Search Results (30)

Tooth bleaching is a widely used esthetic treatment; however, bleaching agents can temporarily alter the surface morphology of enamel, increasing surface roughness and porosity, which may lead to increased susceptibility to discoloration. This in vitro study investigated the effectiveness of fluoride varnish in preventing immediate discoloration of bovine incisors after bleaching. Specimens were bleached with 35% hydrogen peroxide and treated with either Clinpro White Varnish (CW) or Enamelast Fluoride Varnish (EN), whereas control specimens received no treatment after bleaching. The samples were immersed in coffee for 24 h, and the color difference (ΔE₀₀) was calculated using the CIEDE2000 formula. The surface morphology of enamel was examined using SEM. The fluoride varnish groups showed significantly lower color difference values than the control group (p < 0.05), with ΔE₀₀ reduced by approximately two-thirds in both the CW and EN groups. SEM observations showed that the enamel surfaces in the varnish-treated groups exhibited reduced surface irregularities compared to the untreated group, suggesting remineralization. These results suggest that the immediate application of fluoride varnish after bleaching can effectively reduce short-term discoloration by providing physical protection and promoting remineralization. Fluoride varnish may serve as a simple and effective strategy to maintain whitening outcomes and minimize early discoloration. Full article

Background/Objectives: Tooth bleaching is a widely requested aesthetic procedure in modern dentistry. However, the structural effects of high-concentration peroxide-based bleaching agents on enamel remain insufficiently understood. This study aims to evaluate and compare the effects of three in-office bleaching agents—Opalescence Boost (40% hydrogen peroxide [HP]), Opalescence Quick (45% carbamide peroxide [CP]), and BlancOne Ultra + (35% hydrogen peroxide [HP])—on enamel surface characteristics and color change using confocal laser scanning microscopy (CLSM) and spectrophotometric analysis. Methods: Forty-two extracted human teeth were sectioned and divided into experimental and control halves. Each experimental specimen underwent bleaching according to the manufacturer’s protocol. Color measurements were conducted at baseline, immediately post-treatment, at 3 days, 7 days, and 6 months following treatment using the Vita Easyshade^® spectrophotometer. Color differences were calculated using the CIEDE2000 (ΔE₀₀) formula. Enamel surface morphology was assessed by CLSM. Data were analyzed using Wilcoxon and Kruskal–Wallis tests (p < 0.05), performed with SPSS v23. Results: All bleaching agents produced clinically perceptible color changes (ΔE₀₀ > 3.3). Opalescence Boost achieved the highest and most consistent whitening effect (mean ΔE₀₀ > 11), while Opalescence Quick showed moderate efficacy (ΔE₀₀ ~6–8), and BlancOne Ultra+ induced milder changes (ΔE₀₀ ~4–5). CLSM imaging revealed surface alterations in all bleached samples, with more pronounced changes observed in specimens treated with higher peroxide concentrations. Conclusions: All three bleaching systems were effective in improving enamel color, with Opalescence Boost delivering the most substantial and durable effect. CLSM analysis confirmed morphological changes in enamel without evidence of severe damage. These results underscore the importance of selecting bleaching protocols that balance efficacy with enamel safety. Further in vivo studies are recommended to validate long-term structural effects and support clinical decision-making. Full article

Background/Objectives: In the oral environment, tooth-colored restorations are frequently exposed to staining agents, affecting their aesthetic and physical properties. This study assessed the impact of stains and bleaching agents on the surface roughness, microhardness, and color stability of four different composite materials (Omnichroma, Charisma, Z350, and TPH). Methods: Based on group distribution, the discs of all the composite material samples were prepared. All the ninety-six-disc specimens (n = 96) were then randomly divided into four different groups based on different composite resin groups. The samples were then immersed into four different immersing media [each group had twenty-four-disc samples (n = 24)]. Finally, all the samples then faced the challenge of a bleaching agent application. Measurements were taken at baseline, post-immersion, and post-bleaching stages. Results: Red wine caused increased roughness in Filtek™ Z350 and significant color change in Omnichroma, while coffee increased roughness in Omnichroma and altered the color of TPH spectra. Soda led to increased roughness and significant color change in TPH spectra. Additionally, Filtek™ Z350 experienced reduced microhardness across all solutions after bleaching. Conclusion: This study concluded that staining and bleaching adversely affected the tested composites, with increases in surface roughness, color change, and microhardness reduction observed. Overall, Charisma diamond demonstrated the greatest resilience to staining and bleaching challenges, whereas Filtek™ Z350 XT exhibited the most pronounced degradation, indicating that composite formulation critically governs both aesthetic and mechanical stability under clinically relevant conditions. Full article

