scholarly journals Efficacy of fluoride associated with nano-hydroxyapatite in reducing enamel demineralization adjacent to orthodontic brackets: in situ study

2019 ◽  
Vol 24 (6) ◽  
pp. 48-55
Author(s):  
Carina Faleiros Demito ◽  
Julyano Vieira da Costa ◽  
Marina de Lourdes Calvo Fracasso ◽  
Adilson Luiz Ramos
Keyword(s):  
Polarized Light ◽  
Orthodontic Brackets ◽  
Control Group ◽  
In Situ Study ◽  
Depth Analysis ◽  
Different Depths ◽  
Bovine Enamel ◽  
Light Group ◽  
Experimental Group

ABSTRACT Objective: To assess in situ the effect of fluoride associated with nano-hydroxyapatite for the prevention of demineralization of the enamel adjacent to orthodontic brackets. Material and Methods: Eight volunteers wore palatal devices prepared with 6 bovine enamel blocks (5x5x2 mm) with bonded brackets. The volunteers used the devices in two different moments of 14 days each. During the first 14 days, a product containing fluoride + nano-hydroxyapatite was applied twice (experimental group, GNH, n = 48), and for the other 14 days no prevention product was applied (control group, CG, n = 48). In both groups, along the experiment, the blocks were dripped with 20% sucrose eight times daily. After the experiment, all the specimens were sectioned and examined for lesion depth analysis (µm) under polarized light microscopy, and for enamel longitudinal microhardness (measured under the bracket, at 30 µm and at 130 µm from the margin), at seven different depths (10, 20, 30, 50, 70, 90, and 110 µm). Results: Under polarized light, group GNH presented significantly less demineralization depth ( X ¯= 15.01 µm, SD = 33.65) in relation to CG ( X ¯= 76.43 µm, SD = 83.75). Enamel longitudinal microhardness demonstrated significantly higher microhardness for group GNH when compared to CG. Conclusion: Fluoride + nano-hydroxyapatite can be an alternative preventive procedure for demineralization of the enamel adjacent to orthodontic brackets.

Resin-Based Materials Protect Against Erosion/Abrasion—a Prolonged In Situ Study

2019 ◽  
Vol 44 (3) ◽  
pp. 302-311
Author(s):  
D Rios ◽  
GC Oliveira ◽  
CR Zampieri ◽  
MC Jordão ◽  
EJ Dionisio ◽  
...  
Keyword(s):  
Dental Erosion ◽  
Additional Treatment ◽  
The Other ◽  
Control Group ◽  
Material Loss ◽  
In Situ Study ◽  
Phase Study ◽  
And Control ◽  
Bovine Enamel

SUMMARY While patient compliance is key to preventive measures related to dental erosion, the application of resin-based materials could serve as an additional treatment to inhibit erosion progression. This in situ study evaluated the effect of applying resin-based materials, including resin infiltrant, on previously eroded enamel subjected to prolonged erosive and abrasive challenges. The factors under study were types of treatment (infiltrant [Icon], sealant [Helioseal Clear], adhesive [Adper Scotchbond Multi-Purpose Plus], and control [no treatment]); wear conditions (erosion [ERO] and erosion + abrasion [ERO + ABR]) and challenge time (5 and 20 days) in a single-phase study. The blocks were prepared from bovine enamel, eroded (0.01 M HCl, pH 2.3 for 30 seconds) and randomized among treatments, wear conditions, and volunteers. The application of resin-based materials followed the manufacturers' recommendations. Twenty-one volunteers wore the palatal intraoral device, in which one row corresponded to ERO and the other to ERO + ABR. In each row, all treatments were represented (2 blocks per treatment). For 20 days, the erosive challenge was performed 4 times/day (immersion in 0.01 M HCl, pH 2.3, for 2 minutes) for the ERO condition. For the ERO + ABR condition, two of the erosive challenges were followed by abrasion for 15 seconds with fluoride dentifrice slurry. Enamel and/or material loss was measured using profilometry (initial, after treatment, and after the end of the fifth and 20th days of in situ erosive challenge) and analyzed by ANOVA models and Tukey's test (α=0.05). The results showed that the application of resin-based materials did not cause superficial enamel loss. The infiltrant group showed a thicker layer of material above the enamel compared with the other materials (p=0.001). After the erosive challenge, there was no difference between the conditions ERO and ERO + ABR (p=0.869). All materials protected the enamel against erosion progression compared with the control group (p=0.001). Based on these results, we conclude that the application of resin-based materials results in protection of previously eroded enamel subjected to in situ erosive and abrasive challenge for 20 days.

