scholarly journals Transenamel and Transdentinal Penetration of Hydrogen Peroxide Applied to Cracked or Microabrasioned Enamel

2014 ◽  
Vol 39 (2) ◽  
pp. 166-173 ◽  
Author(s):  
ALF Briso ◽  
APB Lima ◽  
RS Gonçalves ◽  
MO Gallinari ◽  
PH dos Santos
Keyword(s):  
Hydrogen Peroxide ◽  
Deionized Water ◽  
Acetate Buffer Solution ◽  
Control Group ◽  
Buffer Solution ◽  
Tooth Whitening ◽  
Significance Level ◽  
Leucocrystal Violet ◽  
Peroxidase Enzyme ◽  
Visible Reflectance

SUMMARY The present study evaluated transenamel and transdentinal penetration of hydrogen peroxide during tooth whitening recognized in altered enamel by the presence of cracks or microabrasion. We used 72 experimental units (n=20) obtained from bovine incisors: GI-sound enamel; GII-teeth showing visible enamel cracks (4 mm to 5.7 mm in length); and GIII-microabrasioned enamel. The 12 remaining specimens were used to analyze the enamel surface morphology using scanning electron microscopy. The specimens were cylindrical and 5.7 mm in diameter and 3.5 mm thick. A product based on 35% hydrogen peroxide was used for bleaching, following the manufacturer's recommendations for use. To quantify the H2O2 penetration, the specimens were placed in artificial pulp chambers containing an acetate buffer solution. After bleaching, the solution was collected and adequately proportioned with leucocrystal violet, peroxidase enzyme, and deionized water. The resulting solution was evaluated using ultraviolet visible reflectance spectrophotometer equipment. The data were analyzed by analysis of variance (ANOVA) and Fisher's PLSD at a significance level of 0.05, and significant differences in the penetration of peroxide in different substrate conditions were observed (p<0.0001). The penetration of hydrogen peroxide was more intense in cracked teeth. The group in which the enamel was microabraded showed intermediate values when compared to the control group. Microabrasion and the presence of cracks in the enamel make this substrate more susceptible to penetration of hydrogen peroxide during in-office whitening.

Effects of the Concentration and Composition of In-office Bleaching Gels on Hydrogen Peroxide Penetration into the Pulp Chamber

2015 ◽  
Vol 40 (2) ◽  
pp. E76-E82 ◽  
Author(s):  
AP Mena-Serrano ◽  
SO Parreiras ◽  
EMS do Nascimento ◽  
CPF Borges ◽  
SB Berger ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Control Group ◽  
Pulp Chamber ◽  
Pulp Tissue ◽  
Buffer Solution ◽  
Bleaching Procedure ◽  
Blue Solution

SUMMARY In tooth whitening, the hydrogen peroxide (HP) diffuses in the enamel and dentin, reaching the pulp. This in vitro study aimed to quantify the penetration of HP in the pulp chamber in teeth submitted to bleaching agents of different concentrations of HP without calcium (HP 20% [20CF], HP 35% [35CF]) and with calcium (HP 20% [20CC], HP 35% [35CC]). Method Fifty human premolars were sectioned 3 mm from the cemento-enamel junction and the pulp tissue was removed. The teeth were divided into five groups according to treatment and with a control group (n=10). An acetate buffer solution was placed in the pulp chamber of all teeth. The control group was exposed only to distilled water, while the other groups were treated with a bleaching procedure, according to the manufacturer's recommendations. After treatment, the acetate buffer solution was transferred to a glass tube in which leuco-crystal violet and peroxidase solutions were added, resulting in a blue solution. The optical density of this blue solution was determined spectrophotometrically and converted into micrograms equivalent to the HP. Data were analyzed using analysis of variance and Tukey tests (α=0.05). Results The HP concentration did not affect the HP inside the pulp chamber, but the presence of calcium significantly reduced it (p<0.0001). Conclusion The amount of HP that reaches the pulp chamber depends on the bleaching protocol and the product employed, and it seems to be less affected by HP concentration.

