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Copyright of Revista Kiru is the property of Universidad de San Martin de Porres and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To evaluate how tluoride- or chitosan-based toothpaste used during at-home bleaching affects enamel roughness, tooth color, and staining susceptibility. Methods: Bovine enamel blocks were submitted to a 14-day cycling regime considering a factorial design (bleaching agent x toothpaste, 2 x 3), with n= 10: (1) bleaching with 16% carbamide peroxide (CP) or 6% hydrogen peroxide (HP), and (2) daily exposure of a fluoride (1,450 ppm F-NaF) toothpaste (FT). chitosan-based toothpaste (CBT), or distilled water (control). Then, 24 hours after the last day of bleaching procedure the samples were exposed to a coffee solution. Color (AE.,b, AEoo, L: a*, b*) and roughness (Ra, kim) analyses were performed to compare the samples initially (baseline), after bleaching, and after coffee staining. The results were evaluated by linear models for repeated measures (L: a: b: and Ra), 2-way ANOVA (AE.,b and AEoo) and Tukey's test (a= 0.05). Results: After the at-home bleaching procedure (toothpaste vs. time, P< 0.0001), the toothpaste groups presented a statistically lower Ra than the control (CBT 0.05). After coffee exposure, CBT presented lower AEat, and AEoo values in the H P groups (toothpaste, P< 0.0001), and lower b* and a* values in the CP groups (toothpaste vs. time, P= 0 .004). [ABSTRACT FROM AUTHOR]

This study aimed to compare changes in oral health-related quality of life (OHRQoL) resulting from three vital tooth bleaching protocols. The participants (n = 105) were randomly assigned to one of three vital bleaching treatment groups: home bleaching (HB), in-office bleaching (IOB), or combined bleaching (CB). HB involved the use of custom-made trays and 10% carbamide peroxide for a 14-day treatment period. IOB utilized 37.5% hydrogen peroxide applied in three cycles. CB treatment involved the use of IOB followed by HB. Tooth colour change was evaluated using a shade guide (ΔVS) and a digital spectrophotometry device (ΔES). The Oral Health Impact Profile-14 (OHIP-14) and Oral Impact on Daily Performance-22 (OIDP-22) instruments were used to assess changes in OHRQoL at baseline, 15-days and 6-month recalls. Linear mixed models were used to estimate between- and within-group differences. All bleaching protocols led to significant improvements in overall OHIP-14 scores at the 6-month recall (p ≤ 0.037). CB and IOB treatments were associated with more substantial positive impacts on overall scores, psychological discomfort, physical disability (CB only), and psychological disability (CB only) compared to HB (p ≤ 0.011). Significant enhancements in OIDP-22 scores were observed in the CB and HB groups at the 6-month recall compared to baseline (p ≤ 0.006), with evidence indicating that these improvements were greater in the CB group compared to the IOB group (p = 0.007). All bleaching treatments demonstrated a positive impact on OHRQoL. However, the positive impact was most consistent across domains and age groups in the CB group. The positive impact was less pronounced in older age groups. [ABSTRACT FROM AUTHOR]

Copyright of Revista Kiru is the property of Universidad de San Martin de Porres and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Stomatologica Croatica is the property of Acta Stomatologica Croatica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article focuses on Coltene's Brilliant Lumina product, designed to provide a comfortable and effective teeth-brightening treatment without causing tooth sensitivity.

Purpose: To evaluate the influence of diet and exposure to red wine on the treatment velocity, clinical results, postoperative tooth sensitivity, and patient satisfaction after tooth bleaching. Methods: 45 subjects undergoing home bleaching with 16% carbamide peroxide (CP) were randomly separated into three groups, depending on the restriction of colored food and the use of a red wine mouthwash. Shades of teeth I I and 21 were assessed using a digital spectrophotometer (VITA Easy Shade) at TO (before treatment). T7 (7 days after treatment), TI 5 (15 days after treatment), and T30 (30 days after treatment). The assessments were verified using the CIELab system (values of L*. a*, and b*) and the change in shade was calculated (AE, AL, Aa, and Ab). Results: No statistically significant differences in AE, AL, Aa, and Ab were found between the groups. However, at TA the group restricted from colored foods without red wine mouthwash had meaningful variations in L*, a*, and b*. Statistically, there was no difference in tooth sensitivity between the groups in the 7- and 15-day periods. Patients in the restricted colored foods without red wine mouthwash group were more satisfied after the end of treatment. [ABSTRACT FROM AUTHOR]

The aim of this in vitro study was to evaluate the effect of high-concentration hydrogen peroxide (HP) and carbamide peroxide (CP) bleaching solutions on the dentin-resin interface and the shear bond strength (SBS) of restorative materials. A total of 56 extracted human premolars were prepared with flat dentin windows and divided into groups according to the bleaching protocol: group A, bleached with 35% HP (n = 24); group B, bleached with 35% CP (n = 24); and group C, control, no bleaching (n = 8). Groups A and B were each divided into 3 subgroups according to the time of bonding: A0 or B0, bonded immediately after bleaching (n = 8); A1 or B1, bonded 1 week after bleaching (n = 8); and A2 or B2, bonded 2 weeks after bleaching (n = 8). The specimens in group C were bonded without prior bleaching. Scanning electron microscopic analysis was conducted to evaluate the length of the resin tags at the dentin-resin interface. For SBS testing, the specimens were loaded into a universal testing machine at a crosshead speed of 0.5 mm/min. The mean resin tag lengths of groups that were bonded immediately (A0 and B0) or after a 1-week delay (A1 and B1) were significantly shorter than that of group C (P < 0.001; Kruskal-Wallis test), but the differences between the 2-week delayed bonding groups (A2 and B2) and group C were not statistically significant. The SBS values of both the 35% HP and 35% CP groups increased significantly with delayed bonding time (P < 0.05; 1-way analysis of variance). When bonding was delayed until 2 weeks after bleaching, the mean SBSs of the bleaching and control groups were not significantly different (P > 0.05; Tukey test). [ABSTRACT FROM AUTHOR]