In-office teeth bleaching is an esthetic dental procedure performed to whiten teeth. A desensitizing procedure often requires prior in-office bleaching to relieve tooth hypersensitivity. The objective of this study was to evaluate the bleaching efficiency of teeth specimens pre-treated with different desensitizing agents by analyzing the color parameters. A total of 25 bovine specimens were stained and divided into five groups (n = 5). The specimens were pre-treated with GLUMA, ICON, bonding, or fluoride varnish according to the manufacturer’s instructions. Subsequently, the samples underwent three consecutive 20 min bleaching sessions using an in-office bleaching product. Color values in the CIE L*, a*, and b* color space were initially recorded, both before any treatment and after each bleaching session. The color difference (ΔE) was then computed. The data were analyzed using SPSS 24.0 software. The color alteration after pre-treatment was analyzed using a one-way ANOVA test, and the color alteration in each bleaching session was compared using a repeated-measure ANOVA test. A one-way ANOVA analysis showed a statistically significant difference in the bleaching efficiency of teeth specimens pre-treated with different desensitizers (p < 0.001). The repeated-measure ANOVA analysis showed no statistically significant difference in additional bleaching sessions (p = 0.133). The ICON and bonding pre-treatment showed the color alteration of teeth specimens before the bleaching procedure. Although the different desensitizer pre-treatments showed significant differences in bleaching efficiency, the differences in color parameters of the teeth specimens at the end of three bleaching sessions were statistically insignificant. Desensitizer pre-treatment influenced the degree of color change during multiple bleaching sessions; however, the outcome of bleaching was not affected by desensitizer pre-treatment. Full article

The objective of this research was to synthetize a hydroxyapatite-capsaicin composite (HAp-CAP) and assess its physicochemical properties for potential use in an in-office dental bleaching gel. The HAp-CAP nanocomposite was prepared by the precipitation method using a 4:1 ratio of nano-hydroxyapatite (nano-HAp) to capsaicin (CAP) dissolved in 99.5% ethyl alcohol (q.s.p) with the assistance of zirconia beads in a SpeedMixer^®. Characterization of HAp-CAP involved morphological, spectroscopic, and thermal analyses. Subsequently, HAp-CAP was incorporated into an in-office dental bleaching agent to evaluate its impact on reducing hydrogen peroxide diffusion into the pulp chamber and its effect on tooth color alteration during the bleaching process. The HAp-CAP in a bleaching gel slightly decreased the amount of hydrogen peroxide inside the pulp chamber and did not interfere in the bleaching effectiveness of dental bleaching. The physicochemical characterization indicates that the synthesis process of the HAp-CAP composite was successfully carried out, and its use in dental materials poses a challenging task that warrants further investigation since its incorporation. Full article

Background: This study investigated the contact between adult dental pulp stem cells (DPSCs) and carbamide peroxide (CP), a bleaching agent that is a popular choice for at-home whitening products, using an in vitro model. Objectives: The aim of this study was to evaluate the impact of exposure to different concentrations and timings of a commonly used peroxide-based home tooth-whitening product on DPSCs. Materials and methods: Human DPSCs obtained from impacted third molars were cultured and exposed to various concentrations of carbamide peroxide (0.1%, 0.5%, and 1%). The effects of CP on DPSC proliferation and apoptosis were investigated by MTT assay and flow cytometry. Migration was investigated by micrographs of wound healing. An enzyme-linked immunosorbent assay (IL-6 and IL-8) was used to investigate the CP-stimulated cytokine production of DPSCs. Each experiment was performed three times with independent batches of DPSCs. Statistical analysis of the collected data was performed using one-way and two-way ANOVAs with the significance threshold set at p < 0.05. Tukey’s post hoc multiple comparison test was used to identify differences between groups. Results: Cell viability and adherence were lower in the CP-exposed cells compared to the non-stimulated cells, probably due to increased cell death (** p ≤ 0.01, **** p ≤ 0.0001). CP-stimulated DPSCs exhibited a dose-dependent release of IL-6 and IL-8 (**** p ≤ 0.0001). CP did not affect wound healing at any concentration tested. Conclusions: Human DPSCs were able to sense CP. Consequently, CP contributed significantly to cell apoptosis and local inflammatory responses through cytokine release. Full article