Effect of Adhesive Restoration and Bleaching Technique on the Concentration of Hydrogen Peroxide In the Pulp Chamber

2017 ◽  
Vol 42 (2) ◽  
pp. E44-E54 ◽  
Author(s):  
V Cavalli ◽  
BG Silva ◽  
SB Berger ◽  
G Abuna ◽  
FC Marson ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Confocal Microscopy ◽  
Light Emitting Diode ◽  
Acetate Buffer Solution ◽  
Control Group ◽  
Light Activation ◽  
Pulp Chamber ◽  
Buffer Solution ◽  
Light Emitting ◽  
Halogen Light

SUMMARY This study aimed to quantify the concentration of hydrogen peroxide into the pulp chamber in the presence or absence of adhesive enamel restorations and to analyze the resin-dentin interface of bleached groups. Bovine incisors (120) were randomly divided into three groups according to enamel treatment (n=40 each): (1) enamel without restoration (control); (2) enamel cavities (3 mm diameter × 1.5 mm depth) restored with a silorane-based (SB) system; or (3) enamel cavities (3 mm diameter × 1.5 mm depth) restored with a dimethacrylate-based (DB) system. Restorations were thermocycled, and all groups were submitted to one application of 35% hydrogen peroxide (HP) agent for 45 minutes and subjected to four light activation methods (n=10 each): without light, light-emitting diode (LED), LED/diode laser, or halogen light. Acetate buffer solution was placed into the pulp chamber before bleaching, and this solution was collected to spectrophotometrically determine the concentration of HP that reached the pulp chamber after bleaching. Rhodamine B was added to the HP agent and applied on additional enamel samples of each group for 24 hours. Samples were sectioned mesiodistally, and the bleaching agent was traced using confocal microscopy. According to two-way analysis of variance and Tukey test (α=0.05), the HP concentration in the pulp chamber of the control group was significantly lower than that of the SB group (p<0.05), regardless of light activation. No differences were observed between DB and SB groups and between control and DB groups, except for the DB halogen light activated group, which exhibited higher HP intrapulpal concentration (p<0.05). Confocal microscopy exhibited HP diffusion through the interface of the SB and DB restored groups as well as enamel prisms in the control group. The SB restorative system increased the HP diffusion into the pulp chamber, but HP was able to diffuse even in the absence of enamel restorations.

scholarly journals Effect of Dental Pigmentation Intensity on the Transenamel and Transdentinal Penetration of Hydrogen Peroxide

2016 ◽  
Vol 27 (4) ◽  
pp. 399-403 ◽  
Author(s):  
Janaina Cardoso Moreira ◽  
Marjorie de Oliveira Gallinari ◽  
Vanessa Rahal ◽  
Ticiane Cestari Fagundes ◽  
Paulo Henrique dos Santos ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Statistical Tests ◽  
Black Tea ◽  
The Other ◽  
Acetate Buffer Solution ◽  
Distilled Water ◽  
Bleaching Agent ◽  
Buffer Solution ◽  
Peroxidase Enzyme ◽  
Bleaching Treatment

Abastract This study aimed to evaluate the transenamel and transdentinal penetration of hydrogen peroxide (H202) applied to bovine teeth pigmented with black tea at different intensities. The following groups were formed DW: immersion in distilled water; BT100: immersion in an infusion of 1.6 g of black tea per 100 mL distilled water; BT10: immersion in an infusion of 1.6 g black tea per 10 mL distilled water. All groups were immersed for 6 days. To quantify the penetration of H202, the specimens were placed in artificial pulp chambers (APCs) and subjected to bleaching treatment with 38% H2O2 once per week for 3 weeks. After bleaching treatment, the acetate buffer solution of APCs with peroxidase enzyme was evaluated in a reflection spectrophotometer. The transenamel and transdentinal penetration of H2O2 and the L* values obtained at T1, T2 and T3 were subjected to Kruskal-Wallis and Friedman statistical tests. At T1, the H2O2 diffusion in DW was higher than that in BT100 and BT10. At the other evaluation times, the penetration values in BT100 and BT10 increased and remained similar. The L* values increased significantly in all groups at T1. At T2, the L* values were higher in DW, while the values in BT100 and BT10 were similar to each other. At the end of the experiment, BT10 showed the lowest L* values. The pigmentation level did not affect the penetration of H2O2 through the enamel and dentin and the bleaching agent effectively changed the color of the teeth.