To assess the effect of 10% carbamide peroxide (CP) and 6% hydrogen peroxide (HP) home bleaching agents on the translucency and color of monolithic zirconia. Ninety disc specimens were fabricated (diameter, 10 mm) from multi-layered (ML), ultra translucent multi-layered (UTML), and super translucent multi-layered (STML) zirconia blocks at three thicknesses (0.4,1,1.5 mm) (n=5). The samples were divided into two subgroups, which were treated with 6% HP (45 min per day) or 10% CP (8 h per day) for 14 days. The color of specimens was measured before bleaching (T0) and after bleaching on the third (T3), seventh (T7), and 14th (T14) day. Color (ΔE) and translucency (TP) changes were calculated. The thickness varieties used in the samples and the bleaching agent types used created statistically significant differences only in TP and ΔE00, respectively (p<0.05). Bleaching agents can affect TP and ΔE. Patients who have zirconia restorations should be careful when using home bleaching agents. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the degree of stain absorption of resin composite following different finishing and polishing protocols and to evaluate the efficacy of prophylaxis paste with or without addition of carbamide peroxide to remove composite surface stain. Methods: 50 resin composite blocks were prepared using nano-hybrid composite (Filtek Z250XT) and giomer (Beautifil 11 LS). Specimens were either polished with a disk or coated with 5tli~7th generation bonding or glycerin gel. The color parameters (lightness, chroma and hue) of the specimens were measured prior to staining, and after 1 and 2 weeks of staining using a color chromometer. The composite surface stain removal capability of prophylaxis pastes with or without the addition of carbamide peroxide was evaluated before and after polishing. Results: The repeated measures ANOVA showed that composite polished with a polishing disk or coated with glycerin gel have better color stability compared to composite without any polishing or coated with 58 or 76 generation bonding materials. The prophylaxis paste was able to remove composite surface stain; however, the addition of carbamide peroxide did not show any additional benefit. The results suggested that polishing with polishing disks or coating with glycerin gel is useful for the color stability ofresin composite. [ABSTRACT FROM AUTHOR]

Copyright of Acta Stomatologica Croatica is the property of Acta Stomatologica Croatica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to analyze and compare the efficacy of different bleaching agents typically used for internal bleaching of endodontically treated discolored teeth. Electronic databases (PubMed, Web of Science, and Cochrane Library) were searched by 2 reviewers for clinical trials in which the color of endodontically treated discolored teeth before and after internal bleaching was examined using shade guide units (ΔSGU) or a spectrophotometer/colorimeter (ΔE). The efficacies of the bleaching agents were compared using subgroup analyses. Statistical heterogeneity was assessed with the Cochran Q test and I 2 statistic. Publication bias was evaluated using funnel plots. Eight studies were included in the systematic review, 6 of which could be included in the meta-analyses. Internal bleaching led to a significant change in tooth shade (ΔSGU: 6.27 [95% confidence interval, 5.36–7.17], ΔE: 12.83 [95% confidence interval, 9.46–16.20]). With regard to ΔSGU, the use of carbamide peroxide (35% or 37%), hydrogen peroxide (35%), and the combination of sodium perborate and hydrogen peroxide (3% or 30%) led to a better bleaching effect than sodium perborate (adjusted P value ≤.026). Regarding ΔE, there were no significant differences between carbamide peroxide (37%), hydrogen peroxide (35%), and sodium perborate mixed with hydrogen peroxide (P =.051). The risk of bias of the included studies was classified as moderate to high. Carbamide peroxide, hydrogen peroxide, and sodium perborate have a significant bleaching effect on discolored, root canal–treated teeth. For a valid assessment of shade stability and a comparison of bleaching agents and their concentrations, further studies with long-term recalls are necessary. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare color changes, surface roughness and gloss of a microhybrid and nanohybrid composite whitened in a simulated in-office or at-home procedure using 40% hydrogen peroxide or 16% carbamide peroxide, respectively. CIELab coordinates were measured before, during and after treatment using VITA EasyShade V (VITA) and ΔE00 calculated. Surface roughness was measured using a surface roughness tester (SJ210; Mitutoyo). Gloss was measured using a gloss checker (IG-331; Horiba). At-home whitening resulted in ΔE00 of 1.23±0.49 (microhybrid) and 1.01±0.76 (nanohybrid). In-office exposure resulted in ΔE00 of 0.69±0.38 (microhybrid) and 0.72±0.50 (nanohybrid). There were no significant differences in ΔE00, surface roughness and gloss between whitening protocols (p>0.05). Color changes of a microhybrid and nanohybrid composite following simulated in-office or at-home whitening reached CIEDE2000 50:50% perceptibility but not acceptability threshold. Surface roughness and gloss of the microhybrid and nanohybrid composite were not affected by whitening. [ABSTRACT FROM AUTHOR]

