Pesquisa | SciELO

Abstract Acute myeloid leukemia (AML) comprises a heterogeneous group of hematopoietic cell neoplasms of myeloid lineage that arise from the clonal expansion of their precursors in the bone marrow, interfering with cell differentiation, leading to a syndrome of bone marrow failure. AML is a consequence of genetic and epigenetic changes (point mutations, gene rearrangements, deletions, amplifications, and arrangements in epigenetic changes that influence gene expression) in hematopoietic precursor cells, which create a clone of abnormal cells that are capable of proliferating but cannot differentiate into mature hematopoietic cells or undergo programmed cell death. The diagnosis requires more than 20% myeloid blasts in the bone marrow and certain cytogenic abnormalities. Treatment will depend on age, comorbidities, and cytogenetic risk among the most frequent.

Resumen: El objetivo de este estudio fue evaluar, en un modelo ex vivo, el proceso de biomineralización y fuerza de adhesión del MTA Flow® en sus tres diferentes consistencias por medio de la prueba de resistencia al desplazamiento (Push-out). Se utilizaron discos de dentina de 2mm de espesor del tercio medio radicular con cavidades estandarizadas de 1.5mm de diámetro, las cuales se obturaron con diferentes materiales entre ellos: MTA Angelus (Angelus Dental, Brasil), Biodentine (Septodont, Francia), MTA Flow® Consistencia Putty (Ultradent, E.E.U.U), MTA Flow® Consistencia Thick (Ultradent, E.E.U.U) y MTA Flow® Consistencia Thin (Ultradent, E.E.U.U). Las muestras se sometieron al proceso de biomineralización y a pruebas de Push-out. Las muestras obturadas con Biodentine promovieron una mayor precipitación de apatita carbonatada, sin embargo, no se presentó diferencia estadística significativa con respecto al MTA Angelus, MTA Flow® Putty ni Thick (p=0.0536). No obstante, si presentó una diferencia significativa con respecto al grupo de MTA Flow® consistencia Thin (P<0.05). Las muestras con Biodentine presentaron la mayor liberación de iones calcio. De acuerdo a las pruebas de resistencia al desplazamiento, a las 72 horas post-obturación, solamente se encontró diferencia significativa entre las muestras obturadas con Biodentine y las correspondientes al MTA Flow consistencia Thin (p=0.0090), sin embargo las muestras sumergidas 15 días en PBS presentaron diferencia significativa entre todos los grupos con respecto al MTA Flow Thin (p=0.0147). En general se observaron zonas de biomineralización en la interface, sin embargo, no fueron continuas. Se concluye que el MTA Flow en consistencia Putty o Thick presenta un proceso de biomineralización y una resistencia al desplazamiento similar al MTA Angelus y al Biodentine, sin embargo, esta última disminuye considerablemente en presentación Thin.

Abstract: This study evaluated the biomineralization processes and push-out strength of MTA Flow® with radicular dentine in three different consistencies. The push-out test was performed on an ex vivo model, using 2mm thick dentin discs from the middle third of the root with standardized cavities of 1.5 mm. Samples were filled with MTA-Angelus (Angelus Dental, Brazil), Biodentine (Septodont, France), MTA Flow® Putty (Ultradent, USA), MTA Flow® Thick or MTA Flow® Thin. The samples were divided into 3 groups: subgroup 1 (n=5), analysis of the biomineralization process; 2 (n=20), evaluation of the bonding strength and push-out resistance; and 3 (n=5), evaluation of the cement/ dentin interface. The samples filled with Biodentine had a higher precipitation of carbonate apatite. However, there was no significant difference between MTA-Angelus, MTA Flow® Putty, or Thick (p=0.0536), but there was a significant difference in the Thin group (P<0.05). The samples with Biodentine displayed the greatest release of calcium ions. The formation of a partially carbonated intermediate apatite layer was observed in all groups. Zones of biomineralization were observed at the interface but were not continuous. After 72 hours, a significant difference was found between the Biodentine and MTA Flow® Thin groups (p=0.0090) in the push-out test. The samples submerged in phosphate-buffered saline (PBS) for 15 days showed a significant difference between all groups and MTA Flow® Thin (p=0.0147). Putty or Thick consistencies presented a similar bonding strength to MTA-Angelus and Biodentine. MTA Flow® Putty and Thick consistencies show a good adaptation to dentin, similar to MTA-Angelus. However, the thickness of the interface was lower compared to that of Biodentine. MTA Flow® Thin, despite their tubular infiltration, results in gaps and a defective peripheral seal.Therefore, MTA Flow®, in Putty or Thick consistencies, presents a biomineralization process and push-out strength similar to MTA Angelus and Biodentine, however, both characteristics decreases considerably in Thin consistency.

Abstract To identify this increasingly common pathology, known as Multiple Myeloma, it is necessary to refer to the specific factors that characterize it; to this end, the classic criteria known as CRAB (hypercalcemia, renal failure, anemia and lytic lesions) are available, in which renal failure is one of the most frequent complications. Recently, 3 indisputable biomarkers have been described for the diagnostic support for Multiple Myeloma, which are: more than 10% of clonal plasma cells in BM or, a biopsy that corroborates the presence of a plasmacytoma, light chain ratio ≥100 mg/dL and more than one focal lesion on magnetic resonance imaging (MRI). A differential diagnosis for plasma cell leukemia, solitary bone plasmacytoma, and extramedullary plasmacytoma should always be considered. Being this an incurable disease, a lot of research has been done regarding its therapeutic management, whose main objective is the disappearance of plasma cells and the patient clinical improvement. Melphalan was the first drug that showed a benefit in 1958 and afterwards, with the addition of a steroid as a second drug, it was possible to improve response rates. Subsequently, different molecules were studied, forming multiple combinations, and achieving better rates of Overall Survival and Progression-Free Survival. Years later, with the arrival of proteasome inhibitors such as bortezomib, and immunomodulators such as thalidomide and lenalidomide, an important turnaround in the disease has been seen, as deeper responses, more prolonged remissions, and improvement in the quality of life of patients have been achieved. This consensus has the purpose of integrating a group of Mexican specialists and promoting the updating of this pathology.

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