Effect of immune-boosting beverage, energy beverage, hydrogen peroxide superior, polishing methods and fine-grained dental prophylaxis paste on color of CAD-CAM restorative materials.

BACKGROUND: The effect of an immune-boosting beverage (SAM) containing Sambucus Nigra, an energy beverage (ENE), an in-office bleaching (BLE) agent with 25% hydrogen peroxide superior, glazing (GLA) or polishing (POL) methods, and professional dental prophylaxis (PDP) on the color of CAD-CAM restorative materials is unknown. METHODS: In total 210 specimens were prepared, consisting of CAD-CAM feldspathic (FC), zirconia-reinforced lithium disilicate ceramic (ZLS) and hybrid ceramic (HC). The ceramic specimens were divided according to the polishing methods of glazing (GLA) and mechanical polishing (POL). All materials were divided into two groups: with and without BLE. A 25% hydrogen peroxide superior (HPS) gel was used for BLE. After the baseline (BAS) measurement, the specimens were immersed in 3 different beverages (distilled water (DIS), SAM, ENE). After 28 days, a fine-grained (RDA 7) prophylaxis paste was applied. Statistical analysis of ∆E00 color difference values was performed by 3-way ANOVA and Bonferroni test (α = 0.05). RESULTS: The effect of all other actions except material-BLE-beverage on color for BAS-Day 28 was statistically different (p < 0.05). The effect of material, material-BLE, beverage on color for Day 28-PDP was statistically different (p < 0.05). After 28 days, the lowest color change was found in FC-GLA and HC immersed in DIS (p = 0.0001) and the highest in FC-POL immersed in ENE (p = 0.0002). PDP was efficient in color recovery in HC immersed to DIS, ENE and SAM (p = 0.0010). For FC, HC and ZLS, BLE caused a higher color change (p < 0.0001). Regardless of the material, the highest color change for BLE-beverage was found in BLE-treated specimens immersed in ENE (p = 0.0496) and the lowest color change was found in non-BLE-treated specimens immersed in SAM (p = 0.0074). CONCLUSIONS: In materials pre-exposed to 25% HPS, the effect of PDP on color recovery was lower than in unexposed materials. After 28 days, mechanical polishing produced higher color change in FC than glazing, however, in ZLS effects of glazing and mechanical polishing on color were similar. For material/polishing method, HC was the most effective. ENE caused higher color change than DIS and SAM. PDP was more effective than ENE in restoring color to DIS- and SAM-immersed specimens.

Current landscape of research on whitening toothpastes and their effects on dental hard tissue.

PURPOSE: To explore the latest trends in research on whitening toothpaste and to present the issues and future perspectives of these studies. METHODS: An initial PubMed search was performed, followed by a meticulous manual review. A total of 543 papers were initially retrieved, and 54 final research papers were selected and analyzed through a manual review. RESULTS: The number of studies on whitening toothpastes has significantly increased, and while initial studies primarily focused on the efficacy of various whitening toothpastes, recent studies have shifted towards investigating the potential effects on dental hard tissues such as enamel and dentin. Common active ingredients used in these whitening toothpastes include hydrogen peroxide, activated charcoal, and blue covarine. Most studies have used commercial toothpastes with fixed ingredients rather than experimentally manufactured toothpaste, and it was noted that toothpastes from specific major manufacturers were frequently used. CLINICAL SIGNIFICANCE: Whitening toothpastes should be treated as separate entities based on their active ingredients, and more standardized experimental designs are required for better comparisons. Accurate analysis and labeling of other components of toothpaste are also essential.

Co-doped titanium dioxide nanoparticles decrease the cytotoxicity of experimental hydrogen peroxide gels for in-office tooth bleaching.

