Examinando por Materia "Resistencia a la compresión"

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Comparison of the roughness and compressive strength of type IV plasters subjected to manual and non-manual vibration according to time variation in vitro 2022
(Universidad Privada Norbert Wiener, 2023-07-07) Sanchez Veramendi, Yoselina; Morante Maturana, Sara Angelica
The purpose of this research was to compare the roughness and compression resistance of Type IV plasters subjected to manual and non-manual vibration, according to time variation. The study employed an applied methodology with an experimental, cross-sectional, prospective, and comparative design. The population consisted of two Type IV plasters subjected to manual and non-manual vibration, with a total of 120 plaster blocks from both brands. The sample consisted of 60 sample units for each commercial brand, subdivided into two groups of 30 units each, with 15 units measured at 30 minutes and 15 units at 60 minutes for compression and roughness measurements, respectively. A non-probabilistic convenience sampling was used according to the researcher's criteria. Two data collection forms were used: one for measuring compression resistance and another for measuring roughness, with the plasters used being Fujirock and Elite Rock. Results: Significant differences were observed when comparing the roughness between Elite Rock Type IV plaster and Fujirock, with a p-value of 0.001 (p < 0.05), and also in compression between Elite Rock Type IV plaster and Fujirock, with a p-value of 0.000 (p < 0.05).
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Compressive strength of three bioceramic cements: mta, biodentine and mta repair hp, - in vitro. lima 2020
(Universidad Privada Norbert Wiener, 2021-11-23) Luis Fernández, Alessandra Junet; Gil Cueva, Silvia Liliana
Objective: To determine the compressive strength of three bioceramic cements: Mineral Trioxide Aggregate (MTA), MTA Repair HP, and Biodentine in vitro. Methodology: The total sample consisted of 60 blocks, divided into 20 for each bioceramic cement group. The study was experimental, longitudinal, and comparative, where the compressive strength of three bioceramic cements—Mineral Trioxide Aggregate (MTA), MTA Repair HP, and Biodentine—was measured in vitro at 24 and 48 hours after preparation. Statistical analysis was performed using the ANOVA and Shapiro statistical tests. Results: For all three cements, the compressive strength was higher at 48 hours than at 24 hours: MTA 3.69 MPa/2.51 MPa; MTA Repair HP 2.96 MPa/1.47 MPa; and Biodentine 69.97 MPa/51.28 MPa, with a significant difference (p<0.001). A time-dependent difference was observed between MTA and MTA Repair HP (p<0.001). Conclusion: Biodentine demonstrated higher compressive strength compared to MTA and MTA Repair HP, making it a better alternative among calcium silicate-based bioceramic materials.
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Evaluation of resistance to compressive forces in three types of plaster iv according to post setting time
(Universidad Privada Norbert Wiener, 2023-11-27) Vargas Cueva, Gregori Christian; Morante Maturana, Sara Angelica
The objective of the study was to evaluate the resistance to compressive forces in three types of Type IV gypsum from the brands GC, Zhermack, and Protechno according to post-setting time. The methodology used a quantitative, cross-sectional, and prospective approach with a sample of 45 gypsum die models in total, subdivided into three groups of 15 die models for each brand under study. Inclusion criteria were considered, such as models or molds with a diameter of 20 mm and a height of 40 mm, without bubbles or cracks in their formation. The observational technique was used for recording measurements in the data collection sheet. Results showed, according to post-setting time, the compressive forces at 15 minutes for Protechno (Kimberlit) had an average of 16.612, GC (Fujirock) had an average of 6.752, and Zhermack (Elite rock) had an average of 22.53. At 30 minutes, Protechno (Kimberlit) had an average of 22.528, GC (Fujirock) had an average of 12.044, and Zhermack (Elite rock) had an average of 24.296. At 60 minutes, Protechno (Kimberlit) had an average of 18.352, GC (Fujirock) had an average of 24.33, and Zhermack (Elite rock) had an average of 31.18. Conclusion: Zhermack (Elite rock) exhibited the highest compressive force resistance values with an average of 22.53, median of 22.68 at 15 minutes, average of 24.296, median of 25.14 at 30 minutes, and average of 31.18, median of 28.79 at 60 minutes.
