Dimensional change of elastomeric materials after immersion in disinfectant solutions for different times.

Aim: The aim of this study was to evaluate the influence of immersion period in two disinfectant solutions on dimensional change of four elastomeric impression materials.

Materials And Methods: Four representative materials of each class of elastomers: Xantopren (polydimethylsiloxane-PDS), Express (polyvinyl siloxane-PVS); Permlastic (polysulfide- PS) and Soft Impregum (polyether-EP) were mixed according to manufacturers' instructions and then inserted into a metal matrix prepared according to the specification of ISO 4823. The molds were removed from the matrix after 7 minutes and immersed in disinfectant solutions (sodium hypochlorite 0.

Polymerization time for a microwave-cured acrylic resin with multiple flasks.

This study aimed at establishing the polymerization time of a microwave-cured acrylic resin (AcronTM MC), simultaneously processing 2, 4, and 6 flasks. Required time was measured according to the parameters: monomer release in water, Knoop hardness, and porosity. Samples were made with AcronTM MC in different shapes: rectangular (32 x 10 x 2.

Reducing the negative effects of chemical polishing in acrylic resins by use of an additional cycle of polymerization.

Statement Of Problem: The chemical polishing of dentures and orthodontic appliances is an efficient and time-saving technique. However, the process may adversely affect the physical properties of resin.

Purpose: This study evaluated the effect of an additional polymerization cycle in a microwave or water bath on the physical properties of an autopolymerized acrylic resin submitted to chemical polishing.