bleaching agent
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2021 ◽  
Vol 33 ◽  
pp. 271
Author(s):  
Andrzej S. Dyszak

The study concerns the names of clothing, home furnishings, everyday objects, tools, and means of transport contained in the lexicon of the Bydgoszcz city dialect. This lexical stock includes the names of the outer garment (e.g. buks ‘trousers’), recreational clothes (badeje ‘swimming trunks’), headgear (e.g. lujmycka ‘hooligan’s cap’), footwear (e.g. kropusy ‘men’s shoes with high uppers’). Another area is the apartment; for example, the names of kitchen equipment have German origin (e.g. ausgust ‘kitchen sink’, kastrolka ‘saucepan’). This also concerns the names of three stools differing in height: the lowest one is called ryczka, a taller one is szemel, and the tallest is hoker. Texts in the Bydgoszcz city dialect also contain the names of artefacts necessary to perform everyday activities, such as cleaning (e.g. szruber ‘rice brush’) or laundry (e.g. balia ‘large wooden bath tub’). A separate place in the material culture of the inhabitants of Bydgoszcz is occupied by technological vocabulary, such as the names of tools (żaga ‘saw’) and transport (e.g. rolwaga ‘horse-drawn cart for transportation of goods’). Most of the names are Germanisms. A smaller number come from rural or folk dialects (e.g. modre ‘bleaching agent’, rydelek ‘visor of a cap’, szlory ‘old, trodden footwear’, trygiel ‘cast iron pot’). It is concluded that the city dialect is not only a museum or heritage park but also a treasury of old words.


2021 ◽  
Vol 6 (3) ◽  
pp. 130-135
Author(s):  
Nabam Yano ◽  
Sonam Sah ◽  
Lalita Sheoran ◽  
Monika Sehrawat ◽  
Dimple Budhiraja ◽  
...  

In today’s time tooth/teeth whitening has become the most common requested procedure from the clinician. As per the increasing demand by the patient for whiter teeth, there are various home based products are available like gels, tooth pastes and some other products are also available that can be applied by the dentist and it contains high amount of bleaching agent with in it. Some of the aware risk of tooth whitening procedure was also known such as, sensitivity of the tooth, irritation of the gingiva, demineralization of the tooth surface along with roughening of the superficial layer of the tooth.


2021 ◽  
Vol 11 (17) ◽  
pp. 7807
Author(s):  
Georgiana Florentina Gheorghe ◽  
Oana Elena Amza ◽  
Bogdan Dimitriu ◽  
Liliana Garneata ◽  
Ioana Suciu ◽  
...  

(1) Background: What is the effect of 16% and 40% concentration bleaching agents on dental structures in healthy patients compared to predialysis patients? (2) Methods: Forty teeth were included in the study (20 from healthy patients and 20 from predialysis patients). Each group was randomly divided into another two subgroups (n-10), depending on the bleaching agent concentration (16% and 40% gels). Color parameters were registered before and after the whitening process using a spectrophotometer. To determine enamel ultramicroscopic modifications, SEM and AFM analysis were performed before and after bleaching. (3) Results: An increasing trend was identified in the average values of ∆E and ∆L within the groups of predialysis teeth between teeth whitened with 40% concentration gel and those whitened with 16% concentration gel, while for the enamel samples from healthy patients the trend was reversed. The average values for roughness in the case of the two bleaching agents in healthy and predialysis teeth presented statistically significant differences (p < 0.05). (4) Conclusions: The effects of bleaching agents are less significant on teeth from predialysis compared to healthy patients. A direct link exists in terms of the clinical effect between the concentration of the whitening gel and color modifications.


2021 ◽  
Vol 9 (9) ◽  
pp. 98
Author(s):  
Alba Pallarés-Serrano ◽  
Sandra Pallarés-Serrano ◽  
Antonio Pallarés-Serrano ◽  
Antonio Pallarés-Sabater

Internal bleaching is a conservative, non-invasive, and simple treatment that is frequently performed in daily clinical practice. The present in vitro study analyzes the oxygen expansion of different bleaching agents resulting from the oxidation reaction when interacting with enamel and dentin. Enamel and dentin were crushed separately until obtaining a fine powder with particles of an approximate size between 0.06 and 0.2 mm. Each enamel and dentin sample were mixed with 37% carbamide peroxide (CP 37%), 30% hydrogen peroxide (HP 30%), sodium perborate (SP) combined with HP 30% (HP 30% + SP) and SP with distilled water (SP). A total of 280 1 mm diameter glass tubes were used with 70 for each bleaching agent (30 for powdered enamel evaluation, 30 for powdered dentin evaluation, and 10 controls). The bleaching agents were placed in the prepared tubes immediately after mixing the components. As expansion occurred, the oil inside the tube was displaced, through which the resulting expansion was evaluated and measured for 10 days. A significant expansion was observed that varied in magnitude according to the bleaching agent and the tooth structure used. Student’s t test and Welch’s ANOVA were used to analyze the data obtained. The highest mean expansion of both enamel and dentin was observed with 30% HP (66.6 mm for enamel, 94.5 mm for dentin) followed by HP 30% + SP (48.6 mm for enamel, 52.7 mm for dentin), CP 37% (38.4 mm for enamel, 52.6 mm for dentin) and finally SP with water (12.7 mm for enamel, 4.4 mm for dentin). It was observed that the expansion in the SP group with enamel was significantly lower than in the rest of the groups, while that registered for HP 30% was significantly higher. (p < 0.001). The results with dentin were similar, with a significantly lower expansion for SP and higher for HP 30% (p < 0.001). The oxygen expansion observed as a result of the interaction between bleaching agents and dental tissues could contribute to improving our understanding of bleaching and its results. These results suggest that bleaching agents react with the organic component of the tooth structure.