Quantification of Peroxide Ion Passage in Dentin, Enamel, and Cementum After Internal Bleaching With Hydrogen Peroxide

2012 ◽  
Vol 37 (6) ◽  
pp. 660-664 ◽  
Author(s):  
RM Palo ◽  
I Bonetti-Filho ◽  
MC Valera ◽  
CHR Camargo ◽  
SEA Camargo ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
External Surface ◽  
Acetate Buffer Solution ◽  
Bleaching Agent ◽  
Pulp Chamber ◽  
Control Groups ◽  
Buffer Solution ◽  
Exposed Area ◽  
Blue Solution ◽  
Nail Varnish

SUMMARY The aim of this study was to evaluate the amount of peroxide passage from the pulp chamber to the external enamel surface during the internal bleaching technique. Fifty bovine teeth were sectioned transversally 5 mm below the cemento-enamel junction (CEJ), and the remaining part of the root was sealed with a 2-mm layer of glass ionomer cement. The external surface of the samples was coated with nail varnish, with the exception of standardized circular areas (6-mm diameter) located on the enamel, exposed dentin, or cementum surface of the tooth. The teeth were divided into three experimental groups according to exposed areas close to the CEJ and into two control groups (n=10/group), as follows: GE, enamel exposure area; GC, cementum exposed area; GD, dentin exposed area; Negative control, no presence of internal bleaching agent and uncoated surface; and Positive control, pulp chamber filled with bleaching agent and external surface totally coated with nail varnish. The pulp chamber was filled with 35% hydrogen peroxide (Opalescence Endo, Ultradent). Each sample was placed inside of individual flasks with 1000 μL of acetate buffer solution, 2 M (pH 4.5). After seven days, the buffer solution was transferred to a glass tube, in which 100 μL of leuco-crystal violet and 50 μL of horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to Kruskal-Wallis and Dunn-Bonferroni tests (α=0.05). All experimental groups presented passage of peroxide to the external surface that was statistically different from that observed in the control groups. It was verified that the passage of peroxide was higher in GD than in GE (p<0.01). The GC group presented a significantly lower peroxide passage than did GD and GE (p<0.01). It can be concluded that the hydrogen peroxide placed into the pulp chamber passed through the dental hard tissues, reaching the external surface and the periodontal tissue. The cementum surface was less permeable than were the dentin and enamel surfaces.

scholarly journals Chemical Composition and Microhardness of Human Enamel Treated with Fluoridated Whintening Agents. A Study in Situ

2017 ◽  
Vol 11 (1) ◽  
pp. 34-40
Author(s):  
Thais de Mendonça Petta ◽  
Yasmin do Socorro Batista de Lima Gomes ◽  
Renata Antunes Esteves ◽  
Kelson do Carmo Freitas Faial ◽  
Roberta Souza D`Almeida Couto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Morphological Changes ◽  
Dental Enamel ◽  
Hardness Test ◽  
Knoop Hardness ◽  
Control Group ◽  
High Concentration ◽  
Significance Level ◽  
Before And After

Background: Dental whitening has been increasingly sought out to improve dental aesthetics, but may cause chemical and morphological changes in dental enamel surfaces. Objective: Assess in situ the effects of high-concentration hydrogen peroxide with and without fluoride on human dental enamel using the ion chromatography test (IC) and the Knoop hardness test (KHN). Material and Methods: Nineteen enamel specimens were prepared using third human molars. These specimens were fixed on molars of volunteers and were divided into groups: OP38-Opalescence Boost PF38%, PO37-Pola Office 37.5% and CO-Control group. For chemical analysis (n= 3), the dentin layer was removed, keeping only the enamel, which was subjected to acidic digestion by microwave radiation. It was necessary to perform sample dilutions for the elements fluorine (F), calcium (Ca) and phosphorus (P) for quantification using the IC test. The KHN (n= 5) was performed before and after the treatments. Five indentations were made, separated by 100 µm, for each specimen using a load of 25 gf for 5 seconds in the microdurometer. The data were analyzed using ANOVA with a 5% significance level. Results: The OP38 group had the largest concentrations of F, Ca and P ions. The PO37 group showed the lowest concentrations of F and Ca ions. The average KHN was not significantly different between the OP38 and PO37 groups. Conclusion: Enamel whitened with hydrogen peroxide containing fluoride had greater concentrations of F, Ca and P ions. The presence of fluoride in the whitening agent did not influence the enamel microhardness.

scholarly journals Penetration of Hydrogen Peroxide and Degradation Rate of Different Bleaching Products

