scholarly journals Flexural Strength and Depth of Cure of Single Shade Dental Composites

2021 ◽  
pp. 110-118
Author(s):  
Fatin A. Hasanain
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
Dental Composites ◽  
Resin Composites ◽  
Dental Resin ◽  
Depth Of Cure ◽  
Universal Testing ◽  
Significant Difference ◽  
Experimental Laboratory ◽  
Cylindrical Samples

Aims: This work aims to assess the flexural strength and depth of cure of Optishade, Omnichroma and Z350 dental resin composites. Study Design: Experimental Laboratory Study. Methods: To assess flexural strength as per ISO standards, 15 samples of each of the three materials were made (n=5) with the dimensions 25x2x2 mm. They were then subjected to 3 point bending testing on a universal testing machine. To assess depth of cure as per ISO standard, 15 cylindrical samples 4 mm in diameter and 6 mm in height were created (n=5) and scraping test was performed. Results: There was a significant difference between the 3 materials in both flexural strength and depth of cure. Z350 had the lowest depth of cure and the highest flexural strength. Conclusion: Within the limitations of this study, all three tested materials fell within the ISO requirementsfor dental resin compositesfor both flexural strength and depth of cure.

scholarly journals Flexural Properties and Elastic Modulus of Different Esthetic Restorative Materials: Evaluation after Exposure to Acidic Drink

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Scribante ◽  
Marco Bollardi ◽  
Marco Chiesa ◽  
Claudio Poggio ◽  
Marco Colombo
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Water Immersion ◽  
Testing Machine ◽  
Distilled Water ◽  
Resin Composites ◽  
Restorative Material ◽  
Universal Testing ◽  
Restorative Materials ◽  
Acidic Beverages

Background. Acidic beverages, such as soft drinks, can produce erosion of resin composites. The purpose of the present study was to investigate mechanical properties of different esthetic restorative materials after exposure to acidic drink. Methods. Nine different composites were tested: nanofilled (Filtek Supreme XTE, 3M ESPE), microfilled hybrid (G-ænial, GC Corporation), nanohybrid Ormocer (Admira Fusion, Voco), microfilled (Gradia Direct, GC Corporation), microfilled hybrid (Essentia, GC Corporation), nanoceramic (Ceram.X Universal, Dentsply De Trey), supranano spherical hybrid (Estelite Asteria, Tokuyama Dental Corporation), flowable microfilled hybrid (Gradia Direct Flo, GC Corporation), and bulk fill flowable (SureFil SDR flow, Dentsply De Trey). Thirty specimens of each esthetic restorative material were divided into 3 subgroups (n=10): specimens of subgroup 1 were used as control, specimens of subgroup 2 were immersed in 50 ml of Coca Cola for 1 week, and specimens of subgroup 3 were immersed in 50 ml of Coca Cola for 1 month. Flexural strength and elastic modulus were measured for each material with an Instron Universal Testing Machine. Data were submitted to statistical analysis. Results. After distilled water immersion, nanofilled composite showed the highest value of both flexural strength and elastic modulus, but its flexural values decreased after acidic drink immersion. No significant differences were reported between distilled water and acidic drink immersion for all other materials tested both for flexural and for elastic modulus values. Conclusions. Even if nanofilled composite showed highest results, acidic drink immersion significantly reduced flexural values.

Effect of Modification of Aluminum Borate Whiskers with Three Methods on Flexural Properties of Dental Resin Composites

2013 ◽  
Vol 364 ◽  
pp. 687-691
Author(s):  
Yan Bo Yuan ◽  
Xing Xing Li ◽  
Wen Yun Zhang ◽  
Qing Hua Chen ◽  
Yu Hong Xiao ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Sol Gel ◽  
Flexural Properties ◽  
Resin Composites ◽  
Dental Resin ◽  
Dental Resin Composites ◽  
Aluminium Borate ◽  
Significant Difference ◽  
Group A ◽  
Group B