Copyright of Acta Stomatologica Croatica is the property of Acta Stomatologica Croatica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: The aim of this study was to determine whether carbamide peroxide is effective in bleaching vital permanent teeth in children. Methods: A literature search was conducted using all keywords relevant to the research subject. The outcome measures were identified as colour change, tooth sensitivity, oral irritation and patient satisfaction. The certainty of evidence for each outcome was assessed using the current GRADE guidelines. Results: Of 115 potentially relevant articles, 112 were excluded, as they did not exclusively involve children, intervention involved additional treatment such as microabrasion or restorative work, or case studies. Patient satisfaction was not assessed in the three articles so no analysis could be made with regards to this outcome. The GRADE assessment showed that all of the three articles demonstrated very low certainty of evidence for the other assessed outcomes. The overall findings from the studies suggest that a 10% carbamide peroxide overnight tray system is effective at bleaching vital permanent teeth in children and associated tooth sensitivity and oral irritation are found to be in a similar range compared to those reported in adult studies. However, due to the very low certainty of the evidence, it is not possible to draw these conclusions. Conclusion: Better quality randomised controlled trials are needed to investigate the indication, short and long term effectiveness and side effects of carbamide teeth in vital permanent teeth in children. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to assess two groups: the effectiveness, the six month colour stability and the patient's sensibility. Materials and method: 50 patients from the Dental Hygiene Department, Department of Diagnostic and Pediatric Surgical Clinical Sciences of the University of Pavia were selected. The CONTROL group was treated using carbamide peroxide 16% activated by Blancone Arch light. The TEST group was treated using a combination of in office treatment and a 14 days' at home treatment using: Blancone® Duetto: bi-phasic at-home bleaching system to be used instead of the normal toothpaste. This is divided into ACTIVE, to be used in the morning and CARE to be used in the evening. Blancone® Stick: at home whitening pen to be used once a day, in the evening before going to bed and after having brushed teeth using Blancone® Duetto CARE. Before starting the treatment, all patients, were given an informed consent and a preliminary screening questionnaire regarding the home oral hygiene habits, the foodstuffs' habits, the bad habits and the reason why they want to undergo a professional treatment. During the first session we filled in the medical records, registered personal data, filled in the dental and periodontal charting, explained the treatment and instructed the patients regarding a correct oral hygiene. During the second session we performed the following: professional oral hygiene without using prophylaxis pastes, Vita classical shade guide detection via spectrophotometer, sensibility detection via Schiff Air Index and VAS, initial frontal photograph, 3 cycles of 8 minutes in office bleaching with Blancone Touch+, Final Vita classical shade guide detection via spectrophotometer, final frontal photograph and sensibility detection. After this we performed a 30, 60, 90 and 180 days' examination using Vita classical shade guide detection to evaluate the relapse, evaluated the sensibility and took the frontal photographs. Results: at T1 both groups present a significant increase, that means having a strong white shade that goes from 0 to 5 shade in both groups. At T2 there can be seen significant loss in the white shade in both groups and some differences between the T2 groups and the other times without being statistically significant. As regarding the sensibility, it was discovered that the sampling was not homogeneous. During the treatment no patient felt irritation regarding the application of the whitening agent and the photoactivated light. Both groups had a sensibility increase at T1 that diminished after the subsequent examination. Conclusion: From our test it is clear that Blancone Touch+ has, in the majority of cases, an immediate effectiveness (from T0 to T1) that decreases to T1 to T2 and remains constant from T2 to T5; therefore it presents an effectiveness that is not constant in time. On the other hand using carbamide peroxide has reduced the risk and the level of tooth sensibility to figures close to zero. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy, longevity, and bleaching sensitivity of in-office bleaching with 37% carbamide (CP) and 35% hydrogen peroxides (HP). Methods: 45 volunteers were enrolled in this randomized, double blind, controlled, split-mouth clinical trial with a 6-month follow-up. Left and right hemiarches were randomly selected to receive CP or HP in-office bleaching. Three 40-minute applications of both bleaching agents were performed once a week at the same time. Tooth shade and bleaching sensitivity were recorded before and after bleaching sessions, 1 to 7 days after bleaching sessions and up to 6 months after the last bleaching session using, respectively, a shade guide and Visual Analogue Scale (VAS). Color change, global immediate sensitivity - GIS (sum of sensitivity levels reported during three bleaching sessions), trans- and post-bleaching sensitivity were obtained and analyzed using paired Student t-test and twoway ANOVA/Tukey post-hoc tests (P< 0.05). Results: HP had statistically higher global immediate sensitivity than CP. CP showed statistically lower sensitivity levels during bleaching sessions and in two subsequent days than HP. CP and HP provided statistically similar tooth shade at the end of the last bleaching session and 3 and 6 months after the last bleaching session. [ABSTRACT FROM AUTHOR]

The ultrastructural and mechanical properties of enamel surface were evaluated after prolonged bleaching treatments with 10% carbamide peroxide in the presence or absence of orange juice (erosive challenge) and toothbrushing (abrasive challenge). In total, 145 incisor bovine teeth were used in this study. Twenty-five samples were prepared for the ultrastructural evaluations, and 120 samples were prepared for microhardness and roughness tests. These 120 samples were divided into eight experimental groups (n = 15): G1- artificial saliva; G2- abrasion; G3- erosion; G4- dental bleaching; G5- erosion + abrasion; G6- bleaching + abrasion; G7- bleaching + erosion; and G8- bleaching + erosion + abrasion. All groups were tested at T0 (before treatment), T1 (14 days), T2 (21 days), and T3 (28 days). Two-way analysis of variance for repeated measures and the post hoc Sidak tests (p = 0.05) were used. The roughness evaluation demonstrated an increase in damage for all experimental groups with an increase in the time period. For microhardness, the groups exposed to artificial saliva (AS) and abrasive challenge did not show any differences at any time points, while the other groups showed a decrease in microhardness from T0 to T3. Ultrastructural evaluation showed different surface alterations in response to the treatments. Despite prolonged bleaching periods, the procedure caused lesser enamel surface alterations than exposure to orange juice alone or in combination with brushing. [ABSTRACT FROM AUTHOR]