2015 ◽  
Vol 40 (1) ◽  
pp. 72-79 ◽  
Author(s):  
FC Marson ◽  
RS Gonçalves ◽  
CO Silva ◽  
LTÂ Cintra ◽  
RC Pascotto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Residence Time ◽  
Degradation Rate ◽  
Dental Enamel ◽  
Spectrophotometric Analysis ◽  
Acetate Buffer Solution ◽  
Tooth Surface ◽  
Buffer Solution ◽  
Tooth Structure ◽  
Bleaching Gels

SUMMARY This study's aim was to evaluate the degradation rate of hydrogen peroxide (H2O2) and to quantify its penetration in tooth structure, considering the residence time of bleaching products on the dental enamel. For this study, bovine teeth were randomly divided according to the bleaching product received: Opalescence Xtra Boost 38%, White Gold Office 35%, Whiteness HP Blue 35%, Whiteness HP Maxx 35%, and Lase Peroxide Sensy 35%. To analyze the degradation of H2O2, the titration of bleaching agents with potassium permanganate was used, while the penetration of H2O2 was measured via spectrophotometric analysis of the acetate buffer solution, collected from the artificial pulp chamber. The analyses were performed immediately as well as 15 minutes, 30 minutes, and 45 minutes after product application. The data of degradation rate of H2O2 were submitted to analysis of variance (ANOVA) and Tukey tests, while ANOVA and Fisher tests were used for the quantification of H2O2, at the 5% level. The results showed that all products significantly reduced the concentration of H2O2 activates at the end of 45 minutes. It was also verified that the penetration of H2O2 was enhanced by increasing the residence time of the product on the tooth surface. It was concluded that the bleaching gels retained substantial concentrations of H2O2 after 45 minutes of application, and penetration of H2O2 in the dental structure is time-dependent.

scholarly journals Improving shear bond strength of metallic brackets after whitening

2020 ◽  
Vol 25 (5) ◽  
pp. 38-43
Author(s):  
Juan Fernando Aristizábal ◽  
Angela Patricia Polanía González ◽  
James A. McNamara
Keyword(s):  
Hydrogen Peroxide ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Artificial Saliva ◽  
Tooth Bleaching ◽  
Sodium Ascorbate ◽  
Control Group ◽  
Antioxidant Treatment ◽  
Significance Level ◽  
Significant Difference

ABSTRACT Objective: To evaluate a protocol for bonding metallic brackets after bleaching with hydrogen peroxide (HP). Methods: 60 extracted maxillary premolar were randomly divided into an unbleached control group and two groups bleached with a solution of 35% hydrogen peroxide prior to bonding. The teeth in one of the treated groups were bonded immediately after bleaching; while the other group was treated with 10% sodium ascorbate immediately after bleaching and before bonding. The teeth in all groups were stored in an artificial saliva solution for 7 days after bonding. The shear bond strength data was measured in megapascals (MPa) and the fail attempts were verified. The significance level was established at p< 0.05. Results: The unbleached group, in which brackets were bonded to untreated enamel, had the highest bond strength values (11.0 ± 5.7MPa) in comparison to the bleached group (7.14 ± 40MPa), in which brackets were bonded to recently bleached enamel. Slightly improved bond strength was observed in the antioxidant group (8.13 ± 5.4MPa), in which the teeth were bleached and then the antioxidant was applied to the teeth before bonding. Unbleached and bleached groups showed statistically significant difference for shear bond strength (p=0.03) and load strength (p=0.03); no significant differences were noted between unbleached and antioxidant groups (p=0.52). Conclusion: The antioxidant treatment applied immediately after bleaching was effective in reversing the reduction in shear bond strength of brackets after tooth bleaching.

scholarly journals PEMANFAATAN ANIMASI MACROMEDIA FLASH DALAM MENINGKATKAN HASIL BELAJAR

2019 ◽  
Vol 1 (2) ◽  
pp. 1
Author(s):  
Asyti Febliza ◽  
Zul Afdal
Keyword(s):  
Student Learning ◽  
Learning Outcomes ◽  
Hypothesis Test ◽  
Student Learning Outcomes ◽  
Control Group ◽  
Buffer Solution ◽  
Significance Level ◽  
First Semester ◽  
Buffer Solutions ◽  
Improving Student Learning