This study aimed to compare three different methods for the modification of aluminium borate whiskers and investigate the effect of aluminium borate whiskers composites on flexural properties of dental resin composites. Method A was to mix aluminium borate whiskers and silicon dioxide (SiO2) nanoparticles directly. Method B was to modify the mixture of aluminium borate whiskers and SiO2nanoparticles with sol-gel process of tetraethoxysilane (TEOS). Method C was to modify the aluminium borate whiskers with SiO2nanoparticles which were repaired by sol-gel method of TEOS. The effects of the three methods were characterized by the TEM and SEM. There was a significant difference (p<0.05) in the flexural strength among three methods. Group C had a flexural strength of 149.59 ± 12.86 MPa (mean ± SD; n = 5), which is significantly higher than 95.28 ± 4.53 MPa for Group A and 123.14 ± 17.37 MPa for Group B. It is concluded that ceramic whisker reinforcement significantly improves the flexural properties of resin composites; different methods produce different effects.

scholarly journals Effect of Glazing on Flexural Strength of Full-Contour Zirconia

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Hattanas Kumchai ◽  
Patrapan Juntavee ◽  
Arthur F. Sun ◽  
Dan Nathanson
Keyword(s):  
Flexural Strength ◽  
Significant Influence ◽  
Testing Machine ◽  
Surface Treatments ◽  
Bending Test ◽  
Three Point Bending ◽  
Universal Testing ◽  
Heat Treated ◽  
Significant Difference ◽  
Post Hoc

Objective. The purpose of this study was to evaluate the effect of glazing on flexural strength of highly translucent zirconia materials. Materials and Methods. Specimens of three brands of zirconia bars (Prettau Zirconia, Zirkonzahn; inCoris TZI, Sirona; and Zirlux FC, Pentron Ceramics) were prepared and polished according to manufacturers’ instructions. Final specimen dimensions were 20 × 4 × 2 mm. The specimens from each brand were divided into 3 groups (N = 10): control, heat-treated, and glazed. Heat-treated specimens were fired without the application of the glaze material. The glaze material was applied to the glazed specimens before being fired. A three-point bending test (15 mm span) was performed in an Instron universal testing machine (ISO 6872). Data were analyzed by ANOVA and Tukey’s HSD post hoc test (α = 0.05). Results. Two-way ANOVA showed a significant influence of surface treatments on flexural strength of zirconia materials (P≤0.05). There was no significant difference in flexural strength among the different brands of highly translucent zirconia (P≥0.05). Tukey’s HSD post hoc test showed that specimens in the “glazed” group had significantly lower flexural strength than the control and heat-treated groups (P≤0.05). Conclusion. Within the limitations of the study, external glazing decreased the flexural strength of highly translucent zirconia.

scholarly journals The Effect of Mouthwash Containing Alcohol on Flexural Strength of Polymethylmethacrylate and Thermoplastic Nylon

2020 ◽  
Vol 3 (1) ◽  
pp. 17
Author(s):  
Eva Riani ◽  
Octarina Octarina
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
Research Groups ◽  
Anova Test ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Significant Difference ◽  
The Mean ◽  
Materials Used ◽  
Test Result

Introduction: Polymethylmethacrylate (PMMA) and thermoplastic nylon are materials used for making denture bases. Denture users use various methods in order to keep clean their denture. Mouthwash can be an option for cleaning dentures because it is easier to find. Objective: The objective of this research was to investigate the effect of mouthwash containing alcohol as a denture cleanser on flexural strength of polymethylmethacrylate and thermoplastic nylon. Methods: Eighteen samples of polymethylmethacrylate and eighteen samples of thermoplastic nylon with a bar shape (65x10x3 mm) are being used in this research. Each materials are randomly divided into 3 groups (n=6) so there will be six research groups incuded : (A1) PMMA immersed aquades, (A2) PMMA immersed in mouthwash containing alcohol 21.6%, (A3) PMMA immersed in mouthwash containing alcohol 9%, (B1) thermoplastic nylon immersed in aquades, (B2) thermoplastic nylon immersed in mouthwash containing alcohol 21.6%, (B3) thermoplastic nylon immersed in mouthwash containing alcohol 9%. Flexural strength of two materials was tested using universal testing machine (Shimadzu AGS - 5KNX, Japan). All of the data obtained were analyzed using two way Anova test. Result: The mean of flexural strength for group A1 (104.275 ± 15.469 MPa), A2 (103.298 ± 10.387 MPa), A3 (111.626 ± 14.957 MPa), B1 (42.707 ± 4.857 MPa), B2 (38.258 ± 3.246 MPa), and B3 (40.218 ± 1.542 MPa). Result of analysis showed that there was a significant differences between flexural strength of polymethylmethacrylate and thermoplastic nylon (p<0,05), but immersion in mouthwash containing  alcohol showed no significant difference (p>0,05). Conclusion: This research found that flexural strength of polymethylmethacrylate higher than flexural strength of thermoplastic nylon and mouthwash containing alcohol can be an alternative for cleaning a denture because it does not affect the flexural strength of both material significantly.

