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In order to precisely determine the magnesium level in a titanium reduction retort by inductive methods, many interfering influences have to be considered. By using a look-up-table method, the magnesium level can be reliably identified by taking into account the interfering effects of the titanium sponge rings forming at the walls with their unknown geometrical and electrical parameters. This new method uses a combination of numerical simulations and measurements, whereby the simulation model is calibrated so that it represents the experimental setup as closely as possible. Previously, purely theoretical studies on this method were presented. Here, the practical feasibility of that method is demonstrated by performing measurements on a model experiment. The method is not limited to the production of titanium but can also be applied to other applications in metal production and processing.
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INTRODUCTION: This preliminary study compared clinical and radiographic outcomes of regenerative endodontic procedures (REPs) with that of conventional root canal treatment (CRCT) in necrotic mature teeth with periapical radiolucencies. METHODS: Fifty-six mature necrotic teeth with large periapical radiolucencies were distributed into 2 groups: group 1, REPs and group 2, CRCT (n = 28/group). Clinical and radiographic follow-up assessments were undertaken up to 12 months. Statistical analysis was performed using the independent samples t test and the chi-square test, and the level of significance was set at P = .05. RESULTS: With a follow-up rate of about 73.4% of the total patients for 12 months, favorable clinical and radiographic outcomes were found in 92.3% and 80% in REPs and CRCT groups, respectively, and the difference was not statistically significant (P > .05). Half of the teeth treated with REPs responded to the electric pulp test. CONCLUSIONS: Regenerative endodontic procedures have the potential to be used as a treatment option for mature teeth with large periapical radiolucencies.
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Necrosis de la Pulpa Dental , Periodontitis Periapical , Endodoncia Regenerativa , Pulpa Dental , Necrosis de la Pulpa Dental/terapia , Humanos , Periodontitis Periapical/terapia , Tratamiento del Conducto RadicularRESUMEN
PURPOSE: The aim of this study was to investigate the apical transportation of the ProGlider and ProTaper Next using 3 different motions (150° clockwise [CW]; 0° counter clockwise [CCW], 270° CW-30° CCW; and [360° CW] continuous rotation). MATERIALS AND METHODS: 36 simulated, curved, plastic training blocks were randomly distributed into 3 groups for treatment according to the movement kinematics used for ProGlider (Dentsply Maillefer) followed by ProTaper Next (Dentsply Maillefer) instruments (n = 12): 150° CW-30° CCW, 270° CW-30° CCW, and 360° CW (continuous rotation). Pre- and post-instrumentation photographs were taken from the root canals in a standardized manner. Root canal transportation was calculated at 1, 2, 3, 4, and 5 mm from the apical terminus of the canal. Data were analyzed using a Kruskal-Walis H test (p = .05). RESULTS: At the 1- and 2-mm levels, both reciprocating motions (150° CW-30° CCW and 270° CW-30° CCW) resulted in less transportation than those of continuous rotation (p<.05). However, there were no significant differences between the groups at the 3-, 4-, and 5-mm levels (p>.05). CONCLUSIONS: Both reciprocating motions were found to have less canal transportation than the continuous rotation group at the 1- and 2-mm levels. This is the first study about the use of the ProGlider and ProTaper Next activated by different motions. Reciprocating motion can be beneficial for ProGlider and ProTaper Next to reduce transportation of root canals.
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OBJECTIVE:: To evaluate various kinematic movements on postoperative pain using a Reciproc system. MATERIAL AND METHODS:: Fifty-six molar teeth were divided into four groups according to kinematics as follows: continuous rotation, 360° CCW - 30° CW, 270° CCW - 30° CW, and 150° CCW - 30° CW. Preoperative and postoperative pain levels using visual analogue scale (VAS), percussion pain, and analgesic intake were recorded for each subject. Postoperative pain levels at 1, 3, 5, and 7 d were evaluated. Data were analyzed statistically using the Kruskal-Walis, Mann-Whitney-U, one-way analysis of variance, and chi-square tests (p=0.05). RESULTS:: Continuous rotation resulted in more pain at Day 1 when compared with the reciprocating groups (360° CCW - 30° CW and 270° CCW - 30° C) (p<0.05). CONCLUSIONS:: Continuous rotation resulted in more postoperative pain at Day 1 than in reciprocating groups, and thereafter no significant pain was found among the groups.
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Instrumentos Dentales/efectos adversos , Dolor Postoperatorio/etiología , Tratamiento del Conducto Radicular/efectos adversos , Tratamiento del Conducto Radicular/instrumentación , Adolescente , Adulto , Análisis de Varianza , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Periodo Preoperatorio , Estudios Prospectivos , Rotación , Estadísticas no Paramétricas , Factores de Tiempo , Resultado del Tratamiento , Escala Visual Analógica , Adulto JovenRESUMEN
ABSTRACT Objective: To evaluate various kinematic movements on postoperative pain using a Reciproc system. Material and Methods: Fifty-six molar teeth were divided into four groups according to kinematics as follows: continuous rotation, 360° CCW – 30° CW, 270° CCW – 30° CW, and 150° CCW – 30° CW. Preoperative and postoperative pain levels using visual analogue scale (VAS), percussion pain, and analgesic intake were recorded for each subject. Postoperative pain levels at 1, 3, 5, and 7 d were evaluated. Data were analyzed statistically using the Kruskal-Walis, Mann-Whitney-U, one-way analysis of variance, and chi-square tests (p=0.05). Results: Continuous rotation resulted in more pain at Day 1 when compared with the reciprocating groups (360° CCW – 30° CW and 270° CCW – 30° C) (p<0.05). Conclusions: Continuous rotation resulted in more postoperative pain at Day 1 than in reciprocating groups, and thereafter no significant pain was found among the groups.