Impression techniques and materials used for fabrication of complete denture. A survey

In 2013, a survey of Pakistani dental graduates was conducted to determine which techniques and materials are currently prevalent in the teaching of initial and final impression procedures and custom tray fabrication for complete dentures in the undergraduate clinical curriculum. A questionnaire was prepared and distributed among 150 dentists belonging to different regions of the country. The questionnaire consisted of multiple choice questions. All responses remained anonymous. The results highlighted that majority of dental schools were following the traditional approach. Impression compound was used by 93% of the respondents. Self cure acrylic resin was used by 92% for making custom tray. Majority of the respondents [97%] were using Zinc oxide eugenol to record final impression. The findings from this study showed that impression technique and material used in the fabrication of complete denture in the existing prosthodontic curriculum require modification in order to raise the standard of under graduate dental program

Assessment of convergence angle of full-coverage porcelain fused to metal crowns in clinical practice.

Background: Full-coverage porcelain fused to metal crowns is commonly recommended for restoration of extensively damaged teeth. Ability of the dentist to adequately prepare teeth is fundamental to success and longevity of these restorations. Aims: This study was designed to compare recommended convergence angle and taper values of tooth preparation with clinically practiced values and to assess the factors such as tooth position, operator experience, vitality, and restorative status on convergence angle of prepared teeth. Setting and Design: It was a descriptive, cross-sectional study design and held at The Aga Khan University Hospital, Dental Section, for a period of 1 year. Materials and Methods: A minimum of 197 crown preparation models of molar and premolar teeth prepared by residents and specialists were collected in order to achieve the objectives of the study on the basis of convenient sampling technique. Statistical Analysis: One sample t-test used to compare the mean practiced convergence angle values with its recommended values. Independent sample t-test and one-way ANOVA was used to see difference in the convergence angle values of the teeth prepared by different operators, tooth type, vitality status, and restorative status of teeth. Results: Mean reported convergence angle and axial wall taper values were 23.7°±8.9° and 11.3°±7.8°, respectively, which is significantly greater (P<0.001) than the recommended values. Convergence angle values were greater for molars as compared to premolars. Conclusion: There was a considerable disparity between the convergent angles values recorded in this study and the recommended guidelines and are affected by tooth type, vitality, and restorative status of tooth.

El método de elementos finitos y su aplicación en la investigación odontológica / The finite elements method and its application to dental research

Hace aproximadamente dos siglos, basado en la teoría de la elasticidad y mediante la aplicación de diferentes ecuaciones, matemáticos franceses y alemanes propusieron un modelo teórico para predecir los esfuerzos a los que está sometido un cuerpo bajo carga. La solución de este problema fue muy compleja debido al escaso desarrollo tecnológico de la época. Sólo en 1956, Turner, Clough, Martin y Topp presentaron el Método Computarizado de Elementos Finitos (MEF), el cual resuelve con gran aproximación las múltiples ecuaciones utilizadas en esta predicción. El MEF es un procedimiento ejecutado en un computador, que tiene el potencial de simular un modelo matemático equivalente a un objeto real, compuesto por diferentes materiales y de forma complicada. Es un método numérico versátil, aplicable en todos los campos de las ciencias exactas, principalmente en las ingenierías, civil, mecánica, biomédica y nuclear, asimismo, en geomecánica, hidráulica, medicina y odontología. La literatura presenta varios estudios que demuestran su utilidad en la investigación odontológica. Este artículo pretende ilustrar su uso y aplicabilidad en implantología, ortodoncia, ortopedia maxilar, prostodoncia y cirugía maxilofacial