scholarly journals Is It Necessary to Prepare the Enamel before Dental Bleaching?

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Andréa Dias Neves Lago ◽  
Patrícia Moreira de Freitas ◽  
Erika Michele dos Santos Araújo ◽  
Adriana Bona Matos ◽  
Narciso Garone-Netto

The aim of this in vitro study was to assess the influence of distinct surface treatments on the microhardness and color of enamel that will be bleached. Surface treatments are tested, accordingly: G1, no treatment; G2, 2% sodium fluoride; G3, casein phosphopeptide paste; G4, 2% fluoride+Nd:YAG laser. Forty blocks from bovine teeth composed the sample that were tested in Knoop microhardness (n=10) and in color change (n=10). After 24 h, bleaching with 35% hydrogen peroxide was performed for 45 min. Microhardness and color changes (using parametersΔE,ΔL,Δa, andΔb) were assessed before and after bleaching. The data were analyzed by two-way ANOVA and Tukey’s test (p<0.05). Despite all surface treatments, a reduction of enamel microhardness occurred immediately after bleaching in all groups, being greater in G1. Enamel color changed in all groups. Immediately after bleaching, there was a decrease on enamel microhardness. However, after 7 days, some of those specimens previously treated before bleaching significantly recovered their initial microhardness without influencing the esthetic results of bleaching.

2020 ◽  
Vol 32 (4) ◽  
pp. 1-4
Author(s):  
Abeer B Mahmood

Background: Aesthetic archwires are used to overcome the aesthetic problems of stainless steel wires but the color of the coating layer can be changed with time when exposed to oral environments. The aim of this study was to evaluate the degree of color change of different aesthetic archwires from different companies under different coloring solutions. Materials and Methods: One hundred fifty samples of coated archwires from three companies (Highland, G&H and Dany) were immersed in 5 solutions (artificial saliva, turmeric, tea, coffee and Miranda) to evaluate the degree of color changes after 7, 14 and 21 days using visible spectrophotometer. Data were collected and analyzed using one way ANOVA and post hoc Tukey’s tests. Results: Turmeric solution caused high color change than other solutions. Aesthetic archwires from Highland company showed the highest degree of color change than archwires from other companies. Conclusions: Turmeric solution produced more discoloration than other solutions and the effects of these solutions are related to different chemical compositions of those solutions.


2012 ◽  
Vol 38 (1) ◽  
pp. E1-E8 ◽  
Author(s):  
HB Kara ◽  
F Aykent ◽  
B Ozturk

SUMMARY Purpose The aim of this in vitro study was to determine the color changes of five different restorative materials after exposing these materials to two different home bleaching agents. Methods This study applied bleaching agents to an ultralow-fusing porcelain, a low-fusing porcelain, two types of heat-pressed glass ceramics, and a ceromer. A total of 24 disc-shaped specimens were fabricated (with a diameter of 10 mm and a thickness of 2 mm) from each material (n=12). The initial color measurements were taken with a spectrophotometer. The first set of specimens were bleached with 10% hydrogen peroxide (HP) for one hour daily for 10 days. The other set of specimens were bleached with 10% carbamide peroxide (CP) bleaching gel for eight hours daily for 14 days. Data were analyzed with the one-way analysis of variance and Kruskal-Wallis statistical test. The difference in the prebleaching and postbleaching color of each material was considered to be statistically significant at p &lt; 0.05. Results The study found a statistically significant difference among the color changes of the test groups after exposing them to both bleaching agents (p&lt;0.05). Appreciable color change was observed in the Estenia (ΔE=3.99) specimens that were bleached with the HP, and noticeable color changes were observed in the Estenia (ΔE=1.89) and IPS Empress 2 (ΔE=1.66) groups when they were treated with the CP. Conclusions Restorations (especially polymer-containing restorative materials) should be protected before any bleaching procedure due to the high risk of color change.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 245
Author(s):  
Tatiana Zogheib ◽  
André Walter-Solana ◽  
Fernando de la Iglesia ◽  
Eduardo Espinar ◽  
Javier Gil ◽  
...  

