scholarly journals Effect of different surface treatments on the ceramic veneer surface: morphological analysis

2018 ◽  
Vol 21 (1) ◽  
pp. 88
Author(s):  
Karen Cristina Archangelo ◽  
Tabata Prado Sato ◽  
Marcela Moreira Penteado ◽  
Edwin Fernando Ruiz Contreras ◽  
Alexandre Luiz Souto Borges ◽  
...  
Keyword(s):  
Lithium Disilicate ◽  
Surface Treatments ◽  
Control Group ◽  
Diamond Bur ◽  
Before And After ◽  
Veneer Surface ◽  
Group 5 ◽  
Group 2 ◽  
And Control ◽  
Diamond Paste

<p><strong>Objective: </strong>The aim of this study was to evaluate the effect of different surface clinical treatments on the roughness (Ra) of a lithium disilicate ceramic veneer. <strong>Material and Methods: </strong>Forty-eight lithium disilicate discs with ceramic veneer and glaze layer were manufactured and distributed into six groups (n=8) according to the surface treatment performed: G1, glaze layer (control group); G2, diamond bur 4138F; G3, diamond bur 4138F + 4138FF; G4, diamond bur 4138F + new glaze layer; G5, diamond bur 4138F + ceramic polishing kit; G6, diamond bur 4138F + rubber cup with diamond paste + felt with diamond paste. Surface Ra measurement (µm) was performed using a profilometer before and after surface treatments, and one specimen from each group was subjected to Scanning Electron Microscopy (SEM) after treatment. Two-way ANOVA and Tukey's test (5%) were used for data analysis. <strong>Results: </strong>Group 2 (3,00 ± 0,61)<sup>b</sup> showed higher values of Ra, followed by Group 3 (1,93 ± 0,45)<sup>c</sup>, Group 6 (1,56 ± 0,22)<sup>ac</sup>, Group 5 (1,14 ± 0,68)<sup>a</sup> and Group 4 (0,90 ± 0,26)<sup>a</sup>. G4, G5 and G6 were not different between each other and control group (1,11 ± 0,21)<sup>a</sup>. SEM imaging revealed surface smoothness in G1, G4 and G5, and presence of irregularities in G2, G3 and G6. <strong>Conclusion: </strong>it is possible to conclude that different surface clinical treatments influences the roughness of a lithium disilicate ceramic veneer.</p><p> </p><p><strong>Keywords</strong><strong>:</strong> Ceramics; Dental porcelain; Dental polishing.</p>

scholarly journals SURFACE ROUGHNESS OF LITHIUM DISILICATE PRESS CERAMICS AFTER DIFFERENT TYPES OF POLISHING

2021 ◽  
Vol 2 ◽  
pp. 174-177
Author(s):  
Elena Vasileva ◽  
Angelina Vlahova ◽  
Ilian Hristov ◽  
Svetlin Alexandrov ◽  
Zlatina Tomova
Keyword(s):  
Lithium Disilicate ◽  
Ceramic Surface ◽  
Group 4 ◽  
Diamond Bur ◽  
Atomic Force ◽  
Glazed Ceramic ◽  
Before And After ◽  
Group 3 ◽  
Group 2 ◽  
Diamond Paste

INTRODUCTION: The smoothness of a ceramic’s surface is very important of its esthetic and prophylactic qualities. AIM: The purpose of this investigation is to study the possibilities of polishing lithium disilicate ceramics after making a correction on the glazed ceramic surface. MATERIALS AND METHODS: The subject of the study were 20 test samples made of lithium disilicate press ceramics. They were divided into 4 groups according to the method of processing and polishing. Group 1 was treated with a red diamond bur and polishing set; Group 2 was treated with a green diamond bur and polishing set; Group 3 was treated with a red diamond bur, polishing set and diamond paste; Group 4 was treated with a diamond bur with green coding, polishing set and diamond paste. The samples were examined with an atomic force microscope to observe the change in surface relief. The reference point for comparison was the surface of the glazed ceramic. RESULTS: After polishing with diamond paste, the surface became smoother compared to the treatment of the surface with a polishing kit alone. CONCLUSION: Regardless of the polishing protocol used, there was a difference in the topography of the ceramic surface before and after treatment.

scholarly journals Effects of Different Polishing Protocols on Lithium Disilicate Ceramics

