scholarly journals Artificial Saliva Formulations versus Human Saliva Pretreatment in Dental Erosion Experiments

2016 ◽  
Vol 50 (1) ◽  
pp. 78-86 ◽  
Author(s):  
Graziela Ribeiro Batista ◽  
Carlos Rocha Gomes Torres ◽  
Beatrice Sener ◽  
Thomas Attin ◽  
Annette Wiegand
Keyword(s):  
Calcium Release ◽  
Artificial Saliva ◽  
Dental Erosion ◽  
Human Saliva ◽  
Deionized Water ◽  
Vitro Experiment ◽  
In Vitro Experiment ◽  
Calcium Loss

The aim of this study was to evaluate the erosion-preventive effect of different artificial saliva formulations and human saliva in vitro compared to human saliva in situ. In the in vitro experiment, bovine enamel and dentin specimens were stored in artificial saliva (4 different formulations, each n = 20), deionized water (n = 20) or human saliva (n = 6 enamel and dentin specimens/volunteer) for 120 min. In the in situ experiment, each of the 6 enamel and dentin specimens was worn intraorally by 10 volunteers for 120 min. The specimens were then eroded (HCl, pH 2.6, 60 s). Half of the specimens were subjected to microhardness analysis (enamel) and the determination of calcium release into the acid (enamel and dentin), while the other half were again placed in the respective medium or worn intraorally, respectively, for 120 min before a second erosion was performed. Knoop microhardness of enamel and the calcium release of enamel and dentin into the acid were again determined. Statistical analysis was conducted by two-way repeated-measures ANOVA or two-way ANOVA (α = 0.05). Enamel microhardness was not significantly different between all test groups after the first and the second erosive challenge, respectively. Enamel calcium loss was significantly lower in situ compared to the in vitro experiment, where there was no significant difference between all test groups. Dentin calcium loss was significantly lower than deionized water only after the first and than all except one artificial saliva after the second erosion. Under the conditions of this experiment, the use of artificial saliva formulations and human saliva in vitro does not reflect the intraoral situation in dental erosion experiments adequately.

scholarly journals Effects of Two In-Office Bleaching Agents with Different pH on the Structure of Human Enamel: An In Situ and In Vitro Study

2013 ◽  
Vol 38 (1) ◽  
pp. 100-110 ◽  
Author(s):  
Y Sa ◽  
L Sun ◽  
Z Wang ◽  
X Ma ◽  
S Liang ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Storage Condition ◽  
Human Saliva ◽  
Low Ph ◽  
Force Microscopy ◽  
Human Enamel ◽  
And Control

SUMMARY This study evaluated the effects of two in-office bleaching agents (Beyond and Opalescence Boost) with different pH on the structure and mechanical properties of human enamel in vitro and in situ. One hundred and eight enamel slabs were obtained from freshly extracted premolars. The specimens were randomly distributed into nine groups (n=12), and the human saliva (HS) in the volunteers' oral cavities was used to simulate the in situ condition: Beyond + HS, Opalescence Boost (O-Boost) + HS, Control + HS, Beyond + artificial saliva (AS), O-Boost + AS, Control + AS, Beyond + distilled water (DW), O-Boost + DW, and Control + DW. The bleaching treatments were performed on the first and eighth day, and the total bleaching time was 90 minutes. Baseline and final surface roughness (RMS), surface morphology, microhardness, and fracture toughness (FT) were measured before the treatment and on the fifteenth day, respectively. Compared with control groups, surface alterations on enamel were found in the Beyond + AS and Beyond + DW groups under atomic force microscopy evaluation. Two-way analysis of variance and Tukey test revealed that the RMS showed significant intergroup differences for both storage condition and bleaching agent, whereas microhardness and FT revealed no significant alteration. The results indicated that in-office bleaching agents with low pH values could induce enamel morphology alterations under in vitro conditions. The presence of natural HS could eliminate the demineralization effect caused by low pH.

