Mechanical Test of Aluminum-Zirconium-Silicate Composite Prototype with Filler Volume Variation

2019 ◽  
Vol 829 ◽  
pp. 81-86
Author(s):  
Elin Karlina ◽  
Kosterman Usri ◽  
Renny Febrida ◽  
Camellia Panatarani ◽  
I Made Joni ◽  
...  

Recently, ceramic material has become a main object of scientific interest especially in dental material. The advance of dental materials technology has led to use of zirconia-based ceramics for composite filler. In this study, composite filler has been synthesized from natural zircon sand through geopolymerization method. Composite prototype were made with different filler volume to evaluate mechanical properties including hardness number and diametral tensile strength. Samples divided into two groups with 50 wt% filler volume (group A) and 75 wt% filler volume (group B) which 3 samples for each group. The surface micro hardness of each group tested by Leco M-400-H1 vickers microhardness testing machine and for diametral tensile strength tested using universal testing machine (Lloyd) with crosshead speed of 1,0 ± 0,25 mm/min. The data were analyzed using independent sample t-test. The results showed that the average of hardness number on group A was 13,8 VHN while for group B was 24,1 VHN. The average of diametral tensile strength for group A was 20,461 MPa and 27,689 MPa for group B. Statistical result showed that the value (P<0,05). The conclusion, there is a signifficant difference on the result of hardness test between group A (50 wt% filler volume) and group B (75 wt% filler volume) and also on diametral tensile strength test.

2021 ◽  
pp. 088532822098566
Author(s):  
Jinping Wang ◽  
Haixiang Zhang ◽  
Yangmeng Feng ◽  
Yang Sun ◽  
Ruina Ma ◽  
...  

Background As an excellent xenotransplant, the pig trachea can be decellularized and cryopreserved to reduce its immunogenicity. However, few reports are found on the changes of its mechanical properties after cryopreservation and decellularization. Objective To evaluate the structure and biomechanical properties in pig tracheal scaffolds resulting from decellularized and cryopreserved. Material and methods Twenty-five pig tracheal segments were separated into five groups: untreated (group A), only decellularized (group B), only cryopreserved (group C), decellularized after cryopreserved (group D) and cryopreserved after decellularized (group E). Tracheal segments were subjected to uniaxial tension or compression using a universal testing machine to determine structural biomechanical changes. Results It showed that there was no statistically significant difference in the tensile strength of the trachea in each group. The compressive strength of group B, C and D were same as the group A ( P > 0.05), while the group E was lower than that of the group A ( P < 0.05). Conclusions and significance: The histological examination of the decellularization after cryopreservation shows that the removal of epithelial cells and submucosal cells is more thorough, and the biomechanical structure of the trachea is better preserved. This proved to be a new method to prepare xenotransplantation of trachea graft.


2019 ◽  
Vol 829 ◽  
pp. 100-107
Author(s):  
Renny Febrida ◽  
Wafa Sahilah ◽  
Sashya Adriana ◽  
Nina Djustiana ◽  
Elin Karlina ◽  
...  

Dental composite is used to restore disease or fracture tooth structure and modify tooth shape as well as color in order to enhance the aesthetic properties. This restoration should possess sufficient strength and translucency at the same time. Diametral tensile strength and reflectance of dental composite were related to the selection of three main components; filler, coupling agent and resin matrix. Quarsi-experimental. This study was a follow-up study whereby the filler silica-zirconia-alumina system were synthesized by sol-gel technique with precursors composition ratio 70:20:10. The surface of subsequent filler were modified by 3-mercaptoppropyltrimethoxysilane (MPTMS) and aminopropyltrimethoxysilane (APTES) then becoming group A and B respectively. In order to prepared the dental composite, acetone was used to reduce the viscosity of Bisphenol A Glycidyl Methacrylate (BisGMA) thus enable introducing more content of filler into resin matrix. Phase of crystalline and particle morphology were identified by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) consecutively. Universal Testing Machine (Lloyd) with crosshead speed 1mm/min was used to evaluate diametral tensile strength between two samples group. Dental composite contain filler-MPTMS coated were continuing tested to measure the reflectance values. Disc of each samples were prepared (n=3) with different thickness (1.5 mm and 3 mm) and same diameter (20 mm). Both diametral tensile strength and reflectance evaluation data were analysis by t-test unpaired. The result showed no statistically significant differences in diametral tensile strength between group A (47,6548 MPa) and B (41,4265 MPa). Reflectance evaluation also exhibited no statistically significant differences in dental composite contain filler-coated MPTMS with different thickness. Dental composite prototype based on diametral tensile strength and reflectance evaluation were potential to be used as alternative dental restoration.