OBJECTIVE: To evaluate the efficacy and cytotoxicity of experimental 6% and 35% hydrogen peroxide gels (HP6 or HP35) incorporated with titanium dioxide nanoparticles (NP) co-doped with nitrogen and fluorine and irradiated with a violet LED light (LT). METHODS: Bovine enamel-dentin disks adapted to artificial pulp chambers were randomly assigned to bleaching (n = 8/group): NC (negative control), NP, HP6, HP6 + LT, HP6 + NP, HP6 + NP + LT, HP35, HP35 + LT, HP35 + NP, HP35 + NP + LT, and commercial HP35 (COM). Color (ΔE00) and whiteness index (ΔWID) changes were measured before and 14 days after bleaching. The extracts (culture medium + diffused gel components) collected after the first session were applied to odontoblast-like MDPC-23 cells, which were assessed concerning their viability, oxidative stress, and morphology. The amount of HP diffused through the disks was determined. Data were analyzed by generalized linear models or Kruskal Wallis Tests (α = 5%).  RESULTS: HP6 + NP + LT exhibited ΔE00 and ΔWID higher than HP6 (p < 0.05) and similar to all HP35 groups. HP6 + NP + LT showed the lowest HP diffusion, and the highest cell viability (%) among bleached groups, preserving cell morphology and number of living cells similar to NC and NP. HP6 + LT, HP6 + NP, and HP6 + NP + LT exhibited the lowest cell oxidative stress among bleached groups (p < 0.05). HP35, HP35 + LT, and HP35 (COM) displayed the lowest cell viability. CONCLUSION: HP6 achieved significantly higher color and whiteness index changes when incorporated with nanoparticles and light-irradiated and caused lower cytotoxicity than HP35 gels. The nanoparticles significantly increased cell viability and reduced the hydrogen peroxide diffusion and oxidative stress, regardless of HP concentration. CLINICAL SIGNIFICANCE: Incorporation of co-doped titanium dioxide nanoparticles combined with violet irradiation within the HP6 gel could promote a higher perceivable and acceptable efficacy than HP6 alone, potentially reaching the optimal esthetic outcomes rendered by HP35. This approach also holds the promise of reducing cytotoxic damages and, consequently, tooth sensitivity.

Role of the novel aloe vera-based titanium dioxide bleaching gel on the strength and mineral content of the human tooth enamel with respect to age.

There has been an increased demand for dental bleaching globally irrespective of age and gender. Main drawbacks associated with conventional tooth bleaching agents have been compromised strength and mineral-content of tooth enamel which results in sensitivity, discomfort, roughness, and structure loss of human teeth. Currently, nanoparticles synthesized by green synthesis have gained popularity especially in medical and dental applications because of their versatile and beneficial nano-scaled features. Titanium dioxide nanoparticles (TiO2Nps) in this study were prepared from green ecofriendly source using the aloe vera plant extract and were then characterized via dynamic light scattering (DLS), scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD), and energy dispersive X-ray (EDX), for size, shape, composition and true-phase. These TiO2 Nps were incorporated in commercial bleaching gel containing hydrogen peroxide to form a novel TiO2-bleaching gel which was used to bleach extracted anterior teeth belonging to four different age groups: 20-29 years, 30-39 years, 40-49 years and ≥50 years. These teeth were investigated for micro-hardness (Vickers microhardness tester) and mineral-content (EDX spectroscopy) including sodium, magnesium, phosphorus, calcium in an in-vitro environment both before and after bleaching. Results revealed that TiO2 Nps prepared by aloe vera plant were nanos-sized of about 37.91-49 nm, spherical shape, true anatase phase with pure titanium and oxygen in their composition. The values of Vickers micro-hardness and mineral-content (Na, Mg, P, Ca) of enamel specimens belonging to different age groups enhanced in a linear pattern before bleaching with the increase in age (p value < 0.05). There was negligible reduction observed in Vickers micro-hardness and mineral-content elements (Na, Mg, P, Ca) of all enamel specimens belonging to different ages after the bleaching (p value > 0.05). The novel TiO2-bleaching gel prepared was effective enough in preventing the declination in Vickers micro-hardness strength and mineral-content of all the enamel specimens belonging to different age groups even after the bleaching procedure which makes it a promising biomaterial.

Bleaching as a complement to fluoride-enhanced remineralization or resin infiltration in masking white spot lesions.

