Use of team-based learning pedagogy for predoctoral teaching and learning.

PURPOSE: The purpose of the study was to describe the development and implementation of a Team-based Learning (TBL) educational model in a predoctoral education course to assess its effectiveness in promoting student learning as measured by knowledge acquisition and student satisfaction. METHODS: An interprofessional education course used the TBL structure for the second-year dental students, in which students had an opportunity to first work on the questions individually and then in groups. Each instruction session began with a readiness assurance test (RAT), which students were asked to complete in two formats: each student answered on their own, then each team worked on the same questions to arrive at a consensus decision followed by a team-based application exercise. RESULTS: A significant difference existed in which team scores were higher than individual scores and on average, the teams scored higher than when students worked alone. Student feedback showed a strong preference of TBL over the traditional lecture format. Students found that the sessions helped them to understand the clinical cases from the perspective of other health care fields in this pedagogical approach. CONCLUSION: The TBL methods facilitated an interactive learning environment to promote student-centred learning in a predoctoral education course and the teams performed better in correct evaluation compared with the individual students.

A comparative study on biaxial flexural strength and Vicker`smicrohardness of different zirconia materials: Effect of glazingand thermal cycling / Estudo comparativo da resistência à flexão biaxial e microdureza Vickers` em diferentes materiais à base de zircônia: Efeito doglazeamento e da ciclagem térmica

Objetivo: Este estudo avaliou o efeito do glazeamento e da ciclagem térmica na resistência à flexão biaxial e na dureza Vicker’s de diferentes materiais à base de zircônia. Material e Métodos: Espécimes de disco (15 mm x 1,15 mm) de zircônia foram confeccionados usando 3 sistemas (ZirkonZahn, Cercon, Ceramill) de acordo com a recomendação de cada fabricante. Os espécimes de cada sistema cerâmico foram randomicamente divididos em 2 grupos. Enquanto metade dos espécimes foram glazeados, a outra metade permaneceu não glazeado. Adicionalmente, cada grupo foi divido em 4 subgrupos submetidos a diferentes ciclagens térmicas (0-control, 1000, 3000, 5000 ciclos, 5-55 ºC). A resistência à flexão biaxial foi realizada em uma máquina de teste universal (1 mm/min). As amostras não glazeadas foram submetidas a microdureza Vicker’s antes e após a ciclagem térmica (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Os dados foram estatisticamente analisados usando ANOVA 1-fator, ANOVA 2-fatores e teste de Tukey’s (p < 0,05). Resultados: Nas amostras não cicladas (1104-1388 MPa), o glazeamento reduziu significativamente a resistência à flexão biaxial de todos os sistemas cerâmicos (845.65-897.35 MPa) (p = 0,000). Enquanto nos grupos não glazeados todas as modalidades de ciclagem térmica reduziram significantemente a resistência à flexão biaxial (864- 1156 MPa) (p = 0,000), nos grupos glazeados a ciclagem térmica não afetou os resultados (829.4- 854.9 MPa) (p = 0,405). Comparados aos grupos não envelhecidos (1414.1 VHN), a ciclagem térmica reduziu significantemente a dureza Vickers apenas para o Cercon (1365.9 VHN) (p = 0,005). Conclusão: O glazeamento reduz a resistência à flexão biaxial dos sistemas à base de zircônia testados. As amostras não glazeadas foram mais afetadas pela ciclagem que as amostras glazeadas. Estas informações podem ter relevância clínica na durabilidade de reconstruções em zircônia monolítica.

Objective: This study evaluated the effect of glazing and thermal cycling on biaxial flexural strength and Vickers hardness of different zirconia framework materials. Material and Methods: Disc shaped zirconia specimens (15 mm x 1.15 mm) were fabricated using three systems (ZirkonZahn, Cercon, Ceramill) according to each manufacturer`s instructions. The specimens of each system were randomly divided into 2 groups. While half of the specimens were glazed, the other half was left unglazed. Each group was further divided into 4 subgroups to be subjected to thermal cycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Biaxial flexural strength was tested in a universal testing machine (1 mm/min). Unglazed zirconia specimens were subjected to Vickers microhardness with and without thermal cycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Data were statistically analyzed using one-way ANOVA, twoway ANOVA and Tukey’s test (p < 0.05). Results: In non-aged conditions (1104-1388 MPa), glazing significantly decreased the biaxial flexural strength of all zirconia ceramics (845.65-897.35 MPa) (p = 0.000). While in the non-glazed groups, all thermal cycling regimens significantly decreased the biaxial flexural strength (864 -1156 MPa) (p = 0.000), in glazed groups thermal cycling did not affect the results (829.4-854.9 MPa) (p = 0.405). Compared to the non-aged group (1414.1 VHN), thermal cycling decreased the Vickers hardness significantly only for Cercon (1365.9 VHN) (p = 0.005). Conclusion: Glazing decreased the biaxial flexural strength of the zirconia ceramics tested. Unglazed zirconia ceramics were weaker against thermal cycling compared to glazed ones. For the long-term durability of monolithic zirconia reconstructions, this information may have clinical significance.

Fracture resistance of direct inlay-retained adhesive bridges: effect of pontic material and occlusal morphology.

This study evaluated the effect of a) pontic materials and b) occlusal morphologies on the fracture resistance of fi ber-reinforced composite (FRC) inlay-retained fixed dental prostheses (FDP). Inlay-retained FRC FPDs (N=45, n=9) were constructed using a) resin composite (deep anatomy), b) natural tooth, c) acrylic denture tooth, d) porcelain denture tooth and e) resin composite (shallow anatomy), as pontic materials. In addition resin composite beams were fabricated (N=30, n=10): i) 'circular', ii) 'elliptic I', and iii) 'elliptic II'. There was no significant difference between the fracture resistance of Groups a, b, c, and d (598, 543, 539, 509 N, respectively) (p>0.05) (One-way ANOVA). Fracture resistance of Group e (1,186 N) was significantly higher than those of other groups (p<0.05) (Tukey's test). No significant difference was found between Group i (1,750 N) and Group ii (1,790 N). Not the pontic material but the occlusal morphology affects the fracture resistance of FRC FDPs.