RESUMEN
Calcium silicate (C3S) cements are available in kits that do not account for patients' specific needs or clinicians' preferences regarding setting time, radiopacity, mechanical, and handling properties. Moreover, slight variations in powder components and liquid content affect cement's properties and bioactivity. Unfortunately, it is virtually impossible to optimize several cement properties simultaneously via the traditional "one variable at a time" strategy, as inputs often induce trade-offs in properties (e.g., a higher water-to-powder ratio [W/P] increases flowability but decreases mechanical properties). Herein, we used Taguchi's methods and genetic algorithms (GAs) to simultaneously analyze the effect of multiple inputs (e.g., powder composition, radiopacifier concentration, and W/P) on setting time, pH, flowability, diametral tensile strength, and radiopacity, as well as prescribe recipes to produce cements with predicted properties. The properties of cements designed with GAs were experimentally tested, and the results matched the predictions. Finally, we show that the cements increased the genetic expression of odonto/osteogenic genes, alkaline phosphatase activity, and mineralization potential of dental pulp stem cells. Hence, GAs can produce cements with tailor-made properties and differentiation potential for personalized endodontic treatment.
Asunto(s)
Compuestos de Calcio , Cementos Dentales , Humanos , Polvos , Compuestos de Calcio/química , Compuestos de Calcio/farmacología , Cementos Dentales/química , Cementos de Ionómero Vítreo , Silicatos/química , Silicatos/farmacología , Óxidos/química , Combinación de Medicamentos , Ensayo de Materiales , Calcio , Compuestos de Aluminio/químicaRESUMEN
BACKGROUND: Use of human milk is recommended for low birth weight (VLBW) infants, but must be safety fortified with sterile liquid fortifiers to be nutritionally sufficient. Due to clinical concern for a high incidence of metabolic acidosis among VLBW infants fed human milk fortified with acidified liquid human milk fortifier (ALHMF), we aimed to retrospectively compare the outcomes of infants fed ALHMF to those fortified with non-acidified liquid HMF (NLHMF). METHODS: Medical records of VLBW neonates admitted to our institution's neonatal intensive care unit from July 1st, 2013 to June 30th, 2014 were reviewed. 129 patients were included in the study, 61 of which received ALHMF and 68 received NLHMF. Metabolic, nutritional and clinical outcomes, including growth, were compared between the two cohorts. RESULTS: Of the infants who received ALHMF, 70.5% developed metabolic acidosis compared to only 11.8% in the NLHMF group (pâ<â0.001). In addition, infants who received NLHMF had a 10% greater growth velocity during the period of fortification (pâ=â0.01). During the full course of hospitalization, no difference in growth velocity was seen between the groups and greater length gains were found in the ALHMF group. CONCLUSIONS: The use of human milk fortified with ALHMF was associated with an increased incidence of metabolic acidosis and poorer growth during the period of fortification when compared to NLHMF-fortified feedings. These growth effects were not apparent when the duration of hospitalization was considered, suggesting a need for further study to better characterize the advantages and disadvantages of each fortifier.