scholarly journals Evaluation of Surface Microhardness and Abrasion Resistance of Two Dental Glass Ionomer Cement Materials after Radiant Heat Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Dimitrios Dionysopoulos ◽  
Kosmas Tolidis ◽  
Thrasyvoulos Sfeikos ◽  
Christina Karanasiou ◽  
Xanthippi Parisi
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Abrasion Resistance ◽  
Glass Ionomer Cement ◽  
Surface Hardness ◽  
Radiant Heat ◽  
Surface Microhardness ◽  
Surface Loss ◽  
Group 2 ◽  
Vertical Scanning Interferometry

The aim of this study was to evaluate the effect of a radiant heat treatment using a dental LED unit on the surface microhardness and abrasion resistance after toothbrushing simulation of two conventional GIC materials. Two conventional GIC materials were studied in this investigation: Ketac Fil Plus Aplicap and IonoStar Molar. Twenty disk-shaped specimens (n=10) were prepared of each GIC (7 mm × 2 mm) using cylindrical Teflon molds. Group 1 specimens were left in the mold to set without any treatment, while in Group 2 after placement in the mold the specimens were irradiated for 60 sec at the top surface using a LED light-curing unit. Toothbrushing simulation was carried out using a commercial electric toothbrush which was fixed in a constructed device that allowed the heads of the brushes to be aligned parallel to the surface of the specimens and to control the pressure, with the following parameters: load of the toothbrush standardized at 250 g, medium hardness toothbrush head, and rotation sense changing every 30 sec. The toothbrush abrasion test mechanism, based on a 1.25-Hz frequency for 10,000 cycles, was equivalent to 800 days (~2 years) of brushing. Surface hardness, surface roughness, and surface loss after abrasive procedure were evaluated using Vickers method and Vertical Scanning Interferometry. Data were statistically analyzed using one-way ANOVA and Tukey’s post hoc test (a=0.05). The radiant heat treatment increased the surface microhardness and decreased surface roughness and surface loss after abrasive procedures of both the tested GIC materials but to different extent. Between the tested GIC materials there were significant differences in their tested properties (p<0.05).

Anticaries Potential of Commercial Dentifrices as Determined by Fluoridation and Remineralization Efficiency

2007 ◽  
Vol 8 (7) ◽  
pp. 1-10 ◽  
Author(s):  
Elias Casals ◽  
Tchilalo Boukpessi ◽  
Christina M. McQueen ◽  
Sandy L. Eversole ◽  
Robert V. Faller
Keyword(s):  
Surface Hardness ◽  
Reference Standard ◽  
Surface Microhardness ◽  
Fluoride Uptake ◽  
Human Enamel ◽  
Demineralized Enamel ◽  
Group 6 ◽  
Group 3 ◽  
Group 2

Abstract Aim The aim of this in vitro study was to investigate fluoride uptake in human enamel after use of commercially available toothpastes containing different fluoride compounds, or combinations of fluoride actives formulated into a single product, as a means of determining the efficiency of each formula for delivering caries preventing fluoride to demineralized (caries active) enamel. Methods and Materials Four test dentifrices and two controls were assessed and placed in groups as follows: Group 1: Lacer® (Spain); Group 2: Positive control-USP Reference Standard 1100 ppm F; Group 3: Fluocaril® Bi-Fluoré 250 (France); Group 4: Colgate Fluor Active (Denmark); Group 5: Elmex® (France); and Group 6: A placebo (formulated the same as the USP Reference Standard toothpaste with the exception that it contained < 1 ppm F). Cores 3 mm in diameter were removed from erupted human enamel specimens (extracted by local oral surgeons for orthodontic reasons) and stored in 1% Thymol solution prior to use. They were ground and polished to remove the natural fluoride rich enamel layer, then exposed to a demineralization solution, and assessed for surface microhardness to enable randomization for use in the study. Each group of five specimens underwent a daily pH cycling procedure that involved exposure to pooled human saliva (refreshed three times daily). The groups were then exposed to dentifrice slurries four times daily for one minute per exposure and to a demineralization solution for three hours. The cycling procedure was repeated for five days. Specimens were again analyzed for surface microhardness and fluoride uptake upon completion of five days of treatment. Results Average surface hardness: Groups 2 and 3 showed a statistically significant greater (p<0.05) change indicating greater remineralization compared to all other groups. The average change was 23.45 for Group 2 and 22.65 for Group 3. All other groups had changes ranging from 4.25-8.62. No other statistically significant differences were observed between groups. Fluoride uptake results: Groups 2 and 3 showed statistically significantly greater fluoride uptake versus all other groups (p <0.05). Groups 1 and 5 were significantly different from Group 6. No other statistically significant differences were observed for either analysis. Conclusions Of the marketed products included in the study, the Fluocaril® Bi-Fluoré 250 product formulation provided both the highest level of fluoride uptake and mineralization to the demineralized enamel. The clinical significance of these in vitro results is the confirmation Fluocaril® Bi-Fluoré 250 is effective at remineralizing enamel caries lesions. Citation Casals E, Boukpessi T, McQueen CM, Eversole SL, Faller RV. Anticaries Potential of Commercial Dentifrices as Determined by Fluoridation and Remineralization Efficiency. J Contemp Dent Pract 2007 November; (8)7:001-010.

