Are combined bleaching techniques better than their sole application? A systematic review and meta-analysis

Tooth sensitivity in different arches post in-office dental bleaching: A multicenter randomized controlled trial

OBJECTIVE

To compare the risk and intensity of tooth sensitivity (TS) and gingival irritation (GI), as well as bleaching efficacy (BE) in the maxillary and mandibular arches after in-office dental bleaching.

MATERIALS AND METHODS

90 participants were randomly into two groups according to the arch (maxillary or mandibular) in which the patient will first receive a 35 % hydrogen peroxide gel (2 sessions; 1 × 30 min; 1 week apart). TS and GI were recorded immediately after, up to 1 h, 24 h and 48 h after bleaching, using the 0-10 Visual Analogue Scale (VAS). BE was assessed before bleaching and 30 days after the end of the treatment (shade guide units [ΔSGU], CIELab [ΔEab], CIEDE2000 [ΔE00], and Whiteness Index for Dentistry [WID]). TS and GI were compared using McNemar's and paired t-test. BE were compared with Wilcoxon Signed Rank Test (ΔSGU) and paired t-test (ΔEab, ΔE00, and WID) (α = 0.05).

RESULTS

The risk and the intensity of TS was statistically higher for the mandibular arch (p < 0.003). The risk and intensity of GI did not differ between arches (p > 0.38). Both arches demonstrated significant BE (ΔSGU, ΔEab, ΔE00 and WID), without differences between them (p > 0.08).

CONCLUSIONS

In-office dental bleaching induces higher risk and the intensity of TS in the mandibular arch when compared to maxillary arch, without significant differences in gingival irritation, or bleaching efficacy.

CLINICAL RELEVANCE

Most patients experience tooth sensitivity regardless of the dental arch involved. However, when performing in-office dental bleaching, clinicians should consider that the mandibular arch is more likely to experience greater sensitivity compared to the maxillary arch.

The influence of dental bleaching on patient's quality of life: A multistudy analysis of aesthetic and psychosocial outcomes

OBJECTIVES

To assess the Quality of Life (QoL) of participants treated with dental bleaching using different techniques by administering two questionnaires Oral Health Impact Profile (OHIP-14) and Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ), as well as the bleaching efficacy and tooth sensitivity (TS).

MATERIALS AND METHODS

Secondary results for nine randomized clinical trials were included, involving 489 participants who underwent bleaching procedures. The questionnaires were applied at baseline and 30-day post-bleaching. Bleaching efficacy (ΔSGU/ΔEab) and TS were also evaluated (VAS/NRS). The effect of bleaching on aesthetic self-perception was evaluated using the Paired t-test. The Kruskal-Wallis test assessed variations by technique. Also, the correlations between questionnaires and outcomes was evaluated (α = 0.05).

RESULTS

After the bleaching treatment, both questionnaire revealed significant differences compared to the baseline, regardless of the factor evaluated (p < 0.05), except for Physical pain in OHIP-14 (p = 0.53). No correlation was found between OHIP-14 and bleaching efficacy (p < 0.008). A significant correlation was found between bleaching efficacy and dental self-confidence, indicating that dental self-confidence increased as the number of SGU (ΔSGU) increased, while social impact (ΔEab) and aesthetic concern (ΔSGU) decreased. Additionally, a significant correlation was observed between TS and OHIP-14 (Physical pain). For PIDAC, both dental self-confidence and psychological impact were correlated with TS in the VAS.

CONCLUSION

Subjects who underwent dental bleaching treatment improved their self-perception and dental self-confidence. Dental bleaching, besides enhancing the patient's smile, also improves their self-esteem.

CLINICAL RELEVANCE

Dental bleaching, besides improving the patient's smile, also enhances their self-esteem.

The decomposition rate and bleaching efficacy of in-office bleaching gels with different pHs: a randomized controlled trial

BACKGROUND

To evaluate the decomposition rate of active hydrogen peroxide (HP) and bleaching efficacy during in-office bleaching using high-concentration HP gels with different pHs.

