Whitening Effect Research Articles

Enhancement of the Topical Bioavailability and Skin Whitening Effect of Genistein by Using Microemulsions as Drug Delivery Carriers

Genistein, the most abundant isoflavone of the soy-derived phytoestrogen compounds, is a potent antioxidant and inhibitor of tyrosine kinase, which can inhibit UVB-induced skin carcinogenesis in hairless mice and UVB-induced erythema on human skin. In current study, genistein-loaded microemulsions were developed by using the various compositions of oil, surfactants, and co-surfactants and used as a drug delivery carrier to improve the solubility, peremability, skin whitening, and bioavailbility of genistein. The mean droplet size and polydispersity index of all formulations was less than 100 nm and 0.26 and demonstrated the formation of microemulsions. Similarly, various studies, such as permeation, drug skin deposition, pharmacokinetics, skin whitening test, skin irritation, and stability, were also conducted. The permeability of genistein was significantly affected by the composition of microemulsion formulation, particular surfactnat, and cosurfactant. In-vitro permeation study revealed that both permeation rate and deposition amount in skin were significantly increased from 0.27 μg/cm2·h up to 20.00 μg/cm2·h and 4.90 up to 53.52 μg/cm2, respectively. In in-vivo whitening test, the change in luminosity index (ΔL*), tended to decrease after topical application of genistein-loaded microemulsion. The bioavailability was increased 10-fold by topical administration of drug-loaded microemulsion. Conclusively, the prepared microemulsion has been enhanced the bioavailability of genistein and could be used for clinical purposes.

Whitening effect of brushing with activated charcoal-based products on enamel: integrative review

Objective: The purpose in this study was to analyze in the literature whether toothbrushing with charcoal-based products promotes a whitening effect. Methodology: An integrative literature review was carried out in the PubMed/MEDLINE database, which had as its guiding question: Does brushing with activated charcoal-based products have a whitening effect on the tooth? The search strategy was performed through the use of terms (charcoal AND “dentifrice OR toothpaste OR toothbrushing” AND “bleaching OR whitening” AND tooth), and only articles published in English in any period were included. Result: From a total of 34 scientific articles identified, 6 articles were included in the study, between the years 2019 and 2021. According to the evidence, three articles did not observe an advantage in performing brushing with activated charcoal-based products and another three observed a slight whitening effect, generally inferior when compared to other whitening agents. In addition, most articles recommend attention to the use of these products for oral hygiene containing charcoal, since many of these studies observed an increase on the roughness of tooth enamel, which is directly related to the inherent abrasiveness of each product and which depends on the source and the methods used to prepare and mill charcoal. Conclusion: From the studies analyzed so far, it is observed that brushing products based on activated charcoal have few effectiveness of tooth whitening, often lower when compared to other abrasive agents present in whitening dentifrices.

Novel amino acid‐stilbene quaternary ammonium salt fluorescent whitening agents: synthesis, optical properties, acid resistance and anti‐bacterial activity

AbstractWith 4,4'‐diaminostilbene‐2,2'‐disulfphonic acid, 2,4,6‐trichloro‐1,3,5‐triazine and N,N‐dimethyldodecylamine as main raw materials, a stilbene quaternary ammonium salt intermediate was synthesised by condensation and quaternisation reaction under the catalysis of sodium hydroxide, and then reacted with two different amino acids to prepare novel amino acid‐stilbene quaternary ammonium salt fluorescent whitening agents. The structures of target compounds were characterized by Fourier Transform–infrared and proton nuclear magnetic resonance spectroscopy. Their photophysical properties, whitening performance and firmness in aqueous solution were assessed by means of ultraviolet absorption spectra, fluorescence emission spectra and a cotton fibre application test. The results showed that the two amino acid‐stilbene quaternary ammonium salt fluorescent whitening agents had a good whitening effect on cotton fibres and displayed strong acid resistance. Compared with the traditional fluorescent whitening agent C186, their firmness was greatly improved. The anti‐bacterial activities against three strains were evaluated in vitro. The results showed that they exhibited significant anti‐bacterial activity against the selected strains, and the respective minimum inhibitory concentration values against Candida albicans and Escherichia coli were 16.8 and 8.16 μg/ml.

