scholarly journals Microhardness and color monitoring of nanofilled resin composite after bleaching and staining

2014 ◽  
Vol 08 (02) ◽  
pp. 160-165 ◽  
Author(s):  
Isabel Cristina G. Bandeira de Andrade ◽  
Roberta Tarkany Basting ◽  
José Augusto Rodrigues ◽  
Flávia Lucisano Botelho do Amaral ◽  
Cecilia Pedroso Turssi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Analysis Of Variance ◽  
Red Wine ◽  
Light Emission ◽  
Resin Composite ◽  
Distilled Water ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Split Plot ◽  
Plot Design

ABSTRACT Objectives: The present study aimed to investigate the effect of staining solutions on microhardness and shade changes of a nanofilled resin composite, which had been previously in contact with bleaching agents. Materials and Methods: A total of 135 disk-shaped specimens (10 mm × 2 mm) were fabricated with a nanofilled resin (Filtek Supreme) and photocured with a Light Emission Diode (LED) unit and then allocated into three groups to be bleached with 10% or 16% carbamide peroxide (CP) bleaching agents or a 35% hydrogen peroxide (HP) product. Following bleaching, specimens within each group were subdivided into three groups to be immersed in coffee, red wine or distilled water. Microhardness and color were monitored at baseline, after bleaching and after staining. Results: Analysis of variance for split-plot design showed lower microhardness values when the composite had been in contact with HP (P < 0.0001). The specimens immersed in red wine and coffee provided lower microhardness values than those immersed in distilled water, regardless of the bleaching agent to which the composites were previously exposed. Kruskal Wallis and Dunn tests demonstrated that the composite was lighter after bleaching with a 35% HP agent (P < 0.0500). Conclusion: The composite was darker as a result of being immersed either in red wine or coffee, regardless of the bleaching agent.

scholarly journals Effect of internal bleaching agents on the bond strength of glass fiber posts to root dentine

2016 ◽  
Vol 31 (3) ◽  
pp. 120
Author(s):  
Josemar Martins Ferreira ◽  
Sara Rodrigues Renovato ◽  
Fernanda Ribeiro Santana ◽  
Daniel De Almeida Decurcio ◽  
Carlos José Soares ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Bond Strength ◽  
Glass Fiber ◽  
Resin Cement ◽  
Sodium Perborate ◽  
Distilled Water ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Fiber Posts ◽  
Glass Fiber Posts

Objective: This study evaluated the effect of internal bleaching agents on the bond strength of glass fiber posts to root dentine.Methods: Seventy bovine teeth were divided into 7 experimental groups (n=10) according to the bleaching agent used: SpH – sodium perborate + 20% hydrogen peroxide; SpW – sodium perborate + distilled water; Cp37 – 37% carbamide peroxide; Cp16 – 16% carbamide peroxide; Cp10 – 10% carbamide peroxide; H – 35% hydrogen peroxide; C – no bleaching agent (control). After bleaching, posts were cemented with a self-adhesive resin cement (RelyX U100) and the roots were crosssectioned to obtain two discs from each third. The posts underwent micropush-out testing, and bond strength values (MPa) were analyzed using ANOVA in a split-plot arrangement and the Tukey test (p<0.05). Failure mode was evaluated under confocal microscopy.Results: There were no significant differences between the control and bleaching agent groups. Bond strength was greater in the cervical third of the 16% carbamide peroxide (Cp16) group than in the sodium perborate + 20% hydrogen peroxide (SpH) group. The cervical third had a higher bond strength than the apical third in the 10% carbamide peroxide (Cp10), 16% carbamide peroxide (Cp16) and sodium perborate + distilled water (SpW) groups, and no significant differences in the other groups. Adhesive cement-dentine failure was prevalent in all groups.Conclusion: The use of internal bleaching agents did not decrease the bond strength of glass fiber posts to root dentin.