This systematic review examines studies focusing on tooth bleaching and its effects on healthy enamel or incipient caries and bacterial adhesion. The aim is to explore the impact of different bleaching agents on incipient caries lesions and healthy enamel. Clinical studies, in vitro studies, and observational studies that compared at least two groups were included. A search strategy was used to select studies from the MEDLINE via Pubmed and Scopus databases. Two evaluators performed data extraction, screening, and quality assessment independently. Only studies written in English were included. From 968 initial records, 28 studies were selected for a full-text evaluation. Of these, 7 studies were classified as cluster 1 (bacterial adherence on teeth), 12 studies as cluster 2 (no bacteria involved), 4 studies as cluster 3 (no teeth deployment), and 5 clinical studies were cluster 4. Of the selected studies, 6 (21.4%) supported increased bacterial attachment capacity and cariogenic dynamics, 4 (14.3%) decreased adhesion and cariogenic activity, 7 (25%) showed no difference, and 11 (39.3%) followed a different methodological approach and could not be categorized. The risk of bias appeared to be high, mainly because of the different methodologies in the studies, so we cannot reach a confident conclusion. Nevertheless, as far as carbamide peroxide bleaching is concerned, there does not seem to be a clinically significant alteration, neither in microorganism counts nor in enamel microstructure. Full article

The high demand for aesthetic treatments among the population has resulted in a wide array of bleaching products available on the market. It is imperative to investigate the potential adverse effects these products may have on dental health. The objective of this systematic review is to assess, based on available experimental in vitro studies in the scientific literature, whether bleaching products exhibit cytotoxic properties against pulp stem cells and fibroblasts. A comprehensive literature search was conducted across the Medline, Scopus, and Lilacs databases using the search formula ((Tooth whitening) OR (bleaching agent)) AND cytotoxicity AND ((stem cell*) OR fibroblast). Following the application of inclusion and exclusion criteria, 14 articles were deemed suitable for full analysis. The most utilized assay in the evaluated studies was the MTT cell viability assay. Fibroblasts emerged as the most scrutinized cell type due to the potential adverse effects of bleaching, such as invasive cervical resorption, which primarily affects the periodontal ligament where fibroblasts are located. It was observed that as the concentration of hydrogen peroxide increases, so does the cytotoxicity of the product. Additionally, other factors such as application time, activation methods, and the type of peroxide used also play a significant role. Bleaching products have been shown to exert cytotoxic effects on fibroblasts. Further exploration of the impact of bleaching agents on dental pulp stem cells is warranted to better understand their implications for these cells. Full article

Today, molar incisor hypomineralization (MIH), which affects approximately one in seven children, is defined as a hypomineralized developmental enamel defect that often impacts at least one permanent first molar and frequently affects permanent incisors as well. Symptoms and signs include demarcated opacities of various colors, post-eruptive enamel deterioration, atypical caries and restorations, hypersensitivity, tooth loss due to MIH, and difficulty in achieving anesthesia. A detailed review of the scientific literature shows that there are many studies evaluating different treatment approaches for permanent first molars affected by MIH. On the other hand, there are very few scientific studies evaluating treatment approaches for affected incisors in patients with MIH. Most of these studies consist of case reports or series. White/creamy and/or yellow/brown demarcated opacities are commonly observed in affected incisors in patients with MIH. While these opacities increase the susceptibility of enamel to deterioration and dental caries, they also cause aesthetic problems and related psychosocial consequences. Treatment methods, such as resin infiltration, microabrasion, and/or dental bleaching, have been proposed for aesthetic and restorative purposes in affected incisors in patients with MIH. Additionally, various approaches to increase mineral content and relieve hypersensitivity have been recommended. The number of randomized controlled and prospective studies is quite low, but many case reports and case series have been encountered. The purpose of this review was to provide a comprehensive overview of the different treatment management modalities for permanent incisors affected by MIH. As a result, while resin infiltration, dental bleaching, microabrasion, and/or etch–bleach–seal techniques are preferred for aesthetic and restorative purposes in these teeth, it has been observed that agents containing casein phosphopeptide amorphous calcium phosphate, casein phosphopeptide amorphous calcium fluoride phosphate, fluoride, and calcium glycerophosphate increase the mineral content. Additionally, studies have reported that ozone and low-level laser therapy, in addition to these remineralizing agents, reduce hypersensitivity in these teeth. Although the findings of this review indicate that the level of evidence for current approaches is not high, clinicians may prefer one or more of the treatment approaches mentioned in this article based on experience and patient expectations. Full article