2015 ◽  
Vol 26 (5) ◽  
pp. 478-483 ◽  
Author(s):  
Tânia Mara da Silva ◽  
Ana Carolina Rodrigues Danzi Salvia ◽  
Rodrigo Furtado de Carvalho ◽  
Eduardo Galera da Silva ◽  
Clóvis Pagani
Keyword(s):  
Surface Roughness ◽  
Lithium Disilicate ◽  
Sem Analysis ◽  
Surface Treatments ◽  
Control Group ◽  
Morphological Pattern ◽  
Tukey Test ◽  
Polishing Procedures ◽  
Diamond Paste

Abstract: The aim of this study was to evaluate the effect of different polishing protocols on surface roughness and morphology of lithium disilicate ceramics (IPS e.max CAD). Fifty ceramic bars (2.0x3.0x2.5 mm) were produced and randomly divided into five groups (n=10), according to surface treatments: C: Control; Cer: Ceramaster (60 s); CW: cloth wheel with large-grit diamond (30 s) + cloth wheel with fine-grit diamond paste (30 s); E: grey Exa-Cerapol (20 s) + pink Exa-Cerapol (20 s) + Cerapol Super (20 s); F: Felt wheel with large-grit diamond paste (30 s) + Felt wheel with fine-grit diamond paste (30 s). The samples were evaluated quantitatively for surface roughness (Ra) and qualitatively by SEM, at different moments: initial (prior to roughening), after roughening and after polishing procedures. Ra means were submitted to two-way ANOVA and Tukey test (p<0.05). After the different polishing protocols, no statistically significant differences were observed between the Cer and E groups (p=0.6347), E and CW groups (p=0.1366), and CW and FW groups (p=0.5433). Comparing different stages in the same group, it was possible to observe that CW (p<0.0001) and FW groups (p<0.0001) showed significant differences. SEM analysis revealed that both Cer and E groups exhibited a surface morphological pattern similar to that of control group. All polishing systems were effective in reducing the surface roughness of the studied ceramic type.

Effect of Polishing Systems on Surface Roughness and Topography of Monolithic Zirconia

2016 ◽  
Vol 41 (4) ◽  
pp. 417-423 ◽  
Author(s):  
CL Goo ◽  
AUJ Yap ◽  
KBC Tan ◽  
AS Fawzy
Keyword(s):  
Surface Roughness ◽  
Sem Images ◽  
Group 4 ◽  
Diamond Bur ◽  
Before And After ◽  
Monolithic Zirconia ◽  
Polishing Procedures ◽  
Group 5 ◽  
Group 2 ◽  
Post Hoc

SUMMARY This study evaluated the effect of different chairside polishing systems on the surface roughness and topography of monolithic zirconia. Thirty-five monolithic zirconia specimens (Lava PLUS, 3M ESPE) were fabricated and divided into five groups of seven and polished with the following: Group 1 (WZ)—Dura white stone followed by Shofu zirconia polishing kit; Group 2 (SZ)—Shofu zirconia polishing kit; Group 3 (CE)—Ceramiste porcelain polishers; Group 4 (CM)—Ceramaster porcelain polishers; and Group 5 (KZ)—Komet ZR zirconia polishers. All specimens were ground with a fine-grit diamond bur prior to polishing procedures to simulate clinical finishing. Baseline and post-polishing profilometric readings were recorded and delta Ra values (difference in mean surface roughness before and after polishing) were computed and analyzed using one-way analysis of variance and Scheffe post hoc test (p&lt;0.05). Representative scanning electron microscopy (SEM) images of the ground but unpolished and polished specimens were acquired. Delta Ra values ranged from 0.146 for CE to 0.400 for KZ. Delta Ra values for KZ, WZ, and SZ were significantly greater than for CE. Significant differences in delta Ra values were also observed between KZ and CM. The SEM images obtained were consistent with the profilometric findings. Diamond-impregnated polishing systems were more effective than silica carbide–impregnated ones in reducing the surface roughness of ground monolithic zirconia.

scholarly journals Effects of Plyometric, Strength and Change of Direction Training on High-School Basketball Player’s Physical Fitness

2021 ◽  
Vol 78 (1) ◽  
pp. 175-186
Author(s):  
Eduardo Sáez de Villarreal ◽  
Jose Galán Molina ◽  
Guillermo de Castro-Maqueda ◽  
José V. Gutiérrez-Manzanedo
Keyword(s):  
High School ◽  
Physical Fitness ◽  
Repeated Measures ◽  
Control Group ◽  
Basketball Players ◽  
Change Of Direction ◽  
Before And After ◽  
Group 2 ◽  
Post Hoc ◽  
And Control