scholarly journals Surface roughness of a resin composite

2016 ◽  
Vol 64 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Carlos Alberto Camargo ISABEL ◽  
Alexandre Augusto Sarto DOMINGUETTE ◽  
Saulo Galvão dos SANTOS ◽  
José Carlos Rabelo RIBEIRO ◽  
Marcos Ribeiro MOYSÉS
Keyword(s):  
Surface Roughness ◽  
Analysis Of Variance ◽  
Conventional Method ◽  
Red Wine ◽  
Resin Composite ◽  
Statistical Significance ◽  
Black Tea ◽  
Distilled Water ◽  
Resin Composites

ABSTRACT Objective: The aim of the present study was to evaluate the surface roughness (Ra) of the Z-350 resin composite following immersion in different media (distilled water, coca-cola, coffee, black tea and red wine). Methods: Fifty specimens of resin composite measuring 10 mm x 2 mm were prepared. Polymerization was performed using the conventional method (40 s). Each specimen was immersed for one hour per day. Evaluations were performed at baseline as well as after three, six, nine and 12 months. Three Ra readings were taken in opposite directions at each evaluation using a roughness meter. Mean Ra values were subjected to analysis of variance (ANOVA) followed by Tukey's test (p < 0.05). Results: A significant increase in Ra was found in the specimens submitted to coffee, coca-cola(r) and black tea between baseline and the three-month evaluation. Variance was also found among the remaining evaluation times (3 months to 12 months), but the differences did not achieve statistical significance. No statistically significant differences in Ra were found among evaluation times in the specimens submitted to red wine or distilled water. Conclusion: Based on the present findings, coca-cola, coffee and black tea exert an influence on the surface roughness of resin composites.

The Effect of a 10% Carbamide Peroxide Bleaching Agent on the Microhardness of Four Types of Direct Resin-based Restorative Materials

2013 ◽  
Vol 38 (3) ◽  
pp. 316-323 ◽  
Author(s):  
MQ AlQahtani
Keyword(s):  
Vickers Hardness ◽  
Resin Composite ◽  
The Other ◽  
Control Group ◽  
Distilled Water ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Peroxide Bleaching ◽  
Significant Difference ◽  
Restorative Materials

SUMMARY Purpose This in vitro study was undertaken to evaluate the effect of a 10% carbamide peroxide bleaching agent on the microhardness of four types of direct resin-based restorative materials. Materials and Methods Thirty disk-shaped specimens (10.0 mm diameter × 2.0 mm depth) of each material, including a microhybrid resin composite (Z250), a nanofilled resin composite (Z350), a silorane-based low-shrink resin composite (P90), and a hybrid resin composite (Valux Plus), were fabricated and then polished with medium, fine, and superfine polishing discs. After being polished, specimens were cleaned with distilled water for 2 min in an ultrasonic bath to remove any surface debris and then stored in distilled water at 37°C for 24 hours. Specimens from each material were divided into three groups (n=10). One group was selected as a control group (nontreated with bleaching agent). The other two groups were treated with bleaching agent for 14 days (group A) and for 14 days followed by immersion in artificial saliva for 14 days (group B). The top surfaces of the specimens in the different groups were also subjected to the Vickers hardness test with a load of 300 g and 15-second dwell time. Data were analyzed with a one-way analysis of variance and Tukey's HSD test (α = 0.05). Results There was a general reduction of Vickers hardness numbers (VHN) values of treated groups compared with the control group for each material used, but this reduction was minimal, with no significant difference between groups in Z250, whereas the other three materials (Z350, P90, and Valux Plus) showed a significant reduction of VHN of treated groups compared with the control group. Conversely, the findings showed no significant difference between treated groups A and B in all materials used except P90. Conclusion A 10% carbamide peroxide bleaching agent had an adverse effect on the microhardness of nanofilled, silorane-based low-shrink, and hybrid types of resin-based composite materials compared with the microhybrid type.

