Use of virtual reality as a learning environment in dentistry.

Second Life (SL) is an online virtual world with a social environment that may serve as a valuable learning supplement to traditional preclinical teaching methods. The educational advantages of this virtual world include immersion and interactivity. The aim of this study was to compare the efficacy of using 3-dimensional interactive platforms (3DIPs) designed in SL to that of traditional teaching methods for developing students' understanding of dental clinical situations that are difficult to simulate in real life. For this study, 3DIPs were developed to compare the acquisition of 3 learning objectives: understanding concepts, procedural aspects of interaction with the patient, and spatial interpretation of anatomical structure interactions. A representative dental topic, the use of a semiadjustable articulator, was selected. A quasi-experimental design with 2 groups and pretest-posttest comparison was used. The students in the control group received the conventional teaching established for the subject, which does not include SL experiences. The students in the experimental group received conventional instruction and had access to all 3DIPs for 4 weeks without limitation. The pretest and posttest consisted of a multiple-choice test with 20 questions. A Student t test was used to compare the test results of the groups (significance level α = 0.05). The posttest scores for the understanding of concepts and spatial interpretation were significantly higher in the experimental group than in the control group (P < 0.05). However, there was no statistically significant difference between groups in posttest scores on the topic of procedural aspects. Students who used cooperative methods for acquisition of knowledge were observed to be highly motivated. The results suggest that the SL environment helps students to understand anatomical interactions that are difficult to observe in real life, is attractive to students, and contains tools with high didactic potential.

Resistencia a la compresión de espigo muñones elaborados con dos tipos de materiales plásticos / Compressive strenght of post and cores elaborated with two types of plastic materials

Objetivo. Comparar la resistencia a la compresión entre espigo muñones elaborados con resina compuesta y cerómero. Material y métodos. La muestra estuvo conformada por 30 premolares divididas en dos grupos: 15 dientes para los espigos muñones de resina compuesta y 15 dientes los para espigos muñones de cerómero. Se seccionaron las piezas dentarias para obtener un remanente dentario de 18 mm conservando 2mm de estructura coronaria. Los conductos radiculares fueron preparados empleando la técnica step back y obturados con la técnica de condensación lateral activa. La desobturación de conductos fue estandarizada conservando 6 mm del material de relleno endodóntico. Los espigos muñones fueron preparados y cementados para luego colocar las piezas en bases de acrílico. Las muestras fueron llevadas al laboratorio para la prueba de resistencia a la compresión utilizando un tensómetro Houndsfield. Resultados. Los espigos muñones elaborados con resina compuesta presentaron una resistencia a la compresión de 43,25Mpa y los espigos muñones de cerómero 30,42 MPa, observándose una diferencia estadísticamente significativa entre ambos materiales (p:0,001). Conclusiones. Los espigos muñones de resina compuesta presentaron una mayor resistencia a la compresión que los espigos muñones confeccionados con cerómero.

Objective. To compare the compressive strength of post and cores elaborated with composite resin and ceromer. Material and methods. This study included a sample of 30 premolars distributed in two groups: 15 teeth for composite resin post and cores and 15 teeth for ceromer post and cores. The dental pieces were seccionated to obtain an 18mm dental remaining preserving 2mm of coronal structure. The root canal preparation was made with the Step back technique and the filling with the active lateral condensation technique. The root canal desobturation was standardized keeping 6mm of filling material. The post and cores were prepared and cemented and dental pieces placed in acrylic bases. The samples were taken to the laboratory for the compressive strength test using Houndsfield tensometer. Results. The composite post and core had a compressive strength of 43.25 Mpa and the ceromer post and core 30.42 MPa, showing a statistically significant difference between the two materials (p = 0.001). Conclusions. Composite resin post and cores presented a greater compressive strength that ceromer made ones.