Copyright of RGO: Revista Gaúcha de Odontologia is the property of RGO: Revista Gaucha de Odontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: The present study aimed to investigate if the Guatemalan dentist's options on tooth bleaching could be influenced by their time in clinical practice, the level of specialization or their working place. Methods: A representative sample of dentists working in clinical practice in Guatemala was selected. Data were collected using a self-administered questionnaire with information related to gender, professional characteristics (time since graduation in years and working place) and preferences regarding vital (at-home or in-office; type and concentration of bleaching agent) and the nonvital tooth bleaching (bleaching agent used). The analysis was performed and the association between preference for bleaching technique and independent variables were investigated using Fisher's exact test. Results: 200 dentists were interviewed. More than half of dentists were male (57.0%) with time since graduation between 11 and 20 years (n= 64; 32.3%). Dentists mostly (60.5%) preferred in-office technique for vital bleaching, with 10-20% Carbamide peroxide (CP) as the preferred agent (50%). For nonvital teeth, the preferred agent (46.8%) was 37% Hydrogen Peroxide (HP). About the associations, younger dentists (< 20 years of graduation) selected mostly in-office technique, while those with more than 20 years indicated more the at-home technique. Also, the dentists working in private practice chose more frequently in-office technique. Thus, the in-office technique was more popular among Guatemalan dentists, with 10-20% CP and 37% HP selected as favorite bleaching agents for vital and nonvital techniques, respectively. Conclusion: The time of clinical practice and working place influenced some choices. [ABSTRACT FROM AUTHOR]

Aim: Understand EAPD members' practices of vital bleaching for children with dental anomalies. Methods: An anonymous online survey sent via EAPD in January 2019, consisting of 13 questions with possible multiple answers and free text. Results: 110 responses from 24 countries were obtained. The majority worked in hospitals/universities (n = 69, 63%) or private practices (n = 50, 46%) and were specialists (n = 62, 57%) or senior academics (n = 35, 32%). Most respondents (n = 74 68%) did not provide vital bleaching for children. 88 respondents (80%) belonged to EU: of these, 46 (52%) were not aware of bleaching regulations. For respondents who provided bleaching 26 (72%) undertook home bleaching, using 10% carbamide peroxide (n = 21, 58%), most commonly for 2 weeks (n = 14, 39%), following establishment of the permanent dentition (n = 21, 58%). Deciding factors included: extent (n = 27, 75%) and shade (n = 26, 72%) of discolouration and child being teased by peers (n = 23, 64%). Main reasons for not bleaching included: concerns with side effects (n = 41; 55%) and not agreeing with bleaching (n = 23, 31%). Dentists who did not bleach managed a range of conditions, most frequently molar-incisor hypomineralisation (n = 57; 77%). The majority provided composite restorations with removal of tooth structure (n = 50; 68%) with a number opting for no treatment (n = 27, 37%). Conclusion: This study shows wide variations in treatment of children's dental anomalies across Europe. Fears of adverse effects and personal beliefs seemed to be the main deterrents to bleaching in children. Clinicians who provided bleaching tended to opt for more conservative techniques and to take children's concerns into consideration. [ABSTRACT FROM AUTHOR]

• An O – g – C 3 N 4 /H – ZSM-5 composite was synthesized by green synthesis using natural perlite and urea. • The photocatalytic activity was investigated via the degradation of RR 195 under solar light without using H 2 O 2. • The oxygen doping into g – C 3 N 4 improved the photocatalytic activity. A novel oxygen-doped graphitic carbon nitride and zeolite (H - ZSM-5) composite (O – g – C 3 N 4 /H - ZSM-5) was synthesized using hydrogen peroxide and urea as the oxygen and g – C 3 N 4 precursors, respectively, and perlite as the zeolite source, via calcination at 550°C. BET N 2 adsorption - desorption analysis verified that the 40%O – g – C 3 N 4 /H - ZSM-5 composite had a high surface area of 259.13 m2/g with mesopores and micropores, and X-ray photoelectron spectroscopy (XPS) confirmed the existence of the O atom in the g – C 3 N 4 framework. The obtained O – g – C 3 N 4 /H - ZSM-5 catalyst showed excellent photocatalytic performance for the photodegradation of RR 195, approximately 96.6% with a high rate constant of 0.1167min−1 under solar light irradiation without the use of H 2 O 2. It also exhibited remarkable stability and long-term recyclability, with the photodegradation efficiency of RR 195 above 91%. In conclusion, the O – g – C 3 N 4 /H - ZSM-5 composite photocatalyst is suitable for numerous applications in the field of the photocatalytic degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Copyright of RGO: Revista Gaúcha de Odontologia is the property of RGO: Revista Gaucha de Odontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To determine the effect of 16% carbamide peroxide on the shear bond strength of metal brackets bonded to premolars either immediately or 30 days after bleaching and to evaluate the bondfailure sites. Material and Method: Sixty freshly extracted human premolars were randomly divided into three groups, each containing 20 teeth. Specimens in group A (control) were not bleached (etched only with 37% phosphoric acid) before bonding. The teeth in the other two groups were first bleached with 16% carbamide peroxide according to the manufacturer's recommendation. The teeth in group B were bonded immediately, while the teeth in group C were stored in artificial saliva for 30 days prior to bonding. Shear bond strength was measured and recorded in MPa. Adhesive remnant index (ARI) scores were determined after the brackets failed. Data were analyzed with analysis of variance (ANOVA) and the chi-square test. Results: Group A showed higher shear bond strength values than groups B and C, but the differences among the three groups were not significant (P = .053). Moreover, no significant differences in ARI were found. Conclusion: After bleaching with 16% carbamide peroxide, there is a slight, insignificant decrease in shear bond strength. The site of bond failure is not significantly affected by bleaching. [ABSTRACT FROM AUTHOR]