An in-vitro Comparison of the Bleaching Efficacy of 35 Percent Carbamide Peroxide with Established Intracoronal Bleaching Agents

2020 ◽  
Author(s):  
Nandita Bansal
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Perborate ◽  
Distilled Water ◽  
Carbamide Peroxide ◽  
Human Teeth ◽  
Anterior Teeth ◽  
Group I ◽  
Group Ii ◽  
Control Evaluation

Introduction: Intracoronal bleaching is the simplest, least invasive, and least expensive means available to lighten non-vital discolored teeth. The objective of the study: To evaluate the intra coronal bleaching efficacy of 35% Carbamide peroxide relative to 35% Hydrogen peroxide and Sodium perborate using artificially stained extracted human teeth. Materials and Methods: Eighty extracted human permanent maxillary and mandibular anterior teeth and single-rooted premolars were artificially stained using whole human blood and root canal treatment was completed. They were bleached twice 7 days apart using: Group I (n=20) – 35% Carbamide peroxide gel, Group II (n=20) – 35% Hydrogen peroxide gel, Group III (n=20) – 2 gm Sodium perborate mixed with per ml of distilled water, Group IV (n=20)– Distilled water only (control). Evaluation of shade was performed on day 0,7,14. Results: On day 7, In Groups I and Group II, there was a reduction in the shade by 2 vita tab positions, whereas Group IIIlightened by 1-tab position only. On day 14, CP and HP lightened by overall 3-tab positions and SP by 2-tab positions. There were no statistical differences between the groups on day 7 and day 14. Conclusion: 35% Carbamide peroxide, 35% Hydrogen peroxide and Sodiumperborate were equally effective for Intra coronal bleaching.

scholarly journals The effect of a bleaching agent on the pigment removal and the bond strength of bulk-fill resin composites: an in vitro study

2018 ◽  
Vol 47 (5) ◽  
pp. 298-304
Author(s):  
Caroline de Farias CHARAMBA ◽  
Renally Bezerra Wanderley LIMA ◽  
Sônia Saeger MEIRELES ◽  
Rosângela Marques DUARTE ◽  
Ana Karina Maciel ANDRADE
Keyword(s):  
Bond Strength ◽  
Color Change ◽  
Resin Composite ◽  
Distilled Water ◽  
Filling Material ◽  
Resin Composites ◽  
Bleaching Agent ◽  
Microtensile Testing ◽  
Before And After

Abstract Introduction In order to simplify the technique, reduce the time required for direct adhesive restorations, bulk-fill resin composites have been developed be applied in bulk placement up to 4 mm increments. Objective Evaluating the color change (ΔE) and the microtensile bond strength (μTBS) of bulk fill resin composites (BFRC) to dentin after the immersion in regular beverages and the application of bleaching systems. Method Forty-five human molar teeth were randomly distributed in three groups according to the filling material (n=15): Filtek Bulk Fill, Tetric N Ceram Bulk Fill and Filtek Z100. The restored teeth were immersed in coffee, wine and distilled water (n=5) for 72 hours. The color parameters were measured using a spectrophotometer, having as basis the CIE L*a*b*, before and after tooth staining and application of bleaching processes. Subsequently, the teeth were sectioned to obtain the specimens for the microtensile testing. The ΔE values were analyzed applying the Kruskal-Wallis and the Wilcoxon tests, and the μTBS values were analyzed applying the ANOVA and the Bonferroni tests (p<0.05). Result There were no significant differences in the ∆E values when comparing the BFRCs to the conventional resin composite (CRC) in most of the experimental groups. The ∆E values did not present significant differences before and after the application of bleaching processes for all the tested resin composites. The BFRCs presented higher μTBS values than the CRC after exposure to distilled water, wine and bleaching agent. Conclusion The studied BFRCs presented similar color stability to the CRC. The BFRCs presented higher bond strength to the dentin than the CTC in most of the evaluated conditions. The bleaching agent was not effective in whitening the stained restored teeth.

scholarly journals The Effect of Different Bleaching Protocols, Used with and without Sodium Ascorbate, on Bond Strength between Composite and Enamel

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2710 ◽  
Author(s):  
Maroun Ghaleb ◽  
Giovanna Orsini ◽  
Angelo Putignano ◽  
Sarah Dabbagh ◽  
Georges Haber ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Bond Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Sodium Ascorbate ◽  
Control Group ◽  
Carbamide Peroxide ◽  
Total N ◽  
Peroxide Group ◽  
Significant Difference

