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.

scholarly journals How a 16% Carbamide Peroxide Home Bleaching Agent Affects the Surface Properties of Chairside CAD/CAM Materials?

2021 ◽  
pp. 342-353
Author(s):  
Tugba Serin-Kalay ◽  
Beyza Zaim
Keyword(s):  
Surface Roughness ◽  
Surface Analysis ◽  
Lithium Silicate ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Peroxide Bleaching ◽  
Significant Difference ◽  
Computer Aided ◽  
Restorative Materials ◽  
Cad Cam

Surface changes of restorative materials after bleaching have clinical importance in terms of the durability and survival of restorations. This study aimed to evaluate the effect of home bleaching on the surface roughness, microhardness, and surface analysis of four different types of chairside computer-aided design and computer-aided manufacturing (CAD/CAM) materials. Specimens were prepared from composite resin (Brilliant Crios: BC), resin nanoceramic (Lava Ultimate: LU), polymer-infiltrated ceramic-network (Vita Enamic: VE), and zirconia-reinforced lithium silicate glass-ceramic (Vita Suprinity: VS) CAD/CAM materials. Specimens were polished using 800, 1000, 1200, and 2000 grit SiC papers. Each restorative material was randomly divided into two groups; control and bleaching (n=10). The 16% carbamide peroxide bleaching agent (Whiteness Perfect 16%, FGM) was applied to the specimens for 4 h/day for 14 days. Surface roughness values (Ra) were obtained using a profilometer, and microhardness values (VHN) were obtained using a Vickers microhardness test. Surface analysis of specimens was evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Data were analyzed Two-way ANOVA and Fisher’s Least Significant Difference (LSD) test (p<0.05). After bleaching, the surface roughness of BC (p<0.001) and VE (p<0.032) significantly increased. Bleaching did not significantly affect the microhardness of CAD/CAM materials. SEM evaluation showed material-dependent surface damages after bleaching procedures. The effect of 16% carbamide peroxide home bleaching agent on surface roughness and microhardness of chairside CAD/CAM materials is material-dependent. Before bleaching, restorative materials should be protected by applying a protective barrier and contact with the bleaching agent should be minimized. Also, after bleaching, the restoration surface should be carefully inspected, and re-polishing might be beneficial.

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 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.

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.

scholarly journals The Effects of Mouthwashes on the Color Stability of Resin-Based Restorative Materials

2020 ◽  
pp. 346-357
Author(s):  
Ayşe Tuğba Ertürk-Avunduk ◽  
Seçkin Aksu ◽  
Ebru Delikan
Keyword(s):  
Analysis Of Variance ◽  
Color Change ◽  
Resin Composite ◽  
Color Stability ◽  
Multiple Comparison ◽  
Color Measurement ◽  
Distilled Water ◽  
Significant Difference ◽  
Restorative Materials ◽  
Post Hoc

Objective: This study investigated the effects of three types of mouthwash on the color stability of three resin-based restorative materials (nanohybrid resin composite, sonic-activated bulk-fill material, and compomer). Materials and Methods: To this end, 120 cylindrical disc specimens were prepared and polished, after which they were incubated in distilled water for 24 hours for post-polymerization. The baseline color values of each specimen were measured with a spectrophotometer, then the specimens were randomly divided into four groups. Following immersion in the mouthwashes for 24 hours, the specimens were rinsed with distilled water and dried before the color measurement was repeated. The values of color change (∆E₀₀) were subsequently calculated. A two-way analysis of variance and Duncan’s post hoc multiple comparison tests were conducted to determine statistically significant differences among the restorative materials. Results: All samples showed discoloration after immersion, albeit some instances of discoloration were imperceptible. In this respect, a statistically significant difference was found among the restorative materials and mouthwashes (p<0.05). Imperceptible ∆E₀₀ values were derived on the nanohybrid resin composite and compomer, but perceptible and acceptable ∆E₀₀ values were detected on the sonic-activated bulk-fill materials (p<0.05). The clinically unacceptable discoloration was observed on the sonic-activated bulk-fill composite immersed in Listerine®. Conclusions: Clinicians should make recommendations based on the potential staining capacity of mouthwashes prescribed for daily use in restorative materials. In this way, the need for renewal of restorations due to discoloration could be avoided.