In Silico and in Vitro Evaluation of Deamidation Effects on the Stability of the Fusion Toxin DAB389IL-2

2019 ◽  
Vol 16 (4) ◽  
pp. 307-313 ◽  
Author(s):  
Nasrin Zarkar ◽  
Mohammad Ali Nasiri Khalili ◽  
Fathollah Ahmadpour ◽  
Sirus Khodadadi ◽  
Mehdi Zeinoddini
Keyword(s):  
In Silico ◽  
Catalytic Domain ◽  
Md Simulations ◽  
Special Importance ◽  
Native Form ◽  
Vitro Experiment ◽  
In Vitro Experiment ◽  
Pharmaceutical Protein ◽  
The Stability

Background: DAB389IL-2 (Denileukin diftitox) as an immunotoxin is a targeted pharmaceutical protein and is the first immunotoxin approved by FDA. It is used for the treatment of various kinds of cancer such as CTCL lymphoma, melanoma, and Leukemia but among all of these, treatment of CTCL has special importance. DAB389IL-2 consists of two distinct parts; the catalytic domain of Diphtheria Toxin (DT) that genetically fused to the whole IL-2. Deamidation is the most important reaction for chemical instability of proteins occurs during manufacture and storage. Deamidation of asparagine residues occurs at a higher rate than glutamine residues. The structure of proteins, temperature and pH are the most important factors that influence the rate of deamidation. Methods: Since there is not any information about deamidation of DAB389IL-2, we studied in silico deamidation by Molecular Dynamic (MD) simulations using GROMACS software. The 3D model of fusion protein DAB389IL-2 was used as a template for deamidation. Then, the stability of deamidated and native form of the drug was calculated. Results: The results of MD simulations were showed that the deamidated form of DAB389IL-2 is more unstable than the normal form. Also, deamidation was carried by incubating DAB389IL-2, 0.3 mg/ml in ammonium hydrogen carbonate for 24 h at 37o C in order to in vitro experiment. Conclusion: The results of in vitro experiment were confirmed outcomes of in silico study. In silico and in vitro experiments were demonstrated that DAB389IL-2 is unstable in deamidated form.

scholarly journals In Vitro Effects of Resin Infiltration on Enamel Erosion Inhibition

2015 ◽  
Vol 40 (5) ◽  
pp. 492-502 ◽  
Author(s):  
GC Oliveira ◽  
AP Boteon ◽  
FQ Ionta ◽  
MJ Moretto ◽  
HM Honório ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Adhesive System ◽  
Dental Erosion ◽  
Deep Penetration ◽  
Resin Infiltration ◽  
Fluorescence Confocal Microscopy ◽  
In Vitro Effects

SUMMARY Resin-based materials that show promising effects for preventing the progression of erosion have been studied. This in vitro study evaluated the effects of applying resin-based materials, including resin infiltration, on previously eroded enamel subjected to erosive challenges. The influence of enamel surface etching prior to application of the material was also studied. Bovine enamel blocks were immersed in hydrochloric acid (HCl), 0.01 M (pH 2.3), for 30 seconds in order to form a softened erosion lesion. The blocks were then randomly divided into nine groups (n=12) and treated as follows: C = control without treatment; Hel = pit & fissure resin sealant (Helioseal Clear); Adh = two-step self-etching adhesive system (AdheSe); Tet = two-step conventional adhesive system (Tetric N-bond); and Inf = infiltrant (Icon). The Helno, Adhno, Tetno, and Infno groups received the same materials without (or with no) surface conditioning. The depth of the material's penetration into softened erosion lesions was qualitatively analyzed using reflection and fluorescence confocal microscopy. After application of the materials, the blocks were immersed in HCl for two minutes; this step was followed by immersion in artificial saliva for 120 minutes four times a day for five days (erosive cycling). Both the enamel alteration and material thickness were analyzed using profilometry, and the results were submitted to Kruskal-Wallis and Dunn tests (p>0.05). Images from the confocal microscopy showed minimal penetration of Adh/Adhno and deep penetration of Inf/Infno into the erosive lesions. The groups Hel, Adh, Inf, Tetno, and Infno resulted in the formation of a layer of material over the enamel, which was effective in inhibiting the progression of erosion. In conclusion, the infiltrant, with or without etching, was able to penetrate and protect the enamel against dental erosion. The other resin-based materials, except for the two-step conventional adhesive, were able to penetrate and inhibit the progression of erosive lesions only when they were applied after enamel etching.

