Influence of different pigments and accelerated aging on the hardness and the tear strength of facial silicones

• Grant number: 15/11015-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2015
• End date: July 31, 2016
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Marcelo Coelho Goiato
• Grantee: Estefânia Marrega Malavazi
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The maxillofacial prostheses are very important for the patients affected by the loss of anatomical part of the face, because, besides protecting the exposed area, it reinstates the individual in society and improve their quality of life. Several materials are used for manufacturing these prostheses, but the most widely used is silicone. However, these polymeric materials have low thermal stability and low resistance to UV rays, reducing the useful life of the prostheses. One of the most affected properties damaging the durability of maxillofacial prosthesis is the color stability. There are many attempts to development of new pigments, longer lasting, and color scales to facilitate the clinical use, however still none has consecrated in the literature or clinical routine. Although the color is one of the most important properties, other characteristics should be evaluated. The hardness determines the flexibility of the material, and even the edges being slender, they must have good marginal adaptation and be resistant to daily pulls that patient exerts on the prosthesis. This study aims to analyze the influence of three pigments in hardness and tear strength of two silicones submitted to accelerated aging. For samples fabrication, we selected the facial silicones A2 A-2186 and Silastic MDX4-4210 and three pigments, in bronze and black, and a new pigment, medium pink color. For each test, a total of 80 samples will be fabricated and distributed in 8 groups (n = 10), according to silicone and pigment. The samples will be submitted to hardness and tear strength tests before and after 1008 hours of accelerated aging. Data will be submitted to the normal curve adherence test, being applied appropriate statistical test to compare the mean values for each test performed.