This in vitro study aims to evaluate whether a solution of 10% sodium ascorbate (SA) may exert a beneficial effect on the bonding of composite to enamel after using different bleaching agents and protocols. Microtensile bond strength (µTBS) was evaluated on 72 freshly extracted human central incisors, divided into eight experimental groups and one control group (total n = 9): Group 1 serves as control (nonbleached). Group 2 was bleached with 5% carbamide peroxide. Group 3 was bleached with 5% carbamide peroxide and then treated with 10% SA. Group 4 was bleached with 10% carbamide peroxide. Group 5 was bleached with 10% carbamide peroxide, then treated with 10% SA. Group 6 was bleached with 16% carbamide peroxide. Group 7 was bleached with 16% carbamide peroxide, then treated with 10% SA. Group 8 was bleached with 6% hydrogen peroxide. Group 9 was bleached with 6% hydrogen peroxide, then treated with 10% SA. All groups were restored immediately after the different treatments using a resin composite. The µTBS values were measured using a universal testing machine and statistical analysis was performed by means of normality and variance analyses, SIDAK test for univariate test and multiple comparisons, and Student test to compare µTBS values of each group with the control. The mean µTBS values in groups 2, 4, 6, 8 were significantly lower than controls. For groups 3, 5, 7, 9, subjected to antioxidant (10% SA) application, all µTBS values increased significantly. However, only for Groups 3 and 5 there was no significant difference with the control. Applying 10% SA for 10 min may improve the bond strength composite/bleached enamel just when whitening is performed with 5% and 10% carbamide peroxide.

scholarly journals Cabbage Seedpod Weevil Control on Winter Canola, 1996

1998 ◽  
Vol 23 (1) ◽  
pp. 186-187
Author(s):  
J. P. McCaffrey ◽  
B. L. Harmon
Keyword(s):  
Analysis Of Variance ◽  
Methyl Parathion ◽  
Ambient Air ◽  
Winter Canola ◽  
Split Plot ◽  
Small Plot ◽  
Cabbage Seedpod Weevil ◽  
Plot Design

Abstract Plots, 3.5 X 12 ft, arranged in a split-plot design with each chem-ical treatment replicated 3 times, and each of 4 genotypes replicated twice within each treatment strip, were planted at Moscow, ID on 20 Aug, 1995 at 9.5 lb/acre using a small-plot, cone seeder. Capture 2 EC and methyl parathion 4 E were applied 5 Jun with a CO2-pressurized tractor-mounted sprayer equipped with 80° fan nozzles on an 8.3-ft boom that delivered 20 gpa at 30 psi. At the time of treatment, wind conditions were calm (&lt;5 mph), and ambient air tem-perature was above 60°F. Plots were sampled for adult CSW 2 before treatment and 2 d after treatment by dislodging them into a 5-gal plastic bucket with a beat of a hand at each end of a plot. To determine the number of exit holes, 10 pods were removed from 10 racemes from each side of each plot on 17 and 18 Jul. Plots were harvested 15 Aug with a small-plot combine (4.6 ft header). All data were subjected to analysis of variance.

Effect of Carbamide Peroxide Bleaching Gel Concentration on the Bond Strength of Dental Substrates and Resin Composite

2010 ◽  
Vol 35 (4) ◽  
pp. 463-469 ◽  
Author(s):  
D. C. Barcellos ◽  
P. Benetti ◽  
V. V. B. Fernandes ◽  
M. C. Valera
Keyword(s):  
Bond Strength ◽  
Clinical Relevance ◽  
Resin Composite ◽  
Scientific Information ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Peroxide Bleaching ◽  
Mineral Loss

Clinical Relevance According it has been demonstrated that dental substrates can recover from mineral loss after 14 days from the last bleaching agent application, there is no scientific information about this effect on the dental substrate-adhesive restoration interface.

