In-Office Bleaching During Orthodontic Treatment

Effect of a novel low-concentration hydrogen peroxide bleaching gel containing nano-sized sodium trimetaphosphate and fluoride

OBJECTIVES

To evaluate in vitro the effects of nano-sized sodium trimetaphosphate (TMPnano) and sodium fluoride (F) added to a 17.5 % hydrogen peroxide (H2O2) bleaching gel on the color change, enamel mechanical and morphological properties, and H2O2 transamelodentinal diffusion.

MATERIALS AND METHODS

Bovine enamel/dentin discs (n = 180) were divided according to the bleaching gel: 17.5 % H2O2 (17.5 % HP); 17.5 % H2O2 + 0.1 % F (HP/F); 17.5 % H2O2 + 1 % TMPnano (HP/TMPnano); 17.5 % H2O2 + 0.1 % F + 1 % TMPnano (HP/F/TMPnano) and 35 % H2O2 (35 % HP). The gels were applied for 40 min on three sessions, each session spaced 7 days apart. The total color change (ΔE*ab) according to the Commission Internationale de l'Eclairage (CIE) L*a*b* color change measured by CIEDE2000 (ΔE00), whitening index (ΔWID), surface hardness (SH), surface roughness (Ra), cross-sectional hardness (ΔKHN), and transamelodentinal diffusion were assessed. Enamel surfaces were examined using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDS) analysis. The data were analyzed using ANOVA, followed by the Student-Newman-Keuls test (p < 0.05).

RESULTS

ΔE*ab, ΔE00, and ΔWID values were comparable among the gels that produced a bleaching effect post-treatment (p < 0.001). The HP/F/TMPnano group exhibited lower mineral loss (SH and ΔKHN), Ra, and H2O2 diffusion compared to the 17.5 % HP and 35 % HP groups, which had the highest values (p < 0.001). SEM/EDS analysis revealed surface changes in all bleached groups, though these changes were less pronounced with F/TMPnano.

CONCLUSIONS

The 17.5 % HP gel containing F/TMPnano maintains the bleaching effect while reducing enamel demineralization, roughness, H2O2 diffusion, and enamel morphological changes.

CLINICAL RELEVANCE

Low-Concentration H2O2 bleaching gel containing F/TMPnano can be used as a novel approach to enhance safety and maintain the performance of aesthetic effects.

Effect of the type of application tip for 35% hydrogen peroxide on bleaching efficacy and tooth sensitivity: A randomized clinical trial

OBJECTIVES

Evaluate the bleaching efficacy (BE) and tooth sensitivity (TS) of in-office bleaching using different application tips.

METHODS

Forty-eight participants were selected (split-mouth), one to receive bleaching with an attached brush tip and one with a conventional tip. The procedure was performed with Whiteness Automixx Plus 35%. The BE was evaluated at the beginning, weekly, one and 12 months post-bleaching with a Vita Easyshade spectrophotometer (ΔE*ab, ΔE00, and WID) and with Vita classical A1-D4 and Vita Bleachedguide shade guides units (ΔSGU). Absolute risk and intensity of TS were recorded using the Visual Analogue Scale. The equivalence of BE was analyzed using the two one-sided t-tests for paired samples. The absolute risk of TS was evaluated using the McNemar test, and the TS intensity was measured with the paired t test (α = 0.05).

RESULTS

The equivalence of BE was observed for both groups in all color evaluations (p > 0.05). A lower absolute risk and intensity of TS were observed for the attached brush tip when compared with the conventional tip (p < 0.003 and p < 0.0001).

CONCLUSION

Using an attached brush tip showed the same BE as a conventional tip. However, for the attached brush tip, there was a reduction in TS.

CLINICAL SIGNIFICANCE

The applicator-attached brush tip is recommended for in-office dental bleaching, because of the possible reduction in risk and intensity of TS.

Reduction of surface treatment time by combination of citric acid and ascorbic acid while restoring shear bond strength of metal brackets bonded to bleached enamel: a pilot study

BACKGROUND

To investigate the effect of a 50% ascorbic acid with 50% citric acid solution on the immediate shear bond strength (SBS) of metallic brackets after tooth bleaching. The enamel etching pattern and the required quantity of these combined acids as antioxidants following 35% hydrogen peroxide (HP) bleaching were also determined.

