Effects of Light Activated In-office Bleaching on Permeability, Microhardness, and Mineral Content of Enamel

2014 ◽  
Vol 39 (5) ◽  
pp. E225-E230 ◽  
Author(s):  
SO Parreiras ◽  
P Vianna ◽  
S Kossatz ◽  
AD Loguercio ◽  
A Reis
Keyword(s):  
Mineral Content ◽  
Phosphorus Content ◽  
Artificial Saliva ◽  
Control Group ◽  
Light Activation ◽  
Data Set ◽  
Copper Sulphate Solution ◽  
X Ray ◽  
Rubeanic Acid ◽  
Bleaching Treatment

SUMMARY The aim of this study was to evaluate the permeability (PE), microhardness (KHN), and mineral change in enamel after LED/laser activated in-office bleaching. For PE, the coronal portion of premolars (n=51) was subjected to bleaching with 35% hydrogen peroxide (Whiteness HP Maxx, FGM Dental Products, Joinville, SC, Brazil). The samples were stained via the histochemical method, which involves a copper sulphate solution and rubeanic acid. The penetration of dye into the enamel was measured. The KHN of enamel was assessed before treatment, immediately after the bleaching treatment, and again after one week. The calcium and phosphorus content were analyzed with a scanning electron microscope with energy-dispersive X-ray (JSM 6360LV, Jeol Ltd, Tokyo, Japan). The data set from each test was subjected to appropriate parametric statistical analysis (α=0.05). No significant differences were observed for PE in NLA and LA compared to the control group (p=0.98), as well as for calcium (p=0.16) and phosphorus (p=0.80) content. Significant reduction of KHN after bleaching occurred for both groups (p<0.001). After immersion in artificial saliva, the KHN of the enamel for all groups was similar to that seen before bleaching. Light activation during in-office bleaching does not produce significant changes in the enamel compared to a non–light-activated technique.

scholarly journals Comparison of the Efficacy of Different Fluoride Varnishes on Dentin Remineralization During a Critical pH Exposure Using Quantitative X-Ray Microtomography

2018 ◽  
Vol 43 (6) ◽  
pp. E308-E316
Author(s):  
A Sleibi ◽  
A Tappuni ◽  
D Mills ◽  
GR Davis ◽  
A Baysan
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Mineral Content ◽  
Test Group ◽  
Control Group ◽  
Mineral Concentration ◽  
Voxel Size ◽  
X Ray ◽  
Casein Phosphopeptide

SUMMARY Objectives: The objective of this in vitro study was to quantify the amount of mineral change in demineralized dentin at pH 5.5 after the application of dental varnishes containing fluoride with casein phosphopeptide–amorphous calcium phosphate, fluoride and bioglass, or fluoride alone. Methods and Materials: A total of 12 extracted human sound mandibular premolar root samples were coated with an acid-resistant varnish, leaving a 2 × 3 mm window at the outer root surface. These root specimens were then randomly divided into four groups and separately subjected to the demineralizing cycle at a pH of 4.8 for five days to create artificial caries-like lesions in dentin. Subsequently, each sample was imaged using quantitative x-ray microtomography (XMT) at a 15-μm voxel size. Each test group then received one of the following treatments: dental varnish containing casein phosphopeptide–amorphous calcium phosphate and fluoride (CPP-ACP, MI varnish, GC Europe), bioglass and fluoride (BGA, Experimental, Dentsply Sirona), or fluoride alone (NUPRO, Dentsply Sirona), as well as a control group, which received no treatment. These samples were kept in deionized water for 12 hours. The thin layer of varnish was then removed. All samples including the nonvarnish group were subjected to the second demineralizing cycle at pH 5.5 for five days. The final XMT imaging was then carried out following the second demineralizing cycle. XMT scan was also carried out to varnish samples at 25 μm voxel size. The change in mineral concentration in the demineralized teeth was assessed using both qualitative and quantitative image analysis. Results: There was an increase in radiopacity in the subtracted images of all varnish groups; a significant increase in mineral content, 12% for the CPP-ACP and fluoride (p≤0.05 and p≤0.001), 25% BGA (p≤0.001), and 104% fluoride alone varnish (p≤0.001). There was an increase in the size of radiolucency in the lesion area with a significant decrease in mineral content in the nonvarnish group, 10% (p≤0.05 and p≤0.001). Conclusions: There was encouraging evidence of a remineralization effect following the application of dental varnish on dentin and also an observed resistance to demineralization during the acidic challenge in all cases. However, a dental varnish containing fluoride alone appeared to have a much greater effect on dentin remineralization when compared with CPP-ACP with fluoride and bioglass with fluoride.