Ceriporia lacerata Mycelium Culture Medium as a Novel Anti-Aging Microbial Material for Cosmeceutical Application

Skincare is very critical in preventing aging and skin trouble, which is difficult to recover if progressed. However, the development of effective anti-aging solutions is still on the horizon. The purpose of this study was to evaluate the functional efficacy of Ceriporia lacerata exo-pharmaceutical substance (CLEPS) in view of its use in innovative skin care cosmetics. CLEPS was found to have no cytotoxicity against normal human dermal fibroblasts and B16 melanoma cells in a wide concentration range of 0.05–7 mg/mL. It exhibited a whitening effect by inhibiting melanin synthesis comparable to that of the respective reference compound (arbutin). Notably, CLEPS not only substantially increased collagen (65.4%) and filaggrin synthesis (36%), but also significantly inhibited the activity of collagenase (93.4%), suggesting that CLEPS could prevent skin barrier damage or skin wrinkles. In addition, it showed an excellent anti-inflammatory effect and wound-healing effect. Overall, CLEPS exhibited exceptional anti-aging effects in human skin cells, designating as a potential natural cosmeceutical ingredient.

A novel proof-of-concept study assessing the lightening effects and safety of malassezin for treatment of facial hyperpigmentation

To the Editor: Disorders of hyperpigmentation are often disfiguring and can have a profoundly negative impact on one's quality of life. Therefore, there remains an unmet need for new, efficacious, and safe topical treatments.

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.

Effectiveness of sodium fluoride varnish and/or diode laser in decreasing post-bleaching hypersensitivity: A comparative study

BackgroundProfessional tooth whitening has gained popularity in the past several years. The most commonly active chemical agent used in bleaching is hydrogen peroxide (HP). HP is a low molecular weight unstable material that easily diffuses into the tooth structure, causing oxidative reactions with a consequent whitening effect. After bleaching, tooth sensitivity and gingival irritation are anticipated. AimThis study aimed to compare the effectiveness of remineralization and/or diode laser therapies in reducing tooth sensitivity after bleaching. MethodologyThirty-nine participants from Umm Al-Qura University, dental clinics, Makkah, SA. They were divided into three equal groups according to the desensitizing technique used. All participants were subjected to bleaching by 40% opalescence boost HP. Subsequently, 13 participants received 5% sodium fluoride varnish (5% NaF), 13 participants received low-level laser therapy (LLLT), and 13 participants received a combination of both desensitizing techniques. Each participant represented self-control, where tooth sensitivity was measured before and after bleaching. The cold test was used to measure tooth sensitivity before bleaching, immediately after bleaching and after application of the proposed desensitizing technique. Then, a visual analogue scale (VAS) was used for re-assessment. ResultsThe desensitizing methods exhibited a notable reduction in tooth sensitivity post-bleaching with no significant difference among the following therapies (p = 0.544). ConclusionAll the employed desensitizing methods reduced post-bleaching sensitivity, with no significant differences among them. Thus, using one technique individually is enough for effort, time and cost savings.

Glycyrrhiza acid micelles loaded with licochalcone A for topical delivery: Co-penetration and anti-melanogenic effect

The co-penetration of micellar vehicles and the encapsulated drugs into the skin layers, as well as the mechanisms underlying the penetration enhancement have not been clearly elucidated. We developed licochalcone A (LA)-loaded glycyrrhiza acid (GA) (GA+LA) micelles for topical delivery of LA into the epidermis. The in vitro co-penetration, penetration pathways, mechanism of interaction between skin and the micelles, and the in vitro and in vivo whitening effect of GA+LA micelles were evaluated. Co-penetration and penetration pathways were visualized on the abdominal skin of rats model with confocal laser scanning microscopy (CLSM) using a nile blue A-labeled GA (GA-NB). We found that GA significantly increased the transport of LA into the skin predominantly via the hair follicles and GA mainly accumulated in the SC and epidermis, while LA was localized in the epidermis and dermis. Moreover, 73.4% of the LA deposited into the epidermis within 12 h and approximately 9.32% of the LA permeated across the SC in the form of entire micelles within 24 h. GA-NB+LA micelles disaggregated and accumulated in the specific skin layers, and the LA released from the carrier penetrated into deeper layers. Moreover, the GA+LA micelles promoted drug penetration via intracellular or intercellular routes by loosening the skin surface and enhancing fluidization through lipid distortion and keratin denaturation. Furthermore, GA+LA micelles exhibited synergistic whitening effect on B16 cells and UVB-exposed C57BL/6 mice. Collectively, GA micelles can enhance penetration of LA to the epidermis mainly via the hair follicles following topical application, and reduce skin pigmentation.