Ultrasonic Cavitation Peening of Stainless Steel and Nickel Alloy

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Yibo Gao ◽  
Benxin Wu ◽  
Ze Liu ◽  
Yun Zhou ◽  
Ninggang Shen ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Nickel Alloy ◽  
Vibration Amplitude ◽  
Surface Hardness ◽  
Surface Profile ◽  
Ultrasonic Cavitation ◽  
Surface Microhardness ◽  
Workpiece Surface ◽  
Different Depths

Ultrasonic cavitation peening is a peening process utilizing the high pressure induced by ultrasonic cavitation in liquids (typically water). In this paper, ultrasonic cavitation peening on stainless steel and nickel alloy has been studied. The workpiece surface microhardness, the microhardness variation at different depths, the workpiece surface profile, roughness, and morphology have been measured or observed. It has been found that for the studied situations, ultrasonic cavitation peening (at a sufficiently high horn vibration amplitude) can obviously enhance the workpiece surface hardness without significantly increasing the surface roughness. Under the investigated conditions, a surface layer of more than around 50 μm has been hardened under a horn vibration amplitude of ∼20 μm.

Influence of thermal and pH cycles on surface characteristics lithium disilicate glass-ceramic dental crowns milled with CAD/CAM process

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yajvinder Singh ◽  
Vishal Gulati
Keyword(s):  
Surface Roughness ◽  
Glass Ceramic ◽  
Research Work ◽  
Surface Hardness ◽  
Surface Characteristics ◽  
Lithium Disilicate ◽  
Content Type ◽  
Cad Cam ◽  
Group 3 ◽  
Group 2

Purpose The paper aims to evaluate the influence of thermo-chemical cycles of oral fluids on the surface attributes (roughness and microhardness) of lithium disilicate glass-ceramic (LDC) crown restorations manufactured with CAD/CAM technology. Design/methodology/approach There have been 24 LDC crowns manufactured using the CAD/CAM process for their respective preparation dies ply methyl methacrylate (PMMA) of mandibular left second premolar tooth (n = 8 each group). The standard procedure was used to glaze 16 crown samples (Groups 2 and 3).Samples of Group 3 were aged with thermal (563°C and 5563°C) and pH (2–14) cycles. All 24 samples were tested with a Profilometer and a Vicker hardness tester was used for their surface roughness and hardness measurement, respectively. Findings In statistical examination on SPSS Statistics 20 (IBM) software, of surface roughness values (Ra) and Vicker hardness values from different groups, Tukey HSD test was executed in one-way ANOVA (a = 0.05). The means Ra for groups were accordingly Group 3 > Group1 > Group 2 (p < 0.001). Similarly, micro-hardness was in order of Group 2 > Group 1 > Group 3 (p < 0.001). Research limitations/implications The research work does not have any limitations. Originality/value Surrounding temperature and pH significantly impact the surface characteristics of lithium disilicate crown restoration. The study also reveals the inverse relationship between surface roughness and surface hardness parameters. The observed results and facts revealed well in agreement with the past research studies.

scholarly journals Evaluation of the Surface Hardness and Roughness of a Resin-Modified Glass Ionomer Cement Containing Bacterial Cellulose Nanocrystals

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Maryam Saadat ◽  
Marzieh Moradian ◽  
Babak Mirshekari
Keyword(s):  
Surface Roughness ◽  
Bacterial Cellulose ◽  
Cellulose Nanocrystals ◽  
Glass Ionomer Cement ◽  
Surface Hardness ◽  
Glass Ionomer ◽  
Resin Modified Glass Ionomer ◽  
Negative Effect ◽  
The One ◽  
Ionomer Cement

