The Effect of Thermoforming on Tear Strength of Ethylene Vinyl Acetate Mouthguard Material in Various Thicknesses

2017 ◽  
Vol 751 ◽  
pp. 657-662
Author(s):  
Phakphum Srinuan ◽  
Jeerapatr O. Baiyokvichit ◽  
Rasana Boonpeng ◽  
Tanapol Wongwisatekit ◽  
Pacharaporn Pattanasukwasan ◽  
...  
Keyword(s):  
Vinyl Acetate ◽  
Testing Machine ◽  
Ethylene Vinyl Acetate ◽  
Strength Test ◽  
Tear Strength ◽  
Universal Testing ◽  
Significant Difference ◽  
The Mean ◽  
Thermoforming Process ◽  
One Way Anova

The effect of thermoforming on the tear strength of ethylene vinyl acetate (EVA) mouthguard material (Bioplast®) has not been widely investigated. The present study compared the tear strengths of non-processed and processed EVA specimens in various thicknesses. Two groups of EVA sheet (non-processed and processed) in three different thicknesses of 3, 4 and 5 mm were used in specimen fabrication. The processed EVA sheets were achieved by forming the EVA sheet on the cylindrical stone model with the pressure-molding device (Biostar®). Twelve of tear strength specimens of non-processed and processed group in each thickness were prepared following the modified ASTM D 624-00 guideline. The tear strength test was conducted using universal testing machine (Lloyd® 1K series) with the speed of 500 mm/min. The mean thickness and tear strength of the non-processed and processed specimens in each thickness were compared using independent T-test. The differences in the mean tear strength for each thickness of non-processed and process specimens were determined using one-way ANOVA. The mean tear strength and mean thickness of processed EVA specimens was significantly lower than the non-processed EVA specimens for every thickness (P ≤ 0.05). There was no significant difference in the mean tear strength of EVA specimens among each thickness in both non-processed and processed groups. It can be concluded that the thermoforming process has the significant effect on the tear strength of the EVA mouthguard material formed by pressure molding device in every thicknesses. The tear strength of processed specimens were significant lower than the non-processed. Thus, it is more relevant for testing properties of the processed mouthguard material that the mouthguard material before processing.

scholarly journals Effects of various liquid-to-powder ratios on the compressive strength of calcium enriched mixture: Original research

2021 ◽  
Vol 15 (2) ◽  
pp. 129-132
Author(s):  
Mohammad Forough Reyhani ◽  
Sheida Hosseinian Ahangarnezhad ◽  
Negin Ghasemi ◽  
Amin Salem Milani
Keyword(s):  
Compressive Strength ◽  
Testing Machine ◽  
Original Research ◽  
Significance Level ◽  
Cem Cement ◽  
Universal Testing ◽  
Demineralized Water ◽  
Compressive Strength Test ◽  
The Mean ◽  
One Way Anova

Background. Calcium-enriched mixture (CEM) cement has been introduced and marketed as a biomaterial for use in furcal perforation repair and apexogenesis procedures, in which the compressive strength that indicates the material’s resistance against crushing is of utmost importance. This study evaluated the effect of various liquid-to-powder ratios on CEM cement’s compressive strength. Methods. One gram of the cement was mixed with 0.5, 0.34, and 0.25 mL of demineralized water and transferred to stainless steel molds (6 and 4 mm in height and diameter, respectively). Five cells in the mold were considered for each group. The compressive strength test was conducted using the universal testing machine after incubating for seven days under 95% humidity at 37°C. One-way ANOVA was applied for data analysis at P≤0.05 significance level. Results. The mean compressive strength in the liquid-to-powder ratios of 0.5, 0.34, and 0.25 were 3.4456, 3.2960, and 3.3485, respectively, with no significant differences between them. Conclusion. Under this study’s limitations, changing the liquid-to-powder ratio did not affect CEM cement’s compressive strength.

Reinforcement of Ethylene Vinyl Acetate with Carbon Black/Silica Hybrid Filler Composites

2016 ◽  
Vol 852 ◽  
pp. 16-22
Author(s):  
S. Vishvanathperumal ◽  
S. Gopalakannan
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Vinyl Acetate ◽  
Abrasion Resistance ◽  
Crosslink Density ◽  
Testing Machine ◽  
Ethylene Vinyl Acetate ◽  
Hybrid Filler ◽  
Tear Strength ◽  
Silica Hybrid