scholarly journals Influence of Simulated Pulpal Pressure on Efficacy of Bleaching Gels

2014 ◽  
Vol 15 (4) ◽  
pp. 407-412 ◽  
Author(s):  
Carlos Rocha Gomes Torres ◽  
Graziela Ribeiro Batista ◽  
Alessandra Bühler Borges ◽  
Paula Tamião Arantes ◽  
Annette Wiegand ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Artificial Saliva ◽  
Negative Control ◽  
Color Variation ◽  
Color Measurement ◽  
Control Group ◽  
Significant Difference ◽  
Bleaching Gels ◽  
Bleaching Treatment

ABSTRACT Aim The aim of this study was to investigate the influence of simulated pulpal pressure on efficacy of bleaching gels. Materials and methods Cylindrical enamel-dentin specimens from bovine teeth (3 mm diameter, enamel and dentin layer each 1 mm thick) were divided into 4 groups, according to the bleaching treatment: negative control (non-bleached), bleached with 10% carbamide peroxide (CP), bleached with 7.5% hydrogen peroxide (HP) and bleached with 35% hydrogen peroxide. Ten percent CP gel was applied for 8 h/day and 7.5% HP for 1 h/day, during 14 days. For 35% HP treatment, two sessions of 45 minutes each were employed. In intermediate periods specimens were stored in artificial saliva. Experimental groups (n = 19) were subdivided according to the simulation of pulpal pressure (25 mm Hg) during bleaching treatment. Initial color measurement and after bleaching treatment were assessed by spectrophotometry, using CIE L*a*b* system. The data were statistically analyzed by ANOVA and Dunnett's posthoc tests (p < 0.05). Results There was significant difference of ∆E for all experimental groups compared to negative control group, according to Dunnett's test (p < 0.0001). There were no significant difference for total color variation (∆E) among experimental groups (p > 0.05). Conclusion It was concluded that all bleaching gels showed bleaching efficacy compared to non-bleached group and that the simulated pulpal pressure did not influence the bleaching outcomes of the tested gels. Clinical significance Although numerous in vitro studies investigating the efficacy of bleaching agents have been performed, they do not properly simulate the pulpal pressure. In order to make these studies closer to clinical conditions, it is important to reproduce these conditions in laboratory, so the results can be more reliable. This in vitro study was performed under simulated pulpal pressure, aiming to investigate its influence on dental bleaching outcomes. How to cite this article Borges AB, Batista GR, Arantes PT, Wiegand A, Attin T, Torres CRG. Influence of Simulated Pulpal Pressure on Efficacy of Bleaching Gels. J Contemp Dent Pract 2014;15(4):407-412.

Nano-hydroxyapatite could Compensate the Adverse Effect of Soft Carbonated Drinks on Enamel

2016 ◽  
Vol 17 (8) ◽  
pp. 635-638 ◽  
Author(s):  
Mohammad B Rezvani ◽  
Mohammad R Rouhollahi ◽  
Fahimeh Andalib ◽  
Faeze Hamze
Keyword(s):  
Adverse Effect ◽  
Mineral Content ◽  
Protective Factor ◽  
Artificial Saliva ◽  
Soft Drink ◽  
Treatment Protocol ◽  
Control Group ◽  
Tooth Structure ◽  
Before And After ◽  
Carbonated Drinks

ABSTRACT Introduction Since one of the most important disadvantages of soft drinks includes their adverse effect on mineral content of enamel because of their low pH, this study examined the microhardness of enamel before and after exposure to a soft drink containing different concentrations of nano-hydroxyapatite (nano-HA) as an additive. Materials and methods Sixty caries free human premolars were mounted in epoxy resin. After polishing, the baseline microhardness was recorded three times for each specimen using a Vickers indenter at 50 gm load. Subsequently, the samples were divided into six groups, which were treated for 5 minutes at 9°C by a cola-based drink contacting 0, 0.5, 1, 5, and 10 wt.% of nano-HA while the control group was immersed in artificial saliva. Ultimately, the final microhardness was assessed three times again for each specimen. Results Paired t-test showed that in groups containing 0 and 0.5 wt.% of nano-HA, the microhardness was significantly reduced after treatment protocol (p = 0.00 and 0.01 respectively). Whereas in the other groups the microhardness was not significantly changed after treatment (p > 0.05). Conclusion Pure cola-based drink has a pronounced adverse effect on enamel microhardness, while admixing it with nano-HA could act as a protective factor. Clinical significance Although soft beverages are hazardous to tooth structure, some additives could compensate their adverse effect. How to cite this article Rezvani MB, Rouhollahi MR, Andalib F, Hamze F. Nano-hydroxyapatite could Compensate the Adverse Effect of Soft Carbonated Drinks on Enamel. J Contemp Dent Pract 2016;17(8):635-638.