OBJECTIVE: There are many suitable strategies for addressing caries, which is an ongoing worldwide problem. Although white spot lesions (WSLs) can be either remineralized naturally or treated with non- or micro-invasive strategies, their whitish and opaque appearance may persist. To evaluate the effects of tooth bleaching as a complement to fluoride-enhanced remineralization or resin infiltration in masking WSLs, as well as in enamel surface roughness relative to that of the adjacent enamel. METHODOLOGY: Flattened rectangular bovine enamel fragments (6×3×~2.9 mm length, width and thickness) were divided into six groups (L/N, F/N, F.BL/BL, I/N, I.BL/BL, N/N; n=15). Treatments applied to the 3×3 mm left half included: L (Lesion) - WSL simulation with 50 mM acetate buffer, 96 hours, 37ºC; F (Fluoride) - WSL treatment with 2% NaF neutral gel, 1x/week, 8 weeks; I (Infiltration) - WSL treatment with H3PO4 37%/10 s; Icon®-Dry/30 s; Icon®-Infiltrant/3 min+1 min; N (Nothing) - sound enamel/control. Treatments applied to both halves after F and I included: BL (Bleaching) - Opalescence Boost 40%, 3×/20 min each; N (Nothing) - control. The differences in color (ΔE00, ΔL, Δa, Δb) and surface roughness (ΔRa) between the left and right halves were measured. Kruskal-Wallis/post-hoc tests were applied to ΔE00, ΔL, Δa and ΔRa, and 1-way ANOVA/Tukey tests to Δb (α=0.05). RESULTS: The factor under study significantly influenced ΔE00 (p=0.0001), ΔL (p=0.0024), Δb (p=0.0015), and ΔRa (p<0.001), but not Δa (p=0.1592). Both fluoride-enhanced remineralization and resin infiltration were able to mask WSL, regardless of subsequent bleaching. However, when bleaching was performed, ΔE00 median values did not exceed the acceptability threshold for color difference. Only resin infiltration reduced ΔRa between WSL and the adjacent enamel. CONCLUSIONS: Both remineralization and infiltration, particularly if complemented by bleaching, fostered satisfactory esthetic results. Only infiltration without bleaching led to really good results in surface roughness.

Effect of carbamide peroxide treatment on the ion release of different dental restorative materials.

BACKGROUND: To predict the long-term performance of restorative materials in the oral environment, it is important to evaluate their resistance to chemical and mechanical degradation and to know the toxic potential of the type and amount of ions eluted from the filling material. In this study, home bleaching was applied to dental materials with different contents and it was aimed to determine the type and amount of ions released from these materials. METHODS: In this study, amalgam, posterior composite resin, anterior composite resin, bulk fill composite resin, indirect composite resin, hybrid ceramic and all-ceramic were used as restorative materials. 10 specimens of each material were prepared according to the manufacturer's instructions. Each material group was divided into two subgroups as the bleached group and the control group. After bleaching, all specimens were stored in 1 ml of 75% ethanol/water solution. Solutions were renewed after 1, 14 and 28 days. The type and amount of ions released from the materials were determined using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Data were analyzed using the Friedman, Wilcoxon Signed Ranks, and Mann-Whitney U tests (α = 0.05). RESULTS: It was determined that the amount of ions release from the restorative materials decreased over time (p < 0.05). According to the results of the Mann-Whitney U test, there was no difference between the bleaching and control groups in most of the restorative materials (p > 0.05). CONCLUSION: Within the limits of this study, home bleaching system does not have a significant effect on ion release from restorative materials.

Synthesis and characterization of different nano-hydroxyapatites and their impact on dental enamel following topical application for dental bleaching.

OBJECTIVE: This study aims to synthesize, characterize, and assess the penetration of hydrogen peroxide (HP), color change (CC), and surface morphology changes after the application of two distinct nano-hydroxyapatite (nano-HAp). METHODS: Two nano-HAp were previously synthesized by co-precipitation: one with rod-shaped particles (RS) and the other with spherical-shaped particles (SS). The surface charge of the nano-HAp particles was determined at varying pH levels and characterized by X-ray diffraction patterns and Fourier transform infrared spectroscopy. The morphology of the samples was assessed using scanning electron microscopy (SEM). The nano-HAp particles were applied before the dental bleaching procedure. Forty teeth were divided into four groups (n = 10) according to the bleaching treatment: no treatment, bleaching with 35 % HP only, RS application and bleaching with 35 % HP, and SS application and bleaching with 35 % HP. HP concentration (µg mL-1) was measured using UV-Vis, while CC was evaluated with a digital spectrophotometer (ΔEab, ΔE00 and WID). Additionally, four teeth from each group were selected for SEM analysis. Statistical analysis encompassed one-way ANOVA, Tukey's, and Dunnet's tests. RESULTS: RS and SS were successfully synthesized by coprecipitation, primarily differing in pH during synthesis. Both variations of nano-HAp morphology significantly reduced HP diffusion into the pulp chamber (p < 0.001). Regarding enamel morphology, groups analyzed post dental bleaching exhibited greater HAp deposition on the enamel surface. Notably, this deposition did not impede CC. SIGNIFICANCE: The utilization of different nano-HAp morphologies prior to dental bleaching appears to be a promising strategy for mitigating adverse effects associated with dental bleaching procedures.