Carbon black and silica have been used as the main reinforcing fillers that increase the usefulness of rubbers. In this work the effect of carbon black (high abrasion furnace)/silica hybrid fillers on the mechanical properties, crosslink density and morphological behaviour of ethylene vinyl acetate (EVA) was investigated. EVA reinforced with 0/50, 10/40, 20/30, 30/20, 40/10 and 50/0 phr of carbon black (CB)/silica hybrid filler. The total hybrid filler is kept constant at 50 phr (parts per hundred rubbers) and six different compounds were prepared. EVA, CB and silica followed by compounding on a two roll mill and molding at 180°C and 20 megapascal (MPa) pressure. The mechanical properties such as tensile & tear strength, elongation at break and 100% modulus have been measured at 23°C on universal testing machine. Abrasion resistance, hardness and rebound resilience are studied using DIN abrader, Shore A durometer and vertical rebound resilience respectively. The tensile strength, modulus, tear strength, abrasion resistance, hardness and crosslink density increased with the CB filler content in hybrid filler, reached the maximum value at 50 phr of high abrasion furnace carbon black. Morphological properties of composites were evaluated by scanning electron microscopy analysis.

scholarly journals Fracture Resistance of a Bulk-Fill and a Conventional Composite and a Combination of Both for Coronal Restoration of Severely Damaged Primary Anterior Teeth

2019 ◽  
Author(s):  
Shahram Mosharrafian ◽  
Maryam Shafizadeh ◽  
Zeinab Sharifi
Keyword(s):  
Fracture Resistance ◽  
Treatment Time ◽  
Testing Machine ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
One Way Anova

Objectives: This study aimed to compare the fracture resistance of a bulk-fill and a conventional composite and a combination of both for coronal restoration of severely damaged primary anterior teeth. Materials and Methods: In this in vitro experimental study, 45 primary anterior teeth were randomly divided into three groups. After root canal preparation, the canals were filled with Metapex paste such that after the application of 1 mm of light-cure liner, 3 mm of the coronal third of the canal remained empty for composite post fabrication. Filtek Z250 conventional composite was used in group 1, Sonic-Fill bulk-fill composite was used in group 2 and Sonic-Fill with one layer of Filtek Z250 as the veneering were used in group 3. Adper Single Bond 2 was used in all groups. The teeth were thermocycled, and fracture resistance was measured by a universal testing machine. The mode of fracture was categorized as repairable or irreparable. Data were analyzed using one-way ANOVA. Results: The mean fracture resistance was 307.00±74.72, 323.31±84.28 and 333.30±63.96 N in groups 1 to 3, respectively (P=0.55). The mean fracture strength was 14.53±2.98, 15.08±2.82 and 15.26±3.02 MPa in groups 1 to 3, respectively (P=0.77). The frequency of repairable mode of failure was 80% for the conventional, 73.6% for the bulk-fill and 80% for the bulk-fill plus conventional group, with no significant difference (P>0.05). Conclusions: Bulk-fill composites can be used for coronal reconstruction of severely damaged primary anterior teeth similar to conventional composites to decrease the treatment time in pediatric patients.

scholarly journals Evaluation of the shear bond strength of the union between two CoCr-alloys and a dental ceramic

2004 ◽  
Vol 12 (4) ◽  
pp. 280-284 ◽  
Author(s):  
Mariana Pretti ◽  
Edson Hilgert ◽  
Marco Antônio Bottino ◽  
Rander Pereira Avelar
Keyword(s):  
Shear Strength ◽  
Standard Deviation ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Casting Technique ◽  
Universal Testing ◽  
Significant Difference ◽  
Metal Ceramic ◽  
The Mean

INTRODUCTION: Based on the importance of the integrity of the metal/ceramic interface, the purpose of this work was to evaluate the shear bond strength of the metal-ceramic union of two Co-Cr alloys (Wirobond C, Bego; Remanium 2000, Dentaurum) combined with Omega 900 ceramic (Vita Zahnfabrik). MATERIAL AND METHOD: Eleven cylindrical matrixes were made for each alloy, and the metallic portion was obtained with the lost wax casting technique with standardized waxing of 4mm of height and of 4mm of diameter. The ceramic was applied according to the manufacturer's recommendations with the aid of a teflon matrix that allowed its dimension to be standardized in the same size as the metallic portion. The specimens were submitted to the shear bond test in an universal testing machine (EMIC), with the aid of a device developed for such intention, and constant speed of 0.5mm/min. RESULTS AND CONCLUSIONS: The mean resistance was 48.387MPa for Wirobond C alloy, with standard deviation of 17.718, and 55.956MPa for Remanium 2000, with standard deviation of 17.198. No statistically significant difference was observed between the shear strength of the two metal-ceramic alloys.