Abstract This study aims to implement macromedia flash animation in improving student learning outcomes on the topic of buffer solutions. This research was conducted in the first semester of the basic chemistry course with the topic of buffer solution. The samples in this study were first semester students at the University of Riau divided in 2 classes. This study is quasi-experimental, by making treatment in the experimental class (animation class) by comparing with the control group. The hypotheses tested in this study are: Ha = There are differences in the level of learning outcomes of the experimental class and the control class and H0 = There is no difference in the level of learning outcomes of the experimental class and the control class. Hypothesis testing is done by the independent sample T-Test on SPSS 22 with a significance level of 0.05 which used gain score. Based on the results and discussion it can be concluded that the experimental class has an increase in learning outcomes by 57%, while the increase in student learning outcomes in the control class is only 39%, which is about 2/3 of the increase in learning outcomes of the experimental class. Based on the results of the hypothesis test it can be concluded that Ha is accepted, namely there are differences in the level of learning outcomes of experimental class and control class where significance is equal to sig = 0.000, this value is smaller than the significance level of 0.05.   Keywords: animation, macromedia flash, learning media, learning outcomes, buffer solutions  

scholarly journals PENGARUH PEMBELAJARAN INKUIRI TERBIMBING BERBASIS SETS TERHADAP HASIL BELAJAR KIMIA PADA MATERI LARUTAN PENYANGGA

2017 ◽  
Vol 7 (1) ◽  
pp. 66-69
Author(s):  
Dewi Fitriyani ◽  
Zulmanelis Darwis ◽  
Irma Ratna Kartika
Keyword(s):  
Inquiry Learning ◽  
Test Group ◽  
Sampling Technique ◽  
Control Group ◽  
Guided Inquiry ◽  
Buffer Solution ◽  
Significance Level ◽  
Group Design ◽  
Post Test ◽  
Experimental Group

This study aims  to determine of learning result in Guided Inquiry based SETS for buffer solution. The research conducted was SMA 55 Jakarta carried in 3th of April to 24th of Mar 2017. The study used purposive sampling technique,  from three class taken two classes obtained XI MIA A was treated as the experimental group using the Guided Inquiry learning based SETS, obtained class XI MIA B was treated as control group using the Guided Inquiry. The study used post-test group design. Test instruments used essay. Data of test instrument result,analyzed by statistical analysis test is comparison test of both class post-test value. The result is t-count = 1,868 while the t-table value at 5% significance level is 1,669. The concluded that there is influence of student learning result by  using guided inquiry based on SETS. Keywords : guided inquiry learning based SETS, learning result

scholarly journals Effect of exposure frequencies of pear juice on tooth whitening

2013 ◽  
Vol 25 (1) ◽  
Author(s):  
Gobalakrishna Munusamy ◽  
Endang Sukartini ◽  
Ayu Trisna Hayati
Keyword(s):  
Hydrogen Peroxide ◽  
Research Result ◽  
Control Group ◽  
Tooth Whitening ◽  
Whitening Effect ◽  
Significant Difference ◽  
Pear Juice ◽  
The Difference ◽  
Tooth Colour

Introduction: Tooth whitening (Bleaching) is a method to restore discoloured teeth to the original tooth colour with a chemical process. The materials used in the bleaching process are hydrogen peroxide, sodium perborates and carbamide peroxide. Pear fruit consists of hydrogen peroxide which is potentially an oxidizing compound that produces free radicals that react with unsaturated bonding teeth staining substances. This study aims to analyzed tooth whitening effect of exposure of pear juice with different frequencies. Methods: The type of research was true in vitro experiment where samples of 32 maxillary premolar teeth had cut the root to CEJ. The specimens divided into four groups. The first group was soaked in pear juice two times, the second group three times, a third group four times, and the fourth was the control group using only mineral water. Tooth colour was measure using a Spectrophometer, conducted before and after individual soaking. Results: The research result is tested with ANOVA and Newman- Keuls Range Test showed a significant difference of tooth whitening degree between the frequency exposure pear juice after 2 times soaking, 3 times soaking and 4 times soaking. Conclusion: There are difference degree of whitening from the difference frequency exposure of pear juice and Pear juice exposure of 4 times gives higher whitening effect compared to frequency of 3 times, 2 times and control group which is soaked in water.

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