METHOD

A randomized, parallel, double-blind controlled trial was conducted with 40 volunteers randomized into four groups (pH 5.4; pH 7.0; pH 7.7, and pH 8.0). During the first session in-office bleaching, approximately 0.01 g of the gel was collected and titrated with potassium permanganate to obtain the concentration of active HP and pH values were measured using an electrode. Bleaching efficacy was assessed using a spectrophotometer [∆Eab, ∆E00, and WID], Vita Classical and Vita Bleachedguide scales [∆SGU]. The decomposition rate of HP concentration and pH values change were calculated using ANOVA one-way. The bleaching efficacy was assessed using two-way repeated measures ANOVA. Tukey's test was applied as a post-hoc test (p < 0.05).

RESULTS

All gels experienced decreasing HP concentration over time. pH 5.4 gel showed greatest reduction after 50 min (p < 0.001). pH 8.0 and 7.7 gels remained stable; pH 5.4 remained acidic, while pH 7.0 turned acidic (p < 0.001). No significant difference in bleaching degree was observed among gels. They all showed a similar and clinically important color change after two clinical sessions, remained stable 1-month post-treatment (p > 0.05).

CONCLUSIONS

All bleaching gels kept at least 70% of their HP content after 50 min, suggesting that there is a surplus of HP. They provided similar whitening efficacy 1-month after bleaching.

PRACTICAL IMPLICATIONS

It is possible that lower HP concentrations may be equally effective in achieving desired results while reducing the potential for side effects.

CLINICAL TRIAL REGISTRY NAME

RBR-35q7s3v.

Comparison of in-office and at-home bleaching techniques: An umbrella review of efficacy and post-operative sensitivity

Objectives

The objective of this umbrella review is to evaluate the efficacy and adverse effects of different teeth whitening techniques in-office (IO) and at-home (AH), regarding chromatic changes and teeth sensitivity.

Materials and methods

The search was carried out from several databases. The included studies were all systematic reviews with or without meta-analysis of RCT or quasi-RCT. The participants were patients that underwent external dental bleaching in permanent vital teeth. The interventions were in-office (IO) bleaching techniques and at-home (AT) bleaching techniques with different bleaching agents and concentrations.

Results

The search resulted in a total of 257 articles, and 28 SR were included in the qualitative analysis and nine in the quantitative analysis. There is no difference between in-office and at-home techniques in terms of color change (p = 0.95) and post-treatment sensitivity (p = 0.85). There is similarity risk and intensity of teeth sensitivity between AH and IO bleaching. IO bleaching with light-activated systems with low concentrations of bleaching agent showed similar results to IO bleaching techniques with high concentrated bleaching gels. With the application of the criteria of the AMSTAR 2 tool, the reviews were considered critically low to high.

Conclusions

There are no significant differences in terms of color change between the different bleaching techniques compared. Teeth sensitivity is always present regardless of the technique used. The use of light activation systems did not increase the intensity and risk of post-operative sensitivity.

Whitening efficacy and tooth sensitivity in a combined in-office and at-home whitening protocol: A randomized controlled clinical trial

OBJECTIVE

This controlled randomized clinical trial determined the whitening efficacy and the intensity and absolute risk of tooth sensitivity in dual whitening when prefilled at-home whitening trays were used between in-office whitening intervals.

MATERIALS AND METHODS

An in-office whitening agent containing 35% hydrogen peroxide was used. A prefilled tray with a whitening agent containing 6% hydrogen peroxide was used for at-home whitening. Sixty-six subjects were randomly assigned to three groups. Group I: at-home whitening was performed 10 times between the in-office whitening treatments. Group II: at-home whitening was performed five times between the in-office whitening treatments. Group III: only in-office whitening was performed. The tooth color changes were evaluated using a spectrophotometer. A visual analog scale was used to express the pain intensity.

RESULTS

All the groups showed increased ΔE*ab, ΔE00 , and ΔWID with increased whitening sessions. Group I at the 3rd whitening session showed significantly higher ΔE*ab, ΔE00 , and ΔWID than group III. Tooth sensitivity showed higher values up to 24 h after whitening.

CONCLUSIONS

Although dual whitening with the prefilled tray and in-office whitening had higher whitening ability than in-office whitening alone, the intensity and absolute risk of tooth sensitivity was similar.

CLINICAL RELEVANCE

The dual whitening might produce faster and stronger whitening effects than in-office whitening alone.

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).