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.

scholarly journals Retention of provisional crowns cemented with eight temporary cements: comparative study

2004 ◽  
Vol 12 (3) ◽  
pp. 209-212 ◽  
Author(s):  
Mariana Ribeiro de Moraes Rego ◽  
Luiz Carlos Santiago
Keyword(s):  
Tensile Strength ◽  
Comparative Study ◽  
Testing Machine ◽  
Strength Test ◽  
The Other ◽  
Universal Testing Machine ◽  
Tensile Strength Test ◽  
Universal Testing ◽  
Significant Difference ◽  
Crown Preparation

Many temporary cements are commercially available; therefore, it is necessary to indicate them for each clinical requirement with regard to the tensile strength of prosthetic retainers. Thus, the purpose of this study was to compare the retention of provisional crowns cemented with eight temporary cements, over full crown preparations with standardized mechanical principles as height, taper, and length. For that purpose, eighty human first premolars received full crown preparation with standardized height and taper. Provisional crowns were fabricated and luted with eight brands of temporary cements. Twenty four hours after cementation, the restorations were submitted to tensile strength test in a universal testing machine and the data submitted to ANOVA and Bonferroni tests. Mean tensile strength values ranged from 20.1N for Nogenol cement to 67.5N for Hydro C cement. Statistically significant difference (p<0.05) was found between Hydro C and the other groups, except for Temp Bond and Rely X Temp, which presented statistically significant difference when compared to Freegenol and Nogenol temporary cements. The crowns cemented with Hydro C cement were more retentive that than those cemented with the other cements, except for Rely X Temp and Temp Bond. The less retentive crowns were those cemented with Nogenol and Freegenol temporary cements.

Evaluating the Primary Stability of Implants by two Different Insertion Methodsin Compromised Bone – A Pilot Study

2020 ◽  
Vol 13 (4) ◽  
pp. 1833-1838
Author(s):  
Vinod Bandela ◽  
Bharathi Munagapati ◽  
Jayashree Komala ◽  
Ram B Basany ◽  
Santosh R Patil ◽  
...  
Keyword(s):  
Pilot Study ◽  
Testing Machine ◽  
Primary Stability ◽  
Pullout Test ◽  
Osteotomy Site ◽  
Insertion Torque ◽  
Pull Out ◽  
Universal Testing ◽  
Significant Difference ◽  
The Mean

To evaluate the better method of implant insertion into the osteotomy site in compromised quality bone for attaining optimal primary stability and thereby achieving the osseointegration for the ultimate success of implant. A total of 32 specimens (wood blocks) simulating D4 bone, were categorized into two groups. The osteotomy site was prepared as per the protocol and implants were placed till the level of the block. The insertion torque was quantified using digital Kratos torque meter. While the implants were inserted and abutments placed by hand ratcheting in the first group; they were motor-driven in the second group. Later pullout test was carried out in universal testing machine and results were analyzed using IBM SPSS Statistics for Windows Software, version 22 (IBM Corp., Armonk, NY, USA). The mean pull out force values obtained in implants placed by hand driven method were 624.375 N while the force values for implants inserted by motor-driven was 692.625 N. There was a statistically significant difference between hand and motor driven implant into the osteotomy site (p<0.05) between the groups. Of the different methods of implant insertion evaluated in this study, motor-driven imply to have a better primary stability indicating better integration with the bone to become a successful implant.

scholarly journals Push-out bond strength of different mineral trioxide aggregates

2014 ◽  
Vol 08 (03) ◽  
pp. 348-352 ◽  
Author(s):  
Huseyin Ertas ◽  
Ebru Kucukyilmaz ◽  
Evren Ok ◽  
Banu Uysal
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Mineral Trioxide Aggregate ◽  
Human Teeth ◽  
Universal Testing ◽  
Significant Difference ◽  
Bond Strengths ◽  
The Mean ◽  
Post Hoc ◽  
Push Out

ABSTRACT Objective: This study was aimed to evaluate and to compare the push-out bond strength of different brands of mineral trioxide aggregate (MTA) with a calcium enriched mixture cement (CEM). Materials and Methods: Fifteen extracted, single-rooted human teeth were used. The middle-third of the roots were sliced perpendicular to the long axis into 1.00 ± 0.05 mm thick serial slices (15 root × 4 slice = 60 specimen). The specimens were then divided into three groups (n = 20). The standardized root discs were filled with white CEM, ProRoot MTA, MTA-Angelus and wrapped in a serum-soaked gauze. After 3 days at relative humidity, the push-out bond strengths were measured with a universal testing machine. Data were analyzed using one-way analysis of variance and post hoc Tukey tests. Results: The mean push-out bond strength value of the ProRoot MTA group (12.7 ± 2.5 MPa) was the highest and statistically significant difference was recorded between ProRoot MTA and other groups (P < 0.001). There was no significant difference between the mean bond strength of CEM cement (4.6 ± 1.1 MPa) and MTA-Angelus (4.5 ± 1.5 MPa) (P = 0.982). Conclusion: The push-out bond strength of MTA was changed with the brands and ProRoot MTA had the highest push-out bond strength.