Abstract The study aim was to compare the effects of a 7-week plyometric, strength and change of direction (COD) training program on basketball-specific performance measures in high-school players. Forty male players were randomly assigned to one of the four groups: plyometric (PG, n = 10), strength (SG, n = 10), COD (CODG, n = 10), and control group training (CG, n = 10). Two training sessions were performed at weekly intervals before basketball training. Performance of the counter movement jump (CMJ), Abalakov jump (ABKJ), 10 m zig-zag sprint, 20 m in line sprint (measurements at 10 and 20 m), and sit and reach flexibility test (SRFT) was assessed before and after the intervention. A 4 (group) × 2 (time) repeated measures analysis of variances (ANOVA) was conducted for each variable. Bonferroni post-hoc tests were used when the interaction was significant. Significant (all p < 0.05) time x group interaction was noted for SRFT, CMJ, ABK, sprint, and zig-zag 10 m, in favor of the experimental groups compared to the control group. However, improvements in physical fitness were similar between the three experimental groups. In conclusion, 7 weeks of specific plyometric, strength and COD training produced similar medium to large improvements in physical fitness of high-school basketball players.

scholarly journals Effect of the superficial treatment in the repair of silorane-based composite aged artificially

2015 ◽  
Vol 63 (4) ◽  
pp. 376-382
Author(s):  
Chaiane Emilia DALAZEN ◽  
Mario Alexandre Coelho SINHORETI ◽  
Margareth COUTINHO
Keyword(s):  
Bond Strength ◽  
Aluminum Oxide ◽  
Thermal Cycling ◽  
Surface Treatments ◽  
Control Group ◽  
Group 4 ◽  
Diamond Bur ◽  
Composite Methods ◽  
Group 3 ◽  
Group 2

Objective: To evaluate the effects of different surface treatments, in repair bond strength of an aged silorane-based composite. Methods: Specimens were made of a silorane-based composite (P90, 3M/ESPE), aged with thermal-cycling (10,000 cycles; 5-55ºC) and randomly submitted to different surface treatments (each group n = 24): control group (no repair); group 1 (only application of P90 adhesive); group 2 (diamond bur asperization + P90 adhesive); group 3 (aluminum oxide sandblasting + P90 adhesive) and group 4 (asperization + sandblasting + P90 adhesive). Then, the specimens were repaired with the same silorane-based composite and each group randomly subdivided into 2 subgroups: stored in distilled water at 37 °C for 7 days or submitted to thermal-cycling (5,000 cycles). After aging, the tensile test was carried out. The data was submitted to 2-way analysis of variance (2-way ANOVA). Results: The repaired groups aged with oven storage for 7 days did not statistically differ (p>0.05) from the corresponding groups aged with thermal-cycling. The bond strength of the specimens was significantly influenced by the superficial treatment (p<0.01). The highest values of tensile bond strength were found in groups 3 (20.76 ± 4.51 MPa) and 4 (20.67± 3.96 MPa), regardless of aging and repair. Conclusion: The repair of silorane-based composite showed to be stable after aging, and the superficial treatment with aluminum oxide sandblasting was the most effective.

scholarly journals Association of 5-Hydroxytryptamine 3 Receptor Antagonists With the Prognosis of Liver Failure

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuting Chen ◽  
Jingkang Sun ◽  
Xiude Fan ◽  
Xiaoyun Wang ◽  
Lu Zeng ◽  
...  
Keyword(s):  
Liver Failure ◽  
Northwest China ◽  
Tertiary Hospital ◽  
Clinical Syndrome ◽  
Control Group ◽  
Receptor Antagonists ◽  
Before And After ◽  
Group 5 ◽  
Using Data ◽  
And Control