Evaluate the quality of finishing and degree of contamination before and after handling and surface treatment of titanium (Ti) orthodontic mini-implants (OMIs). A scanning electron microscope (SEM) study on ninety-six titanium OMIs was done. Energy-Dispersive X-ray Analysis (EDX) identified the present particles on manufactured OMIs surfaces. Then, OMIs were manipulated with gauze (dry sterile, soaked in chlorhexidine) and gloves (latex, nitrile) to evaluate the contamination of these handling materials. Finally, OMIs underwent surface treatments and were placed in bone to observe the contaminants they released. Roughness (Ra) and wettability with contact angle parameter (CA) were measured on these treated OMIs. Machined OMIs presented surface irregularities and were contaminated with manufacturing-process particles (carbon, plastic Polyvinyl Chloride PVC, aluminum). Hand-manipulated OMIs were also contaminated by the handling materials. OMIs surface characteristics were as follows: acid-etched (Ra ≈ 1.3 μm, CA ≈ 66°), machined (Ra ≈ 0.3 μm, CA ≈ 68°), SB (Ra ≈ 3.3 μm, CA ≈ 78°), and SBAO (Ra ≈ 3.1 μm, CA ≈ 92°). Bone was contaminated by OMIs surface defects and extra particles. Manufactured OMIs have surface contaminants that increase with clinical handling. Surface treatments (SBAO, a combination of sandblasting and anodic oxidation) increase the roughness and contact angle, which play an important role in osseointegration. Surface-treated OMIs leave titanium particles in the bone during their insertion-removal. The use of a gauze soaked in chlorhexidine is recommended when handling OMIs. Further investigations would be interesting to study more variables and confirm the present results.


2014 ◽  
Vol 08 (04) ◽  
pp. 538-545 ◽  
Author(s):  
Cem Peskersoy ◽  
Ayhan Tetik ◽  
Veli Ozgen Ozturk ◽  
Necmi Gokay

ABSTRACT Objective: The aim of this in-vitro study was to evaluate the efficacy of bleaching products, determine the applicability and validation of the measurement methods. Materials and Methods: Freshly extracted 110 human incisor teeth were stained with whole blood and hemolysate solution prior to the application of 10 different home-bleaching products. Spectrophotometric measurements of the tooth shades were performed for each specimen before and after bleaching at the 1st, 3rd, 7th, and 14 days. Differences in lightness (Δl), chroma (Δc), hue (Δh) values and shade changes were measured to evaluate process. Computerized digital imaging analyses to determine the color changes were performed with Photoshop CS4 software (Adobe, San Jose, CA, USA). Statistical analyses were performed with analysis of variance, Scheffe and Tukey tests. Results: In all of the test groups regardless of the material used, a significant increase in lightness and hue, and decrease of chroma were observed, as compared to the control group. After recommended bleaching applications, Δl and Δh values respectively increased in group Zaris White and Brite (ZWB) and group Pola Night and Δc values showed significant decrease in groups ZWB and Rembrandt REM3 (P < 0.05). At the end of the procedure both spectrophotometric and digital imaging analysis showed ZWB was the most effective product among the others while Yotuel and Happy Smile were the least (P < 0.05). Conclusions: Home-bleaching systems showed slower but almost permanent bleaching effect likewise office-based methods. Both software and spectrophotometric analyses have advantages such as evaluating the results objectively and numerically, also treatment outcomes could be preserved.