scholarly journals The Effect of Eugenol-Free Temporary Cement's Remnants on Retention of Full Metal Crowns: Comparative Study

2013 ◽  
Vol 14 (3) ◽  
pp. 473-477
Author(s):  
Hamid Badrian ◽  
Mahmoud Sabouhi ◽  
Saeid Nosouhian ◽  
Amin Davoudi ◽  
Farzaneh Nourbakhshian ◽  
...  
Keyword(s):  
Comparative Study ◽  
Zinc Phosphate ◽  
Testing Machine ◽  
Resin Cement ◽  
P Value ◽  
Tooth Structure ◽  
Universal Testing ◽  
Significant Difference ◽  
Spss Software ◽  
One Way Anova

ABSTRACT Introduction The aim of this study was to evaluate the effects of eugenol-free temporary cement's remnants on the retentive strength of full metal crowns luted via zinc phosphate and resin cement (Maxcem) to the tooth structure. Materials and methods Forty complete standardized Ni-Cr crowns in four groups were cemented by two types of permanent cements: zinc phosphate cement and resin cement (Maxcem). In the two groups before permanent cementation of crowns, temporary acrylic crowns were cemented by eugenol-free temporary cement. Crowns¡¦ retention was evaluated by Universal testing machine. All data were analyzed by means of one-way ANOVA test in SPSS software version 11.5 (α = 0.05). Results There was no significant difference in groups with prior using eugenol-free temporary cement and groups with just using two permanents cement (p-value ≥ 0.05). Discussion The application of temporary cement before permanent cementation of full metal crowns does not have any adverse effect on retention of full metal crowns, when temporary cements are removed properly. How to cite this article Sabouhi M, Nosouhian S, Davoudi A, Nourbakhshian F, Badrian H, Nabe FN. The Effect of Eugenol- Free Temporary Cement's Remnants on Retention of Full Metal Crowns: Comparative Study. J Contemp Dent Pract 2013; 14(3):473-477.

scholarly journals Influence of Resin Cements on the Tension Force of Cast Frameworks Made by the Technique of Framework Cemented on Prepared Abutments

2015 ◽  
Vol 26 (4) ◽  
pp. 390-392
Author(s):  
Ana Paula Perroni ◽  
Érica Alves Gomes ◽  
Amália Machado Bielemann ◽  
Bruna Baseggio ◽  
Leonardo Federizzi ◽  
...  
Keyword(s):  
Tensile Force ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Tension Force ◽  
Polymerization Process ◽  
Resin Cements ◽  
Universal Testing ◽  
Significant Difference ◽  
Positive Results ◽  
One Way Anova

<p>This study evaluated the tension force of cast frameworks made by the technique of framework cemented on prepared abutments using two different resin cements. Forty multi-unit abutment analogs were individually fixed with chemically cured acrylic resin inside PVC cylinders using a parallelometer. Brass cylindrical abutments were tightened to the multi-unit abutments to be used as spacers and then castable UCLA abutments were positioned above. These abutments were cast with Ni-Cr and then divided into 4 groups (n=10): cemented with RelyX U100(r); cemented with RelyX U100(r) and simulation of acrylic resin polymerization process; cemented with Multilink(r); and cemented with Multilink(r) and simulation of acrylic resin polymerization process. Abutments were cemented according to manufacturers' instructions. In a universal testing machine, tensile strength was applied in the direction of the long axis of the abutments at 1 mm/min crosshead speed until displacement of the luted abutments was obtained. The values of maximum tensile force (N) required for the displacement of the luted abutments were tabulated and analyzed statistically by one-way ANOVA with a 95% confidence level. No statistically significant difference was found among the groups (p>0.05). There was an increase in mean tension force when the specimens were subjected to the simulation of acrylic resin polymerization process, but the results did not differ statistically. Both resin cements presented positive results as regards the retention of luted abutments on their respective multi-unit abutments. Both materials may be indicated for the technique of framework cemented on prepared abutments when professionals pursuit better adaptation of implant-supported frameworks.</p>

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