scholarly journals Assessment of Enamel Demineralization Adjacent to Orthodontic Brackets Using a Polarized Microscope

2020 ◽  
pp. 030157422095169
Author(s):  
Santosh Ramegowda ◽  
Shilpa Joy ◽  
Nishitha C Gowda ◽  
Shailaja AM ◽  
Bharath Reddy ◽  
...  
Keyword(s):  
Polarized Light ◽  
Orthodontic Brackets ◽  
Fluoride Varnish ◽  
Control Group ◽  
Single Application ◽  
Enamel Demineralization ◽  
Time Period ◽  
Significant Difference ◽  
Experimental Group ◽  
Effect Of Light

Background and Objectives: This study was conducted to assess the effect of light-curable fluoride varnish on enamel demineralization adjacent to orthodontic brackets using polarized light microscopy and to compare the depth of demineralization at different time periods. Method: In 15 patients, the first premolars were allocated into 2 groups. In the experimental group light-curable fluoride varnish was applied. At the end of each time period (60, 90, and 120 days), first premolar brackets were debonded and premolars were extracted. Buccolingual sections were evaluated under a polarized light microscope and depth of demineralization was assessed. Results: The depth of demineralization in the control group increased from 60 to 120 days, and the experimental group did not show any significant difference during the time period. Conclusion: Single application of light-curable fluoride varnish, Clinpro XT can be effective in reducing enamel demineralization during fixed orthodontic mechanotherapy, especially in noncompliant patients.

scholarly journals CALPAIN ACTIVITY UNDER EXPERIMENTAL INCREASING OF DOPAMINE LEVEL

2019 ◽  
Vol 19 (1S) ◽  
pp. 221-222
Author(s):  
N S Pestereva ◽  
A Z Marshak ◽  
M N Karpenko
Keyword(s):  
Control Group ◽  
Dopamine Level ◽  
Calpain Activity ◽  
In Situ Study ◽  
Calpain 2 ◽  
Casein Zymography ◽  
Experimental Group

The aim of our study was to identify the activity of calpains under conditions of an experimental increase in the level of dopamine. The work was performed at three levels: in vivo, in situ, in vitro. An in situ study was carried on a model of isolated nerve endings - synaptosomes. Using casein zymography in solution with FITC-casein, it was shown that incubation of synaptosomes dopamine leads to calpains secretion into the synaptosomal medium. The dopamine ability to directly activate calpain was demonstrated by casein zymography in a gel. Incubation in an activation buffer containing dopamine instead of the classical activator, calcium chloride, led to the activation of calpain-2. An in vivo experiment was performed on Wistar rats. The experimental group was orally administered the drug L-dopa (100 mg/kg), the control group - saline was injected in the same way.

scholarly journals Effect of Hydrogen Peroxide at 35% on the Morphology of Enamel and Interference in the De-remineralization Process: An In Situ Study

2012 ◽  
Vol 37 (5) ◽  
pp. 518-525 ◽  
Author(s):  
AM de Arruda ◽  
PH dos Santos ◽  
RH Sundfeld ◽  
SB Berger ◽  
ALF Briso
Keyword(s):  
Hydrogen Peroxide ◽  
Dental Caries ◽  
Microscopic Analysis ◽  
Enamel Surface ◽  
In Situ Study ◽  
Bovine Enamel ◽  
Histologic Changes

SUMMARY This study evaluated the microhardness and histomorphology of bovine enamel when 35% hydrogen peroxide is used. A total of 44 specimens were adapted to removable devices used by 11 individuals subjected to dental caries challenge. A decrease in microhardness was observed for all groups after the cariogenic challenge. Microscopic analysis revealed that fragments subjected to cariogenic challenge associated with bleaching had more intense superficial histologic changes, but the depth of the lesions remained unchanged. It was concluded that 35% hydrogen peroxide enhanced the reduction in hardness and histomorphologic changes in the enamel surface exposed to cariogenic challenge.

scholarly journals Influence of toothbrushing on enamel softening and abrasive wear of eroded bovine enamel: an in situ study