Effect of bleaching on ethyl glucuronide in hair: An in vitro experiment

2010 ◽  
Vol 198 (1-3) ◽  
pp. 23-27 ◽  
Author(s):  
Luca Morini ◽  
Alessandra Zucchella ◽  
Aldo Polettini ◽  
Lucia Politi ◽  
Angelo Groppi
Keyword(s):  
Ethyl Glucuronide ◽  
Vitro Experiment ◽  
In Vitro Experiment

Solutions and gels containing a sugarcane-derived cystatin (CaneCPI-5) reduce enamel and dentin erosion in vitro

2021 ◽  
Author(s):  
Lethycia Almeida Santos ◽  
Tatiana Martini ◽  
João Victor Frazão Câmara ◽  
Fabiana Navas Reis ◽  
Adriana de Cássia Ortiz ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
Dental Erosion ◽  
Positive Control ◽  
New Approach ◽  
Enamel Erosion ◽  
Ph Cycling ◽  
Bovine Enamel ◽  
Dentin Erosion ◽  
Positive Controls

The effect of solutions and gels containing a sugarcane-derived cystatin (CaneCPI-5) on the protection against enamel and dentin erosion in vitro was evaluated. Bovine enamel and dentin specimens were divided into two groups (n=135 and 153/group for enamel and dentin, respectively) that were treated with solutions or chitosan gels containing 0.1 or 0.25 mg/ml CaneCPI-5. The positive controls for solutions and gels were Elmex Erosion Protection™ solution and NaF gel (12,300 ppm F), respectively. Deionized water and chitosan gel served as controls, respectively. The solutions were first applied on the specimens for 1 min and the gels for 4 min. Stimulated saliva was collected from 3 donors and used to form a 2 h acquired pellicle on the specimens. Then, the specimens were submitted to an erosive pH cycling protocol 4 times/day for 7 days (0.1% citric acid pH 2.5/90s, artificial saliva/2h, artificial saliva overnight). The solutions and gels were applied again during pH cycling, 2 times/day for 1 min and 4 min, respectively, after the first and last erosive challenges. Enamel and dentin losses (µm) were assessed by contact profilometry. Data were analyzed by 2-way ANOVA and Tukey´s test (p <0.05). All the treatments significantly reduced enamel and dentin loss in comparison with controls. Both CaneCPI-5 concentrations had a similar protective effect against enamel erosion, but only the higher concentration was as effective against dentin erosion as the positive control. Regarding the vehicles, only the 0.1 mg/ml gel performed worse than the positive control for dentin. CaneCPI-5 reduced enamel and dentin erosion to a similar extent as the fluoride-containing vehicles. However, dentin requires higher CaneCPI-5 concentrations, in the case of gels. Solutions or gels containing CaneCPI-5 might be a new approach to protect against dental erosion.

scholarly journals A review of biocompatibility of zirconia: In vitro experiment

2018 ◽  
Vol 56 (4) ◽  
pp. 391 ◽  
Author(s):  
Da-Won Suh ◽  
Young-Kyun Kim ◽  
Yang-Jin Yi
Keyword(s):  
Vitro Experiment ◽  
In Vitro Experiment

scholarly journals Stratified Community Responses to Methane and Sulfate Supplies in Mud Volcano Deposits: Insights from an In Vitro Experiment

PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e113004 ◽  
Author(s):  
Yu Zhang ◽  
Lois Maignien ◽  
Alina Stadnitskaia ◽  
Pascal Boeckx ◽  
Xiang Xiao ◽  
...  
Keyword(s):  
Mud Volcano ◽  
Community Responses ◽  
Vitro Experiment ◽  
In Vitro Experiment
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