2004 ◽  
Vol 12 (4) ◽  
pp. 344-348 ◽  
Author(s):  
Eduardo Bresciani ◽  
Terezinha de Jesus Esteves Barata ◽  
Ticiane Cestari Fagundes ◽  
Akimi Adachi ◽  
Marina Martins Terrin ◽  
...  

The aim of this study was to compare, in different periods of time, the compressive and diametral tensile strength of a traditional high viscous glass ionomer cement: Fuji IX (GC Corporation), with two new Brazilian GIC's: Vitro-Molar (DFL) and Bioglass R (Biodinamica), all indicated for the Atraumatic Restorative Treatment (ART) technique. Fifteen disk specimens (6.0mm diameter x 3.0mm height) for the diametral tensile strength (DTS) test and fifteen cylindrical specimens (6.0mm diameter x 12.0mm height) for the compressive strength (CS) test were made of each GIC. Specimens were stored in deionized water at 37º C and 100% of humidity in a stove until testing. Five specimens of each GIC were submitted to CS and DTS test in each period, namely 1 hour, 24 hours and 7 days. The specimens were tested in a testing machine (Emic) at a crosshead speed of 1.0mm/min for CS and 0.5mm/min for the DTS test until failure occurred. The data were submitted to two-way ANOVA and Tukey tests (alpha=0.05). The mean CS values ranged from 42.03 to 155.47MPa and means DTS from 5.54 to 13.72 MPa, with test periods from 1h to 7 days. The CS and DTS tests showed no statistically significant difference between Fuji IX and Vitro Molar, except for CS test at 1-hour period. Bioglass R had lowest mean value for CS of the cements tested. In DTS test Bioglass R presented no statistically significant differences when compared with all others tested GICs at 1-hour period and Bioglass R presented no difference at 24-hour and 7-day periods when compared to Vitro-Molar. Further studies to investigate other physical properties such as fracture toughness and wear resistance, as well as chemical composition and biocompatibility, are now needed to better understand the properties of these new Brazilian GIC's.


2016 ◽  
Vol 6 (1) ◽  
pp. 19-23
Author(s):  
Amol Mhatre ◽  
VK Ravindranath ◽  
Sachin Doshi ◽  
Girish Karandikar ◽  
PS Vivek

ABSTRACT Aim The aim of this in vitro study was to investigate the efficiency of the new generation of elastomeric ligatures with innovative designs (SlideTM and AlastiKTM Easy-to-Tie) in reducing frictional resistance (FR) during sliding mechanics as compared with conventional ligatures. Materials and Methods Sixty ligature samples divided into four groups were used for the study. Group A: QuiK-StiK™ (3M Unitek, Monrovia, CA, USA), Group B: AlastiK™ Easy-to-Tie (3M Unitek, Monrovia, CA, USA), Group C: Slide™ (Leone, Firenze, Italy), and Group D: SS ligatures 0.010” (Libral Traders, New Delhi, India). Universal Testing Machine, Instron was used for measuring FR at the bracket-wire interface. Results There was statistically significant difference in FR among all the four groups of ligatures tested (p < 0.001). Slide ligatures produced the least amount of FR followed by SS ligatures, Easy-to-Tie, and QuiK-StiK in the increasing order of the FR values registered. Conclusion SlideTM ligatures may represent a valid alternative to passive self-ligating brackets when minimal amount of friction is desired. Angulation introduced into the elastomeric ligatures reduces the friction in comparison to conventional elastomeric ligatures. How to cite this article Vivek PS, Ravindranath VK, Karandikar G, Doshi S, Mhatre A, Sonawane M. Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures. J Contemp Dent 2016;6(1):19-23.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 436
Author(s):  
Lucía Barallat ◽  
María Arregui ◽  
Sandra Fernandez-Villar ◽  
Blanca Paniagua ◽  
Andrés Pascual-La Rocca

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.