Evidence-based fact checking for selective procedures in restorative dentistry

OBJECTIVES

Similar to other dental specialties, there are many clinical procedures in restorative dentistry that may or may not be supported by good evidence. Thus, the effectiveness of these procedures is uncertain. The aim of this paper is to reduce this knowledge gap by critically inspecting selective procedures in restorative dentistry and exploring if these well-established or widely advocated treatment modalities are necessary for improving treatment outcomes based on the best available evidence.

MATERIALS AND METHODS

A MEDLINE search was conducted to identify research on selective procedures while focusing on clinical trials and systematic reviews. Due to their practical relevance in the decision-making process, cost-effectiveness analyses were also included.

RESULTS

Mixed results were identified regarding the included interventions. Some procedures had adequate evidence supporting them while others were mostly based on beliefs.

CONCLUSIONS

A critical review of the available literature indicates that some common restorative procedures lack adequate support from high-quality research evidence.

CLINICAL RELEVANCE

This paper attempts to highlight the need to critically examine the scientific validity of traditional knowledge and techniques through the context of current research evidence. This will not only help generate consensus between educators, clinicians, and researchers regarding restorative procedures but will also lead to improved patient care and outcomes.

Influence of smoking on the effectiveness of tooth whitening: a systematic review

OBJECTIVES

Perform a systematic review to evaluate the influence of smoking on the effectiveness of tooth whitening (TW) and to analyze whether tooth sensitivity is different between smokers and non-smokers.

MATERIALS AND METHODS

A systematic review modeled according to the PRISMA guidelines was conducted. PubMed, Embase, Web of Science, Cochrane, Scopus, and OpenGrey databases were searched for related clinical trials. The population, exposure, comparison, outcomes (PECO) was individuals who had TW performed, smoking individuals, non-smoking individuals, and effectiveness of TW, respectively. Risk of bias was assessed with the ROBINS-I tool, and data from included studies were extracted by two researchers independently. The certainty of the evidence was evaluated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach.

RESULTS

Five studies were selected for qualitative analysis. The ROBINS-I tool classified 3 studies as having a moderate risk of bias, one study as having a serious risk of bias, and one with a critical risk. GRADE performed only for color change results and showed a low certainty of evidence. Limited evidence suggests that effectiveness of TW between smokers and non-smokers is similar. The tooth sensitivity also does not seem to be influenced by smoking. Due to the heterogeneity of the data, a meta-analysis could not be performed.

CONCLUSIONS

Effectiveness of TW between smokers and non-smokers is comparable. The tooth sensitivity also does not seem to be influenced by smoking.

CLINICAL RELEVANCE

The effectiveness of bleaching among smokers and non-smokers appears to be similar. Tooth sensitivity during TW also appears not to be influenced by smoking.

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.

Surface Morphological Changes and Predisposition to Staining in Dental Enamel Bleached with Different Hydrogen Peroxide Concentrations

Background:

The tooth bleaching treatment can cause structural changes in the surfaces of the teeth; these changes can increase the absorption of staining agents.

Purpose:

This study assessed surface morphological changes and predisposition to staining in dental enamel bleached with different hydrogen peroxide (HP) concentrations, with or without the use of a light source (LS).

Methods:

25 bovine incisor specimens were divided into five groups (n = 5): Control- no treatment; HP35 - hydrogen peroxide 35%; HP35+LED - hydrogen peroxide 35% + light emission; HP20 - hydrogen peroxide 20%; and HP7 - hydrogen peroxide 7,5%. Twenty days after bleaching, the specimens were immersed in staining solutions four hours a day for 28 days. The morphological alterations of the bovine enamel surface were evaluated by means of scanning electron microscopy, X-ray dispersive energy spectroscopy and predisposition to the staining of the brightened enamel by means of colorimetry.

Results:

ANOVA with Tukey's test (p<0.05) showed that HP7 had the highest ΔL values (p=0.176) (brightest), with a better lightening effect. The bleached groups exhibited morphological changes in the enamel. The groups did not exhibit significant changes in oxygen, calcium, and phosphorus values (p=0.020). The presence or absence of light was not significant (p=0.007) for the predisposition to staining in bleached teeth.

Conclusion:

The time of exposure to the staining solution was significant for staining bovine dental enamel. High concentrations of HP were not necessary for achieving effective bleaching. HP caused an increase in enamel porosity and depressions. The light source did not influence bleaching.

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.