Effectiveness of Three Bleaching Techniques for Endodontically Treated Teeth: A Randomized Clinical Trial.

BACKGROUND: Various techniques, products, and protocols are used for the bleaching of non-vital teeth. The walking bleach technique involves sealing the bleaching agent in the pulp chamber. In the inside/outside technique, a low-concentration bleaching agent is applied at home using a custom tray. In the in-office technique, a high-concentration bleaching agent is applied by a dental professional. Limited research has compared the effectiveness of these techniques. OBJECTIVE: This clinical trial aimed to evaluate the effectiveness of the walking bleach, the inside/outside, and the in-office bleaching techniques. METHODS AND MATERIALS: Fifty-four discolored teeth were selected according to eligibility criteria, randomized, and assigned to three treatment groups (n=18): walking bleach (sodium perborate - SP), inside/outside bleaching (7.5% hydrogen peroxide -HP7.5), and in-office bleaching (35% hydrogen peroxide - HP35). A cervical seal was placed in all the teeth, and nonvital bleaching was performed according to each technique. The CIELab color coordinates were measured using a clinical spectrophotometer at baseline, weekly, and at the 1-week follow-up. ΔE00 and ΔWID were calculated between the baseline and each evaluation time point. The ANOVA, Fisher exact, and Kruskal-Wallis tests were used to compare the quantitative variables, and the Fisher exact test, to determine the association among categorical variables. Bleaching effectiveness was interpreted by 50:50% perceptibility and acceptability thresholds. RESULTS: As the treatment progressed, all techniques presented a significant increase in L* and WID (p<0.001), and a significant decrease in a* and b* (p<0.001). HP7.5 and HP35 presented greater increases in WID mean values, in comparison with SP (p=0.006). No significant differences were observed among the techniques for ΔE00 after treatment completion (p=0.383). There were no statistical differences in bleaching effectiveness among the techniques after treatment completion (p=0.098). CONCLUSION: All techniques presented excellent effectiveness after treatment completion. However, HP7.5 and HP35 techniques provided a more rapid whitening response.

Masking efficacy of bleaching and/ or resin infiltration of fluorotic spots on anterior teeth - a systematic review and meta-analysis.

OBJECTIVES: The aim of this systematic review and meta-analysis was to evaluate the masking success of bleaching and/or resin infiltration treatment of fluorotic lesions in anterior teeth of adults and adolescents. DATA SOURCES: PubMed, Cochrane Library, and Embase were systematically searched from the beginning of documentation to December 31, 2023. PRIMARY OUTCOME WAS THE NUMBER OF MASKED TEETH: A tooth was considered masked when the color difference (ΔE CIE76) between fluorotic areas and the surrounding sound enamel was ≤3.7 and unmasked if ΔE > 3.7. Secondary outcomes were mean ΔE values between fluorotic and sound enamel reported for a treatment group at baseline and after any intervention as well as patient satisfaction. STUDY SELECTION: Of 1575 search results 4 publications met the inclusion criteria, comprising 230 treated anterior teeth with fluorosis in 47 patients. Meta-analyses were performed comparing the result after treatment (bleaching, resin infiltration, or bleaching followed by resin infiltration) to baseline. RESULTS: Bleaching and resin infiltration were suitable intervention strategies to improve the esthetics of fluorosis affected anterior teeth, with a combination of both treatment approaches being particularly effective in reducing the color difference between fluorotic defects and the surrounding sound enamel below the acceptability thresholds of 3.7 (success rate [95 %CI]: 0.75 [0.44, 1.06]). Patient satisfaction increased after treatments, indicating a beneficial impact on their mental health. The overall bias of the included studies was 2.5 (ROBINS-I analysis tool). CONCLUSION: There is evidence that resin infiltration with preceding bleaching therapy is more effective in masking fluorotic lesions in anterior teeth than bleaching alone. The combination therapy also showed a tendency towards higher success rates compared to infiltration alone. However, this difference was statistically not significant, and more studies are needed to further assess the efficacy of specific treatments and their combinations as well as the certainty in the evidence. The methodologic heterogeneity of study designs regarding estimation of color difference before and after treatment and bleaching protocols calls for unification in future studies. CLINICAL SIGNIFICANCE: Results of this systematic review and meta-analysis revealed the combination of bleaching followed by resin infiltration as efficacious approach for masking fluorotic lesions in young adults. While resin infiltration alone improves the aesthetic appearance of fluorotic lesions, dentists should consider a combined bleaching-infiltration regimen to achieve more favorable clinical outcome for their patients.