scholarly journals A comparative study of the effects of two carbamide peroxide bleaching agents on the structure of enamel

2016 ◽  
Vol 64 (3) ◽  
pp. 293-298
Author(s):  
Roberto Paulo de ARAÚJO ◽  
Danilo Barral de ARAÚJO ◽  
Márcio Cajazeira AGUIAR
Keyword(s):  
Electron Microscopy ◽  
Artificial Saliva ◽  
Control Group ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Peroxide Bleaching ◽  
The Third ◽  
Dental Whitening ◽  
Different Sources ◽  
Scanning Electron

ABSTRACT Objective: Considering that different sources of carbamide peroxide bleaching agent may cause greater or lesser damage to the enamel and may have reduced effectiveness in dental whitening, the aim of this study was to compare the effects on the structure of enamel of two bleaching agents, drugstore-compounded and commercial carbamide peroxide bleaching agents. Methods: The specimens in the first group (drugstore-compounded carbamide peroxide) and second group (commercial carbamide peroxide) were treated with to 16% carbamide peroxide for 4 h per day for 20 days. The third group served as a control and was kept in artificial saliva during the test period. After the treatments, all specimens were examined via scanning electron microscopy. Results: Changes in the enamel morphology were similar in both experimental groups, but these changes were greater than those observed in the control group. The changes were mild and included only pores. Conclusion: There were no differences regarding damage to the enamel between drugstore-compounded and commercial carbamide peroxide bleaching agents.

scholarly journals Do mouthwashes with and without bleaching agents degrade the force of elastomeric chains?

2013 ◽  
Vol 83 (4) ◽  
pp. 712-717 ◽  
Author(s):  
Matheus Melo Pithon ◽  
Ailana Cardoso Rodrigues ◽  
Érica Luiza Santana Moreira Sousa ◽  
Lília Paula de Souza Santos ◽  
Natália dos Santos Soares
Keyword(s):  
Artificial Saliva ◽  
Initial Period ◽  
Test Group ◽  
Experimental Period ◽  
The Other ◽  
Control Group ◽  
Distilled Water ◽  
Bleaching Agent ◽  
Time Intervals ◽  
Elastomeric Chains

ABSTRACT Objective: To evaluate, in vitro, the effect of mouthwashes with and without bleaching agents on the force of elastomeric chains. Materials and Methods: A total of 108 elastomeric chain specimens was divided into six groups (n  =  18 in each group). Two test groups were exposed to two types of commonly used mouthwashes (Plax and Listerine), and two groups were exposed to mouthwashes containing bleaching agent (Plax Whitening and Listerine Whitening). Immersion in the solutions was performed twice a day for 60 seconds. One group of control specimens remained immersed in artificial saliva throughout the entire experimental period, and the other control specimens were exposed to distilled water. Force measurements were performed at six time intervals (initial, 1 day, 7 days, 14 days, 21 days, and 28 days). Results: No statistically significant differences were found between the groups in the initial period (P &gt; .05). Statistically significant differences were found between the control group and the Plax, Plax Whitening, and Listerine groups at the time intervals of 7, 14, and 21 days. In the initial period, the force was statistically significantly higher than it was in any of the other experimental periods (P &lt; .05). The control group with distilled water and the test group with Plax Whitening maintained the most force during the experimental period. Conclusion: The presence of bleaching agent has no influence on the force degradation of elastomeric chains.

scholarly journals Comparison of enamel hardness after dental bleaching agent application strawberry gel and carbamide peroxide 10%