• Hybrid light associated with carbamide peroxide potentiates bleaching effectiveness. • Hybrid light applied to carbamide peroxide with TiO 2 potentiated dental bleaching. • Carbamide peroxide with TiO 2 did not potentiate color change in the absence of light. The effectiveness of dental color change was assessed by incorporating titanium dioxide (TiO 2) into 37% carbamide peroxide bleaching agent associated with hybrid light. Fifty bovine incisors were selected to receive the bleaching treatment, and separated into five groups (n = 10): 35% hydrogen peroxide (HP) (Whiteness HP, FGM/HP); 37% carbamide peroxide (CP) (Whiteness SuperEndo, FGM/CP); CP + hybrid light (HL) (CP HL); CP + 1% TiO 2 (CP TiO 2); CP TiO 2 + hybrid light (CP TiO 2 HL). The bleaching gels were applied to the dental surface for 30 min. Hybrid light (Whitening Plus, DMC/infrared laser diodes + blue LEDs +violet LEDs) was applied with 1 min of active light, alternating with 1 min of pause. A spectrophotometer (VITA Easyshade® Advance, Vita) was used to determine the color of the dental elements at baseline and time points after the 1st, 2nd and 3rd bleaching sessions. Color change effectiveness was evaluated using Vita Classical, CIEL*a*b*, WI D and ΔE ab , ΔE 00 and ΔWI D parameters. Generalized mixed linear models for repeated measures (α = 5%) showed significant decrease in Vita Classical scores and a* and b* values, as well as an increase in L* and ∆W ID values for all the groups. Higher color change values for ΔE ab were observed for CP HL and CP TiO 2 HL, while those of ΔE 00 and ΔWI D were higher for CP TiO 2 HL at the end of the bleaching treatment. Hybrid light applied with TiO 2 incorporated into CP potentiated the effectiveness of the color change in the tooth structure. [ABSTRACT FROM AUTHOR]

• Lighter teeth benefit from the use of 35% hydrogen peroxide or 37% carbamide only. • Changing the color of darker teeth is potentiated with violet LED light. • Violet LED used alone did not present acceptability bleaching effect. The effectiveness of in-office bleaching protocols performed with violet LED light either combined with a bleaching agent containing 37% carbamide peroxide, or not, was determined by comparing teeth with different degrees of darkening. Eighty bovine incisors were separated into groups of "light" teeth (luminosity greater than or equal to B3) and "dark" teeth (less than or equal to A3.5) to receive the protocols: HP - 35% hydrogen peroxide (Whiteness HP), CP - 37% carbamide peroxide (Whiteness SuperEndo), LED - violet LED light (Bright Max Whitening), CPLED - CP associated with the LED. For color analysis the CIEL*a*b* e WI D , ΔE ab , ΔE 00 e ΔWI D parameters were used. Data were analyzed using Mann-Whitney, Kruskal-Wallis, Dunn, Friedman or Nemenyi tests (α = 5%). HP and CP resulted in similar color change values (ΔE ab , ΔE 00 e ΔWI D) for light and dark teeth (p > 0.05). Dark teeth showed better bleaching effectiveness (ΔE ab , ΔE 00 e ΔWI D) than light teeth when CPLED was used (p < 0.05). LED showed color change that were below the limits of acceptability and perceptibility for ΔWI D. light teeth are effectively bleached with the use of HP or CP, whereas dark teeth respond better to treatment with the CPLED protocol. Violet LED used alone did not show a satisfactory result. [ABSTRACT FROM AUTHOR]

To effectively control the escape of odorous chemicals like trichloroethylene (TCE) in soil remediation sites, a novel technology for iron-loaded bentonite activated urea peroxide (FBT/UHP) was developed in this study. This was significantly higher than the 51.40% removal in the untreated bentonite and UHP (BT/UHP) system. The stability test revealed that FBT remained stable after five uses. The hydroxyl radical was primarily responsible for the degradation process, accounting for almost 82.74% of total TCE removal. Intermediate identification and theoretical calculations further analyzed the possible degradation pathways of TCE. Intermediate identification combined with theoretical calculation further analyzed the potential degradation pathways of TCE. According to experimental results, the FBT/UHP system decreased the TCE cumulative relative escape rate by almost 91.90%. In summary, the FBT/UHP system shows promising potential for controlling TCE and other odour leakages during soil remediation at pesticide sites. • An odor control technology involving FBT activated UHP has been developed. • Hydroxyl radical was the main reason for the degradation of TCE by FBT/UHP system, accounting for 82.74% of the total of TCE removal. • The possible degradation pathways of TCE were proposed. • The FBT/UHP system demonstrates remarkable effectiveness in real field applications, greatly reducing TCE soil-air emissions. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of aging on the microtensile bond strength (uTBS) between composite resin and human dentin bleached with 35% hydrogen peroxide (HP) or 10% carbamide peroxide (CP). Thirty intact extracted third molars were selected for the study. After the dentin surface was exposed, the smear layer was abraded with silicon carbide paper to ensure standardization. The teeth were randomly divided into 3 groups: 1 (G1), no treatment (control); 2 (G2), dentin bleached with CP (at-home bleaching); and 3 (G3), dentin bleached with HP (in-office bleaching). G2 and G3 were bleached according to the manufacturers' instructions and stored in distilled water for 21 days. The teeth in all 3 groups were then bonded with a dental bonding agent and nanohybrid composite resin. Each tooth was sectioned and divided into groups to allow evaluations at 3 time periods: 24 hours, 6 months, and 12 months. The specimens were stored in distilled water at 37°C ± 1°C until use. The µTBS of the specimens was tested on a universal testing machine. Fracture mode analysis was performed with a stereoscopic loupe. The data were analyzed statistically by 2-way analyses of variance and Tukey tests. After 24 hours, G3 had a significantly lower mean [SD] µTBS value (20.00 [5.67] MPa) than G1 (31.14 [8.83] MPa), but their means were statistically similar at 6 months (29.42 [7.72] MPa vs 22.97 [7.48] MPa, respectively). Tukey tests revealed that there was no statistically significant change in µTBS over time for G2 or G3. After 12 months of aging, only G1 specimens showed statistically lower pTBS values compared with the 24-hour time period (P < 0.05). Based on the results, the durability of the bond between composite resin and dentin is not affected by the choice of bleaching treatment. [ABSTRACT FROM AUTHOR]