Effect of Repeated Preheating Cycles on Flexural Strength of Resin Composites

2013 ◽  
Vol 38 (1) ◽  
pp. 33-38 ◽  
Author(s):  
M D'Amario ◽  
S Pacioni ◽  
M Capogreco ◽  
R Gatto ◽  
M Baldi
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Testing Machine ◽  
Bending Test ◽  
Resin Composites ◽  
Control Groups ◽  
Three Point Bending ◽  
Universal Testing ◽  
Group A ◽  
Significant Factors

SUMMARY The aim of this study was to assess the flexural strengths of three resin composites prepared at room temperature or cured after 20 or 40 cycles of preheating to a temperature of 45°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium) (HFO), Enamel Plus HRi (Micerium) (HRi), Opallis + (FGM) (OPA). One group of specimens for each composite was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 20 or 40 preheating cycles to a temperature of 45°C in a preheating device. Ten specimens were prepared for each group. A three-point bending test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed with a two-way analysis of variance (ANOVA) test and a Games-Howell test (α = 0.05). The two-way ANOVA showed that both the material and the number of heating cycles were significant factors, able to influence the flexural strength values (p&lt;0.05). However, there was not a statistically significant interaction (p&gt;0.05). For all three composites flexural strengths were not affected after 20 preheating cycles in comparison with the control groups (0 preheating cycles) but were, however, significantly decreased when 40 prewarming cycles were conducted. The HRi and OPA groups had the highest flexural strengths, with no statistically significant differences among them. HFO presented significantly lower flexural strengths in comparison with HRi.

In-vitro Comparative Evaluation of Flexural Strength and Depth of Cure of Bulkfill Composite

2021 ◽  
Vol 13 ◽  
pp. 16-21
Author(s):  
K K Nanjamma ◽  
Shameem P Puthiyottil ◽  
K C Ponnappa
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
Composite Resins ◽  
Depth Of Cure ◽  
Shake Test ◽  
Significant Difference ◽  
Three Point Bend Test ◽  
Point Bend ◽  
Post Hoc

Aims and objectives: Bulkfill composite resins have been used for the posterior restorations in an attempt to speed up the restorative process. Here 4 to 5mm thickness of composite resins can be placed andcured in asingle step so that time consuming layering technique can be eliminated. The purpose of this study was to investigate the flexural strength and depth of cure of two bulk fill composites and to compare it with a universal composite. Materials and method: Two bulk fill composites (Sonic fill and Filtekbulkfill) and one universal composite (Filtek Z350 XT) were used. Ten samples per group were made using rectangular split brass mold following ISO standard 4049 to measure the flexural strength. Each sample was then subjected to three point bend test using universal testing machine until failure occurred. For depth of cure measurements, ten samples per group were made using cylindrical brass mold and were subjected to acetone shake test for 30 sec. The dimensions of the samples were measured using Vernier callipers and compared. One-way analysis of variance followed by Tukey’s post-hoc test was used to determine the statistical differences among groups at significance of p<0.05. Results: Sonicfillgave highest flexural strength value and Filtek Z350 XT the least. There was no statistically significant difference between the flexural strength of Filtekbulkfill and Filtek Z350 XT. For depth of cure, Filtekbulkfill showed higher value than other tested groups. Conclusion: All the tested materials showed significantly higher flexural strength values than the minimum flexural strength (80MPa) that is required for use in stress bearing areas. Sonicfill composite produced highest value of flexural strength than other composites, which may bedue to its increased percentage of filler content. For depth of cure, both the tested bulkfill composites showed lesser value of depth of cure than that claimed by manufacturers .