Effect of Bleaching Treatments on the Mechanical Properties of the Dentin Matrix and on Collagen Biodegradation by Endogenous Protease.

This study evaluated the mechanical properties of demineralized dentin matrix submitted to different bleaching treatments, as well as the changes in mass and collagen biodegradation brought about by endogenous protease. Dentin collagen matrices were prepared to receive the following treatments (n=12): no bleaching treatment (C-control), 10% carbamide peroxide (CP-Opalescence PF, Ultradent, South Jordan, UT, USA) 10%/8 hours/ day/14 days, and 40% hydrogen peroxide (HP-Opalescence Boost, Ultradent), 40 minutes per session/3 sessions. The dentin matrices were evaluated for elastic modulus and mass before and after treatments and ultimate tensile strength after treatments. The solution collected during storage was evaluated for hydroxyproline release. There was no statistically significant difference between CP and C in terms of the elastic modulus (p=0.3697) or mass variation (p=0.1333). Dentin beams treated with HP and C presented significant mass loss after the first session (p=0.0003). HP treatment led to complete degradation of collagen matrices after the second bleaching session. After the second session, CP showed higher hydroxyproline concentration than C (p<0.0001). Ultimate tensile strength was lower for CP than C (p=0.0097). CP did not affect the elastic modulus or the dentin collagen matrix mass but did promote hydroxyproline release by endogenous protease and reduce the ultimate tensile strength. HP significantly affected the mechanical properties of dentin and promoted complete degradation of the demineralized dentin collagen matrix.

Effect of Successive At-home Bleaching Sessions on the Surface Properties, Biaxial Flexural Strength, and Reliability of CAD-CAM Monolithic Materials.

Although at-home bleaching can recover the optical properties of stained CAD-CAM monolithic materials, little is known about its impact on their surface and mechanical properties, especially when successive sessions are performed. This study evaluated the effect of successive at-home bleaching sessions on the microhardness, roughness, topography, biaxial flexural strength (BFS), and reliability of CAD-CAM monolithic materials. Disks from Lava Ultimate (LU), Vita Enamic (VE), and IPS Empress CAD (EMP) were fabricated and submitted to up to three bleaching sessions. At-home bleaching was performed with 10% carbamide peroxide, and each session consisted of one application for 10 hours/day for 14 days. The analyses of the aforementioned parameters were assessed before and after the first, second, and third bleaching sessions, except for BFS, which was evaluated at baseline and after the third session. The Weibull modulus was calculated from the BFS data. The microhardness of the three materials as well as the roughness of LU were not affected by the sessions, whereas the roughness of VE and EMP increased from the second session. All materials displayed topographic changes, which became more pronounced with the increase in the number of sessions. Although bleaching decreased the BFS of the materials, it did not adversely affect their reliability. Successive at-home bleaching sessions with the protocol used in the present study cannot be considered a safe procedure for the materials evaluated.

Comparison of various methods of restoring adhesion to recently bleached enamel.