Glyphosate is one of the most widely used pesticides globally. However, glyphosate and its residual metabolite, aminomethyl phosphonic acid (AMPA), are persistent and mobile chemicals. Large amounts of glyphosate residue can accumulate in the environment, causing adverse effects in organisms. Urea hydrogen peroxide (UHP) in soil slow-release H 2 O 2 undergoes a Fenton-like reaction with Fe2+, and the resulting hydroxyl radical (·OH) degrades glyphosate. This experiment investigated the effects of three fertilisers (UHP, ferrous sulphate, and urea) on the degradation of glyphosate in agricultural soils and their effects on soil ammonia nitrogen effectiveness and enzyme activity. Among all treatments, the half-life of glyphosate in the mixed application of UHP and ferrous sulphate was the shortest (11.9 d), and its degradation rate was the highest (70.64%), degrading within 28 d. Throughout the experimental cycle, in 1–7 d, the application of UHP reduced the effect on indigenous microorganisms and maintained nitrogen availability and enzyme activity in the soil; in 7–14 d, the mixed application of UHP and ferrous sulphate alleviated the nitrification of soil nitrogen and reduced the loss of ammonia from the soil; in 14–28 d, the mixed or single application of UHP and ferrous sulphate and the low dose of glyphosate remaining in the soil had a catalytic effect on enzyme activity, promoting the secretion of catalase and nitratase, which participate in soil glyphosate degradation and nitrogen cycling. Therefore, this study provides a scientific basis for the in-situ remediation of herbicide-contaminated soil in agricultural fields using chemical fertilisers. [Display omitted] • Potential role of urea hydrogen peroxide in degradation of glyphosate in soil. • A method for in-situ remediation of glyphosate contaminated soil. • Urea hydrogen peroxide slowly releases H 2 O 2 and produces Fenton-like reaction with Fe2+. • Glyphosate degradation affects soil nitrogen and enzyme activity. • Urea hydrogen peroxide can increase the content of ammonium nitrogen in soil. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the bleaching efficacy and time required for color stability immediately after dental office bleaching. Methods: 40 subjects were randomly divided into two groups, according to the bleaching agent used: GHP - 35% hydrogen peroxide gel and GCP - 37% carbamide peroxide gel. The color was measured with a spectrophotometer before and immediately, 24 hours, 72 hours, 7 days and 15 days after the bleaching procedure. The color parameters were evaluated and the ΔE*, ΔL*, Δa* and Δb* values were calculated for each evaluation period. The data was statistically analyzed with Student's T-test, one-way ANOVA and Tukey's post hoc test (P ≤ 0.05). Results: Regarding the ΔE* values, in the assessed periods there were no significant differences between groups (P≥ 0.05). However, the luminosity (ΔL*) decreased considerably in both groups in the first 72 hours (P≤ 0.05), followed by an increase at 15 days (P≤ 0.05) in the hydrogen peroxide group. Regarding the Δb* values, the GHP showed higher negative alterations in the b* axis in the first 24 hours. The 37% carbamide peroxide gel and the 35% hydrogen peroxide gel were effective and there was no reversal of tooth color within 15 days; however a more accentuated bleaching effect was observed immediately after bleaching. [ABSTRACT FROM AUTHOR]

Highlights • Process model is developed for interactions of consistency of pulp, temperature and dosage of carbamide peroxide on Kappa number. • Spectral analysis of pulp bleaching with carbamide peroxide is done using FTIR, XRD and FT-Raman spectroscopy. Abstract The study focuses on delignification of Kraft pulp using carbamide peroxide as bleaching agent. The Kappa number reduction of bleached pulp is favored at low consistency of pulp and higher reaction temperature. The optimal Kappa reduction was achieved at temperature of 68 °C, 0.8 g of carbamide peroxide per 100 ml of solution and 2% consistency in the range of variables studied. Fourier transform infrared spectral analysis done on bleached pulp to determine bond stretches and bending vibrations. X ray diffraction spectral data observation provided that the crystallinity index increased from 81.7% before bleaching to 85% after bleaching which indicates the removal of amorphous species in sample. FT-RAMAN spectral analysis concludes the possible conformational changes pre and post bleaching. The absence of some native lignin bands post bleaching indicates lignin removal. Scanning electron microscope images of bleached pulp samples were observed with less amounts of fibrillar type lignin network on surface of pulp fibers when compared to unbleached samples. The activation energy and rate constants were determined for delignification of pulp using carbamide peroxide process. Sequential treatment of Kraft pulp with carbamide peroxide and sodium percarbonate were also evaluated. [ABSTRACT FROM AUTHOR]

