleaching (first and second weeks), and post-bleaching (one month). The perceptions of sensitivity were recorded by the patients through the numerical rating scale (0 to 4) and 0 to 10 visual analog scales daily. Data from the shade guide units was subjected to a one way repeated measures (RM) analysis of variance (ANOVA) test (a = 5%). The overall AE, absolute risk and intensity of tooth sensitivity were calculated as well as the 95% confidence interval. The absolute risk of tooth sensitivity was 65% and the intensity was mild. Data from ASGU and AE after 1 month of bleaching for H2O2 10% showed significant whitening, 4 units for Vita Classical, 5 units for Vita Bleachedguide and 9.7 units for spectrophotometer. At-home bleaching using 10% hydrogen peroxide is effective in 14 days of bleaching. The most common adverse events were mild tooth sensitivity, and no subjects discontinued use early because of a treatment-related adverse event. At-home dental bleaching with 10% hydrogen peroxide gel reduces the time of use of the tray, maintaining the effectiveness with low intensity of dental sensitivity. Brazilian clinical trials registry (REBEC) RBR-45xmzj.

Evaluation of several clinical parameters after bleaching with hydrogen peroxide at different concentrations: A randomized clinical trial

ObjectiveThis randomized double-blind clinical trial compared tooth sensitivity (TS), bleaching efficacy, and cytokine levels after applying in-office bleaching treatments containing 15% and 35% hydrogen peroxide (HP15% and HP35%, respectively). MethodsTwenty-five volunteers were randomly assigned to receive HP15% or HP35% treatment. The bleaching agent was applied in three 15-min applications per session. Two bleaching sessions were separated by a 1-week interval. The participants scored TS using a visual analog scale and numerical rating scale. Bleaching efficacy was determined by subjective and objective methods. Gingival crevicular fluid was collected from three jaws sites per patient for the analysis of fluid volume. Flow cytometry was used to analyze gingival crevicular fluid levels of interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor, and interferon-gamma. All measurements were obtained before and after bleaching. All data were statistically analyzed (α = 0.05). ResultsThe absolute risk and intensity of TS was higher for HP35% than for HP15% (p > 0.002). One month post-bleaching, HP35% produced more bleaching than HP15% (p = 0.02). However patient perception (p = 0.06) and patient satisfaction (p = 0.53) with regard to bleaching were not significantly different. No significant differences existed in the gingival fluid volume (p > 0.38) or in any cytokine level (p > 0.05) for either HP concentration. ConclusionTreatment: with HP35% is more effective than HP15%, but generates a greater risk and intensity of TS. No inflammatory changes occurred despite the difference in the HP concentrations. Clinical significanceHydrogen peroxide at a lower concentration (e.g., 15%) should be considered a good treatment alternative for in-office bleaching because the higher concentration for in-office bleaching generates a greater risk and intensity of TS for patients.

Clinical Evaluation of Genotoxicity of In-office Bleaching.

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. 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). The frequency of MN was not increased after bleaching with 35% hydrogen peroxide in both study groups (p>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. 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.

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. 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). 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. 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.

At-home vs In-office Bleaching: A Systematic Review and Meta-analysis.

A systematic review and meta-analysis were performed to evaluate the risk and intensity of tooth sensitivity during in-office and at-home bleaching in adult patients. The efficacy of dental bleaching was also evaluated. A comprehensive search was performed in the MEDLINE via PubMed, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database, Brazilian Library in Dentistry, Cochrane Library, and System for Information on Grey Literature in Europe without restrictions. The annual conference of the International Association for Dental Research abstracts (1990-2014) and unpublished and ongoing trials registry were also searched. Dissertations and theses were searched using the ProQuest Dissertations and Periódicos Capes Theses databases. Only randomized clinical trials that compared the prevalence or intensity of tooth sensitivity during in-office and at-home bleaching in adult patients were included and studies that evaluated the efficacy of these dental bleaching techniques, in terms of shade guide units (ΔSGU) and in terms of color difference measured with a spectrophotometer (ΔE*). After the removal of duplicates, 1139 articles were identified. After title and abstract screening, 29 studies remained. Fifteen studies were further excluded, whereas 12 studies remained for qualitative analyses and 8 for the meta-analysis of the primary and secondary outcomes. No significant difference in the risk/intensity of tooth sensitivity or in bleaching efficacy was observed in the present study. In an overall comparison of at-home and in-office bleaching, no differences were detected, either regarding risk/intensity of tooth sensitivity or the effectiveness of the bleaching treatment. This comparison, however, does not take into consideration variations in the protocols (daily usage time, number of bleaching sessions, and product concentration) of the bleaching techniques in the studies included.

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

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. 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). 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). 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.

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

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. 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). 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). 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.

Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial.

The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0-4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fisher's exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.