Liver failure is a severe clinical syndrome with high mortality. 5-Hydroxytryptamine 3 receptor antagonists (5-HT3RAs) can reduce liver damage in animal models. We investigated whether 5-HT3RAs may improve the prognosis of liver failure. We analyzed the 28 and 90 days mortality of liver failure patients in relation to the use of 5-HT3RAs using data from a tertiary hospital in northwest China. According to the use of 5-HT3RAs, 419 patients with liver failure (46 acute, 93 sub-acute, 44 chronic, 236 acute on chronic) were divided into 5-HT3RA group (n = 105) and control group (n = 314). 5-HT3RAs were associated with decreased 28 days (HR 0.18, 95% CI 0.10-0.34, p &lt; 0.001) and 90 days (HR 0.21, 95% CI 0.13-0.33, p &lt; 0.001) mortality. After propensity score matching (PSM) (n = 67 in each group), 5-HT3RAs were still significantly associated with reduced 28 days (HR 0.10, 95%CI 0.04-0.26, p &lt; 0.001) and 90 days (HR 0.16, 95%CI 0.08-0.31, p &lt; 0.001) mortality. 5-HT3RA group patients had significantly higher 28 and 90 days survivals than controls both before and after PSM (all p &lt; 0.001). This study shows that 5-HT3RAs are associated with increased survival of liver failure patients and thus may be used to treat liver failure if the findings are confirmed by additional studies.

scholarly journals The effects of different nickel-titanium instruments on dentinal microcrack formations during root canal preparation

2015 ◽  
Vol 09 (01) ◽  
pp. 041-046 ◽  
Author(s):  
Yakup Ustun ◽  
Tugrul Aslan ◽  
Burak Sagsen ◽  
Bertan Kesim
Keyword(s):  
Control Group ◽  
Chi Square ◽  
Mandibular Incisor ◽  
Group 4 ◽  
Chi Square Test ◽  
Group 5 ◽  
Group 2 ◽  
Movement Group ◽  
And Control ◽  
Reciprocating Movement

ABSTRACT Objective: The aim of the present study was to investigate the incidence of dentinal microcracks caused by different preparation techniques. Materials and Methods: 120 extracted human mandibular incisor teeth were divided into five experimental groups and one control group (n = 20): Group 1: Hand preparation with balanced force technique up to #25 K-file. Group 2: Preparation with only ProTaper F2 instrument in a reciprocating movement. Group 3: Preparation with Reciproc R25 instrument in a reciprocating movement. Group 4: Preparation with ProTaper instruments up to F2 instrument. Group 5: Preparation with ProTaper Next instruments up to X2 instrument. No procedure was applied to control group. The roots were sectioned horizontally at 3, 6 and 9 mm from the apex and examined. Absence or presence of dentinal microcracks was noted. Results: The Chi-square test was performed to compare the appearance of cracked roots between all groups. There were no significant differences among the groups (P > 0.05). Conclusions: In conclusion, except the hand file and control group, all experimental groups showed microcrack formations.

Effects of Time and Perceptual Orientation on Actors' and Observers' Attributions

1984 ◽  
Vol 58 (1) ◽  
pp. 23-30
Author(s):  
Donald S. Martin ◽  
Ming-Shiunn Huang
Keyword(s):  
Video Recording ◽  
Control Group ◽  
Control Groups ◽  
Video Recordings ◽  
Before And After ◽  
Perceptual Orientation ◽  
Initial Difference ◽  
Variety Show ◽  
And Control ◽  
Unrelated Variety

The actor/observer effect was examined by Storms in a 1973 study which manipulated perceptual orientation using video recordings. Storms' study was complex and some of his results equivocal. The present study attempted to recreate the perceptual reorientation effect using a simplified experimental design and an initial difference between actors and observers which was the reverse of the original effect. Female undergraduates performed a motor co-ordination task as actors while watched by observers. Each person made attributions for the actor's behaviour before and after watching a video recording of the performance. For a control group the video recording was of an unrelated variety show excerpt. Actors' initial attributions were less situational than observers'. Both actors and observers became more situational after the video replay but this effect occurred in both experimental and control groups. It was suggested the passage of time between first and second recording of attributions could account for the findings and care should be taken when interpreting Storms' (1973) study and others which did not adequately control for temporal effects.