scholarly journals Effect of Accelerated Aging on Some Mechanical Properties and Wear of Different Commercial Dental Resin Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2769
Author(s):  
Jonne Oja ◽  
Lippo Lassila ◽  
Pekka K. Vallittu ◽  
Sufyan Garoushi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Accelerated Aging ◽  
Wear Depth ◽  
Resin Composites ◽  
Expiration Date ◽  
Dental Resin ◽  
Hydrothermal Aging ◽  
Dental Resin Composites

The aim of current in vitro research was to determine the effect of hydrothermal accelerated aging on the mechanical properties and wear of different commercial dental resin composites (RCs). In addition, the effect of expiration date of the composite prior its use was also evaluated. Five commercially available RCs were studied: Conventional RCs (Filtek Supreme XTE, G-aenial Posterior, Denfil, and >3y expired Supreme XTE), bulk-fill RC (Filtek Bulk Fill), and short fiber-reinforced RC (everX Posterior). Three-point flexural test was used for determination of ultimate flexural strength (n = 8). A vickers indenter was used for testing surface microhardness. A wear test was conducted with 15,000 chewing cycles using a dual-axis chewing simulator. Wear pattern was analyzed by a three-dimensional (3D) noncontact optical profilometer. Degree of C=C bond conversion of monomers was determined by FTIR-spectrometry. The specimens were either dry stored for 48 h (37 °C) or boiled (100 °C) for 16 h before testing. Scanning electron microscopy (SEM) was used to evaluate the microstructure of each material. Data were analyzed using ANOVA (p = 0.05). Hydrothermal aging had no significant effects on the surface wear and microhardness of tested RCs (p > 0.05). While flexural strength significantly decreased after aging (p < 0.05), except for G-aenial Posterior, which showed no differences. The lowest average wear depth was found for Filtek Bulk Fill (29 µm) (p < 0.05), while everX Posterior and Denfil showed the highest wear depth values (40, 39 µm) in both conditions. Passing the expiration date for 40 months did not affect the flexural strength and wear of tested RC. SEM demonstrated a significant number of small pits on Denfil’s surface after aging. It was concluded that the effect of accelerated aging may have caused certain weakening of the RC of some brands, whereas no effect was found with one brand of RC. Thus, the accelerated aging appeared to be more dependent on material and tested material property.

scholarly journals Effects of Fluorosis and Self Etching Primers on Shear Bond Strengths of Orthodontic Brackets

2009 ◽  
Vol 03 (03) ◽  
pp. 173-177 ◽  
Author(s):  
Ahmet Yalcin Gungor ◽  
Hakan Turkkahraman ◽  
Necdet Adanir ◽  
Huseyin Alkis
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Orthodontic Brackets ◽  
Universal Testing ◽  
Adhesive Remnant Index ◽  
Halogen Light ◽  
Significant Difference ◽  
Bond Strengths ◽  
Group Ii ◽  
Clinical Changes