Effectiveness of and tooth sensitivity with at-home bleaching in smokers: A multicenter clinical trial

BackgroundThe authors conducted a 2-center controlled clinical study to show the equivalence of at-home bleaching in smokers and nonsmokers at 1 week and 1 month and evaluate tooth sensitivity (TS). MethodsThe authors selected 60 smokers and 60 nonsmokers with central incisors of shade A2 or darker. The participants performed bleaching with 10% carbamide peroxide for 3 hours daily for 3 weeks. The authors evaluated the color by using a shade guide and a spectrophotometer before, during, and after bleaching (1 week and 1 month). Patients recorded TS by using a 0-4 scale and a visual analog scale. The authors used multivariable regression analysis to test factors associated with color change and TS (α = .05). ResultsSmokers and nonsmokers showed significant color change statistically equivalent to within ± 2.0 units at 1 week after bleaching. Overall, color shade improved by 4.1 shade guide units (95% confidence interval [CI], 3.7-4.5) and 7.8 units of color change measured with the spectrophotometer (95% CI, 7.1-8.5) at 1 month. None of the factors affected the TS risk. TS absolute risk and intensity were similar between groups (P > .05), with an overall estimate of 47% (95% CI, 38-56%). ConclusionsThe immediate effectiveness of whitening- and bleaching-related TS were not affected by smoking. Practical ImplicationsSmoking did not affect the immediate color change (1 week). Effective whitening was achieved regardless of whether the patient was a smoker. However, this equivalence was not apparent 1 month after bleaching, with smokers having slightly darker teeth.

In-office bleaching with a two- and seven-day intervals between clinical sessions: A randomized clinical trial on tooth sensitivity

ObjectivesIn-office bleaching is usually performed in 2–3 sessions with one-week interval. The impact of shorter interval times on tooth sensitivity has not been evaluated. This study aimed to compare the absolute risk of tooth sensitivity (TS) and colour change after in-office bleaching with a two- and seven-day intervals between sessions. MethodsWe selected for this randomized, single-blind study, 40 patients with colour C2 or darker. We performed two bleaching sessions with a 35% hydrogen peroxide gel with either a 1-week or 2-day interval. We recorded the TS up to 48h with a VAS scale and the colour at baseline and 30 days after bleaching with a value-oriented shade guide and a spectrophotometer. The risk and intensity of TS were compared with the Fisher's exact test and two-way repeated measures ANOVA. Colour change (ΔSGU and ΔE) were evaluated by Student's t-test (alpha=5%). ResultsApproximately 60% of the participants reported TS (65% and 55% for the 7 and 2-day groups). A significant whitening of approximately 6 shade guide units was detected for both groups. No difference was detected between groups. ConclusionsThe reduction of the interval between bleaching sessions from seven to two days reduced the treatment time without increasing the bleaching-induced TS (clinicaltrials.gov identifier: NCT1959789). Clinical significanceIn-office bleaching with a 2-day interval did not increase the risk and intensity of bleaching-induced tooth sensitivity.

Effectiveness of a desensitizing agent before in-office tooth bleaching in restored teeth

The aim of this clinical trial was to evaluate the effectiveness and tooth sensitivity associated with bleaching in patients with composite restorations in anterior teeth after the application of a desensitizing agent. Bleaching was performed with 35 % hydrogen peroxide gel in 30 patients with composite restorations in anterior teeth, divided according to the prior application of a desensitizing agent (De), or a placebo (Pl), on maxillary superior teeth. Color was recorded at baseline, 1 week after each session and 6 months after treatment. The experience of tooth sensitivity (TS) was recorded on an NRS (0-4) during bleaching and 24 h after each session. Bleaching effectiveness was evaluated by one-way ANOVA and Tukey's tests (α = 0.05). The percentage of TS was evaluated by Fisher's exact test. For each treatment, periods were compared using the Wilcoxon signed-rank test (α = 0.05), and at each period, treatments were compared using Mann-Whitney U test. Both groups showed similar tooth color enhancement and color stability after 6 months (p < 0.05). No significant difference in prevalence of sensitivity was detected between groups (p < 0.001). Higher TS intensity (median [first/third quartiles]) was observed for Pl (1.5 [1/1.75]) compared with De (0.5 [0/1]) during treatment (p < 0.05). The use of a desensitizing gel (5 % potassium nitrate, 2 % sodium fluoride) before tooth bleaching in patients with composite restorations did not reduce the prevalence of tooth sensitivity, but reduced the intensity of TS during bleaching. Although the use of a desensitizing agent before bleaching, in patients with composite resin restorations, did not reduce the prevalence of TS, a reduction of the TS intensity during the protocol was observed without jeopardizing the whitening outcome.