2021 ◽  
Vol 21 ◽  
pp. e225232
Author(s):  
Jaqueline Lazzari ◽  
Walbert Vieira ◽  
Vanessa Pecorari ◽  
Brenda Paula Figueiredo de Almeida Gomes ◽  
José Flávio Affonso de Almeida ◽  
...  

Aim: The objective of this study was to describe a case series concerning internal bleaching of anterior traumatized teeth that underwent regenerative endodontic procedures (REP). Methods: Seven non-vital maxillary anterior teeth discolored after regenerative endodontic procedures were included and divided into two groups according to the medication protocol used in the REP: (1) Triple antibiotic paste (TAP) group (n=4); (2) Calcium hydroxide and 2% chlorhexidine gel (HC+CHX) (n=3). The bleaching technique used was walking bleach, where sodium perborate associated with distilled water was used. Bleaching agent was replaced weekly until the darkened tooth was slightly lighter than the adjacent tooth. The color was recorded with the aid of a digital spectrophotometer in two moments (T1: prior the first session of bleaching, T2: fourteen days after the last session of bleaching). The change in color after the procedure (ΔE) was calculated and reported in a descriptive analysis. Results: The ΔE for all teeth showed color differences exceeding the perceptibility threshold (ΔE > 3.7). Both groups showed similar ΔE (TAP: 18.3 ± 11.5; HC+CHX: 14 ± 11.2) at the end of the treatment. The average number of sessions needed to achieve satisfactory results was 1.7 ± 0.6 for HC+CHX group and 2.3 ± 0.5 for TAP group. Conclusion: Internal bleaching with sodium perborate associated with distilled water is effective in treating discolored teeth after regenerative endodontic procedures.


Author(s):  
Tugba Serin-Kalay ◽  
Beyza Zaim

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.


2021 ◽  
Vol 55 (5-6) ◽  
pp. 667-673
Author(s):  
MOHAMED EL-SAKHAWY ◽  
AMAL H. ABD EL-KADER ◽  
TAMER Y. A. FAHMY ◽  
ESSAM S. ABD EL-SAYED ◽  
NESRINE F. KASSEM

Non-wood raw materials are an essential fiber source in regions where forest resources are limited. Therefore, chemi-mechanical high-yield bagasse pulp was prepared and then bleached with a dithionite bleaching agent. One- and two-stage bleaching of the pulp was carried out by using sodium dithionite (Y) as a sole bleaching agent, or after bleaching with hydrogen peroxide to achieve high brightness for the prepared pulp. Different parameters, such as consistency, concentration, temperature, time and pH were investigated. The effect of various additives, such as diethylenetriaminepentaacetic acid (DTPA) as chelating agent or Zn compounds and hexamethylenetetramine to stabilize the bleaching solution, was studied. The effect of dissolved oxygen in liquor was also considered.


2021 ◽  
Author(s):  
RC Kiyuna ◽  
LM Martins ◽  
TA Hanzen ◽  
A Reis ◽  
AD Loguercio ◽  
...  

SUMMARY Objective: This single-blind, split-mouth, randomized trial was aimed at evaluating the bleaching efficacy (BE) and tooth sensitivity (TS) of a 20% hydrogen peroxide (HP) bleaching agent used under active or passive application. Methods and Materials: Twenty-two patients with canines darker than C2 were selected. Teeth were bleached in two sessions, with a one-week interval between treatments. The bleaching agent was applied using active (HPactive) or passive (HPpassive) application. Each tooth in the HPactive-allocated hemiarch received bleaching gel with sonic activation after 10 and 30 minutes from the start of treatment, with rounded movements all over the buccal surface. The color changes were evaluated by subjective (Vita Classical and Vita Bleachedguide) and objective (VITA Easyshade Spectrophotometer) methods at baseline and 30 days after the second session. TS was recorded up to 48 hours after treatment using a 0–10 visual analog scale. Color change in shade guide units (SGUs) and ΔE was analyzed using a Wilcoxon test (α=0.05). The absolute risk and intensity of TS were evaluated using McNemar test and a Wilcoxon test, respectively (α=0.05). Results: Significant whitening was observed in both groups after 30 days of clinical evaluation. The activation did not significantly influence BE (ΔSGU HPpassive=5.6 and HPActive=5.8; p=0.98; and ΔE HPpassive=10.6 and HPactive=10.3; p=0.83). Absolute risk of TS (HPactive=36.4% and HPpassive=31.8%; p=0.94) was similar for both groups (Fisher exact test). TS intensity (visual analogue scale) was higher during the bleaching sessions and up to 24 hours thereafter for both groups, with no differences between groups (twoway analysis of variance and Tukey). Conclusion: The active application of a 20% HP gel did not improve BE and TS.


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