scholarly journals Differences in surface roughness of enamel after whey-extract application and CPP-ACP in post extracoronal-tooth bleaching

2018 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Afiatul Mukarromah ◽  
Irfan Dwiandhono ◽  
Dian Noviyanti Agus Imam
Keyword(s):  
Surface Roughness ◽  
Artificial Saliva ◽  
Enamel Surface ◽  
Tooth Bleaching ◽  
Control Group ◽  
Group Iii ◽  
Group I ◽  
Significant Difference ◽  
Group Ii ◽  
Bleaching Treatment

Demineralization is a process of partial or full tooth mineral loss which caused by acidic environment, for example the side effect of extracoronal bleaching treatment. Demineralization increases enamel surface roughness which leads plaque accumulation. Whey extract and calcium phosphopeptide-amorphous calcium phophate (CPP-ACP) contain calcium and phosphate that can stop the demineralization through remineralization process. This study aimed to determine the differences of enamel surface roughness after whey extract and CPP-ACP application post- extracoronal bleaching. Experimental laboratory with pre- and post-test control group design was performed on 24 first maxillary premolars which devided into 3 groups. On group I, specimens were immersed in artificial saliva. Specimens in group II were immersed in whey extract meanwhile specimens were immersed in CPP-ACP on group III. Whey extract and CPP-ACP immersions were conducted 10 minutes every 12 hours for 15 days. The enamel surface roughness test was performed twice, after extracoronal bleaching treatment and after 15 days remineralization agent application. This study result indicated significant differences between group I and group II and between group I and group III (p<0.05), but there was no significant difference between group II and group III (p>0.05). This study showed whey extract decreased more enamel surface roughness than CPP-ACP but the difference was not significant statistically. So, whey extract and CPP-ACP showed similar remineralization potential.

scholarly journals Analysis of the Chemical Modification of Dental Enamel Submitted to 35% Hydrogen Peroxide “In-Office” Whitening, with or without Calcium

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Rudá França Moreira ◽  
Fábio Pinheiro Santos ◽  
Estevão Antero Santos ◽  
Ramon Silva dos Santos ◽  
Marcelino José dos Anjos ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphorus Content ◽  
Dental Enamel ◽  
Significant Loss ◽  
Human Teeth ◽  
X Ray ◽  
Calcium And Phosphorus ◽  
Group 2 ◽  
Bleaching Treatment ◽  
Group 1

Purpose. The purpose of this study was to evaluate changes in calcium and phosphorus content in dental enamel when subjected to “in-office” whitening for an extended time by using a 35% hydrogen peroxide solution, with and without calcium. Materials and Methods. 10 human teeth, from which the roots had been removed, were embedded in epoxy resin, and their surfaces were smoothed. The specimens were divided into two groups; in group 1, a whitening solution without calcium was used, while in group 2, the solution included calcium. Each specimen was evaluated at 6 different points before the bleaching treatment, and these points were reassessed after each session. A total of five sessions were carried out. Concentrations of calcium and phosphorus were measured by using the technique of X-ray fluorescence. Results. After performing a statistical analysis, it was found that there was no statistically significant loss of calcium and phosphorus during the whitening treatment, and the groups showed no statistical differences. Conclusion. Excessive use of hydrogen peroxide, with or without calcium, causes no loss of calcium and phosphorus.

scholarly journals A Chitosan–Agarose Polysaccharide-Based Hydrogel for Biomimetic Remineralization of Dental Enamel

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1137
Author(s):  
Viorica Muşat ◽  
Elena Maria Anghel ◽  
Agripina Zaharia ◽  
Irina Atkinson ◽  
Oana Cătălina Mocioiu ◽  
...  
Keyword(s):  
Tooth Enamel ◽  
Artificial Saliva ◽  
Dental Enamel ◽  
Control Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Human Enamel ◽  
Rod Structures ◽  
Natural Tooth ◽  
Scanning Electron