Liver, Kidney Function Tests and Oxidative Damage During and after Treatment of Salmonella typhimurium Infection in Experimental Local Rabbits

2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Mustafa Salah Hasan ◽  
Ayman Barzan Abdulgafor ◽  
Maher Saber Owain ◽  
Mohammed Ali Hussein ◽  
Qusay Mohammed Aboud ◽  
...  
Keyword(s):  
Single Dose ◽  
Oxidative Damage ◽  
Salmonella Typhimurium ◽  
Infected Group ◽  
Post Treatment ◽  
Kidney Damage ◽  
Control Group ◽  
Post Inoculation ◽  
Group 5 ◽  
Group 2

This study aimed to evaluate the liver, kidney damage caused by S. typhimurium and to estimate the oxidative damage in association with this bacteria. A highly virulent isolates of S. typhimurium were obtained from the department of internal and preventive medicine/ College of Veterinary Medicine/ University of Baghdad. A twenty five local rabbits of both genders with age range (2-4 months) weeks old were used for this study, the rabbits were divided randomly into five groups each group contains 5 rabbits :- group 1: drenched orally with 5 ml of normal saline and consider as control group, group 2: were drenched orally with (5 ml) suspension which contain (5��109 CFU) of Salmonella typhimurium and regarded as infected group, group 3 were drenched orally with (5 ml) suspension which have (5��109 CFU) of Salmonella typhimurium then treated with a single dose of gentamicin alone at 0.05ml/kg (5mg/ml) orally after presence of signs (after 24hrs. post inoculation), group 4 were drenched (5 ml) suspension having (5��109 CFU) of Salmonella typhimurium then treated with a single dose of Ca-EDTA alone at 40mg/kg orally after presence of signs (after 24hrs. post inoculation) and group 5 were drenched (5 ml) suspension that contain (5��109 CFU) of Salmonella typhimurium then treated with a single dose of combined gentamicin at 0.05ml/kg (5mg/ml) orally after presence of signs (after 24hrs. post inoculation) and Ca-EDTA 40mg/kg after presence of signs (after 24hrs. post inoculation).The results of biochemical profile showed a significant increase (p less than 0.05) in ALT, creatinine and urea levels in infected group as compared with control group, while, the treated groups especially group 5 showed a significant improvement in ALT, Urea and creatinine levels which returned to relative normal levels as compared with infected group after 96hrs. post treatment. Also, the results of oxidative stress showed a significant increase in the levels of MDA in G2, G3, G4 and G5 after 48 hrs. post treatment, while the level of GSH showed a significant decrease in the level at 48hrs., both were returned to relative normal levels after 96hrs.post treatment especially in group 5.In conclusion, S. typhimurium can causing liver and kidney damage which is manifested by increase ALT, Urea and Creatinine. Also, MDA and GSH is increased due to salmonellosis.

Melatonin Improves Erythropoietin Hyporesponsiveness via Suppression of Inflammation

2019 ◽  
Vol 14 (3) ◽  
pp. 203-208
Author(s):  
Evan Noori Hameed ◽  
Haydar F. Hadi AL Tukmagi ◽  
Hayder Ch Assad Allami
Keyword(s):  
Iron Status ◽  
Transferrin Saturation ◽  
Control Group ◽  
Base Line ◽  
Inadequate Response ◽  
Inflammatory Parameters ◽  
Tnf Α ◽  
Before And After ◽  
And Control ◽  
Controlled Clinical Study

Background: Inadequate response to Erythropoietin Stimulating Agents (ESA) despite using relatively larger doses regimen represents a potential risk factor of Cardiovascular (CV) related mortality in addition to health-care economic problems in anemic patients with Chronic Kidney Disease (CKD). Erythropoietin (EPO) hyporesponsiveness related to inflammation has been increased progressively. Melatonin is well known as a potent anti-inflammatory agent. Therefore, the current study was designed to evaluate whether melatonin could improve anemic patients response to EPO. Methods: This single controlled clinical study was carried out in 41 CKD patients with hemoglobin (Hb) levels less than 11g/dl divided randomly in a 1:1 ratio into 2 groups; treatment group who received 5mg melatonin plus their regular treatments and control group who received their regular treatments only. Hematological and iron status parameters include Hb level, serum iron (S. iron), Transferrin Saturation Ratio (TSAT) and serum ferritin (S. ferritin) in addition to inflammatory parameters that include tissue necrotic factor alfa (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6) determined before and after 12 weeks of treatment. Results: Melatonin remarkably increases the Hb level with a significant increase in S. iron and TSAT compared to baseline. The elevation of S. iron and TSAT was significantly higher in the melatonin group. Additionally, all inflammatory markers estimated were reduced significantly by melatonin compared to base line and control group. Conclusion: The results of the current study showed that melatonin has an advantageous effect on improving EPO response in anemic patients with CKD.

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