2006 ◽  
Vol 20 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Daniela Rios ◽  
Heitor Marques Honório ◽  
Ana Carolina Magalhães ◽  
Marília Afonso Rabelo Buzalaf ◽  
Regina Guenka Palma-Dibb ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
The Other ◽  
In Situ Study ◽  
Significant Difference ◽  
The Mean ◽  
Student’S T ◽  
Bovine Enamel ◽  
Enamel Layer ◽  
Student’S T Test

This study assessed the surface softening and abrasive wear of eroded bovine enamel with or without the influence of toothbrushing. Five volunteers took part in this in situ study of 5 days. They wore acrylic palatal appliances containing 6 bovine enamel blocks divided in two rows with 3 blocks, which corresponded to the studied groups: erosion without toothbrushing (GI) and erosion with toothbrushing (GII). The blocks were subjected to erosion by immersion of the appliances in a cola drink for 10 minutes, 4 times a day. After that, no treatment was performed in one row (GI), whereas the other row was brushed (GII). The appliance was then replaced into the mouth. Enamel alterations were determined using profilometry and microhardness tests. Data were tested using paired Student’s t test (p < 0.05). The mean wear values (µm) and percentage of superficial microhardness change (%SMHC) were respectively: GI - 2.77 ± 1.21/91.61 ± 3.68 and GII - 3.80 ± 0.91/58.77 ± 11.47. There was a significant difference in wear (p = 0.001) and %SMHC (p = 0.001) between the groups. It was concluded that the wear was more pronounced when associated to toothbrushing abrasion. However, toothbrushing promoted less %SMHC due to the removal of the altered superficial enamel layer.

Remineralizing Potential of a Low Fluoride Toothpaste with Sodium Trimetaphosphate: An in situ Study

2016 ◽  
Vol 50 (6) ◽  
pp. 571-578 ◽  
Author(s):  
Eliana M. Takeshita ◽  
Marcelle Danelon ◽  
Luciene P. Castro ◽  
Robson F. Cunha ◽  
Alberto C. B. Delbem
Keyword(s):  
Oral Cavity ◽  
Repeated Measures ◽  
Surface Hardness ◽  
Repeated Measures Anova ◽  
Treatment Groups ◽  
Fluoride Toothpaste ◽  
Sodium Trimetaphosphate ◽  
In Situ Study ◽  
Bovine Enamel

Objective: To evaluate the effect of a low-fluoride (F) toothpaste supplemented with sodium trimetaphosphate (TMP) on enamel remineralization in situ. Design: Bovine enamel blocks were selected on the basis of their surface hardness (SH) after caries-like lesions had been induced, and randomly divided into 4 treatment groups, according to the toothpastes used: without F or TMP (placebo); 500 ppm F; 500 ppm F plus 1% TMP; and 1,100 ppm F. The study design was blinded and crossover and performed in 4 phases of 3 days each. Eleven subjects used palatal appliances containing 4 bovine enamel blocks which were treated 3 times per day during 1 min each time, with natural slurries of saliva and toothpaste formed in the oral cavity during toothbrushing. After each phase, the percentages of surface (%SHR) and subsurface hardness recovery (%ΔKHNR) were calculated. F, calcium (Ca), and phosphorus (Pi) contents in enamel were also determined. Data were analyzed by 1-way, repeated-measures ANOVA, followed by the Student-Newman-Keuls test (p < 0.05). Results: Toothpaste with 500 ppm F + TMP and 1,100 ppm F showed similar %SHR and %ΔKHNR as well as enamel F, Ca, and Pi concentrations. Conclusion: The addition of TMP to a low-fluoride toothpaste promoted a similar remineralizing capacity to that of a standard (1,100 ppm F) toothpaste in situ.

scholarly journals Evaluation of home bleaching gel modified by different thickeners on the physical properties of enamel: An in situ study

2018 ◽  
Vol 12 (04) ◽  
pp. 523-527 ◽  
Author(s):  
Bruna Guerra Silva ◽  
Thayla Helle Nunes Gouveia ◽  
Marcelo de Assumpção Pereira da Silva ◽  
Gláucia Maria Bovi Ambrosano ◽  
Flávio Henrique Baggio Aguiar ◽  
...  
Keyword(s):  
Physical Properties ◽  
Color Variation ◽  
Control Group ◽  
Carbamide Peroxide ◽  
Treatment Control ◽  
In Situ Study ◽  
Knoop Microhardness ◽  
Treatment Control Group ◽  
Intraoral Devices