Acid Demineralization Susceptibility of Dental Enamel Submitted to Different Bleaching Techniques and Fluoridation Regimens

2014 ◽  
Vol 39 (4) ◽  
pp. E178-E185 ◽  
Author(s):  
DLF Salomão ◽  
DM Santos ◽  
RD Nogueira ◽  
RG Palma-Dibb ◽  
VR Geraldo-Martins
Keyword(s):  
Hydrogen Peroxide ◽  
Analysis Of Variance ◽  
Dental Enamel ◽  
Knoop Hardness ◽  
Carbamide Peroxide ◽  
Cross Sectional ◽  
Knoop Microhardness ◽  
Different Depths ◽  
Group 2 ◽  
Bovine Enamel

SUMMARY The aim of the current study was to assess the acid demineralization susceptibility of bleached dental enamel submitted to different fluoride regimens. One hundred bovine enamel blocks (6×6×3 mm) were randomly divided into 10 groups (n=10). Groups 1 and 2 received no bleaching. Groups 3 to 6 were submitted to an at-home bleaching technique using 6% hydrogen peroxide (HP; G3 and G4) or 10% carbamide peroxide (CP; G5 and G6). Groups 7 to 10 were submitted to an in-office bleaching technique using 35% HP (G7 and G8) or 35% CP (G9 and G10). During bleaching, a daily fluoridation regimen of 0.05% sodium fluoride (NaF) solution was performed on groups 3, 5, 7, and 9, while weekly fluoridation with a 2% NaF gel was performed on groups 4, 6, 8, and 10. The samples in groups 2 to 10 were pH cycled for 14 consecutive days. The samples from all groups were then assessed by cross-sectional Knoop microhardness at different depths from the outer enamel surface. The average Knoop hardness numbers (KHNs) were compared using one-way analysis of variance and Tukey tests (α=0.05). The comparison between groups 1 and 2 showed that the demineralization method was effective. The comparison among groups 2 to 6 showed the same susceptibility to acid demineralization, regardless of the fluoridation method used. However, the samples from groups 8 and 10 showed more susceptibility to acid demineralization when compared with group 2 (p&lt;0.05). Groups 7 and 9 provided similar results to group 2, but the results of those groups were different when compared with groups 8 and 10. The use of 6% HP and 10% CP associated with daily or weekly fluoridation regimens did not increase the susceptibility of enamel to acid demineralization. However, the use of 35% HP and 35% CP must be associated with a daily fluoridation regimen, otherwise the in-office bleaching makes the bleached enamel more susceptible to acid demineralization.

scholarly journals Clinical and Spectrophotometric Evaluation of LED and Laser Activated Teeth Bleaching

2016 ◽  
Vol 10 (1) ◽  
pp. 242-250 ◽  
Author(s):  
R. Lo Giudice ◽  
G. Pantaleo ◽  
A. Lizio ◽  
U. Romeo ◽  
G. Castiello ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Mean Value ◽  
Ease Of Use ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Power Sources ◽  
Chromatic Scale ◽  
Whitening Agent ◽  
Auxiliary Power ◽  
Before And After

Background: Auxiliary power sources (LED and laser) are used in in-office teeth bleaching techniques to accelerate the redox reaction of the whitening gel to increase ease of use, to improve comfort and safety, and to decrease the procedure time. Objective: The aim this study is to evaluate the efficiency of the teeth whitening procedures performed with hydrogen peroxide and carbamide peroxide, LED or Laser activated. Method: 18 patients, affected by exogenous dyschromia, were treated with a bleaching agent composed by 35% hydrogen peroxide and 10% carbamide peroxide. They were divided into two groups: in the first group the bleaching agent was activated by a LED lamp; in the second group it was activated by a Laser diode lamp. Both groups were subjected to 3 bleaching cycle of 15’ each. The chromatic evaluations were performed before and after one week from the treatment, using a chromatic scale and a spectrophotometer. The mean value of pre, post bleaching and follow-up were analyzed using a T-test, with results statistically significant for P<0,05. Results: Results showed that the variations in brightness, chroma and hue are significantly influenced by the interaction between the whitening agent and the original colour of the teeth. Laser-activation has marginally improved the bleaching effectiveness. All patients treated with laser activation complained an increase in dental sensitivity. Conclusion: The use of laser-activating systems did not improve the efficacy of bleaching.

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