METHODS

The stability of the solution at room temperature was assessed at various time intervals. Fifty teeth were randomly divided into five groups: non-bleached (G1), bleached then acid etched (G2), bleached followed by a 10-minute treatment with 10% sodium ascorbate and acid etched (G3), 5-minute treatment with 50% ascorbic acid (G4), and 5-minute treatment with a combination of 50% ascorbic acid and 50% citric acid (G5). Groups G2, G3, G4 and G5 were bleached by 35% HP gel for a total of 32 min. Acid etching in groups G1, G2, and G3 was performed using 37% phosphoric acid (Ormco®, Orange, CA, USA) for 15 s. In all groups, metal brackets were immediately bonded using Transbond™ XT primer and Transbond™ PLUS adhesive, with light curing for 40 s. The SBS was tested with a universal testing machine, and statistical analysis was conducted using one-way ANOVA followed by Tukey's HSD test. The level of significance was set at p < 0.05 for all statistical tests.

RESULTS

Stability tests demonstrated that the combined acids remained effective for up to 21 days. Group G5 significantly increased the SBS of bleached teeth to the level of G1 (p < 0.05), while G3 did not achieve the same increase in SBS (p > 0.05). SEM analysis revealed enamel etching patterns similar to those of both control groups (G1 and G2). Kinetic studies at 6 min indicated that the antioxidation in G5 reacted 0.2 mmole lower than in G3 and G4.

CONCLUSION

5-minute application of the combined acids enhanced the SBS of bleached teeth comparable to unbleached teeth. The combined acids remain stable over two weeks, presenting a time-efficient, single-step solution for antioxidant application and enamel etching in orthodontic bracket bonding.

Bleaching versus color change resistant adhesive in the discoloration of bracket-bonded tooth surfaces: an in vitro study

OBJECTIVES

The aim of this study was to compare the effect of office bleaching of teeth bonded with Transbond XTTM (3M Unitek, Monrovia, CA, USA) (TRXT) and the use of color change resistant Orthocem (FGM, Joinville, Brazil) in bracket bonding on coffee-induced enamel discoloration.

MATERIALS AND METHODS

Eighty premolars were distributed in equal numbers (n = 20) to group 1 (TRXT + distilled water), group 2 (TRXT + coffee solution), group 3 (TRXT + coffee solution + bleaching), and group 4 (Orthocem + coffee solution). Color was measured using a SpectroShade Micro (MHT, International, Verona, Italy) device at the beginning (T0), after coloring (T1), after bleaching (T1B), and after debonding (T2). ΔE color change values were calculated as T1-T0, T1B-T0 and T2-T0 differences. The conformity of the data to the normal distribution was examined with the Shapiro-Wilk test. Multiple comparisons were made with Tamhane's T2 test and Tukey's HSD test using one-way analysis of variance in the comparison of normally distributed data, and multiple comparisons were made with Dunn's test using the Kruskal-Wallis H test for comparison of non-normally distributed data. The significance level was set at p < 0.050.

RESULTS

A statistically significant (p < 0.001) difference was found between the T1-T0 and T2-T0 stages for group 1-4 ΔE values. A statistically significant (p < 0.001) difference was also found when the T1B-T0 ΔE values of group 3 were compared with the T1-T0 ΔE values of groups 1, 2, and 4.

CONCLUSIONS

After coffee-induced enamel discoloration, bleaching of teeth bonded with TRXT produced acceptable color difference of the incisal, middle, and gingival regions of the crown. In teeth bonded with Orthocem, acceptable color difference was seen only in the middle of the crown.

CLINICAL RELEVANCE

The presented study will guide the clinician on how enamel discoloration side effect of fixed orthodontic appliance can reduce.

Does the composite attachment of clear aligners compromise the effectiveness of dental bleaching? An in vitro study

INTRODUCTION

This study aimed to evaluate the effectiveness of dental bleaching with hydrogen peroxide 35% on the surface below the attachments.

METHODS

Twenty-four blocks of bovine incisors were equally divided into 2 groups. The control group comprises the enamel surface free of attachments, whereas the attachment group comprises the enamel surface with attachment. Initial staining of samples was performed with black tea for 7 days; then, an attachment was made in the attachment group with Z250 resin and new staining for another 7 days in all samples. After staining, in-office bleaching was performed in both groups, and the attachments from the attachment group were removed. Color reading was performed with a spectrophotometer at all stages: initial (baseline), after 7 days of staining, after 14 days of staining, after immediate bleaching, and after 24 hours of bleaching. The color difference was calculated, and data analysis was performed using the t test for intergroup analysis.

RESULTS

The results showed effective bleaching in both groups; however, there was a statistically significant difference in color change between them 24 hours after bleaching.

CONCLUSION

It was concluded that the presence of attachment did not impair the action of the bleaching agent on the tooth surface.