Objective: To perform a systematic review to answer the following research question: Is athome bleaching in adults with more concentrated carbamide peroxide (CP) gels as effective and safe as bleaching performed with 10% carbamide peroxide gels? Methods and Materials: A comprehensive search was carried out in the MEDLINE via PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and SIGLE, without restrictions. IADR abstracts (1990 to 2016) and unpublished and ongoing trial registries, dissertations and theses (ProQuest Dissertations and Periodicos Capes Theses Databases) were also searched. The risk of bias of the included studies was analyzed using the Cochrane Risk of Bias tool from the Cochrane Collaboration. We meta-analyzed the data using the random effects model to compare 10% CP and more concentrated CP gels in terms of color change (ΔSGU or ΔE) and risk and intensity of tooth sensitivity (TS). The quality of the evidence was rated using the GRADE approach. Results: After the database screening, 182 articles remained, and this number was reduced to 17 after examination of the abstracts and/or full texts. Four articles were follow-ups of earlier studies, and thus we collected 13 studies. Ten studies were at unclear risk of bias, while three were at low risk of bias. Lower risk and intensity of TS was observed for 10% CP. The odds ratio for the risk of TS was 0.41 (95% CI 0.20 to 0.84, p=0.01), and the difference in means for TS intensity was 0.44 (95% CI 0.67 to -0.20, p=0.0003). No significant difference was observed in terms of color change in DSGU (difference in means 0.29; 95% CI 0.25 to 0.83, p=0.29) and for ΔE (difference in means -0.16; 95% CI 0.38 to 0.06, p=0.16). Except from the ΔSGU, for which the evidence was graded as low quality, the other outcomes were considered at moderate quality. Conclusions: At-home bleaching with 10% CP showed similar bleaching efficacy with lower risk and intensity of TS in comparison with more concentrated carbamide peroxide gels. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Clinical Dentistry & Research is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background The effects of HP-based products upon dental enamel and dentin are inconclusive. Aim To evaluate changes in micromorphology and composition of calcium (Ca) and phosphate (P) in enamel and dentin after the application of 37.5% hydrogen peroxide (HP) and 35% carbamide peroxide (CP) Methods Crowns of 20 human teeth were divided in two halves. One half was used as control specimen and the other as experimental specimen. The control specimens were kept in artificial saliva, and the experimental specimens were divided into four groups (n = 5 each): group 1 (enamel HP for 45 min); group 2 (dentin HP for 45 min); group 3 (enamel CP for 90 min); and group 4 (dentin CP for 90 min). The morphological changes were evaluated using confocal laser scanning microscopy (CLSM), while the changes in the composition of Ca and P were assessed using environmental scanning electron microscopy combined with a microanalysis system (ESEM + EDX). The results within each group and between groups were compared using the Wilcoxon test and Mann–Whitney U-test, respectively (p < 0.05). Results Similar morphological changes in the enamel and no changes in dentin were assessed with both products. Ca and P decreased in enamel and dentin, without significant differences between them or with respect to their control specimens (p > 0.05). Conclusions When bleaching products with a neutral pH are used in clinical practice, both, the concentration and the application time should be taken into account in order to avoid possible structural and mineral changes in enamel and dentin. [ABSTRACT FROM AUTHOR]

Copyright of RGO: Revista Gaúcha de Odontologia is the property of RGO: Revista Gaucha de Odontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To compare the effect of simulated bleaching with a 10% carbamide peroxide (CP) or a 40% hydrogen peroxide (HP) system on surface roughness of resin composite and resin-modified glass ionomer cement (RMGI) and streptococcal biofilm formation on these surfaces. Methods and Materials: Specimens of nanofilled resin composite and RMGI (n=108 each) were randomly divided into three groups (n=36 each): no treatment control, 10% CP, and 40% HP. The surface roughness values (Ra) were measured before and after treatments. The specimens in each group were randomly divided into three subgroups (n=12) and incubated with Streptococcus mutans, Streptococcus sanguinis, and trypticase soy broth control for 24 hours. Biofilm formation was quantified by crystal violet staining, and the structure was visualized by scanning electron microscopy. The differences between the mean changes in Ra between the 10% CP and 40% HP groups of each material were evaluated with an independent t-test. The quantity of biofilm formation on each material was analyzed with one-way analysis of variance with the post hoc Tukey test (α=0.05). Results: Surface roughness significantly increased after bleaching in all groups. There was no significant difference between the 10% CP and 40% HP groups of each material. For S. mutans biofilm formation, bleaching with 10% CP and 40% HP increased biofilm on both materials compared to controls. However, S. sanguinis biofilm formation was significantly higher on bleached resin composite but not on RMGI specimens. Conclusions: Simulated bleaching with 10% CP or 40% HP increased both surface roughness and biofilm formation on resin composite and RMGI, except for S. sanguinis biofilm on RMGI. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the efficacy of two products used for at-home bleaching with different application times. Methods: 80 participants were enrolled and divided into four groups, (1) 10% carbamide peroxide 1 hour a day; (2) 10% carbamide peroxide overnight; (3) 7.5% hydrogen peroxide 1 hour a day; and (4) 7.5% hydrogen peroxide overnight. The duration of treatment was 14 days. Color measurement was performed using a dental spectrophotometer on the right maxillary central incisor and the canine, at baseline and 2 weeks after. Participants recorded daily tooth sensitivity. To evaluate the influence of concentration and time on bleaching results (ΔE) the one-way ANOVA with Bonferroni post-hoc test and the Student's t-test were used. Results: Group 2 showed the highest value of ΔE (ΔE = 10.59 ± 2.68), followed by Group 4 (ΔE = 8.95 ± 2.32), Group 1 (ΔE = 8.05 ± 3.86), and Group 3 (ΔE = 7.08 ± 1.99). There were differences between Groups 2 and 3 (P= 0.001) and between Groups 2 and 1 (P= 0.032). The same product applied overnight was more effective than applied 1 hour a day (P< 0.05). Different concentrations during the same application time achieved similar results. The reported tooth sensitivity was mild. [ABSTRACT FROM AUTHOR]

• Bleaching without light leads to the lowest buccal surface and pulpal temperatures. • Continuous application of LED for 30 min led to the highest temperatures. • The use of LED leads to an increase in pulp and buccal surface temperatures. • Fractionated or continuous application of violet LED for 20 or 30 min leads to greater effectiveness of color change. Dental color change and the temperature of the pulp chamber and of the buccal surface were evaluated during bleaching with 37% carbamide peroxide (CP) with continuous vs fractionated violet LED light protocols. Bovine incisors received in-office bleaching for 30 min using different light protocols (Bright Max Whitening, MMOptics). Teeth were separated into groups (n = 10): HP) 35% hydrogen peroxide (Whiteness HP, FGM)/no light; CP) 37% carbamide peroxide (Whiteness SuperEndo, FGM)/no light; CP10) CP+10 min of continuous light; CP20) CP+20 min of continuous light; CP30) CP+30 min of continuous light; CPF) CP+20 cycles of 60 s light / 30 s no light (fractionated). Color evaluations were performed at different times. Evaluations of pulp and buccal surface temperatures were performed before and throughout the 30 min of bleaching. Generalized linear models for repeated measures over time were applied to the data (α=5%). After the 1st session, CP20 and CP30 had significantly lower b* values ​​than CP and CP10 (p = 0.0071). For ΔE ab and ΔE 00 , CPF, CP20 and CP30 showed the highest color change among the treatments after the third bleaching (p <0.05). For temperature evaluations, CP30 showed higher pulp and buccal surface temperatures than the other protocols (p <0.0001) after 20 min. Fractionated or continuous application of violet LED for 20 or 30 min leads to greater effectiveness of color change. All protocols with the application of LED led to an increase in pulp and buccal surface temperatures during bleaching, although the fractionated application appeared to be safer than the use of continuous light. [ABSTRACT FROM AUTHOR]