ABSTRACTObjectives: To evaluate the effects fluorosis and self etching primers (SEP) on shear bond strengths (SBS) of orthodontic brackets.Methods: A total of 48 (24 fluorosed and 24 non-fluorosed) non-carious freshly extracted human permanent premolar teeth were used in this study. Fluorosed teeth were selected according to the modified Thylstrup and Fejerskov index (TFI), which is based on the clinical changes in fluorosed teeth. Fluorosed and non-fluorosed teeth were randomly assigned to 4 groups of 12 each. In groups I (non-fluorosed teeth) and II (fluorosed teeth), standard etching protocol was used and brackets were bonded with Light Bond. In groups III (non-fluorosed teeth) and IV (fluorosed teeth), Transbond Plus SEP was used and brackets were bonded with Transbond XT Light Cure Adhesive. All specimens were cured with a halogen light. After bonding, SBS of the brackets were tested with Universal testing machine. After debonding, all teeth and brackets in the test groups were examined under 10x magnifications. Any adhesive remained after debonding was assessed and scored according to the modified Adhesive Remnant Index (ARI).Results: ANOVA indicated a significant difference between groups (P<.001). SBS in group II (Light Bond+Fluorosis) were significantly lower than other groups. ARI scores of the groups were also significantly different (P<.001). There was a greater frequency of ARI scores of 1,2 and 3 in group II (Light Bond+Fluorosis).Conclusions: When standard etching protocol was used enamel fluorosis significantly decreased the bond strength of orthodontic brackets. Satisfactory bond strengths were obtained when SEP was used for bonding brackets to the fluorosed teeth. (Eur J Dent 2009;3:173-177)

scholarly journals Load-Application Devices: A Comparative Strain Gauge Analysis

2015 ◽  
Vol 26 (3) ◽  
pp. 258-262 ◽  
Author(s):  
Renato Sussumu Nishioka ◽  
Luis Gustavo Oliveira de Vasconcellos ◽  
Renata Pilli Jóias ◽  
Sigmar de Mello Rode
Keyword(s):  
Strain Gauge ◽  
Repeated Measures ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Load Application ◽  
Chromium Alloy ◽  
Axial Loads ◽  
Nickel Chromium ◽  
Universal Testing ◽  
Significant Difference

In view of the low loading values commonly employed in dentistry, a load-application device (LAD) was developed as option to the universal testing machine (UTM), using strain gauge analysis. The aim of this study was to develop a load-application device (LAD) and compare the LAD with the UTM apparatus under axial and non-axial loads. An external hexagonal implant was inserted into a polyurethane block and one EsthetiCone abutment was connected to the implant. A plastic prosthetic cylinder was screwed onto the abutment and a conical pattern crown was fabricated using acrylic resin. An impression was made and ten identical standard acrylic resin patterns were obtained from the crown impression, which were cast in nickel-chromium alloy (n=10). Four strain gauges were bonded diametrically around the implant. The specimens were subjected to central (C) and lateral (L) axial loads of 30 kgf, on both devices: G1: LAD/C; G2: LAD/L; G3: UTM/C; G4: UTM/L. The data (με) were statistically analyzed by repeated measures ANOVA and Tukey's test (p<0.05). No statistically significant difference was found between the UTM and LAD devices, regardless of the type of load. It was concluded that the LAD is a reliable alternative, which induces microstrains to implants similar to those obtained with the UTM.

scholarly journals Effect Of Accelerating Aging On Retention And The Release Period Of Clips In A Bar Retained Maxillary Implant Overdenture

2021 ◽  
Vol 8 ◽  
Author(s):  
Dalia El naggar ◽  
Ahmed Mohamed Alam-Eldein ◽  
Maha Mostafa Halim ◽  
Hoda Mohammed Amin Rashad
Keyword(s):  
Testing Machine ◽  
Accelerated Aging ◽  
The Other ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Retention Loss ◽  
Significant Difference ◽  
Implant Overdenture

Objectives: This study was made to detect the effect of accelerating aging on retention and measuring the release period of clips in a 2 and 3 bar retained maxillary implant overdenture. Materials and Methods: Four implants were placed in two maxillary edentulous epoxy models. One model had two bar attachments with two clips overdenture while the other model had three bar attachments with three clips in the overdenture. Retention and release period of the clips were checked before applying insertion removal cycles. Retention was measured using universal testing machine after 540 cycles (6 months) and 1080 cycles (1 year) of insertion removal on a chewing simulator.Results and Conclusions: There was a significant difference in retention and release period between two bars and three bars implant retained maxillary overdentures. A significant difference was also seen in each group after accelerated aging. Therefore, the three bar implant retained overdenture had higher retention values than two bar. Retention loss occurred in both groups after the insertion removal cycles. Release period value was lower in two bar overdenture than three bar overdenture.

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