Inflammatory parameters and color alterations of dental bleaching in patients wearing fixed orthodontic appliance: a randomized clinical trial

BACKGROUND

Many orthodontic patients request dental bleaching during orthodontic treatment to achieve a faster aesthetic resolution, however, no attention has been paid to the inflammatory processes that can occur when both therapies are indicated together. So, this clinical trial evaluated the inflammatory parameters and color alterations associated with dental bleaching in patients wearing a fixed orthodontic appliance.

METHODS

Thirty individuals aged between 18 and 40 years were equally and randomly allocated into three groups: FOA (fixed orthodontic appliance), BLE (dental bleaching), and FOA + BLE (fixed orthodontic appliance + dental bleaching). The orthodontic appliances and the bleaching procedures were performed in the maxillary premolars and molars. For dental bleaching a 35% hydrogen peroxide was used. The gingival crevicular fluid (GCF) and nitric oxide (NO-) levels were evaluated at different time-points. Color evaluation was performed using an Easyshade spectrophotometer at baseline (FOA, FOA + BLE, BLE), one month after (FOA + BLE) and 21 days after appliance removing (FOA + BLE and FOA groups), in each tooth bleached. The ANOVA and Tukey's tests, with a significance level of 5%, were used for statistical analysis.

RESULTS

The GCF volume in the FOA + BLE and FOA groups significantly increased at the time points evaluated (p < 0.001); however, this did not occur in the BLE group (p > 0.05). On the other hand, NO- levels significantly decreased during dental bleaching with or without fixed orthodontic appliances (FOA + BLE and BLE groups; p < 0.05), while no significant changes were observed in the FOA group (p > 0.05). Significant changes in color were observed in the FOA + BLE and BLE groups compared to in the FOA group (p < 0.01). However, the presence of fixed orthodontic appliance (FOA + BLE) negatively affected the bleaching efficacy compared to BLE group (p < 0.01).

CONCLUSIONS

Dental bleaching did not increase the inflammatory parameters in patients wearing fixed orthodontic appliance. However, in the presence of orthodontic appliances, the bleaching efficacy was lower than that of bleaching teeth without orthodontic appliances.

TRIAL REGISTRATION

RBR-3sqsh8 (first trial registration: 09/07/2018).

Effectiveness of dental whitening in patients with active fixed orthodontic treatment: a narrative review

Introduction

Currently dental aesthetics during fixed orthodontic treatment is an option required by patients, due to the frequent pigmentations that can occur in tooth enamel as a result of inadequate oral hygiene and plaque retention caused by fixed appliances.

Objective

To determine the effectiveness of dental whitening and its side effects during active fixed orthodontic treatment, as an alternative aesthetic treatment in certain cases that merit it.

Materials and methods

This narrative review evaluated 35 scientific articles from the Medline information sources (via PUBMED), EMBASE, SCOPUS, SCIELO and LILACS from the last 10 years, published in Spanish, Portuguese and English. We included 17 articles that met the selection criteria which were randomized clinical trials and observational studies, in vitro studies and in vivo studies that evaluated in-office dental clearance, performed on patients using fixed orthodontic treatment at that time. Systematic reviews, case reports and editorials were excluded.

Results

It was observed that dental whitening in patients with active orthodontic treatment minimally affects the adhesion of the orthodontic apparatus to the tooth surface. In addition, some studies observed that the brackets interfere with the extension of the dental lightening, evidencing slightly darker areas.

Conclusions

Dental whitening during orthodontic treatment can be given efficiently in clinical practice, depending on the aesthetic requirement of the patient. However, it is a recommended procedure in certain cases of great need for immediate aesthetics, since, the material with which the brackets are installed on the dental surface, will interfere with the extension of the lightening material, resulting in a darker shade in that sector and different from the surrounding tissue. Likewise, it will intervene in the adhesion to the dental surface, having many probabilities that the orthodontic apparatus can detach.

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.

Planning and orthodontic preparation for maxillary incisors reshaping

Introduction:

Having a beautiful smile is the main desire of people seeking dental treatment. To achieve this goal, many variables must be considered. These include tooth alignment, color, shape and size, besides their harmonious relationship with the lips and face. An individualized diagnosis is essential to achieve the best result. Within this context, facial analysis and the characteristics of shape, size and position of maxillary incisors play a key role.

Methods:

This paper describes clinical situations in which interdisciplinary treatment was performed to achieve esthetic results in a conservative manner and ensuring greater stability. In most cases requiring reshaping of maxillary incisors for esthetic reasons, prior orthodontic movement is essential. The main focus of this paper is to discuss the many variables involved in these situations.