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Evaluation of the compressive strength of a composite resin inserted directly incrementally versus block insertion and with pre-photopolymerized resin: in vitro study, 2021
(Universidad Privada Norbert Wiener, 2024-06-06) Sobrevilla Alarcón, Anai Yesenia; Arauzo Sinchez, Carlos Javier
One of the major disadvantages of composite resins is their post-photopolymerization shrinkage effect when incremented by more than 2mm in thickness. Due to this, alternative options such as Bulk Fill resins, which allow for an increase of up to 5mm in thickness, and the use of previously photopolymerized resins, are available in the market. Objective: To determine which composite resin insertion technique in proximal cavities has greater compressive strength. Methodology: 45 resin samples were made using acrylic tooth cavities measuring 4x10mm, which were replicated through condensation silicone impressions. The resin samples were from the 3M ESPE brand and divided into three groups: G1: n=15 (Filtek Z350 XT Resin); G2: n=15 (Filtek Bulk Fill Resin); G3: n=15 (Filtek Z350 Resin with Z350 XT Flowable Resin). The resin insertion techniques for G1 used an incremental technique of 2mm thickness; G2 used a block technique with a single 5mm increment; and G3 used a mixed technique with flowable resin and pre-photopolymerized resins. The samples were calibrated and measured using a caliper and periodontal probe. Once the samples were obtained, they were subjected to a compressive strength test using a mechanical testing machine and a Digital Vernier (LG-CMT-5L Mitutoyo-200mm). Results: The compressive strength was 994.88 Newtons using the block technique, 1458.19 Newtons with the incremental technique, and 1241.30 Newtons with the pre-photopolymerized resin technique. There was a significant difference showing higher resistance using the incremental technique compared to the block technique (p<0.05). Conclusion: The incremental resin insertion technique has greater resistance to fracture compared to the block and pre-photopolymerized resin techniques.
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Experimental compressive strength of Portland cement associated with zirconium microparticles compared to the mineral Trioxide added-in vitro. Lima-2020
(Universidad Privada Norbert Wiener, 2021-05-11) Cherres Sevilla, Reina Ysabel; Garavito Chang, Enna Lucila
Calcium silicate cements are commonly used in the field of endodontics. For this reason, Portland cement, due to its very similar composition, is being used for various endodontic therapies. This thesis aims to determine the experimental compressive strength of Portland cement associated with zirconia microparticles compared to MTA in Lima, 2020. The study is in vitro experimental. Portland cement, MTA Angelus cement, and Portland cement associated with zirconia microparticles were used in a sample consisting of 10 test bodies per group, totaling (n=30). The experimental compressive strength of the cements was evaluated using the Universal Instron® testing machine with compressive load in kN at a speed of 1mm/min, expressed in MPa. The results showed that Portland cement (CP) had the highest strength, followed by MTA-Angelus, and the Portland cement + zirconium microparticles (CP + OZi) group showed the lowest strength after 48 hours. Conclusion: Zirconia microparticles associated with Portland cement did not improve the mechanical properties after 48 hours, but Portland cement could potentially be used as an alternative to MTA-based materials.
Acceso abierto
In vitro study of the compressive strength in the surface microhardness of four cements based on calcium silicate: white portland cement, gray portland cement, added trioxide mineral (MTA Angelus®) and biodentinetm, Lima- 2020.