A novel tooth bleaching gel based on peroxymonosulfate/polyphosphates advanced oxidation process: Effective whitening avoiding pulp damage and sensitivity

Pulp damage and bleaching sensitivity caused by existing hydrogen peroxide (HP) bleaching gel is a major challenge that needs to be solved urgently in the field of vital bleaching, mainly due to HP’s intrinsic high penetrability and strong oxidative property. The present study has successfully developed a novel non-hydrogen peroxide bleaching system based on peroxymonosulfate (PMS)/polyphosphates advanced oxidation process, with suitable penetration depth in dental structure. In addition to oxidizing active ingredients similar to HP gel, the new PMS gel also contains its characteristic free radical---•SO4−. Benefitting from excellent oxidative performance, novel bleaching gel exhibits a favorable tooth whitening effect. And tooth color stability after bleaching is better because it only induces a minor change on the enamel surface. Furthermore, cytological studies demonstrate that the new gel has less damage to human dental pulp fibroblasts (cell viability reaches 87.5% after 2 h’ exposure), which is mainly due to the relatively low content of oxidant (15.4%) and limited penetration depth (middle dentin). More excitingly, histological results show PMS gel applied on the molars of rats induce no inflammation of pulp tissues and no activation of pain-related receptors or peptides, consistent with the performance of blank control. These findings suggest that the new PMS/polyphosphates bleaching system has the advantages of good bleaching effectiveness, minor enamel alterations and non-damaged pulp tissue. It is expected to provide a new strategy for clinical vital bleaching treatment.

Herbal Lepa Formulation Preparation and its Evaluation

The concept of beauty is as old as humanity itself. It is the natural desire of every human being to look beautiful and glamorous. The beauty and glamour are because of perfect skin. Herbs have been used for beautification from historic times and have also been described in Ayurvedic literature. Herbs as whole or herbal extracts have been used to treat the various ailments of the skin, hair, body odor, and overall beautification. The demand for Ayurveda in cosmetology is established because it is effective, cheaper, and long-lasting without any side effects. The present study aimed to formulate and evaluate the beneficial effect of herbal Lepa formulation for beautification. Beautification in terms of skin lightening, removal of scars and pigmentation, dark circles, and ultimately healthy glowing skin. The advantage of herbal cosmetics compared to chemical products is they are non-toxic in nature. The Lepa formulation is the suitable dosage form prepared using various natural components in the appropriate and desired quantity for better effectiveness. The formulation has shown significant improvement in various skin problems, including skin pigmentation, melasma, acne marks, and skin lightening effect with no further moisturizing cream requirements.

Bibliometric analysis of the effects of ginseng on skin.

Ginseng is widely used in cosmetics and skin care. The progress of research on the effect of ginseng on the skin was explored through a summary and analysis of skin-related studies on ginseng conducted over in the past 20years, and this exploration aimed to elucidate new research opportunities with regard to the development and application of ginseng treatments for the skin. Keywords were used to retrieve human studies related to the use of ginseng to treat skin conditions from the Web of Science. Scientometric analyses were performed in R to analyze the studies on the human skin-related effects of ginseng conducted from 2000 to 2019. The main active ingredient in ginseng is ginsenoside, and its effects on the skin are mostly anti-aging and whitening. Ginseng extract regulates the levels of matrix metalloproteinases in human fibroblast type I collagen to improve the elasticity and water content of skin. In addition, ginseng inhibits the transcription factors or signaling pathways involved in the formation of melanin, it exerts a whitening effect. The authors of the retrieved studies are mostly located in Asia, mainly South Korea and China. Wang Y, Kim JH, and Kim YJ are relatively influential scholars, these ginseng-related articles published in the Journal of Ginseng Research, Molecules and other journals are very important in this field. This study shows the development of trends in research on ginseng as a raw cosmetic material used on the skin and thus enables researchers to rapidly understand the key information in the field of ginseng research, comprehend the research directions, and improve their research efficiency.