Results and Conclusion:

The results of treatments described in this paper were obtained by means of a multidisciplinary approach, involving Orthodontics and Esthetic Dentistry, acting in harmony and recognizing their possibilities and limitations, in order to offer patients the best esthetic solution for their smile. The best treatment option is not always the easiest or fastest. The dentist, as a health professional, should consider the patients’ wishes but also perform treatments with minimal intervention, and the best and most predictable esthetic result, also focusing on function and health.

The perception of tooth whitening practices during and after orthodontic treatment: A survey of orthodontists

Background

At present, there are limited studies on how tooth whitening procedures are applied in orthodontic patients. Therefore, the objective of this study was to assess the perception of tooth whitening practices during and after orthodontic treatment.

Material and Methods

A survey of orthodontists in Medellín (Colombia) between January and October 2020 was carried out. The survey instrument was developed to obtain information regarding the perception and practices of tooth whitening during and after orthodontic treatment.

Results

133 orthodontists with a mean age of 41,6 years old participated in the survey. Over 60% of participants reported >6 years of experience as orthodontist. The majority (99,2%) reported that their patients request tooth whitening. Of these, 71,2% refer the patient to another dental professional for the procedure while 28,8% administers it. More than half of orthodontists reported that their patients request dental whitening during orthodontic treatment. The majority (>90%) of orthodontists do not recommend tooth whitening during orthodontic treatment. Furthermore, >80% consider that tooth whitening is best recommended after brackets have been removed.

Conclusions

Requests for tooth whitening from orthodontic patients is very frequent and most orthodontists favor the referral to another dental professional for the procedure. The majority do not recommend tooth whitening during orthodontic treatment and prefer waiting 1 to 3 months after brackets removal for the procedure.

Key words:Tooth whitening, orthodontic treatment, brackets.

Whitening effect of 35% hydrogen peroxide in simulation of tooth with orthodontic bracket

OBJECTIVE

To evaluate the color change and tooth whitening perception in 2 and 3 mm dental specimens simulating the orthodontic bracket for a 14-day period.

MATERIALS AND METHODS

Forty bovine tooth fragments (8 × 7 mm) of 2 mm (G2, n = 20) and 3 mm (G3, n = 20) were divided into Control (C: without bracket simulation and whitening) and Experimental (E: with composite resin simulating orthodontic bracket cementation area). Analyses of color change (ΔE₀₀ ) and perception of tooth whitening (WI_D ) were performed before (T₀ ) and after (T₁ ) the first bleaching session; before (T₂ ) and after (T₃ ) the second bleaching session; and after 7 days of the second bleaching session (T₄ ).

RESULTS

After 14 days (T4), ΔE₀₀ and WI_D showed similarity results, except for G2C and G3E_. The thickness did not influence the ΔE₀₀ and WI_D (G2C = G3C and G2E = G3E). The presence of orthodontic bracket did not interfere in the color change or tooth whitening perception after 14 days, except for comparison of G2C and G3E. Additionally, dentin thickness did not influence the color change.

CLINICAL SIGNIFICANCE

Teeth with orthodontic brackets showed similar color change and whitening perception to teeth without orthodontic bracket, but it is not influenced by dentin thickness.

Color heterogeneity and individual color changes in dentin and enamel bleached in the presence of a metallic orthodontic bracket

OBJECTIVE

This in-vitro study evaluated the color changes in enamel and dentin bleached in the presence of an orthodontic bracket, as well as the heterogeneity of the color and contribution of each tissue to the color change (CTCC).

MATERIALS AND METHODS

Enamel-dentin specimens from extracted bovine teeth were bleached before or after bracket removal or maintained without any treatment (control). The colors of the dentin and enamel were measured individually and after recombining these substrates. The changes in the color (ΔE₀₀ ) and whitening index (ΔWID) were estimated by the color difference between the bleached specimens and those of the control. The CTCC was also calculated by recombining the tissues from different treatments. Images of specimens obtained from a stereomicroscope were used to analyze the color homogeneity within each tissue.

RESULTS

The highest values of ΔE₀₀ and ΔWID were observed in the specimens bleached in the absence of a bracket. Bleaching in the presence of a bracket resulted in enamel with a center that was whiter than the periphery. Dentin and enamel presented similar CTCC values.

CONCLUSIONS

Tooth bleaching performed in the presence of a metallic bracket resulted in a reduced bleaching effect and increased color heterogeneity within both tissues.

CLINICAL SIGNIFICANCE

Tooth bleaching before the orthodontic bracket removal reduces the bleaching effect in both dentin and enamel. Moreover, a heterogeneous color of enamel surface can be observed after tooth bleaching in the presence of a nickel-free metallic orthodontic bracket.