Developing multifunctional systems for the biomimetic remineralization of human enamel is a challenging task, since hydroxyapatite (HAP) rod structures of tooth enamel are difficult to replicate artificially. The paper presents the first report on the simultaneous use of chitosan (CS) and agarose (A) in a biopolymer-based hydrogel for the biomimetic remineralization of an acid-etched native enamel surface during 4–10-day immersion in artificial saliva with or without (control group) fluoride. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, Fourier transform infrared and Raman spectroscopies, X-ray diffraction, and microhardness tests were applied to investigate the properties of the acid-etched and remineralized dental enamel layers under A and CS-A hydrogels. The results show that all biomimetic epitaxial reconstructed layers consist mostly of a similar hierarchical HAP structure to the native enamel from nano- to microscale. An analogous Ca/P ratio (1.64) to natural tooth enamel and microhardness recovery of 77.4% of the enamel-like layer are obtained by a 7-day remineralization process in artificial saliva under CS-A hydrogels. The CS component reduced carbonation and moderated the formation of HAP nanorods in addition to providing an extracellular matrix to support growing enamel-like structures. Such activity lacked in samples exposed to A-hydrogel only. These data suggest the potential of the CS-A hydrogel in guiding the formation of hard tissues as dental enamel.

scholarly journals Do different bleaching protocols affect the enamel microhardness?

2015 ◽  
Vol 09 (01) ◽  
pp. 025-030 ◽  
Author(s):  
Rafael Francisco Lia Mondelli ◽  
Taisa R. Conti Garrido Gabriel ◽  
Fabio Antonio Piola Rizzante ◽  
Ana Carolina Magalhães ◽  
Juliana Fraga Soares Bombonatti ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Bleaching ◽  
Control Group ◽  
Light Activation ◽  
Surface Microhardness ◽  
Surface Alteration ◽  
Bovine Enamel

ABSTRACT Objective: Tooth bleaching tends to increase enamel roughness and porosity, in addition to reducing surface microhardness. The aim of this in vitro study was to evaluate the effects of bleaching treatments using different hydrogen peroxide (HP) concentrations, with and without light activation on bovine enamel microhardness. Materials and Methods: The buccal surfaces of sixty bovine incisors were flattened and polished and the enamel specimens were divided into six groups: G1: Control, exposed to artificial saliva; G2: 35% HP applied in two sessions (45’ each); G3: 35% HP applied in two sessions (3 × 15’ each); G4: 35% HP applied in one session (3 × 7’30”) plus hybrid light (HL); G5: 25% HP applied in one session (3 × 7’30”) plus HL; and G6: 15% HP applied in one session (3 × 7’30”) plus HL. After the treatment, the enamel specimens were stored in artificial saliva. The surface microhardness (Knoop) was measured at the baseline, 24 h and 7 days after bleaching. The data was analyzed using the ANOVA test, followed by the Tukey–Krummer test (P < 0.05). Results: All bleaching procedures lead to a decrease in surface microhardness when compared with the control group after 24 h. The lowest change in surface microhardness was found in the specimens treated with 15% HP plus HL. However, 35% HP plus HL induced the highest decrease in surface microhardness. After 7 days of remineralization, the surface microhardness returned to normal levels for all bleached specimens. Conclusion: Therefore, it can be concluded that the bleaching protocols caused a slight enamel surface alteration. However, the remineralization process minimized these effects.

scholarly journals Effect of bleaching protocols with 38% hydrogen peroxide and post-bleaching times on dentin bond strength

2011 ◽  
Vol 22 (4) ◽  
pp. 317-321 ◽  
Author(s):  
Aline Evangelista Souza-Gabriel ◽  
Lilian Oliveira Cambaúva Vitussi ◽  
Camila Milani ◽  
Edson Alfredo ◽  
Danielle Cristine Furtado Messias ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Bond Strength ◽  
Light Source ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Adhesive System ◽  
Control Group ◽  
Light Activation ◽  
Single Bond ◽  
Bleaching Treatment