A prospective observational case series included six patients who presented with discoloured upper and lower teeth extending from the right second premolar to the left second premolar. The photoactivation dosimetry and treatment protocol were as follows: λ 450 nm, 1 W, CW; flattop beam profile; 1 cm²; 15 J/spot; 10 irradiated spots; an irradiation time of 15 s/spot; three whitening cycles in a single session. Blanc One ULTRA⁺ was the bleaching agent. A visual analogue scale (VAS) was utilised to evaluate the pain intensity and dental hypersensitivity during treatment immediately after complete treatment (T1), 24 h (T2), and 8 h (T3) postoperatively, and at an 8-month follow-up timepoint (T4), whereas the dental colour shade change was assessed using the VITA colour shade guide pre-treatment (T0), T1, and T4. The Gingival index and modified Wong Baker faces scale were utilised to evaluate gingival inflammation and patients’ treatment satisfaction, respectively. Our findings revealed a reduction in the dental colour shade of the six cases between 2 and 10- fold (average of 3.5-fold) at T1 and maintained at T4, indicating significant improvement in the colour shade change with optimal outcomes. The percentage of this improvement for all the patients was ranged between 16.6% and 33.3%. At all timepoints, a “0” score was provided for pain intensity, dental hypersensitivity, and gingival inflammation. Our study demonstrates the feasibility and safety of a λ 450 nm laser delivered with a flattop handpiece to achieve optimal whitening outcomes without adverse effects. This offers a useful guide for dental clinicians for vital in-office tooth whitening. Extensive clinical studies with large data are warranted to validate our study protocol. Full article

Internal bleaching is a conservative treatment applied to a darkened endodontically treated tooth to restore its original colour, either as a single treatment or as a treatment prior to a subsequent prosthetic phase. The aim of this study was to objectively measure and compare using an experimental model the expansive capacity of four bleaching groups: carbamide peroxide 37% (CP 37%), hydrogen peroxide 30% (HP 30%), HP 30% mixed with sodium perborate (SP) and SP mixed with distilled water. A total of 150 lower incisors (n = 30 in each group) were prepared for the Walking Bleach technique and a glass tube with oil was introduced into the coronal access cavity to measure the expansive capacity through oil displacement, due to the reaction that occurs when bleaching agents interact with dental tissues. The results after 10 days were analysed with the Games–Howell post hoc test to compare the samples. Significant higher expansion was observed with HP 30% (p < 0.05) and lower expansion with SP (p < 0.05) compared to the other groups. No significant differences were observed between CP 37% (p > 0.05) and HP 30% + SP (p > 0.05). This provides significant and observable information on the behaviour of each bleaching group and its evolution after 10 days. Full article

In modern times, patients are not only seeking oral health but also aiming for a flawless smile. Despite the progress made in aesthetic dentistry, there are instances where insufficient teeth whitening results contrast with the considerable cost of professional treatments. Patient discomfort and the potential for tooth damage further compound these challenges. In this study, we conducted a comparative split-mouth ex vivo investigation to evaluate the innovative BlancOne ULTRA⁺ (IDS SpA) in comparison with established professional products: Opalescence Extraboost (ULTRADENT), Zoom WhiteSpeed (Philips Research Eindhoven High Tech), and Pola Office (SDI Limited). Our initial focus was on the whitening effectiveness of each product, which was measured using a spectrophotometer. Subsequently, we assessed any structural changes in enamel post-treatment using an atomic force microscope (AFM) and a nanoindentation procedure. All tested bleaching agents demonstrated teeth-brightening effects. BlancOne ULTRA⁺, Zoom WhiteSpeed, and Pola Office caused minor alterations in the texture of the enamel surface within nanometric limits. However, Opalescence Extraboost exhibited notably more pronounced changes, indicating significant modifications in surface roughness and potential reductions in material hardness due to consequential shifts in mechanical properties. BlancOne ULTRA⁺ appears to offer the most favourable cost–benefit outcome. Full article