Oxidative stress in the skin: Impact and related protection.

Skin, our first interface to the external environment, is subjected to oxidative stress caused by a variety of factors such as solar ultraviolet, infrared and visible light, environmental pollution, including ozone and particulate matters, and psychological stress. Excessive reactive species, including reactive oxygen species and reactive nitrogen species, exacerbate skin pigmentation and aging, which further lead to skin tone unevenness, pigmentary disorder, skin roughness and wrinkles. Besides these, skin microbiota are also a very important factor ensuring the proper functions of skin. While environmental factors such as UV and pollutants impact skin microbiota compositions, skin dysbiosis results in various skin conditions. In this review, we summarize the generation of oxidative stress from exogenous and endogenous sources. We further introduce current knowledge on the possible roles of oxidative stress in skin pigmentation and aging, specifically with emphasis on oxidative stress and skin pigmentation. Meanwhile, we summarize the science and rationale of using three well-known antioxidants, namely vitamin C, resveratrol and ferulic acid, in the treatment of hyperpigmentation. Finally, we discuss the strategy for preventing oxidative stress-induced skin pigmentation and aging.

Improved skin permeability and whitening effect of catechin-loaded transfersomes through topical delivery

The aim of the study was to prepare catechin-loaded transfersomes to enhance drug permeability through topical administration for the skin protection against ultraviolet radiation induced photo-damage. The results showed that the catechin-loaded transfersomes were monodispersed with polydispersity index (PDI) < 0.2, <200 nm in particle size and with high encapsulation efficiency (E.E.%) greater than 85%. The in vitro skin permeation test indicated that the catechin-loaded transfersomes enhanced the skin permeability by 85% compared to the catechin aqueous solution. Similarly, the in-vivo skin whitening study demonstrated that F5 transfersome formulation was effective in tyrosinase inhibition and had good biocompatibility to the guinea pig skin. Finally, the stability study showed that both physicochemical properties and E.E.% of the F5 transferosome formulation were fairly stable after 3 months storage. Therefore, topical administration of catechin-loaded transfersomes could be considered as a potential strategy for the treatment of UV-induced oxidative damage to the skin.

Efficacy and tooth sensitivity of at-home bleaching in patients with esthetic restorations: a randomized clinical trial.

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. 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 [∆WID]) were assessed using a spectrophotometer at baseline, 2weeks, and 1 and 3months 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). Higher ΔE*ab, ΔE00, and ∆WID 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). 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 2weeks of bleaching. After 2weeks of at-home bleaching, a lower whitening effect was observed in patients with anterior restorations when compared with patients with sound teeth. ClinicalTrials.gov identifier RBR-52j6gmg.

Does Consumption of Coloring Substances during Tooth Whitening Treatment Influence the Final Outcome? A Systematic Review

The purpose of this systematic review recorded in PROSPERO (CRD4201913125) was to test the hypothesis that dye substances during and / or immediately after treatment can affect the effectiveness of tooth whitening. Two independent reviewers performed a search was conducted in the PubMed / MEDLINE, Web of Science databases and Cochrane Library. Articles were selected based on the inclusion criteria: in vitro studies with direct comparisons between groups undergoing treatment with or without dying substances consumption during or immediately after bleaching treatment; reflectance spectrophotometry was used as evaluation method; studies in which any type of dye was used, studies in which treatment was performed on human and / or bovine teeth. Of the 8 studies selected, including 347 samples analyzed in vitro. The coffee does not appear to influence tooth whitening when consumed during tooth whitening sessions or immediately after treatment (up to 24 hours after treatment). However low-alcoholic beverages such as red wine and cola drinks may have the potential to change pigmentation and influence the change in tooth color.