The purpose of this study was to evaluate the performance of a resin-modified glass ionomer cement (RMGIC) to which bacterial cellulose nanocrystals (BCNs) were added. BCNs were incorporated into the RMGIC powder in ratios of 0.3%, 0.5%, and 1% (w/w). One control and three experimental groups were enrolled in the study: unmodified RMGIC (control), 0.3% (w/w) BCN-modified RMGIC, 0.5% (w/w) BCN-modified RMGIC, and 1% (w/w) BCN-modified RMGIC. The surface hardness and surface roughness were the parameters assessed. The materials were characterized by scanning electron microscopy (SEM). The data were analyzed using the one-way ANOVA and Kruskal–Wallis tests for surface hardness and roughness, respectively. The addition of BCN resulted in the improvement of surface roughness in all the specimens compared with the control material. The RMGIC modified by 1% (w/w) BCN showed the lowest surface roughness (decreased by 52%) among all tested groups. However, BCN had a negative effect on the surface hardness of RMGIC. The group with 0.3% (w/w) BCN had the least decrease in microhardness (13%). According to the results, the RMGIC group modified by 1% (w/w) BCN had a smoother surface than the other groups. The surface microhardness of the RMGIC decreased after BCNs were added to it.

scholarly journals Surface Analysis and Spectrophotometric Evaluation of Different Esthetic Restorative Materials Frequently Exposed to a Desensitizing Agent

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Neven S. Aref ◽  
Reham M. Abdallah
Keyword(s):  
Surface Roughness ◽  
Color Change ◽  
Resin Composite ◽  
Surface Hardness ◽  
Test Surface ◽  
Surface Microhardness ◽  
Restorative Materials ◽  
Desensitizing Agents ◽  
Nanohybrid Composite ◽  
Frequent Exposure

Background. Patients with tooth sensitivity are frequently exposed to desensitizing agents on a regular basis. These agents might have an impact on the surface properties and color of existing oral restorations. Accordingly, this study aimed to investigate the color stability, surface microhardness, and surface roughness of resin-modified glass ionomer (RMGIC), amalgomer CR, nanohybrid, and bulk-fill resin composites restorative materials after frequent exposure to a desensitizing agent. Materials and Methods. One hundred and twenty specimens were prepared; 10 specimens for each restorative material were equally subdivided into control and desensitizing-agent-exposed groups in each test. Surface microhardness and surface roughness were evaluated using the Vickers microhardness tester and surface profilometer, respectively. The color change was measured by using a spectrophotometer using the CIE L ∗ a ∗ b ∗ formula. Surface topography was analyzed using a scanning electron microscope (SEM). The collected data were analyzed with Student’s t-test, one-way ANOVA, and Tukey post hoc tests for pairwise comparison at a level of significance of 0.05. Result. The frequent use of a desensitizing agent significantly decreased surface hardness of RMGIC, amalgomer, and bulk-fill composite materials. However, nanohybrid composite exhibited a significant surface hardness increase. The surface roughness of RMGIC, amalgomer, and nanohybrid composite increased significantly. Meanwhile, the bulk-fill resin composite showed a nonsignificant decrease. Both RMGIC and amalgomer exhibited significantly higher values of color change in comparison to those of nanohybrid and bulk-fill composites. Conclusion. The bulk-fill composite seems to be more resistant to discoloration and surface topographical changes than other tested materials on frequent exposure to the desensitizing agent. However, this exposure may pose a negative impact on its surface hardness. Bulk-fill resin composite may be the most suitable esthetic restorative in patients who frequently use desensitizing agents.

scholarly journals PERBEDAAN KEKERASAN PERMUKAAN ENAMEL SETELAH APLIKASI FLUORIDE VARNISH DAN CASEIN PHOSPO PEPTIDE-AMORPHOUS CALSIUM PHOSPHATE FLUORIDE (CPP-ACPF) (PENELITIAN IN VITRO)