2017 ◽  
Vol 41 (2) ◽  
pp. 120-125 ◽  
Author(s):  
Ahmed Nour El-din Ahmed Habib ◽  
Soad Abdelmoniem Abdelmoniem ◽  
Sara Ahmed Mahmoud

Aim: To assess the effect of four different children's drinks on color stability of resin dental composites. Study design: A total of one hundred and twenty specimens were prepared from Grandio SO, Filtek Z350 XT and Filtek Z250 XT (forty specimens each). Specimens were thermocycled, then each group was further subdivided into four subgroups (n=10) according to the immersion media which were chocolate milk, mango juice, orange fizzy drink, and water (control). The initial color parameters of each specimen were recorded before immersion (baseline) and color change values were recorded three and seven days after immersion in each solution using a digital spectrophotometer. Atomic force microscope was used to measure the surface roughness in randomly selected samples after one week immersion in children's drinks. Results: All the children's drinks produced color changes in the examined resin dental composites, yet there was no statistical significant difference between the effects of tested drinks on the color changes (mean ΔE) of the three different dental composites (P&gt;0.05). Conclusions: All tested children's drinks caused clinically unacceptable color changes of the tested resin dental composites. Immersion in chocolate milk and orange fizzy led to the highest color changes in the tested resin dental composites.


Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 160 ◽  
Author(s):  
Roxana-Diana Vasiliu ◽  
Sorin-Daniel Porojan ◽  
Mihaela-Ionela Bîrdeanu ◽  
Ion-Dragoș Uțu ◽  
Liliana Porojan

Dental ceramic restorations are widely used in restorative dentistry. However, these restorations can be affected once cemented in the oral cavity by several factors. How can conventional surface treatments, such as glazing and mechanical polishing, diminish the effects of aging? The purpose of this in vitro study was to evaluate the effect of thermocycling and conventional surface treatments on the surface roughness and microhardness of three types of glass-ceramics by using a profilometer, scanning electron microscopy (SEM), atomic force microscopy (AFM), and a microhardness tester. Three types of ceramic systems (zirconia reinforced lithium silicate glass-ceramic, lithium disilicate glass-ceramic, and feldspathic glass-ceramic) (n = 48) were prepared. The samples were subjected to thermocycling for 10,000 cycles. Surface roughness was evaluated numerically using a profilometer and visually by using SEM and AFM. Microhardness was performed using a microhardness tester. The data were interpreted using the ANOVA test, and the results were correlated using Pearson’s correlation formula (r). Significant differences were found before and after thermocycling for the Ra (p < 0.01) and Rz (p < 0.05) parameters. As well, differences between glazed and polished surfaces were significant before and after thermocycling for surface roughness and microhardness (p < 0.05). A correlation was made between average surface roughness and microhardness (r = −460) and for the maximum surface roughness and microhardness (r = −606). Aging increases the roughness and decreases in time the microhardness. The tested ceramic systems behaved differently to the aging and surface treatments. Surface treatments had a significant impact on the microhardness and surface characteristics. The glazed groups were reported with higher surface roughness and lower microhardness when compared to the polished groups before and after thermocycling. The measuring roughness techniques determine the scale-dependent values for the Ra (Sa) and Rz (Sq) parameters. Thermocycling almost doubled the surface roughness for all the tested samples. Microhardness decreased only for the Celtra glazed samples. Nano-roughness increased the values for Vita and slightly for Emax. Thermocycling had little effect on Emax ceramic and a more significant impact on Celtra Press ceramic.


2020 ◽  
Vol 14 (03) ◽  
pp. 335-341 ◽  
Author(s):  
Sandra Sarembe ◽  
Joachim Enax ◽  
Maria Morawietz ◽  
Andreas Kiesow ◽  
Frederic Meyer

Abstract Objective Oral care formulations aim to prevent oral diseases such as dental caries and gingivitis. Additionally, desire for white teeth still exists across all age groups. It is known that most whitening toothpastes are highly abrasive and can be harmful to teeth and gingiva. Therefore, a gel formulation with biomimetic hydroxyapatite (HAP; Ca5[PO4]3[OH]) as active ingredient was developed. This formulation was tested with respect to its tooth whitening properties in an in vitro study. Materials and Methods Enamel samples were allocated to either group (a) HAP gel, (b) whitening mouth rinse with phosphates, or (c) negative control (distilled water). Test products were applied by finger (a) or were rinsed (b, c) for 1, 3, and 9 (b and c only) cycles, respectively. Results Color changes (ΔE) were measured spectrophotometrically. Group (a) showed a significant increase in color changes with respect to whitening after one cycle (mean ΔE = 5.4 [±2.66], p ≤ 0.006) and three cycles (mean ΔE = 11.2 [±3.11], p < 0.0001) compared to groups (b) and (c). For group (b), a significant increase in color change was measured after three (mean ΔE = 2.77 [±1.01], p = 0.02) and nine cycles (mean ΔE = 3.27 [±1.61], p = 0.006) compared to (c). Group (c) showed only minor and statistically insignificant color changes. Conclusion This in vitro study demonstrated a significantly higher ad hoc whitening effect of the HAP gel compared to the mouth rinse and water after short-time application.