In vivo evaluation of whitening toothpaste efficiency and patient treatment satisfaction: a randomized controlled trial.

To assess the whitening efficiency and patient satisfaction after usage of commercially available toothpastes with the different whitening ingredients. This randomized controlled trial study comprised 161 participants who were randomly divided into eight groups based on used whitening or control/conventional toothpaste (Colgate Max Expert White [CMEW], n = 20; Signal Daily White [SDW], n = 20; Himalaya Sparkly White Herbalis [HSWH], n = 20; Signal White System [SWS], n = 20; Rembrandt Deeply White + Peroxide [RDWP], n = 20; Splat Extreme White [SEW], n = 20; Splat White Plus [SWP], n = 21; and Kalodont Multi Repair [control], n = 20). Tooth color and color change were evaluated using a spectrophotometer (CIELAB coordinates, ΔEab*, ΔE00, whiteness index change [ΔWID]). Measurements were performed at baseline, 30days and 60days after the beginning of treatment, and 30days after completing treatment - follow-up. Side effects and satisfaction with the whitening outcome were reported throughout the questionnaire. The results for ΔL*, Δa*, and Δb* showed an increase in lightness and decrease in yellowness for all tested whitening toothpastes compared to the control group after 30days of use (p ≤ 0.05). Also, significant tooth color difference (ΔEab*, ΔE00) and whiteness index change (ΔWID) were recorded for all tested whitening toothpastes 30days and 60days from the beginning of use (p ≤ 0.05). Toothpaste containing a combination of urea peroxide and enzyme ingredients (SEW) demonstrated the highest and the longest whitening effect. Whitening toothpastes can show perceptibly whitening effect after a short time of usage, but without a long-lasting impact. Toothpaste containing a combination of enzymes and peroxides showed the best whitening performance compared to those containing only enzymes, peroxides, or abrasives. ClinicalTrials.gov: NCT04460755.

Effects of different bleaching application durations on enamel in terms of tooth color, microhardness, and surface roughness

AbstractThe aim of this research was to assess the color differences (∆E00), Vickers microhardness, whiteness index, and surface roughness values of different durations of bleaching the enamel. One hundred and eight teeth were utilized for color evaluation, roughness, and microhardness (n = 36). Teeth were assigned to three groups (n = 12) based on the durations of the bleaching application. Bleaching agent was applied for 20 minutes in group 1, 40 minutes in group 2, and 60 minutes in group 3. The color was measured with a Vita Easyshade Advance 4.0 spectrophotometer before applying the bleach, and 24 hours, 7, and 14 days after bleaching application. The CIEDE2000 and whiteness index for dentistry values were calculated. The microhardness and surface roughness values were obtained before application and 7 and 14 days after application. Data were analyzed using two‐way ANOVA and post‐hoc LSD tests Group 3 had the largest color and whiteness changes. The whiteness index for dentistry values were statistically significantly increased, considering baseline measurements within all groups (P &lt; .05). For the Vickers micohardness values, in group 3, a statistically significant difference was observed among baseline, and 7 days after application (P &lt; .05). However, the surface roughness values showed no significant difference in any measurement (P &gt; .05). According to this research in all groups, effective whitening was accomplished. Based on the results evaluated for whiteness, color alteration, microhardness, and roughness, the optimal bleaching duration of application was in 40 minutes.