Administration of Ascorbic Acid to Prevent Bleaching-induced Tooth Sensitivity: A Randomized Triple-blind Clinical Trial

This study evaluated the effect of ascorbic acid, 500 mg every eight hours, on bleaching-induced tooth sensitivity. A triple-blind, parallel design, and placebo-controlled randomized clinical trial was conducted on 39 adults. The pills (placebo or ascorbic acid) were administered three times per day for 48 hours; the first dose was given one hour prior to each bleaching session. Two bleaching sessions with 35% hydrogen peroxide gel were performed with a one-week interval. Tooth sensitivity was recorded up to 48 hours after bleaching. The color evaluation was performed before and 30 days after bleaching. The absolute risk and intensity of tooth sensitivity were evaluated by Fisher exact and Mann-Whitney U-tests, respectively. Color changes were evaluated by unpaired t-test (α=0.05). There were no significant differences in the absolute risk and intensity of tooth sensitivity and color change between the groups. Both groups showed a similar risk of tooth sensitivity (p>0.05). The perioperative use of an antioxidant, such as ascorbic acid (500 mg, three times daily) perorally, was not able to prevent bleaching-induced tooth sensitivity or reduce its intensity.

Clinical Effects of Exposure to Coffee During At-home Vital Bleaching

The purpose of the present study was to evaluate whether exposure to coffee during bleaching treatment with 16% carbamide peroxide (CP) affects the degree of whitening and tooth sensitivity. Forty patients with central incisors darker than A2 were selected. Participants who did not drink coffee were assigned to the control group (CG), while participants who drink coffee at least twice a day were assigned to the experimental group (EG). For CG, foods with dyes were restricted. For EG there was no restriction on food and patients were asked to make coffee rinses for 30 seconds, four times daily. For both groups 16% CP was used for a period of three hours daily for three weeks. Shade evaluation was assessed visually by Vita classical shade guide and by the Easyshade spectrophotometer at baseline, during bleaching (first, second, and third weeks), and postbleaching (one week and one month). Patients recorded their sensitivity perceptions by means of the numerical rating scale and 0-10 visual analog scales. Variation in shade guide units and the two colors (ΔE) were evaluated by two-way analysis of variance and Tukey tests (α=0.05). Absolute risk of tooth sensitivity and intensity of tooth sensitivity was evaluated by Fisher exact and Mann-Whitney tests (α=0.05). Effective bleaching was observed for both groups after three weeks, without statistical difference. No difference in terms of risk of tooth sensitivity and intensity of tooth sensitivity was detected between groups. Approximately 57% of the participants experienced tooth sensitivity, which was recorded mainly as "mild." Exposure to coffee during bleaching treatment does not seem to affect the degree of bleaching and tooth sensitivity.

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

The aim of this study was to determine the effect of etoricoxib 60 mg on tooth sensitivity (TS) caused by in-office bleaching. A triple-blind, parallel design, randomized clinical trial was conducted on 30 healthy, young adults who received either a placebo or etoricoxib. The drugs were administered 1 h before the bleaching process and after 24 h. Treatment was performed with 35 % hydrogen peroxide gel. The TS was recorded on three scales: VAS, 0-4, and 0-100. Shade evaluations were performed before and 30 days after bleaching with a visual shade guide and a spectrophotometer. The percentage of patients who reported TS at least once during treatment and the TS intensity were evaluated by Fisher's exact and Mann-Whitney U tests, respectively. Tooth color changes were evaluated by repeated measures ANOVA. There were no significant differences in the percentage of patients with TS, intensity of TS, and color between the groups. The anti-inflammatory medication etoricoxib 60 mg was unable to reduce the presence and intensity of TS. NCT01300780 (protocol No. 17838/2010).

Tooth sensitivity and efficacy of in-office bleaching in restored teeth

ObjectivesThe aim of this clinical trial was to evaluate efficacy (BE) and tooth sensitivity (TS) of in-office bleaching with a 35% hydrogen peroxide (HP) in patients with aesthetic restorations. MethodsHydrogen peroxide 35% was applied in two sessions, of three 15min applications, in 15 patients with upper anterior sound teeth (S) and 15 with aesthetic restorations (R). The colour was recorded at baseline, one week and 6 months after treatment completion. Patients recorded TS on a 0–4 scale. The BE was evaluated by two-way ANOVA and Tukey's tests (α=0.05). The percentage of patients with TS was evaluated by Fisher's exact test and TS intensity of treatments was compared with Mann–Whitney U-test (α=0.05). ResultsAll participants experienced TS at least once during treatment. Higher TS intensity was observed in R (1.5 [1/1.75]) compared to S (0.5 [0/1.25]) during the bleaching (p<0.05). S and R demonstrated similar tooth colour enhancement compared to baseline (p<0.05) and both presented colour stability after 6 months of evaluation (p>0.05). ConclusionsThe in-office bleaching with 35% HP was effective in patients with aesthetic restorations, however, a higher intensity of TS was observed during the bleaching protocol. Clinical relevanceIn-office dental bleaching can be performed in patients with adhesive restorations promoting satisfactory results; however, it can promote higher intensity of sensitivity compared to patients with sound teeth.

