Examinando por Materia "Adhesive strength"

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Acceso abierto
Adhesive strength of fiberglass bolts using two resinous cement systems. in vitro study. Lima Peru. 2021.
(Universidad Privada Norbert Wiener, 2022-11-12) Muñoz Rodríguez, Senith Aide; Menacho Angeles, Gregorio Lorenzo
Objective: To compare the adhesive resistance of fiberglass posts using two resin cement systems. Methodology: 7 teeth were used for each cement type (Relyx U200 and RelyX Ultimate). A transverse cut was made at 2 mm from the cement-enamel junction on each tooth. The root canal treatment was then performed. For cementing with Relyx Ultimate, 37% phosphoric acid and Scotchbond universal adhesive were used beforehand, while for Relyx U200 cementing, the cement was applied directly. After cementing the fiberglass post, all teeth were cut into 1 mm thick discs, resulting in 6 discs. These root portion discs were taken to the DHL mechanical testing laboratory, where they underwent push-out testing to measure adhesive strength using a universal testing machine. Results: The adhesive strength of the fiberglass posts with Relyx Ultimate resin cement was 37 ± 14.59 Mpa in the cervical portion, 32.61 ± 8.44 Mpa in the middle portion, and 34.29 ± 9.13 Mpa in the apical portion. For Relyx U200 cement, the values were 34.05 ± 9.23 Mpa in the cervical portion, 38.43 ± 14.29 Mpa in the middle portion, and 30.15 ± 15.17 Mpa in the apical portion. Conclusion: No significant difference was found in the adhesive strength of fiberglass posts using the resin cement systems Relyx U200 and RelyX Ultimate in all three root thirds.
Acceso abierto
Comparison of the adhesive resistance to removal of brackets with etching acid conditioning applying deproteinization with and without 5.25% naocl in two composite resins
(Universidad Privada Norbert Wiener, 2024-06-21) Ortega Chaucca, Lidia Dayanna; Rojas Ortega, Raúl Antonio
This research aimed to compare the adhesive strength to bracket detachment with acid etching conditioning, applying deproteinization with and without NACOL at 5.25% in two composite resins. The study used the hypothetical-deductive method, formulating general assumptions about a specific phenomenon, which were studied in detail. It was an in vitro experimental study as the variable was manipulated, with a quantitative approach, focusing specifically on organized analysis methods and numerical values. The study was applied in nature, aiming to understand and provide practical application, characterized by systematic and objective characteristics. The sample consisted of 60 permanent mandibular bovine teeth extracted from sheep heads. The results of the study determined that the minimum resistance in subgroups A1 and B1, with acid etching conditioning applying deproteinization with NACOL at 5.25%, in the Heliosit and Orthocem resins, was slightly higher than the value for subgroups A2 and B2, which did not undergo deproteinization. It was concluded that there is no significant difference, as P = 0.375 > 0.05, among the 4 study groups regarding the adhesive strength to bracket detachment with acid etching conditioning applying deproteinization with and without NACOL at 5.25%.