Role of Grain Size Fluctuations on the Environmental Resistance of Alumina-Zirconia Composite in Comparison with Commercially Available Monolithic Zirconia Femoral Head

2010 ◽  
Vol 76 ◽  
pp. 235-239
Author(s):  
Nobuhiko Sugano ◽  
Giuseppe Pezzotti
Keyword(s):  
Grain Size ◽  
Femoral Head ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference ◽  
In Vitro Exposure ◽  
Before And After ◽  
Moist Environment ◽  
Monolithic Zirconia

Raman microprobe spectroscopy and atomic force microscopy (AFM) were systematically used to characterize the surface of an advanced alumina/zirconia composite (henceforth also referred to as zirconia toughened alumina, ZTA), in comparison with a commercially available femoral head made of monolithic zirconia. Experiments were conducted before and after in vitro exposure in water moist environment up to 100 h. Both materials contained zirconia partly stabilized with yttria. Tetragonal-to-monoclinic phase transformation, which was quantitatively characterized by confocal Raman spectroscopy as a function of grain size, showed significant difference between the investigated samples. Such difference was similarly found with respect to both roughness level and time needed for such topologic changes to occur. Variation of phase fractions and of topologic surface parameters were plotted as a function of in vitro exposure time and compared.

scholarly journals Comparative abrasive wear resistance and surface analysis of dental resin-based materials

2018 ◽  
Vol 12 (01) ◽  
pp. 057-066 ◽  
Author(s):  
Maleeha Nayyer ◽  
Shahreen Zahid ◽  
Syed Hammad Hassan ◽  
Salman Aziz Mian ◽  
Sana Mehmood ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Structural Changes ◽  
Wear Testing ◽  
Dental Resin ◽  
Force Microscopy ◽  
Atomic Force ◽  
Custom Made ◽  
Significant Difference ◽  
Before And After ◽  
Roughness Analysis

ABSTRACT Objective: The objective of this study was to assess the surface properties (microhardness and wear resistance) of various composites and compomer materials. In addition, the methodologies used for assessing wear resistance were compared. Materials and Methods: This study was conducted using restorative material (Filtek Z250, Filtek Z350, QuiXfil, SureFil SDR, and Dyract XP) to assess wear resistance. A custom-made toothbrush simulator was employed for wear testing. Before and after wear resistance, structural, surface, and physical properties were assessed using various techniques. Results: Structural changes and mass loss were observed after treatment, whereas no significant difference in terms of microhardness was observed. The correlation between atomic force microscopy (AFM) and profilometer and between wear resistance and filler volume was highly significant. The correlation between wear resistance and microhardness were insignificant. Conclusions: The AFM presented higher precision compared to optical profilometers at a nanoscale level, but both methods can be used in tandem for a more detailed and precise roughness analysis.

scholarly journals Effect of Hydrofluoric Acid Surface Treatments on Surface Roughness and Three-Point Flexural Strength of Suprinity Ceramic

2020 ◽  
Author(s):  
Nazanin Keshmiri ◽  
Homayoon Alaghehmand ◽  
Faraneh Mokhtarpour
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Hydrofluoric Acid ◽  
Testing Machine ◽  
Etching Time ◽  
Control Group ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference ◽  
Before And After

Objectives: This study aimed to evaluate the effects of hydrofluoric acid (HF) concentration and etching time on the surface roughness (SR) and three-point flexural strength of Suprinity and to analyze the surface elements before and after etching. Materials and Methods: To measure the SR, 70 specimens of Suprinity (2×4×5mm3) were assigned to seven groups (n=10). Six groups were etched for 20, 60, and 120 seconds with 5% and 10% HF and 7th group was the control group. Specimens were evaluated using atomic force microscopy (AFM). One specimen from each group was used to analyze the surface elements using scanning electron microscopy (SEM). For measuring the three-point flexural strength, 60 specimens were divided into six groups (n=10) and etched as previously described. The flexural strength was measured using a universal testing machine. T-test, one-way analysis of variance (ANOVA), and two-way ANOVA were used for statistical analyses (P<0.05). Results: The 10% concentration of HF caused higher SR compared to the 5% HF. The effect of HF concentration on the flexural strength was significantly different in the 20- and 60-second etching groups. Different etching times had no significantly different effect on the SR. With 5% HF, the flexural strength was significantly higher for 20-second etching time than for the etching times of 60 and 120 seconds. With 10% HF, there was a significant difference in flexural strength between etching times of 20 and 120 seconds. The atomic percentage (at%) of silica was enhanced by increasing the etching time. Conclusions: The best surface etching protocol comprises 10% HF used for 20 seconds.