2019 ◽  
Vol 7 (2) ◽  
pp. 130
Author(s):  
Sinta Puspita ◽  
Adioro Soetojo ◽  
Sri Kunarti
Keyword(s):  
Tooth Enamel ◽  
Surface Hardness ◽  
Enamel Surface ◽  
Fluoride Varnish ◽  
Initial Surface ◽  
Surface Microhardness ◽  
Demineralized Enamel ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Background: Caries is a chronic, slowly progressing disease, with symptoms not detected at the onset of the disease but generally much later. Its initiation is associated with demineralization (calcium and phosphate loss) of subsurface tooth enamel, resulting in the formation of a subsurface lesion. To restore the natural equilibrium, either remineralization must be enhanced or demineralization must be retarded. There are some topical agents that can enhance remineralization such as topical fluor and casein phosphopeptide – amorphous calcium phosphate (CPP-ACP). Purpose: The aim of this study is to analyze the differences of the enamel surface microhardness after application of fluoride varnish and CPP-ACPF. Methode: 27 blocks bovine enamel were devided into 3 groups. Group 1 – control (No surface treatment), group 2 – fluoride varnish and group 3 – CPP-ACPF. Initial surface hardness enamel was measured for all enamel specimens. Artificial enamel carious lesions were created by immersing enamel samples to demineralization solution (pH 4,5) for 72 hours at temperature 370 C. The surface microhardness of demineralized enamel specimens was measured. A caries progression test (pH cycling) was carried out, which consisted of alternative demineralization (3 hours), remineralization with artificial saliva (21 hours) and application topical agent twice a day for 14 days. Then, the last surface enamel microhardness is measured. Result: Group 3 showed significantly highest Vickers hardness number (P<0,05) followed by group 2 and the lowest is group 1. Conclusions: This study proved that enamel surface microhardness after application of CPP-ACPF was higher than fluoride varnish.

scholarly journals Influence of Self-Etching Adhesive Systems on Restorative Material Surfaces

2011 ◽  
Vol 2 (2) ◽  
pp. 93-98 ◽  
Author(s):  
Daphne Câmara Barcellos ◽  
Cesar Rogério Pucci ◽  
Carlos Rocha Gomes Torres ◽  
Ana Paula Martins Gomes ◽  
Sergio Eduardo de Paiva Gonçalves ◽  
...  
Keyword(s):  
Glass Ionomer Cement ◽  
Surface Hardness ◽  
Adhesive System ◽  
Acid Etching ◽  
Adhesive Systems ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Adhesive Factor ◽  
Material Factor

ABSTRACT This study evaluated the microhardness of restorative materials after the use of self-etching and acid-etching adhesives. Specimens were divided into four groups: Group 1 (CR): Composite resin, Group 2 (GIC): Glass ionomer cement chemically activated, Group 3 (EC): Dual resinous cement, Group 4 (E): Dual resinous cement. Each group was divided into three subgroups, according to the type of adhesive system applied on the surface: Subgroup 1 (C): Control subgroup, Subgroup 2 (XE): Xeno III self-etching adhesive, Subgroup 3 (SB): Single bond acid-etching adhesive. Vickers microhardness analysis was performed on the surfaces and the data were submitted to the two-way ANOVA and the Tukey's test. The means for the material factor: GIC: (35.61)a; CR: (43.54)b; E: (44.65)b; EC: (50.13)c. The means for the adhesive factor: SB: (36.35)a; XE: (38.44)a; C: (55.65)b. All materials tested showed a decrease in surface hardness after application of the adhesive systems, irrespective of the system. The lowest microhardness was shown by GIC and the highest by Enforce Core.

scholarly journals Efek Perendaman Air Jeruk Nipis dan Air Jeruk Lemon pada Kekasaran Permukaan Semen Ionomer Kaca

2018 ◽  
Vol 7 (2) ◽  
pp. 11
Author(s):  
Rosalina Tjandrawinata ◽  
Andreas Julianto
Keyword(s):  
Surface Roughness ◽  
Mineral Water ◽  
Glass Ionomer Cement ◽  
Lemon Juice ◽  
Lime Juice ◽  
Significant Difference ◽  
Food And Beverage ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

The surface of Glass Ionomer Cement (GIC) restoration changes because of mastication forces, shear force, other functional forces, and also tooth brushing process. Things that can also change the surface of GIC restoration is kind of food and beverage consumption, such as in Indonesia, lime and lemon juice are usual beverage, and mixed in food. The purpose of this study is to determine the changes in surface roughness of GIC restoration due to lime and lemon juice immersion. Three groups GIC sample, each of ten samples were 5 mm in diameter and 2.5 mm in height. Group 1 was immersed in mineral water (as control) for 10 days. In 10 days, Group 2 was immersed in lime juice, each day 9 times @ 15 minutes and brushed with soft toothbrush for 9 times @ 3 minutes. Similar way with group 2, 10 samples of group 3 was immersed in lemon juice. Samples immersed in mineral water show changes in surface roughness of 0.977+0.503 μm, while samples immersed in lime juice show 4.267+1.489 μm, and samples immersed in lemon juice show 4.293+1.311 μm. One way ANOVA test shows significant differences among the samples (p<0.05). Post hoc Tukey test shows significant difference (p<0.05) between group 1 and group 2 and between group 1 and group 3. However, there is no significant difference between group 2 and group 3 (p>0.05). Conclusion, lime juice and lemon juice cause changes in the surface roughness of GIC more than mineral water.