Effects of domestic tooth whitening: literature review/ Efeitos do clareamento dental doméstico: revisão de literatura

Objectives: The scope is tooth whitening at home, the study focuses on the effectiveness of whitening and treatment effects.Material and Method: A search was carried out in the Medline, PubMed, Lilacs and Scielo databases, between the years 2000 to 2019. The keywords used in the databases were as follows: Tooth whitening, hydrogen peroxide, carbamide peroxide, whitening products , tooth, at home, whitening, effects, efficacy, whitening.Results: Of the 23 studies included in this review, 6 studies evaluated the effectiveness of tooth whitening, 4 studies evaluated the effect of whitening on tooth structure, 1 study evaluated the association of whitening treatment with dentifrice, 3 studies evaluated on cytotoxicity / toxicity, 3 studies evaluated the effect of whitening on dental materials, 2 studies assessed the social impact of tooth whitening, 3 studies assessed sensitivity during treatment and 1 study assessed the effect of bleaching gel storage.Conclusion: In order to try to minimize adverse effects that may arise such as sensitivity, cytotoxicity and gingival irritation, use with the minimum exposure time of the product is indicated; the home whitening technique shows less chance of recurrence after treatment.

Determination of Phenolic Content, Antioxidant Activity, and Tyrosinase Inhibitory Effects of Functional Cosmetic Creams Available on the Thailand Market.

Recently, the global trend toward the use of natural extracts and antioxidant agents in the cosmetic cream industry to produce whitening effects has been increasing. This has also been a persistent trend in Thailand. In this study, samples of commercial cosmetic creams on the Thai market were assessed for a functional evaluation of their antioxidant activity, tyrosinase inhibitory effects, and phenolic contents. Samples were extracted using hot water and sonication extraction method to obtain the functional cream extracts. Total phenolic contents in all samples were within the range of 0.46–47.92 mg GAE/30 g cream. Antioxidant activities of the cream extracts were within the range of 3.61–43.98 mg Trolox equivalent/30 g cream, while tyrosinase inhibition activities were within the range of 2.58–97.94% of inhibition. With regard to the relationship between the total phenolic content and the antioxidant activity of the cosmetic creams, Pearson’s correlation coefficient revealed a moderately positive relationship with an r value of 0.6108. Furthermore, the relationship between the antioxidant activity and the tyrosinase inhibitory activity of the cosmetic creams was highly positive with an r value of 0.7238. Overall, this study demonstrated that the total phenolic contents in the functional cosmetic creams could play a role in antioxidant activity and anti-tyrosinase activities. The findings indicate how the whitening and antioxidant effects of cosmetic creams could be maintained after the products have been formulated, as this concern can affect the consumer’s decision when purchasing cosmetic products.

Evaluation of At-home Bleaching Times on Effectiveness and Sensitivity with 10% Hydrogen Peroxide: A Randomized Controlled Double-blind Clinical Trial.

The aim of this randomized double-blind controlled clinical trial was to evaluate different protocols for at-home use of 10% hydrogen peroxide in whitening effectiveness and tooth sensitivity. Seventy-two patients were selected according to the inclusion and exclusion criteria, with the upper central incisors having color A2 or darker according to the Vita Classical scale (VITA Zahnfabrik, Bad Säckingen, Germany) and randomized into two groups: 10% hydrogen peroxide applied once daily for 15 minutes (HP 15) or applied once daily for 30 minutes (HP 30). Bleaching was performed for 14 days in both groups. The color was evaluated before bleaching, during bleaching (1st and 2nd weeks), and 1 month after the bleaching treatment using the Vita Classical, Vita Bleachedguide 3D-MASTER, and Vita Easyshade spectrophotometer (VITA Zahnfabrik). Dental sensitivity was recorded by the patients using the numerical rating scale (0-4) and visual analogue scale (0-10 cm). Color data were evaluated by two-way analysis of variance (ANOVA) of repeated measures (group vs. treatment time). The Mann-Whitney test was performed to contrast the means (α=0.05). Tooth sensitivity was assessed by Fisher's exact test (p=1.00) and intensity of tooth sensitivity was evaluated by the Mann-Whitney test (α=0.05) for both scales. A significant whitening effect was observed after 2 weeks of bleaching for all color measurements (p=0.01), with no difference between HP 15 and HP 30 (p>0.05). Also, the absolute risk and intensity of tooth sensitivity were similar (47%; p>0.05). The effectiveness and tooth sensitivity of at-home bleaching carried out with 10% hydrogen peroxide applied for 15 minutes or 30 minutes are similar.