Author(s):  
Yemineni BhavanChand ◽  
R Ranzani ◽  
H Annapoorani

ABSTRACT Objective To evaluate the hemocompatibility of titanium after various surface treatments. Materials and methods A total of 27 disk-shaped specimens (3 ⨯ 10.0 mm) were prepared from a cylindrical rod of medical grade titanium. The disks were divided into three groups, of which one was considered as the control (mechanical surface polished surface). The other groups being sandblasted disks and anodized disks. Surface evaluation was done for sandblasted and anodized disks with scanning electron microscope. The specimens were placed in polystyrene culture plates and agitated with phosphate buffered saline for 5 minutes before they were exposed to blood taken from human volunteer. The materials were under 30 minutes agitation at 75 ± 5 rpm using an Environ shaker thermostated at 35 ± 20°C. The total hemoglobin from the initial sample was measured using automatic hematology analyzer. Percentage hemolysis, thrombin time, platelet adhesion and activation were assessed. Significant differences between different treated titanium materials were determined using Minitab® Version 15.1.1.0. A two-sample t-test was performed to find the p-values for different groups of data. Results After 30 minutes of agitation, cells began to spread on the test surfaces. There was a clear reduction in the number of platelets before and after exposure to titanium samples. Reduction of leukocytes was seen to a least extent on the anodized surface. Rough surface induced higher hemolysis than other groups. Platelet reduction and leukocyte reduction in all the three surfaces was quite higher than that obtained for reference plate. Surface variation has no significance on the thrombogenic capabilities of medical grade titanium (p < 0.05). Significance The hemocompatibility of medical grade titanium did not vary with different surface modifications. How to cite this article BhavanChand Y, Ranzani R, Annapoorani H. Evaluation of Hemocompatibility of Titanium after Various Surface Treatments: An in vitro Study. Int J Prosthodont Restor Dent 2012;2(4):136-142.


2020 ◽  
Vol 25 (1) ◽  
pp. 26-27
Author(s):  
Shaza M. Hammad ◽  
Noha A. El-Wassefy ◽  
Mohamed A. Alsayed

ABSTRACT Objective: To qualitatively and quantitatively assess the color changes effect and the color stability of the resin infiltrant on white spot lesions (WSLs), in comparison with nano-hydroxyapatite (nano-HA) toothpaste and microabrasion. Methods: WSLs were artificially created on sixty human premolars enamel surfaces and randomly assigned to equal four groups (n = 15 each): nano-HA toothpaste, microabrasion (Opalusture), resin infiltrant (Icon) treatment, or artificial saliva (control group). The color change (ΔE) of each specimen was measured by dental spectrophotometer (Vita Easyshade) at different time points: baseline, after WSLs’ creation, after application of treatments, one month, three and six months after treatments application. Results: The ΔE value did not differ significantly for the four groups at baseline measurement before treatment (p> 0.05). Icon resin infiltrant improved the color of WSLs significantly immediately after its application, giving the lowest ΔE value (3.00 ± 0.59), when compared to other treatments (p< 0.001). There were no significant changes in ΔE (p> 0.05) for all groups during the follow up intervals (one month, three and six months after treatments application). Conclusion: Resin infiltrant can improve the color of WSLs and restore the natural appearance of enamel better than nano-HA toothpaste and microabrasion.


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