scholarly journals Surface Roughness of Commercial Composites after Different Polishing Protocols: An Analysis with Atomic Force Microscopy

2010 ◽  
Vol 4 (1) ◽  
pp. 191-194 ◽  
Author(s):  
Luca Giacomelli ◽  
Giacomo Derchi ◽  
Andrea Frustaci ◽  
Orlando Bruno ◽  
Ugo Covani ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Bacterial Colonization ◽  
Average Height ◽  
Resin Composites ◽  
Composite Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference

Background and Aims: Polishing may increase the surface roughness of composites, with a possible effect on bacterial growth and material properties. This preliminary in vitro study evaluates the effect of three different polishing systems (PoGo polishers, Enhance, Venus Supra) on six direct resin composites (Gradia Direct, Venus, Venus Diamond, Enamel Plus HFO, Tetric Evoceram, Filtek Supreme XT). Materials and Methods: For each composite, 12 square specimens were prepared: 9 specimens were polished, three for each different method, while three specimens were used as controls. Surface roughness was determined with AFM by measuring Root Mean Square (RMS) of average height. Results: PoGo polisher determined a significantly rougher surface, versus controls, in 5 out of 6 composites evaluated. Some significant differences from unpolished controls were observed also for Enhance polishing. Polishing with Venus Supra did not result in any significant difference in surface roughness versus controls. No differences were observed between different polishing systems. Conclusions: These preliminary results suggest that Venus Supra polishing system could determine a smoother composite surface if compared to the other polishing systems tested. On this basis, we are conducting an in vivo study to evaluate bacterial colonization on some combinations of composites and polishing protocols.

scholarly journals The effect of denture cleanser 48% sodium bicarbonate on surface roughness changes of heat-cured acrylic resin

2021 ◽  
Vol 5 (1) ◽  
pp. 19-23
Author(s):  
Syahrial , ◽  
Pocut Aya Sofya ◽  
Adellya Tasya Sukma
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Sodium Bicarbonate ◽  
Acrylic Resin ◽  
Force Microscopy ◽  
Atomic Force ◽  
Liquid Absorption ◽  
Significant Difference ◽  
Before And After ◽  
Artificial Teeth

The surface of heat-cured acrylic resin on the base of artificial teeth has a risk of surface roughness. Its causes are liquid absorption and chemical processes. Fluid absorption can be affected by immersion in denture cleaners containing sodium bicarbonate. This study aims to determine the effect of a denture cleanser containing 48% sodium bicarbonate on changes in heat-cured acrylic resin's roughness. This study used 16 specimens of heat-cured acrylic resin (brand Meliodent) and was square in size of 10x10x2.0 ± 0.5 mm. The samples' roughness is measured by using Atomic Force Microscopy (AFM). The specimens were immersed in denture cleansing tablets containing 48% sodium bicarbonate for 17 days at room temperature ± 25 °C and were replaced within 8 hours. After immersion, the specimens were measured again using Atomic Force Microscopy (AFM) to determine the final roughness. The data obtained were analyzed by using paired t-test. The analysis showed no significant difference between surface roughness before and after soaking with a denture cleansing tablet containing 48% sodium bicarbonate (p 0.05). This study concluded that there was no increase in the roughness of heat-cured acrylic resin after immersion in denture cleansing tablets containing 48% sodium bicarbonateKEYWORDS: Fittydent, heat-cured acrylic resin, surface roughness

Nano-Scale Evaluation of Surface Morphology Before and After Environmental Exposure In Vitro of an Advanced Alumina/Zirconia Composite for Arthroplastic Applications

2010 ◽  
Vol 76 ◽  
pp. 224-228
Author(s):  
Kengo Yamamoto ◽  
Giuseppe Pezzotti
Keyword(s):  
Surface Roughness ◽  
Environmental Exposure ◽  
Hip Prostheses ◽  
Force Microscopy ◽  
Head Surface ◽  
Before And After ◽  
Moist Environment