AIM: This study compared the effectiveness of several techniques in restoring compromised bonding to recently bleached enamel. METHODS: Seventy-five healthy bovine incisors were divided into five groups (n = 15). Fifteen teeth (Group 1) remained intact, whereas 60 (Groups 2 to 5) underwent at-home bleaching with 16% carbamide peroxide. The bonding procedures were as follows: Group 1: Bonding of resin composite to unbleached enamel; Group 2: Bonding immediately after bleaching; Group 3: Application of a 10% sodium ascorbate solution for 10 min before bonding; Group 4: Enamel removal to the depth of 0.5 mm; and Group 5: Increased curing time of the bonding agent to 80 instead of 20 s. After 24 h, the specimens were subjected to micro-shear testing, and the failure mode was determined. RESULTS: ANOVA revealed a significant difference in bond strength among the groups (P < 0.001). The mean bond strength was significantly lower in group 2 than in other groups (P < 0.05), which showed comparable bond strength to each other (P > 0.05). Adhesive failure was the most predominant failure type in all groups. The mixed failure occurred with a frequency of 26.7% in groups 3 and 5. The Fisher's exact test revealed a significant difference in failure modes among the groups (P = 0.047). CONCLUSIONS: The three experimental procedures used in this study, including the application of 10% sodium ascorbate before bonding, enamel removal to the depth of 0.5 mm, and increasing the curing time of the bonding agent to 80 s, were effective in restoring the compromised bonding to recently bleached enamel.

Effect of hydrogen peroxide versus charcoal-based whitening mouthwashes on color, surface roughness, and color stability of enamel.

BACKGROUND: Patients tend to favor the whitening mouthwashes as they are easily applied and affordable. This study aimed to evaluate the effect of hydrogen peroxide versus charcoal-based whitening mouthwashes on color, surface roughness, and color stability of enamel. In the current study, the whitening mouthwashes used have the ability to stop future stains due to their white seal technology. METHODS: A total of 21 permanent central incisor teeth extracted for periodontal reasons were used in the present study. Teeth roots were sectioned and crowns were mounted in self-cured acrylic resin blocks. The specimens were randomly divided into three groups (n = 7) according to the tested whitening mouthwash: Control group ? DW" (Distilled water), ?OW" group: Peroxide-based mouthwash (Colgate Optic White) and ?CP" group: Charcoal-based mouthwash (Colgate® Plax Charcoal). Regarding ?OW" and ?CP" groups, the specimens were immersed in 20 ml of the tested mouthwash in each corresponding group for 1 min twice daily (morning and evening) for a total of 12 uninterrupted weeks. Color change was assessed using VITA Easyshade spectrophotometer and surface roughness (Ra) was measured using a white light interferometer. The specimens were stained using black tea solution and color was measured after 24 h of immersion for assessment of color stability. RESULTS: Color change results revealed that both whitening mouthwashes were able to restore color comparable to the control group with no significant difference between them. Regarding surface roughness, the control group showed the highest mean Ra value, followed by ?OW" group while ?CP" group showed the lowest mean Ra value. While color stability after staining, the control group showed a significantly higher value than the ?CP" and ?OW" groups. CONCLUSION: Hydrogen peroxide and charcoal-based whitening mouthwashes improve the color of enamel with no adverse effect on the surface roughness. Both whitening mouthwashes were beneficial to maintain the color after staining and prevent future enamel stains.

Impact of Carbonated Beverages on Color Stability and Home Bleaching Efficacy of BulkFill Composite Resins.

Purpose: The purpose of this study was to assess, in vitro, the color stability and bleaching response of three bulk-fill composite resins-Activa™, Tetric®-N-Ceram Bulk-Fill, and Filtek™ One Bulk-Fill???and one conventional composite resin, Filtek™ Z250, after immersion in commonly consumed carbonated beverages and subsequent home bleaching with 15 percent carbamide peroxide. Methods: Ninety-six samples (two- and four-mm thick) of the materials were immersed in malt drink, energy drink, cola, or distilled water for one day, one week, and two months. After two months, samples underwent home bleaching with 15 percent carbamide peroxide gel. Spectrophotometric analysis measured color and whiteness changes pre-immersion, post-immersion, and post-bleaching. Statistical significance was determined using factorial mixed analysis of variance (ANOVA), three-way ANOVA, and Bonferroni post hoc tests (P<0.05). Results: All tested composite resins exhibited unacceptable discoloration (color change greater than 3.3) after two months in carbonated beverages. Filtek™ One Bulk-Fill and Filtek™ Z250 displayed the most significant discoloration, particularly when immersed in the malt drink (P<0.05). In contrast, Activa™ samples reached unacceptable discoloration within just one week in malt and cola drinks. Home bleaching yielded limited whiteness recovery, with Activa™ presenting acceptable whiteness post-bleaching after staining with cola and energy drinks. Conclusions: This study highlights the aesthetic risks of prolonged carbonated beverage consumption and the limitations of the assessed home bleaching technique using 15 percent carbamide peroxide. Enhanced dental education on the dietary effects of some beverages on restorative materials is indicated by these findings.