2021 ◽  
Vol 10 (3) ◽  
pp. e30510312486
Author(s):  
Patrícia Capellato ◽  
Ana Paula Rosifini Alves Claro

This study was done in order to evaluate the changes in flexural strength and surface roughness in dental material restorations after immersion in coffee. Bars specimens (2mm x 2mm x 25 mm) of Z100 3M/ESPE were made according to ISO 4049 using aluminum molds. After curing, the specimens were then randomly divided into five groups and conditioned at 37°C in physiological serum. In all groups, except control, samples were immersed in coffee for ten minutes daily. In group A, the samples were immersed in coffee. For group B, after to be immersed in coffee, samples were immersed in distilled water for one minute. For group C, samples were immersed in mouthwash for one minute. For group D, samples were brushing for ten minutes, with load of 250g and 4250 cycles after all treatments the samples were stored in physiological serum again. In control group, samples were only stored in physiological serum. The five groups were then divided into 2 subgroups according storage time, six and nine weeks, respectively. Flexural strength was determined using three point bending test in a universal testing machine. All the tests were carried out at a room temperature and samples were maintained in physiological serum during the test. Surface roughness measurements were made using a surface roughness tester. All data were analyzed using one-way analysis of variance (ANOVA) followed by Dunnet tests. The ANOVA indicated no difference in the means of surface roughness and significant was observed for flexural strength between control group and one group (coffee).


2005 ◽  
Vol 19 (4) ◽  
pp. 267-271 ◽  
Author(s):  
Renata Garcia Fonseca ◽  
Juliana Gomes dos Santos ◽  
Gelson Luis Adabo

In metallic restorations, the polymerization of dual-curing resin cements depends exclusively on chemical activation. The effect of the lack of photoactivation on the strength of these cements has been rarely studied. This study evaluated the influence of activation modes on the diametral tensile strength (DTS) of dual-curing resin cements. Base and catalyst pastes of Panavia F, Variolink II, Scotchbond Resin Cement, Rely X and Enforce were mixed and inserted into cylindrical metal moulds (4 x 2 mm). Cements were either: 1) not exposed to light (chemical activation = self-cured groups) or 2) photoactivated through mylar strips (chemical and photo-activation = dual-cured groups) (n = 10). After a 24 h storage in 37ºC distilled water, specimens were subjected to compressive load in a testing machine. A self-curing resin cement (Cement-It) and a zinc phosphate cement served as controls. Comparative analyses were performed: 1) between the activation modes for each dual-curing resin cement, using Student’s t test; 2) among the self-cured groups of the dual-curing resin cements and the control groups, using one-way ANOVA and Tukey’s test (alpha = 0.05). The dual-cured groups of Scotchbond Resin Cement (53.3 MPa), Variolink II (48.4 MPa) and Rely X (51.6 MPa) showed higher DTS than that of self-cured groups (44.6, 40.4 and 44.5 MPa respectively) (p < 0.05). For Enforce (48.5 and 47.8 MPa) and Panavia F (44.0 and 43.3 MPa), no significant difference was found between the activation modes (p > 0.05). The self-cured groups of all the dual-curing resin cements presented statistically the same DTS as that of Cement-It (44.1 MPa) (p > 0.05), and higher DTS than that of zinc phosphate (4.2 MPa). Scotchbond Resin Cement, Variolink II and Rely X depended on photoactivation to achieve maximum DTS. In the absence of light, all the dual-curing resin cements presented higher DTS than that of zinc phosphate and statistically the same as that of Cement-It (p > 0.05).


2021 ◽  
Vol 9 (02) ◽  
pp. 104-110
Author(s):  
Akshay Punjabi ◽  
◽  
Rahul Rao ◽  
Ashish K. Jain ◽  
Meenakshi Verma ◽  
...  