This study assessed the effect of bleaching protocols with 38% hydrogen peroxide (HP) and post-bleaching times on shear bond strength of a composite resin to dentin. One-hundred slabs of intracoronary dentin were included and randomly assigned into 2 groups according to the bleaching protocol: HP (2 applications of 10 min each) and HP activated by LED laser (2 applications of 10 min each/45 s of light activation). Groups were subdivided according to the post-bleaching time (n=10): 1 day, 3 days, 7 days, 10 days and 14 days. The control group was unbleached and restored (n=10). The specimens were restored with Single Bond adhesive system/Filtek Z250 resin using a polytetrafluorethylene matrix and were submitted to the shear bond strength testa after 24 h,. Data were analyzed by ANOVA and Tukey's test (α=0.05). Unbleached group (0.283 ± 0.134) had the highest bond strength and was statistically similar (p>0.05) to HP/10 days (0.278 ± 0.064), HP + LED laser/10 days (0.280 ± 0.078), HP/14 days (0.281 ± 0.104), HP + LED laser/14 days (0.277 ± 0.093). Lower bond strength were verified in HP/1 day (0.082 ± 0.012), HP/3 days (0.079 ± 0.013), HP + LED laser/1 day (0.073 ± 0.018) and HP + LED laser/3 days (0.080 ± 0.015), which were statistically similar (p>0.05). HP/7 days (0.184 ± 0.154) and HP + LED laser/7 days (0.169 ± 0.102) had intermediate values (p<0.05). The restorative procedure of intracoronary dentin bleached with 38% HP with or without the use of light source should be performed after at least 10 days after the bleaching treatment.

scholarly journals Whitening mouthwash containing hydrogen peroxide decreases enamel microhardness in vitro.

2017 ◽  
Vol 16 ◽  
pp. 1-9 ◽  
Author(s):  
Fernando Pelegrim Fernandes ◽  
Cecília Pedroso Turssi ◽  
Fabiana Mantovani Gomes França ◽  
Roberta Tarkany Basting ◽  
Flávia Lucisano Botelho do Amaral
Keyword(s):  
Hydrogen Peroxide ◽  
Repeated Measures ◽  
Artificial Saliva ◽  
Control Group ◽  
Carbamide Peroxide ◽  
Knoop Microhardness ◽  
Bovine Enamel ◽  
Bleaching Treatment ◽  
Over Time

Aim: To assess the effect of a mouthwash containing hydrogen peroxide (HP) on Knoop microhardness (KMH) of bovine enamel. Methods: Fifty-one enamel slabs were polished and divided into groups (n=17), according to the product used during 28 days: HP – mouthwash containing 1,5% of HP (4 min, once/day); CP - 10% carbamide peroxide gel (2 hours/day); AS - no treatment (kept in artificial saliva (AS). Each fragment was submitted to KMH test (three indentations/fragment, with a 50 g load for 5 sec) four times: before (baseline); during (14 and 28 days) and after (7 days immerged in AS) the bleaching treatment. The data were submitted to repeated-measures two-way ANOVA (α=0.05). Results: There was no effect of the interaction between the time and treatment factors (p=0.327). No significant effect was observed from the time factor (p = 0.054). The factor treatment showed significant effect (p =0.002). Regardless of time, the KMH of the enamel submitted to HP was lower than the value observed with the use of CP, which did not differ significantly from the control group (AS). Conclusion: Although there was a trend of decreasing enamel microhardness over time, only the mouthwash containing hydrogen peroxide had a significant effect.

Effect of Delaying Toothbrushing During Bleaching on Enamel Surface Roughness: An In Vitro Study

2013 ◽  
Vol 38 (2) ◽  
pp. 218-225 ◽  
Author(s):  
EJ Navimipour ◽  
N Mohammadi ◽  
S Mostafazadeh ◽  
M Ghojazadeh ◽  
PA Oskoee
Keyword(s):  
Surface Roughness ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Enamel Surface ◽  
Control Group ◽  
Bleaching Procedure ◽  
Bleaching Treatment ◽  
Control Group Group ◽  
Group 1

SUMMARY This study aimed to evaluate the effect of toothbrushing on enamel surface roughness at three different intervals after daily bleaching treatment. Eighty enamel slabs were initially evaluated for surface roughness and then randomly divided into four groups. The bleaching procedure was carried out for 21 days, six hours daily. In the control group (group 1), the specimens were not brushed after bleaching, but in groups 2–4, they were brushed with toothpaste immediately, one hour, or two hours after bleaching, respectively. Then the specimens were stored in artificial saliva. Enamel surface roughness was reevaluated at the end of the period. Kruskal-Wallis and Mann-Whitney U tests showed statistically significant differences in the means of surface roughness values between the immediately brushed group and the three other groups (p&lt;0.001). Daily toothbrushing immediately after bleaching increased enamel surface roughness; however, postponing the procedure for one or two hours after daily bleaching and exposing the specimens to artificial saliva during the study period resulted in enamel surface roughness comparable to that of the control group.

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