Efficacy of and Effect on Tooth Sensitivity of In-office Bleaching Gel Concentrations: A Randomized Clinical Trial

With the aim of reducing the side effects of in-office bleaching agents, less-concentrated hydrogen peroxide (HP) gels have been released by manufacturers. We evaluated the tooth sensitivity (TS) and bleaching efficacy (BE) of two HP concentrations in this study. Gels containing 35% and 20% HP (HP35 and HP20, respectively) were applied on teeth of 60 caries-free patients. Color was recorded at baseline and one week after the first and second bleaching sessions using the Vita Classical shade guide. TS was recorded on a 0-4 scale. BE at each weekly recall was evaluated by Kruskall-Wallis and Mann-Whitney tests (α=0.05). Absolute risk of TS and its intensity was evaluated by Fisher exact and Mann-Whitney tests, respectively (α=0.05). After two bleaching sessions, color change of approximately eight tabs was obtained with HP35; whereas, with HP20 it was six tabs (p<0.05). Only 26.7% (HP35) and 16.7% (HP20) of the participants reported TS, and no statistical differences were detected among them. Both in-office bleaching gels showed similar TS intensity, but the 35% HP agent produced faster bleaching.

Tooth sensitivity and bleaching effectiveness associated with use of a calcium-containing in-office bleaching gel

The authors conducted a study to evaluate tooth sensitivity (TS) and the bleaching effectiveness associated with use of a calcium-containing (CC) in-office bleaching gel. The authors used a 35 percent calcium-free (CF) hydrogen peroxide gel and a 35 percent CC hydrogen peroxide gel according to the manufacturer's instructions in 40 caries-free participants 18 years or older. They performed two bleaching sessions with a one-week interval between sessions. The authors registered the color at baseline and after the first and second bleaching sessions by using a shade guide and by gauging the participant's perception of TS as registered on a scale from 0 (none) to 4 (severe). The authors evaluated the bleaching effectiveness at each week's recall visit by means of the Friedman test, and they compared the groups at each assessment point by means of the Mann-Whitney test. They evaluated the percentage of participants with TS and the intensity of the TS by using the Fisher exact and Mann-Whitney tests. Both groups demonstrated equivalent and significant tooth color enhancement compared with color values at baseline (P < .05), with an average bleaching of 7 to 8 shade guide units. Most of the participants from the CF group (80 percent) experienced sensitivity while undergoing the bleaching regimen, whereas only 40 percent of participants from the CC group reported experiencing TS (P = .02). The intensity of TS was significantly higher (P < .01) for the CF group during in-office dental bleaching. The CC 35 percent hydrogen peroxide gel reduced the TS during in-office dental bleaching without jeopardizing the bleaching effectiveness. The results of this study support the findings that a CC 35 percent hydrogen peroxide gel can reduce TS during in-office dental bleaching.

Effect of Light Activation on Tooth Sensitivity After In-Office Bleaching

This clinical study evaluated the effects of light-emitting diode (LED)/laser activation on bleaching effectiveness (BE) and tooth sensitivity (TS) during in-office bleaching. Thirty caries-free patients were divided into two groups: light-activated (LA) and non-activated (NA) groups. A 35% hydrogen peroxide gel (Whiteness HP Maxx, FGM Dental Products, Joinville SC, Brazil) was used in three 15-minute applications for both groups. For the LA group, LED/laser energy (Whitening Lase Light Plus, DMC Odontológica, São Carlos SP, Brazil) was used, in accordance with the manufacturer's directions. Two sessions of bleaching were performed at one-week intervals. Color was registered at baseline and after the first and second bleaching sessions using a Vita shade guide. Patients recorded TS on a 0 to 4 scale during bleaching and within the next 24 and 48 hours of each session. BE at recall each week and intensity of TS were evaluated by repeated measures analysis of variance (ANOVA) and Tukey tests (α=0.05). Tooth sensitivity was compared using the Friedman repeated measures analysis of variance by rank and the Wilcoxon sign-ranked test. Faster bleaching was observed for the LA group than for the NA group after the first session (4.8 and 3.8 shade guide units [SGUs]; p=0.0001). However, both techniques were capable of bleaching the same number of SGUs after the second bleaching session (p=0.52). Most of the LA group (53.3%) had sensitivity even 24 hours after each bleaching session, but only 26.6% from the NA group reported TS. The intensity of TS was similar for both groups immediately after bleaching but significantly higher for the LA group 24 hours after each bleaching session (p=0.001). After two bleaching sessions, the use of LED/laser light activation did not improve bleaching speed. Persistent tooth sensitivity and higher tooth sensitivity after 24 hours of bleaching were observed when light activation was used.