• Carbamide peroxide and violet LED could be used on early-stage eroded/abraded teeth. • Violet LED increased the efficacy of 20% and 45% carbamide peroxide. • Bleaching with carbamide peroxide did not affect enamel surface properties. This study evaluated enamel with early-stage erosion/abrasion following bleaching with 20% and 45% carbamide peroxide (CP) gels containing fluoride (F) and irradiated with violet LED (LED). Enamel blocks were immersed in 1% citric acid (5 min) and artificial saliva (120 min) three times to produce early-stage enamel erosion. Simulated toothbrushing was performed only after the first saliva immersion, to provoke enamel abrasion. The erosive/abraded enamel samples were submitted to (n=10): LED/CP20, CP20, LED/CP20_F, CP20_F, LED/CP45, CP45, LED/CP45_F, CP45_F, LED, and control (without treatment). The pH of the gels was assessed, and color (ΔE 00) and whiteness index (ΔWI D) changes were calculated after cycling (T 1), and 7 days from bleaching (T 2). Enamel surface roughness average (Ra) and Knoop microhardness (kg/mm2, %SHR) were evaluated at baseline (T 0) at T 1 and T 2. Scanning electron microscopy evaluated the enamel surface morphology at T 2. The gels' pH was neutral and CP20 and CP45 exhibited no differences in ΔE 00 and ΔWI D (p>0.05) but LED increased these parameters for CP20_F and CP45. Erosion/abrasion significantly decreased mean kg/mm2, and the LED group was the only one not increasing microhardness after bleaching (p>0.05). None of the groups fully recovered the initial microhardness. All groups exhibited %SHR similar to the control (p>0.05) and the increase in Ra was detected only after erosion/abrasion. CP20_F groups exhibited a more preserved enamel morphology. Light irradiation combined with low-concentrated CP gel promoted a bleaching effect comparable to the high-concentrated CP. The bleaching protocols did not adversely impact the surface of early-stage eroded/abraded enamel. [ABSTRACT FROM AUTHOR]

Organoarsenics in soil urgently desired careful remediation. Unfortunately, it did not receive enough attention. Herein, we report a versatile Fe2+/Urea Hydrogen Peroxide (UHP) process for not only organoarsenic remediation but also nitrogen supplement in soil. Insight mechanism was firstly studied in water. Roxarsone (ROX) was efficiently degraded by 99.6% following a kinetics of v= 33.91 × [ROX]× [UHP]1.2175 × [Fe2+]1.8990. Aromatic ring cleavage of ROX was realized, resulting in a satisfying mineralization performance. After degradation processes, 88.5% of total arsenic was removed from the solution at pH 5.0 via adsorption processes by generated Fe(OH) 3 particles. The particles showed much higher adsorption capacity to inorganic arsenic species than that to organoarsenic. The degradation of ROX facilitated the immobilization of total arsenic. The remediation was further carried out in soil. Satisfying removal of ROX (95.5%) and immobilization of total arsenic (89.3%) was achieved. More importantly, 94.2%− 94.6% less arsenic was transferred into the lettuce. By the injection of Fe2+/UHP, a sixteen times higher concentration of total nitrogen was achieved. The growth of lettuce was significantly promoted due to the multi-functions including arsenic immobilization and nitrogen supplement. The achievements suggested Fe2+/UHP system potentials in applications for organoarsenic remediation in soil and also soil amelioration. [Display omitted] • The first approach for soil remediation by a Urea Hydrogen Peroxide based process. • Both organoarsenics and inorganic arsenic were efficiently remediated. • Nitrogen supplement was achieved during the remediation processes. • The transfer of arsenic from soil to plants/crops was intercepted. • The growth of plant was promoted due to arsenic remediation and nitrogen supplement. [ABSTRACT FROM AUTHOR]

Objective: This clinical study evaluated the color longevity after 30 months of at-home bleaching with 10% carbamide peroxide (CP) in smokers and nonsmokers. Methods: Sixty patients, 30 smokers and 30 nonsmokers, were subjected to bleaching with 10% CP (Whiteness Perfect-FGM) for three hours daily for three weeks. The color was measured at baseline and at one month and 30 months after the completion of dental bleaching using the shade guide Vita classical organized by value (?SGU) and the shade guide Vita Bleachedguide 3D-MASTER. At the 30-month recall, the color was assessed before and after dental prophylaxis. Data from color evaluation were analyzed by two-way repeated-measures analysis of variance and Tukey test for the contrast of means (a=0.05). Results: Twenty-one smokers and 22 nonsmokers attended the 30 month recall. For both shade guides, only the main factor of assessment time was statistically significant (p<0.001). Effective whitening was observed in both groups at the baseline, which was stable at one month. However, color rebound was observed after 30 months for both groups of participants when color was measured before and after dental prophylaxis. Conclusion: Thirty months after at-home bleaching with 10% CP gel, dental darkening was detected in both groups, which cannot be solely attributed to stains caused by extrinsic staining from daily food, drinks, and smoke (in smokers). [ABSTRACT FROM AUTHOR]

Plaque accumulation, dental caries and periodontal disease are an increasing concern for elderly, special care and orthodontic patients as a result of numerous predisposing factors which make maintenance of adequate oral hygiene difficult, even with traditional oral hygiene practices. This article will propose a technique whereby the anti-bacterial properties of tray-applied carbamide peroxide are used to improve oral health for these patients. [ABSTRACT FROM AUTHOR]