The aim of this laboratory study was to investigate and compare the impact of five desensitizing techniques as a treatment fortooth sensitivity on the exposed dentin after an in-office tooth bleaching procedure. Thirty intact human molars were collected for this investigation. The specimens were obtained by transversely cutting 2.5 mm of the crowns, leading to exposure of the dentin. The specimens were cleaned in an ultrasonic bath and treated initially with EDTA gel 15% for 4 min and then with Opalescence Boost bleaching gel (40% H₂O₂) for two sets of 20 min. Then, the samples were randomly divided into six groups (n = 5) and received one of the following treatments: Group 1 (no treatment—control group), Group 2 (Emofluor gel—0.4% SnF₂), Group 3 (MI Paste—CPP-ACPF), Group 4 (BioMinF paste—calcium phospho-fluoro-silicate), Group 5 (air-abrasion with ProSylc—Bioglass 45S5), and Group 6 (Er,Cr:YSGG laser). Subsequently, each sample was observed utilizing scanning electron microscopy (SEM) in order to detect the rate of occlusion of dentin tubules. SEM-EDS analysis revealed no occlusion of the dentin tubules in the control group, while Groups 2, 4, and 5 presented high effectiveness (>95% percentage of occluded tubules), and Groups 3 and 6 presented lower values (21.6 and 26.8%, respectively). It was concluded that althoughall the tested groups presented higher percentages of occlusion of the dentinal tubules compared to the control group, there were differences in effectiveness among them. The most effective treatments were the daily use of BioMinF paste and SnF₂-containing gel, as well as air-abrasion with ProSylc powder. Full article

Background: Dental aesthetic procedures aim to rectify flaws in dental elements’ shape, alignment, or overly dark color. One of the most common dental aesthetic procedures is tooth whitening. This study attempts to introduce key aspects of bleaching and describe the different techniques and the mechanism of action of bleaching agents, focusing on the clinical implications in orthodontic and on composite restorations. Methods: The research was performed on PubMed, Web of Science, and Science Direct databases for articles on our topic published between 2017 and 2023, and we found a total of 1512 studies. In total, 57 papers were considered for the qualitative analysis in the review. Results: This study found that both carbamide peroxide and hydrogen peroxide were clinically effective, although patients’ level of tooth sensitivity seemed to be lessened by the latter. However, the latter appears to be more effective at reducing patient-experienced tooth sensitivity. Conclusion: Carbamide and hydrogen peroxide based whitening techniques were shown to be equally successful at treating tooth discoloration after bracket composite removal, with no discernible differences between them. To increase the effectiveness of whitening on composites, more research is needed. To achieve the desired results and avoid the negative effects of whitening gels on teeth and soft tissue, a patient-specific approach is advised. Full article

Purpose: To evaluate and compare the tooth-whitening potential of five over-the-counter (OTC), peroxide-free dental bleaching methods as well as an experimental tooth-whitening solution containing 0.1% hydrogen peroxide complexed with doping agents with a gold standard (positive control) containing 16% carbamide peroxide. Material and Methods: Eighty permanent bovine incisor teeth were randomly allocated to eight different groups. Two teeth from each group were immerged into five staining solutions represented by coffee, tea, red wine, and curry mixed in warm oil or distilled water (control group) and stored at 37 °C for 28 days in an incubator. The teeth were then reallocated to the eight groups, resulting in ten samples per group, and each group was matched with a bleaching product. The bleaching procedures were executed following the manufacturer’s recommendations. The color of each sample was assessed over a white and black background using a quantitative numerical measurement approach with a calibrated spectrophotometer. Spectrophotometric measurements were performed after exposing the teeth to the bleaching agent for 60 min (T2), 100 min (T3), and 200 min (T4), and ΔE00 was calculated. Results: When analyzed over a white background, the mean ΔE00 values ranged from 2.14 (placebo) to 6.32 (Opalescence PF). When analyzed over a black background, the mean ΔE00 values ranged from 2.31 (placebo) to 5.78 (Opalescence PF). Statistically significant ΔE00 color changes over time for the eight groups and five staining solutions at T1 and T4 were assessed for both backgrounds using repeated ANOVA followed by Fisher’s LSD post hoc test (p-value < 0.01). Conclusions: All tested over-the-counter whitening kits except one exhibited positive color variation. However, the individual performance differed vastly from one brand to the other, and the overall performance was less effective compared to the conventional carbamide-peroxide-based positive control. Full article