In view of the imminent release on the Japanese market of hip prostheses made of an advanced alumina/zirconia, we performed morphologic and spectroscopic assessments of their surfaces with high spatial resolution. Femoral heads were characterized to a degree of statistical accuracy in the as-received state and after long-term exposures in vapor-moist environment. Surface and sub-surface screening was made by atomic force microscopy (AFM) and by confocal Raman spectroscopy, respectively. AFM scanning was systematically repeated with nanometer resolution on portions of surface as large as several tens of micrometers, randomly selected on the head surface, while in-depth scanning by the Raman probe allowed non-destructive analysis of phase structure in the sub-surface slab of material. Polymorphic transformation in zirconia was confined to the first few micrometers below the surface and involved no significant increase in surface roughness even after long-term environmental exposure. Surface roughness lied in a range <10 nm after environmental exposures up to 100 h, corresponding to an exposure time in vivo of several human lifetimes (i.e., according to experimentally derived thermal activation energy).

Bond Integrity and Surface Topography of Orthodontic Metal Brackets to Ceramic and Polymer-Based Restorations. An In-Vitro Study Design

2021 ◽  
Vol 13 (4) ◽  
pp. 650-655
Author(s):  
Ali Alqerban
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Lithium Silicate ◽  
Topographic Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference

The present laboratory study aimed to assess shear bond strength (SBS) of orthodontic metal brackets bonded to different ceramic and polymer-based restorations after artificial aging. Eighty metal brackets were bonded using Transbond-X to eighty disks which were fabricated using five different ceramic and polymer-based materials (n = 16): group LD: lithium disilicate ceramic, group LS: zirconia-reinforced lithium silicate ceramic, group PI: polymer-infiltrated ceramic, group FC: feldspathic ceramic, and group PM: Polymethyl methacrylate PMMA. Bonded specimens were stored in distilled water (37 °C) for 24 h before they underwent 37,500 thermal cycles between 5 °C and 55 °C. After storage, the SBS was performed using a universal testing machine. Then, the data was analyzed using one-way analysis of variance (ANOVA) and Tukey’s test (α = 0.05). A 2-dimensional topographic analysis of the specimens was performed using atomic force microscopy. The Adhesive Remaining Index (ARI) was also evaluated at 50x magnification. A significant difference was observed between SBS means in the different groups’ materials (P < 0.05). The outcomes of the LD and LS groups were similar (17.55± 0.63 MPa and 18.26±0.33 MPa) but different from those of the PM, PI, and FC groups (15.23±0.29 MPa, 14.22 ±0.56 MPa, and 12.68 ±0.86 MPa). For FC group, however, it provided statistically significantly lower SBS than the other groups. There was predominance of score 3 for ARI in all groups. The type of dental substrate has a significant influence to the shear bond strength of the metal brackets.

scholarly journals Effect of the Insertion and Polymerization Technique in Composite Resin Restorations: Analysis of Marginal Gap by Atomic Force Microscopy

2010 ◽  
Vol 16 (6) ◽  
pp. 779-784 ◽  
Author(s):  
Marcos Aurélio Bomfim da Silva ◽  
Guilherme José Pimentel Lopes de Oliveira ◽  
Josealdo Tonholo ◽  
José Ginaldo da Silva Júnior ◽  
Lucineide de Melo Santos ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Quadratic Forms ◽  
Marginal Gap ◽  
Force Microscopy ◽  
Atomic Force ◽  
Halogen Light ◽  
Significant Difference ◽  
Group B ◽  
Light Group

AbstractThisin vitrostudy evaluated the marginal gap at the composite tooth/resin interface in class V cavities under the influence of two insertion techniques and a curing system by means of atomic force microscopy (AFM). Forty enamel and dentin cavities were prepared on the buccal surface in bovine teeth with quadratic forms measuring 2 mm × 2 mm and depth of 1.5 mm. The teeth were then divided into four groups: group A, 10 cavities were restored in one increment, light cured by halogen light; group B, 10 cavities filled with bulk filling, light cured by the light emitting diodes (LED); group C, 10 cavities were restored by the incremental technique, light cured by halogen light; group D, 10 cavities were restored by the incremental technique, light cured by the LED. The teeth underwent the polishing procedure and were analyzed by AFM for tooth/restoration interface evaluation. The data were compared between groups using the nonparametric Kruskall-Wallis and Mann-Whitney tests (p< 0.05). The results showed a statistically significant difference between groups A and B and groups A and C. It was concluded that no insertion and polymerization technique was able to completely seal the cavity.