Influence of using different toothpaste during bleaching with violet LED light (405 nm) on the colour and roughness of dental enamel: an in vitro study.

This in vitro study aimed to investigate potential changes in the color and roughness of dental enamel resulting from the use of different toothpaste formulations during bleaching with violet LED light (405 nm). Sixty specimens of bovine incisors, each measuring 6 × 6 × 3 mm, were segregated into six distinct experimental groups based on their respective treatments (n = 10): C + VL: Brushing with Colgate® Total 12 + bleaching with violet LED; LB + VL: Brushing with Colgate® Luminous White Brilliant + bleaching with violet LED; LI + VL: Brushing with Colgate® Luminous White Instant + violet LED bleaching; C: Brushing with Colgate® Total 12; LB: Brushing with Colgate® Luminous White Brilliant; LI: Brushing with Colgate® Luminous White Instant. The examined variables included alterations in color (∆L*, ∆a*, ∆b*, ∆Eab, and ∆E00), surface roughness (Ra), and scanning electron microscopy observations. No statistically significant distinctions emerged in total color variations (∆E00 and ∆E) among the groups under scrutiny. Notably, the groups that employed Colgate® Luminous White Instant displayed elevated roughness values, irrespective of their association with violet LED, as corroborated by scanning electron microscopy examinations. It can be concluded that whitening toothpastes associated to violet LED do not influence the color change of dental enamel in fifteen days of treatment. Toothpastes with a higher number of abrasive particles showed greater changes in enamel roughness, regardless of the use of violet LED.

Anatomical characteristics of different tooth groups. Effect on in-office bleaching treatment

AIM: The objective of the present study was to investigate the association between the anatomical characteristics of different tooth groups and the diffusion and bleaching effect of hydrogen peroxide (H2O2). MATERIALS AND METHODS: Computed tomography (CT) images from five patients were used to assess the hard tissue thickness and pulp volume (PV) of four tooth groups: lower (mandibular) incisors (LI), upper (maxillary) incisors (UI), canines (C), and premolars (PM). Additionally, 80 bovine tooth disks were divided into four groups (n = 20) to match the thickness of each tooth group studied. All the specimens were exposed to a 35% H2O2 bleaching gel, with 50 µL applied for 45 min during the first, second, and third sessions. Diffusion was evaluated using the peroxidase enzyme method. Color change analyses (∆E, ∆E00, and ∆WID) were performed after the three application sessions and 7 days after the bleaching treatment using a spectrophotometer. RESULTS: The PM group showed greater thickness and PV, followed by the C, UI, and LI groups (P 0.001). The LI group had six times greater H2O2 diffusion compared with the PM group (P 0.001), while the PM group exhibited a PV nine times larger than the LI group. Furthermore, the LI and UI groups achieved color saturation with one fewer session than the C and PM groups. CONCLUSIONS: Specific tooth groups have anatomical characteristics that interfere with bleaching treatment in terms of the diffusion and whitening effect of H2O2. Furthermore, the diffusion capacity of H2O2 was inversely proportional to the thickness of the tooth groups.

Enhanced tooth bleaching with a hydrogen peroxide/titanium dioxide gel.