scholarly journals Physical Properties of Newly Developed Resin Modified Glass Ionomer Cement with Synthesised Coumarin Derivatives

2021 ◽  
Vol 50 (8) ◽  
pp. 2433-2444
Author(s):  
Fatimah Suhaily Abdul Rahman ◽  
Dasmawati Mohamad ◽  
Habsah Hasan ◽  
Hasnah Osman
Keyword(s):  
Surface Roughness ◽  
Glass Ionomer Cement ◽  
Surface Hardness ◽  
Surface Characteristics ◽  
Coumarin Derivatives ◽  
Glass Ionomer ◽  
Irregular Surfaces ◽  
Resin Modified Glass Ionomer ◽  
Surface Morphologies ◽  
Ionomer Cement

The aim of this study was to determine the effects of two types of coumarin derivatives, namely, 3-acetylcoumarin (AC) and coumarin thiosemicarbazone (CT) on surface characteristics such as the roughness, hardness, and morphology of resin-modified glass-ionomer cement (RMGIC). The release of coumarin from the fabricated RMGIC was also investigated. AC and CT at 1.0% (w/w) concentration were added into 0.3 g of RMGIC powder and mixed with 0.1 g of polyacrylic acid. The fabricated RMGIC-AC and RMGIC-CT were evaluated for surface characteristics such as roughness, hardness and topography. The coumarin release of AC and CT from RMGIC was also determined. The RMGIC-CT demonstrated a decreased roughness value among the materials. The surface roughness exhibited by the RMGIC was statistically higher (p < 0.05) than that of fabricated materials. The RMGIC-AC was observed to have the highest hardness value compared to the RMGIC-CT and RMGIC, and this value was significantly higher (p < 0.05). The surface morphologies of the RMGIC-AC and RMGIC-CT showed a number of pores and irregular surfaces. Meanwhile, the surface roughness value of the RMGIC was statistically higher (p < 0.05) than both RMGIC-AC and RMGIC-CT. In conclusion, the large-sized AC particles significantly increased the surface hardness of the fabricated RMGIC. Conversely, the particle size of both coumarins were not influenced the surface roughness value and the coumarin release profile of fabricated RMGICs.

scholarly journals Sesame Oil (Sesamum Indicum L.) as a New Challenge for Reinforcement of Conventional Glass Ionomer Cement, Could It Be?

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Neven S. Aref
Keyword(s):  
Surface Roughness ◽  
Compressive Strength ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Glass Ionomer Cement ◽  
Color Stability ◽  
Sesame Oil ◽  
Glass Ionomer ◽  
Surface Microhardness ◽  
Ionomer Cement

Purpose. Despite the advantages of glass ionomer cement (GIC) including chemical bonding to the tooth structure and fluoride release, its low-grade mechanical properties make it a topic for research. Accordingly, this study was conducted to assess the ability of sesame oil as a natural bioactive additive to reinforce conventional glass ionomer cement. Materials and Methods. Sesame oil was blended into the liquid component of the cement in ratios of 3 and 5 ( v / v % ). One control and two experimental groups were enrolled in the study; I: unmodified GIC (control), II: 3 ( v / v % ) sesame oil-modified GICs, and III: 5( v / v % ) sesame oil-modified GICs. Compressive strength, shear bond strength, diametral tensile strength, surface microhardness, surface roughness, and color stability were the parameters assessed. A representative specimen of each group was analyzed for its chemical structure by Fourier transformation infrared spectroscopy. One-way ANOVA followed by Tukey test was used to analyze the collected data of all evaluated parameters except the color stability results, which were analyzed by Student t-test at p < 0.05 . Results. Three and 5 ( v / v % ) sesame oil-modified GICs exhibited significant increase in their compressive strength, shear bond strength, diametral strength, and surface microhardness. Concurrently, there was a significant decrease in surface roughness ( p < 0.05 ) in both formulations of the modified cement. Both 3 and 5 ( v / v % ) sesame oil-modified GICs showed a clinically acceptable color change. Conclusions. Sesame oil seems to be a promising natural bioactive product for reinforcement of conventional GIC with a clinically agreeable esthetic.

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