Context:The quality of light curing units can profoundly influence mechanical properties of dental composite materials. Aim: To compare effect of Woodpecker RTA Mini-S and Elipar Deep Cure-L curing units onmechanical properties (compressive strength, diametral tensile strength and microhardness) of Filtek Bulk-Fill. Methods and Materials: A total of 32 samples of Filtek Bulk Fill composite were divided into 2 equal groups (n=16). 12 samples in each group were fabricated using a tooth shaped mold and 4 in circular rings to test compressive strength, microhardness and diametral tensile strength, respectively. Theblocks were evaluated for the above parameters using Universal Testing Machine and Vickers Microhardness Tester.Independent sample-t test was used in this study (p< 0.05). Results: The results of this study showed that the group of composites cured using Elipar Deep Cure-L curing unit showed better mechanical properties and the difference between the groups was statistically significant for compressive strength and diametral tensile strength (p < 0.05) Conclusion: It was concluded that a curing unit of higher intensity and quality of output used in conjugation with bulk fill composites are likely to give better results.


2020 ◽  
Vol 19 ◽  
pp. e208204
Author(s):  
Maria Helena Rossy Borges ◽  
Carmen Gilda Tavares Dias ◽  
Cristiane de Melo Alencar ◽  
Cecy Martins Silva ◽  
Renata Antunes Esteves

Aim: The purpose of this study was to compare the microhardness, diametral tensile strength, compressive strength and the rheological properties of self-adhesive versus conventional resin cements. Methods: Specimens of a conventional (RelyX ARC) and 3 self-adhesive (RelyX U200, Maxcem Elite, Bifix SE) types of resin cements were prepared. The Knoop test was used to assess the microhardness, using a Microhardness Tester FM 700. For the diametral tensile strength test, a tensile strength was applied at a speed of 0.6 mm/minute. A universal testing machine was used for the analysis of compressive strength and a thermo-controlled oscillating rheometer was used for the Rheology test. One-way ANOVA and Tukey’s test (α=0.05) were used for data analysis. Results: According to microhardness analysis, all the cements were statistically similar (p>0.05), except for Maxcem that presented lower hardness compared with the other cements in relation to the top surface (p<0.05). In the diametral tensile strength test, Relyx U200 and RelyX ARC cements were statistically similar (p>0.05), presented higher value when compared to the Maxcem and Bifix cements (p<0.05). The compressive strength of RelyX ARC and Maxcem Elite cements was statistically higher than RelyX U200 and Bifix cements (p<0.05). Regarding the rheology test, Maxcem Elite and RelyX ARC cements showed a high modulus of elasticity. Conclusions: The self-adhesive cements presented poorer mechanical properties than conventional resin cement. Chemical structure and types of monomers employed interfere directly in the mechanical properties of resin cements.


2020 ◽  
pp. 229255032096964
Author(s):  
Leslie Tze Fung Leung ◽  
Mark Hill

Background: Stenosing tenosynovitis is a condition due to a size mismatch between the flexor tendons and the first annular pulley. Corticosteroid injection is the mainstay treatment. The purpose of this study is to compare different dosages and volumes of triamcinolone in the treatment of primary stenosing tenosynovitis. Methods: Patients with primary Quinnell grades 1 or 2 stenosing tenosynovitis were recruited in this prospective, blinded, randomized trial. Patients were randomized into 1 of 2 groups. Group A received 0.25 mL of triamcinolone 40 mg/mL, mixed with 0.25 mL of 1% lidocaine with epinephrine (10 mg of triamcinolone, 0.5 mL in total volume). Group B received 0.5 mL of triamcinolone 40 mg/mL, mixed with 0.5 mL of 1% lidocaine with epinephrine (20 mg of triamcinolone, 1 mL in total volume). Patients were assessed by a blinded hand therapist at 2 and 4 weeks, and by a blinded hand surgeon at 6 weeks. The primary outcome was complete symptom resolution at 6 weeks. Both per-protocol and intention-to-treat analyses were performed. Results: One hundred ninety-one patients were recruited from 2009 to 2018. Eighty-two and 77 patients had complete data in group A and B, respectively. There was no difference in success rates in complete symptom resolution at 6 weeks between group A (59.8%) and group B (62.3%). The mean visual analogue pain scores on injection were 4.31 ± 2.11 for group A and 4.30 ± 2.09 for group B. Conclusions: Triamcinolone 10 mg was as effective as 20 mg in the resolution of symptoms of Quinnell grade 1 or 2 stenosing tenosynovitis at 6 weeks.


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