ABSTRACT Objective: This in situ study evaluated the influence of 10% carbamide peroxide (CP) in combination with different thickeners on physical characteristics of enamel. Materials and Methods: Eighty-four bovine blocks of enamel and dentin (4 mm × 4 mm × 2.5 mm) were divided into seven groups (n = 12), fixed in palatal intraoral devices, and submitted to different treatments: CP + carbopol (FGM), CP + carbopol + glycerin (ultradent), CP + natrosol (experimental gel), carbopol, carbopol + glycerin, and natrosol, without treatment (control group). The physical properties tested were color (ΔE), roughness (Ra), and Knoop microhardness (KHN). Statistical Analysis Used: Data were submitted to ANOVA, Tukey's, and Dunnett's tests (α = 0.05). Results: all groups presented significant color variation, except carbopol. For microhardness, all bleached groups did not differ from control. Roughness increased in all bleached groups when compared to the control group, but CP + natrosol presented statistical lower results than CP + carbopol. Conclusion: Replacement of carbopol by natrosol caused less change on roughness surface, at the same time yielding an effective whitening result.

An Intra-oral Single-section Demineralization/Remineralization Model

1992 ◽  
Vol 71 (3_suppl) ◽  
pp. 860-863 ◽  
Author(s):  
J.S. Wefel ◽  
M.E. Jensen
Keyword(s):  
Polarized Light ◽  
Plaque Formation ◽  
In Situ Study ◽  
Single Section ◽  
Typical Experiment ◽  
Before And After ◽  
Section Model ◽  
Time Frames ◽  
Mineral Changes

This paper reviews the use of our intra-oral crown single-section model for the evaluation of in situ demineralization and remineralization. The model uses normal, healthy adults who are in need of a gold crown. A slot is placed in the working crown which can hold 3–4 single sections. A typical experiment would use an enamel lesion, root lesion, and sound root section which are characterized with polarized light microscopy and/or microradiography prior to insertion in the crown. After the experimental regimen, the sections are removed and re-characterized for any changes. The model has been used to evaluate mineral changes from the use of fluoride dentifrices and rinses, chewing gum, and food sequencing. The advantages of the model system are the before-and-after measurements on the same section, a natural plaque formation, interaction with saliva, episodic demineralization and remineralization, no bulky appliances, and the use of reasonable time frames. This model, therefore, reduces the artificiality of the in situ study to a great extent and appears to be a useful predictor of demineralization/remineralization interactions.

scholarly journals Application of Deep Learning-Based Integrated Trial-Error + Science, Technology, Reading/Writing, Engineer, Arts, Mathematics Teaching Mode in College Entrepreneurship Education

2021 ◽  
Vol 12 ◽  
Author(s):  
Guangfu Qu ◽  
Wenbo Hu ◽  
Wenxiu Jiao ◽  
Jiangbo Jin
Keyword(s):  
Deep Learning ◽  
Teaching Methods ◽  
Scientific Literacy ◽  
Teaching Method ◽  
Entrepreneurship Education ◽  
Control Group ◽  
Teaching Concept ◽  
Depth Analysis ◽  
And Control ◽  
Experimental Group

The purpose is to achieve a high-quality teaching effect in quality education using the new teaching concept. Firstly, the Deep Learning (DL) theory is introduced to improve the trial-error teaching method, then the trial-error teaching is combined with STREAM education. Afterward, the conical section hyperbola teaching in college entrepreneurship education is specifically studied under experimental analysis using the proposed DL-based integrated trail-error + STREAM teaching methods. The experimental results read: student’s average veracity on the multiple-choice question is 93.4% and 90.1% for the experimental group and control group, respectively; student’s average veracity on short-answer questions is 92.3% and 90.3% for the experimental group and control group, respectively. The results show that the application of DL to the trial-error teaching method can cultivate students’ in-depth analysis and logical thinking ability for mathematical problems. Meanwhile, the DL-based integrated trial-error + STREAM teaching methods stimulate students’ initiative to learn more difficult knowledge, establish integral knowledge systems, and more comprehensively and deeply understand the teaching content. As a result, students’ scientific literacy and humanistic literacy are both improved. Therefore, the proposed DL-based integrated trial-error + STREAM teaching method in college entrepreneurship education has a guiding significance for other disciplines and provides ideas for the expansion and development of STREAM teaching in the future.

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