Structural and Biomechanical Effects of Photooxidative Collagen Cross-Linking with Photosensitizer Riboflavin and 370 nm UVA Light on Human Corneoscleral Tissues

2013 ◽  
Vol 19 (5) ◽  
pp. 1334-1340 ◽  
Author(s):  
Samjin Choi ◽  
Jae-Ho Shin ◽  
Youjin Cheong ◽  
Kyung-Hyun Jin ◽  
Hun-Kuk Park
Keyword(s):  
Adhesion Force ◽  
Cross Linking ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Uva Light ◽  
Stromal Edema ◽  
Biomechanical Changes ◽  
Collagen Cross Linking

AbstractThis study quantitatively investigated the immediate effects of a photooxidative collagen cross-linking treatment with photosensitizer riboflavin (RF) and 370 nm UVA light in in vitro human corneoscleral collagen fibrils using histology, thickness, scanning electron microscopy, and atomic force microscopy analyses. Twenty 8 × 2 mm corneoscleral strips were dissected sagittally from donor tissue using a scalpel. Four parameters were investigated, including the density, thickness, adhesion force, and stiffness of corneoscleral tissues before and after the collagen cross-linking treatment. The RFUVA-catalyzed collagen cross-linking treatment led to an increase in the density of both corneal (8%) and scleral (23%) stromal collagens. However, there was no difference in corneoscleral thickness. Furthermore, RFUVA-catalyzed collagen cross-linking treatment led to an increased biomechanical response of corneosclera: 25 and 8% increases in corneoscleral stiffness, and 24 and 22% increases in corneoscleral adhesion force. The collagen cross-linking treatment through RF-sensitized photoreaction may cause structural and biomechanical changes in the collagen fibril network of the cornea and the sclera. This is due to narrowing of the interfibrillar spacing and the stromal edema.

scholarly journals In-Vitro Comparative Adhesion Evaluation of Bioceramic and Dual-Cure Resin Endodontic Sealers Using SEM, AFM, Push-Out and FTIR

2021 ◽  
Vol 11 (10) ◽  
pp. 4454
Author(s):  
Radu Marcel Chisnoiu ◽  
Marioara Moldovan ◽  
Doina Prodan ◽  
Andrea Maria Chisnoiu ◽  
Dana Hrab ◽  
...  
Keyword(s):  
Bond Strength ◽  
Force Microscopy ◽  
Gutta Percha ◽  
Atomic Force ◽  
Significant Difference ◽  
Afm Analysis ◽  
Endodontic Sealers ◽  
Root Canal Sealers ◽  
Push Out

(1) Background: Which are the adhesion characteristics of four root canal sealers: two experimental (dual cure resin based endodontic sealer (E1-DCR) and bioceramic based sealer (E2-BC)), and two commercial (RealSeal and TotallFill BC (FKG Germany)). (2) Methods. One-hundred-twenty extracted monoradicular teeth received mechanic-antiseptic preparation and then endodontic filling using gutta-percha in combination with one of the four sealers. Samples from the apical third were selected from each tooth and were randomly distributed for Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and push-out bond strength. Fourier Transform Infrared (FTIR) Spectroscopy was made exclusively for experimental sealers. (3) Results. The two experimental materials did not present a significant difference in apical sealing ability based on SEM evaluation. Gaps were identified in case of RealSeal samples and also lower penetration into the dentinal tubules compared to TotalFill BC. On AFM analysis a more pronounced penetration into the tubules was observed in case of E2-BC sealer was observed. E1-DCR registered a lower bond strength (0.7177 ± 0.55) in the apical third compared to Total Fill BC (p = 0.01). (4) Conclusions. Within the limitations of the current study, it can be stated that the two experimental sealers’ characteristics are comparable to that of the two consecrated materials.

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