2018 ◽  
Vol 3 (1) ◽  
pp. 17
Author(s):  
Asmawati Asmawati ◽  
Irene E. Rieuwpassa
Keyword(s):  
Treatment Group ◽  
Malic Acid ◽  
Tooth Enamel ◽  
Surface Hardness ◽  
Bleaching Agent ◽  
Carbamide Peroxide ◽  
Dental Bleaching ◽  
Peroxide Bleaching ◽  
Bleaching Procedure ◽  
Significant Difference

Objective: Carbamide peroxide 10% is commonly used in home bleaching procedure. Effectiveness of carbamide peroxide bleaching process as a home bleaching has no successor yet, but its use is still being debated due to the effects on oral cavity. Strawberries are one of natural ingredients that currently used to whiten decolorized teeth because it contains ellagic acid and malic acid. On contrary, malic acid is said to be involved in the process of erosion. The aim of this study was to compare tooth enamel hardness after application of dental bleaching agent carbamide peroxide 10% and strawberry gel.Material and Methods: Sample consists of 30 maxillary incisors were divided into 3 groups. The first group as control soaked in aquades. The second treatment group were applied with carbamide peroxide 10%  and a third group applied with strawberry gel. Before and after the sample application, tests were performed to determine the hardness of tooth enamel as measured using Universal Hardness Tester.Results: Based on Friedman test, p-value = 0,000 (p <0,05; significant). This means that there was a significant difference in tooth enamel surface hardness of each group and treatment group using bleaching carbamide peroxide 10% and strawberry gel.Conclusion: There was a decrease on tooth enamel hardness after application of carbamide peroxide 10%  compared strawberry gel.

scholarly journals Corneal Biomechanical Parameters and Central Corneal Thickness in Glaucoma Patients, Glaucoma Suspects, and a Healthy Population

2021 ◽  
Vol 10 (12) ◽  
pp. 2637
Author(s):  
Mª. Ángeles del Buey-Sayas ◽  
Elena Lanchares-Sancho ◽  
Pilar Campins-Falcó ◽  
María Dolores Pinazo-Durán ◽  
Cristina Peris-Martínez
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Mean Difference ◽  
The Other ◽  
Control Group ◽  
Healthy Population ◽  
Diagnostic Categories ◽  
Significant Difference ◽  
Biomechanical Parameters ◽  
The Mean

Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group.

scholarly journals The Effect of Geogebra on Students’ Conceptual and Procedural Knowledge: The Case of Applications of Derivative

2017 ◽  
Vol 7 (2) ◽  
pp. 67 ◽  
Author(s):  
Mehmet Fatih Ocal
Keyword(s):  
Conceptual Knowledge ◽  
Teaching And Learning ◽  
Procedural Knowledge ◽  
Dynamic Geometry ◽  
The Other ◽  
Control Group ◽  
Other Hand ◽  
Significant Difference ◽  
Before And After ◽  
Post Test

Integrating the properties of computer algebra systems and dynamic geometry environments, Geogebra became an effective and powerful tool for teaching and learning mathematics. One of the reasons that teachers use Geogebra in mathematics classrooms is to make students learn mathematics meaningfully and conceptually. From this perspective, the purpose of this study was to investigate whether instruction with Geogebra has effect on students’ achievements regarding their conceptual and procedural knowledge on the applications of derivative subject. This study adopted the quantitative approach with pre-test post-test control group true experimental design. The participants were composed of two calculus classrooms involving 31 and 24 students, respectively. The experimental group with 31 students received instruction with Geogebra while the control group received traditional instruction in learning the applications of derivative. Independent samples t-test was used in the analysis of the data gathered from students’ responses to Applications of Derivative Test which was subjected to them before and after teaching processes. The findings indicated that instruction with Geogebra had positive effect on students’ scores regarding conceptual knowledge and their overall scores. On the other hand, there was no significant difference between experimental and control group students’ scores regarding procedural knowledge. It could be concluded that students in both groups were focused on procedural knowledge to be successful in learning calculus subjects including applications of derivative in both groups. On the other hand, instruction with Geogebra supported students’ learning these subjects meaningfully and conceptually.

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