(Universidad Privada Norbert Wiener, 2021-03-20) Navarro Huamani, Bayoleth Celia; Guillén Galarza, Carlos Enrique
The objective of this study was to determine the compressive strength and surface microhardness of four calcium silicate-based cements: White Portland Cement, Gray Portland Cement, Mineral Trioxide Aggregate, and Biodentine™. This research was experimental, cross-sectional, and prospective with a comparative design. The non-probabilistic sample consisted of 80 calcium silicate-based cement cylinders, divided into 20 cylinders per group. A data collection sheet was used to record the fracture measurements of each sample. The database and statistical analysis were performed using SPSS version 22.0. Results: After 24 hours, the compressive strength and surface microhardness of the Biodentine cement was 33.33 kg/mm², followed by White Portland Cement and Gray Portland Cement with values of 6.18 and 6.81 kg/mm², respectively, and Mineral Trioxide Aggregate (MTA-Angelus) with 5.07 kg/mm². After 48 hours, the compressive strength and surface microhardness of Biodentine was 38.42 kg/mm², followed by White Portland Cement and Gray Portland Cement with values of 7.95 and 8.41 kg/mm², respectively, and Mineral Trioxide Aggregate (MTA-Angelus) with 7.44 kg/mm². These differences between groups were statistically significant (p>0.05). Conclusion: Biodentine cement demonstrated significantly higher compressive strength and surface microhardness compared to MTA, White Portland Cement, and Gray Portland Cement at both 24 and 48 hours.
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Resistance to compression of composite resins at different densities. in vitro study. lima – peru. 2021
(Universidad Privada Norbert Wiener, 2021-11-17) Tantaleán Mendoza, Licet Amparo; Girano Castaños, Jorge Alberto
Objective: To determine the compressive strength of composite resins with different densities. Methodology: Two high-density resins (Filtek Z350XT – 3M Espe and Tetric N Ceram – Ivoclar Vivadent) and two low-density resins (Filtek Flow – 3M Espe and Tetric Flow – Ivoclar Vivadent) were used. These resins were molded into resin cylinders with 10 mm in height and 4 mm in diameter using a plastic mold, where increments of 2 mm were added until the required dimensions were reached. Once the resin cylinders were formed, they were taken to the mechanical testing laboratory for the compression test, where the universal testing machine applied a downward force of 1 mm/min on each resin cylinder until fracture. Data were recorded electronically by the testing equipment. Results: The results showed that the compressive strength of the high-density resins was 218.86 ± 31.18 MPa for Filtek Z350XT and 218.86 ± 31.18 MPa for Tetric N Ceram. The compressive strength of the low-density resins was 225.96 ± 23.32 MPa for Filtek Flow and 186.30 ± 17.3 MPa for Tetric Flow. Conclusion: The low-density resin Filtek Flow exhibited the highest compressive strength, followed by the high-density resins Filtek Z350XT and Tetric N Ceram, and lastly, the low-density resin Tetric Flow.
Acceso abierto
Resistance to compression of the Nanohybrid resin in comparison with the Bulk Fill type resin using the incremental and Monoincremental technique. in vitro study
(Universidad Privada Norbert Wiener, 2021-01-12) Gámez Céspedes, Elmer Iván; Llerena Meza De Pastor, Verónica
Objective: To compare the compressive strength of nanohybrid resin and bulk-fill resin using the incremental and monoincremental techniques. Methodology: Two types of resins were used: a nanohybrid resin and a bulk-fill resin. Both were molded into cylindrical shapes with dimensions of 8 mm in length and 4 mm in diameter. Cylinders formed using the incremental technique were created in 2 mm increments, while those formed using the monoincremental technique were created in 4 mm increments. These cylinders were subjected to compression testing using a universal testing machine, applying compressive force until fracture. Data analysis was performed using SPSS version 23 with the Student's t-test for independent samples. Results: The compressive strength of nanohybrid resin using the monoincremental technique was 254.90 ± 38.97 MPa, while for the incremental technique, it was 199.65 ± 44.29 MPa. On the other hand, the compressive strength of bulk-fill resin using the monoincremental technique was 226.36 ± 28.17 MPa, and for the incremental technique, it was 211.16 ± 19.97 MPa. Conclusion: The compressive strength of bulk-fill resin using the monoincremental technique was greater than that of nanohybrid resin using the incremental technique.