Vicker’s-Hardness Evaluation of Light Cured Resin Impregnated Fiber Glass Reinforced Complete Denture

Document Type : Original Article

Authors

1 Ass. Lecturer at Oral Removable Prosthodontics Department, Faculty of Oral and Dental Medicine, South Valley University

2 Prof. of Oral Removable Prosthodontics Department, Faculty of Dentistry (Cairo), Azhar University (Boys).

3 Assistant Prof. of Oral Removable Prosthodontics Department, Faculty of Dentistry (Cairo), Azhar University (Boys).

Abstract

Background: Hardness could found to be sensitive to the residual monomer content in the polymerized resins; the hardness is an effective method to evaluate the polymerization depth of resin materials. In addition, hardness had used to predict the wear resistance of dental materials. Materials and Methods: Acrylic resin specimens had divided into two groups according to the type of material tested (group I: conventional heat cured acrylic resin, group II: resin impregnated fiberglass reinforced complete denture base). Vicker`s micro hardness tester was used to measure Vicker`s hardness number (VH) of the acrylic specimens in which diamond indenter was applied under 25 g load for 10 seconds time evaluated by 20 x objective lens. Results: The VH values of resin impregnated fiberglass reinforced acrylic resin showed statistically insignificant lower values (as P < 0.05) than conventional heat cured acrylic resin. Conclusion: Unreacted monomer would act as a plasticizer and weaken the matrix. Heat cured PMMA could perform better in this aspect that the residual monomer content was less when compared to PMMA reinforced through other mechanisms. Key words: Hardness, Fiber, Reinforce, Denture.

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