BACKGROUND: This study aimed to explore the effects of the titanium dioxide (TiO2) concentration and particle size in hydrogen peroxide (HP) on tooth bleaching effectiveness and enamel surface properties. METHODS: TiO2 at different concentrations and particle sizes was incorporated into 40% HP gel to form an HP/TiO2 gel. The specimens were randomly divided into 8 groups: C1P20: HP + 1% TiO2 (20 nm); C3P20: HP + 3% TiO2 (20 nm); C5P20: HP + 5% TiO2 (20 nm); C1P100: HP + 1% TiO2 (100 nm); C3P100: HP + 3% TiO2 (100 nm); C5P100: HP + 5% TiO2 (100 nm); C0: HP with LED; and C0-woL: HP without LED. Bleaching was conducted over 2 sessions, each lasting 40 min with a 7-day interval. The color differences (ΔE00), whiteness index for dentistry (WID), surface microhardness, roughness, microstructure, and composition were assessed. RESULTS: The concentration and particle size of TiO2 significantly affected ΔE00 and ΔWID values, with the C1P100 group showing the greatest ΔE00 values and C1P100, C3P100, and C5P100 groups showing the greatest ΔWID values (p < 0.05). No significant changes were observed in surface microhardness, roughness, microstructure or composition (p > 0.05). CONCLUSIONS: Incorporating 1% TiO2 with a particle size of 100 nm into HP constitutes an effective bleaching strategy to achieve desirable outcomes.

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.

EFFECTS OF ACID ETCHING ON COLOR CHANGES AND SURFACE MORPHOLOGY OF ENAMEL TO BE BLEACHED WITH DIFFERENT TECHNIQUES.

Aims - to compare the color changes, the surface roughness and morphology of the enamel bleached with two different bleaching solutions (chemical and laser activated), preceded or not with acid etching. Thirty teeth of bovine prepared and haphazardly assigned to 2 groups (n=15) depending on bleaching technique. Each group subdivided to 3 subgroup (n=5) consistent with acid etching by 37% phosphoric acid. Atomic force microscopy and VITA easy shade spectrophotometer were performed twice for all the specimens before and after bleaching. ANOVA, the Paired sample t-test, and the independent sample t-test used for statistical analysis. As for the color changes, the groups that were bleached by the chemical method, the difference among the three subgroups was statistically significant. This also applies to the groups bleached with the laser method. When comparing the results of the chemical bleaching subgroups with the laser bleaching ones, the difference was not significant. Roughness results showed significant differences between certain subgroups and non-significant differences among others. However, the difference was statistically significant between the chemical and laser groups, laser technique resulted in less surface roughness than the chemical one. Acid etching before bleaching produced better colour change in both the chemical and laser assisted bleaching. In chemical bleaching, surface roughness was higher when acid etching was used. This was also true for laser bleaching technique. In general, laser assisted bleaching produced less surface roughness than chemical bleaching.

Effects of Different Concentrations of Carbamide Peroxide on Color, Surface Roughness, and Hardness of CAD/CAM Dental Ceramics.

OBJECTIVES: This study assessed the effects of 15% and 20% carbamide peroxide (CP) on color, surface roughness, and hardness of computer-aided design/computer-aided manufacturing (CAD/CAM) dental ceramics. MATERIALS AND METHODS: This in vitro study was conducted on 120 Vita Mark II, Celtra Duo, and Suprinity CAD/CAM ceramic specimens. The ceramic specimens in each group (n = 40) were randomly assigned to two subgroups (n = 20) for polishing and glazing, and their baseline color, surface roughness (Ra), and hardness were assessed. In each subgroup, half of the specimens were exposed to 15% CP, while the other half were exposed to 20% CP. Their color change (ΔE), surface roughness, and hardness were then measured again. Surface roughness, hardness, and color were analyzed sequentially by profilometer, Vickers hardness tester, and spectrophotometer, respectively. Data were analyzed by repeated measures ANOVA, one-way ANOVA, and post hoc Bonferroni test (α = 0.05). RESULTS: The surface roughness of all groups significantly increased after bleaching treatment (p < 0.05). Surface hardness of all groups decreased after bleaching treatment, but this reduction was only significant in Vita Mark II subgroups (glazed, polished, 15%, and 20% CP). The ΔE was not clinically and visually perceivable in any group. CONCLUSION: The present results revealed that concentration of CP and type of surface treatment affected the surface properties of CAD/CAM ceramics. Type of surface treatment only affected the surface hardness of Vita Mark II ceramics (p < 0.05). Concentration of CP had a significant effect only on polished Vita Mark II.