Abstract: The aim of this in vitro study was to assess the mechanical properties of five commercially available subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) milled splint materials, as well as to compare them with conventional heat-polymerized and autopolymerizing resins used in the con struction of conventional splints. Material and methods: Five CAD-CAM milled (ProArt CAD Splint, Therapon Transpa, Temp Premium Flexible Transpa, Cast, and Aqua), one autopolymerizing (Palapress), and one heat-polymerized (Paladon 65) resin materials were evaluated. Flexural strength, E-modulus, Vickers hardness, fracture toughness, fracture work, water sorption, and water solubility were measured. Samples were evaluated after dry and water storage for 30 days at 37 ? C. Data were collected and statistically analyzed. Results: Under both storage circumstances, the flexural strength values of Paladon 65, Therapon Transpa, Temp Premium Flexible Transpa, and Aqua were statistically non-significant (P=0.055). The polycarbonate-based CAD-CAM material Temp Premium Flexible Transpa had the highest statistically significant values of the frac ture toughness and fracture work (P<0.001). Moreover, it exhibited the lowest percentages of water sorption and water solubility among the investigated materials (P<0.001). All of the CAD-CAM materials exhibited dry elastic moduli greater than Palapress and lower than Paladon 65. One of the CAD-CAM materials, Cast, had the highest dry Vickers hardness value, which was nonsignificant when compared to Therapon Transpa (P=0.762). Conclusion: CAD-CAM polycarbonate-based splint materials exhibit higher fracture toughness and fracture work as well as lower water sorption and solubility than polymethyl methacrylate-based ones. The mechanical characteristics of the assessed CAD-CAM milled splint materials were not typically superior to those of the conventional heat-polymerized resin. However, some of them outperformed the autopolymerizing acrylic resin in terms of flexural strength, surface microhardness, water sorption, and water solubility. Resumen: El objetivo de este estudio in vitro fue evaluar las propiedades mecánicas de cinco disponibles comercialmente materiales de férula fresados de diseño sustractivo asistido por computadora y fabricación asistida por computadora (CAD-CAM), como así como compararlos con resinas convencionales polimerizadas por calor y autopolimerizantes utilizadas en la industria. Construcción de férulas convencionales. Material y métodos: Cinco fresados CAD-CAM (ProArt CAD Splint, Therapon Transpa, Temp Premium Flexible Transpa, Cast y Aqua), una resina autopolimerizable (Palapress) y una resina termopolimerizada (Paladon 65). Se evaluaron los materiales. Resistencia a la flexión, módulo E, dureza Vickers, tenacidad a la fractura, trabajo de fractura, Se midieron la sorción de agua y la solubilidad en agua. Las muestras se evaluaron después del almacenamiento seco y en agua durante 30 días a 37 ? C. Los datos fueron recolectados y analizados estadísticamente. Resultados: En ambas circunstancias de almacenamiento, los valores de resistencia a la flexión de Paladon 65, Therapon Transpa, Temp Premium Flexible Transpa y Aqua no fueron estadísticamente significativos (P = 0,055). La base de policarbonato El material CAD-CAM Temp Premium Flexible Transpa tuvo los valores estadísticamente significativos más altos de fractura tenacidad de la estructura y trabajo de fractura (P <0,001). Además, exhibió los porcentajes más bajos de sorción de agua y solubilidad en agua entre los materiales investigados (P<0,001). Todos los materiales CAD-CAM mostraron elasticidad seca. módulos mayores que Palapress e inferiores que Paladon 65. Uno de los materiales CAD-CAM, Cast, tuvo el mayor valor de dureza Vickers seco, que no fue significativo en comparación con Therapon Transpa (P = 0,762).

Abstract: Statement of problem: The fracture incidence of implant-supported overdentures is more frequent in the area of attachment because of stress concentration and denture deformation in this area. How Eglass fiber reinforcement can address this problem is unclear. Purpose: The purpose of this in vitro study was to evaluate the influence of unidirectional E-glass fiber reinforcement on the mid-line denture base strains of single implant-supported overdentures. Material and methods. An experimental acrylic resin cast was constructed with a single implant placed in the mid-line area and a ball attachment screwed to the implant. Twenty-four experimental overdentures were constructed and divided into 4 groups: group AP fabricated from autopolymerizing acrylic resin without fiber reinforcement, group APF fabricated from autopolymerizing acrylic resin with unidirectional E-glass fiber reinforcement running over the residual ridge and the ball matrix, group HP fabricated from heatpolymerized acrylic resin without fiber reinforcement, and group HPF fabricated from heat-polymerized acrylic resin with unidirectional E-glass fiber reinforcement running over the residual ridge and the ball matrix. A biaxial rosette strain gauge was attached to the incisor areas of each overdenture above the attachment level (Ch1, Ch2) and to a multichannel digital strain meter. A static vertical load of 100 N was applied to the first molar area bilaterally by using a universal testing device during strain measurement procedures. The differences in the mean strain and deflection values among the investigated groups were evaluated for statistical significance using 1-way analysis of variance (ANOVA) with the Tukey post hoc multiple comparison (a =.05). Results. The type of acrylic resin did not have a statistically significant effect on the mean strain values among groups (P=.350), while the reinforcement did significantly affect them (P<.001). The interaction between reinforcement and acrylic resin was not statistically significant (P=.552). Both strain gauge channels in group APF and group HPF recorded significantly lower strain values by almost 50% than those of group AP and group HP (P<.05). Conclusions. Unidirectional E-glass fiber reinforcement placed over the residual ridge and implant attachment significantly reduced denture base strains and deformation of single implantsupported overdentures. Resumen: Declaración del problema. La incidencia de fracturas de las sobredentaduras implantosoportadas es más frecuente en el área de inserción debido a la concentración de tensiones y la deformación de la dentadura postiza en esta área. No está claro cómo el refuerzo de fibra de vidrio E puede abordar este problema. Objetivo. El propósito de este estudio in vitro fue evaluar la influencia de unidireccional Refuerzo de fibra de vidrio E en la línea media de la base de la dentadura postiza de un solo implante. Material y métodos. Se construyó un modelo experimental de resina acrílica con un solo implante. colocado en la zona de la línea media y un accesorio de bola atornillado al implante. Veinticuatro se construyeron sobredentaduras experimentales y se dividieron en 4 grupos: grupo AP fabricado de resina acrílica autopolimerizable sin refuerzo de fibra, grupo APF fabricado con resina acrílica autopolimerizable con refuerzo de fibra de vidrio E unidireccional que recorre el cresta residual y matriz de bolas, grupo HP fabricados con resina acrílica termopolimerizada sin refuerzo de fibra, y grupo HPF fabricado a partir de resina acrílica termopolimerizada con Refuerzo unidireccional de fibra de vidrio E que recorre la cresta residual y la matriz de bolas. Se adjuntó un medidor de tensión de roseta biaxial a las áreas de los incisivos de cada sobredentadura por encima del nivel de conexión (Ch1, Ch2) y a un medidor de tensión digital multicanal.