Analysis of polymerization time on abrasive wear of dental resins

Abstract

An evaluation was made of the abrasive wear of six composite thermofixed dental resins subjected to different polymerization times. The method of evaluation was based on sharpness measurements to quantify the abrasive wear resistance of the resins. To this end, a test bench was built, consisting of a rotating porcelain cylinder that wears out a resin-coated cylinder placed above it, thus causing vertical displacement of the contact as the wear progresses. The values of vertical displacement, i.e., the input variables, were read and recorded by means of a computer program to obtain the sharpness values. These data indicated that the resins displayed different behaviors as a function of the polymerization times applied, reinforcing the importance of using a practical and rapid method of analysis in order to ensure that the behavior of new materials is fully understood before they are launched on the market.

Wear mechanisms of dental composite restorative materials by two different in-vitro methods

“…Size, shape and amount of fillers, as well as their mechanical properties, interface adhesion between matrix and filler particles, the characteristics of the polymer matrix itself and its curing process, are some of the main factors that affect the wear properties of dental composites 4 . Due to the intrinsic difficulties in performing in-vivo evaluation of wear, several methodologies have been specifically developed for in-vitro wear assessment of dental materials, with the so-called wear simulators 5 19,20 . It is nowadays well accepted that no test can provide an undisputable evaluation when one has in mind the wear performance of dental materials, as different methods involve different wear mechanisms resulting in different wear rates.…”

Desgaste abrasivo de uma resina composta, através de três diferentes métodos (disco retificado, escovação e nanodurômetro)

“…Esses mesmos resultados foram observados no trabalho anterior da autora, , para os espécimes fotopolimerizados também por 30 segundos, ou seja, 0,1301 mm 3 /N.s para o PMMA, 0,5882 mm 3 /N.s para a C4 e 0,7675 mm 3 /N.s para a Incisal. Não pode ser feita nenhuma outra comparação com quaisquer outros trabalhos, como Coelho (1991); Dias (1995); Bianchi et al (1996); Salgado (1996); Salgado, Freitas e Bianchi (1997); Bianchi et al (2000b); Bianchi (2002); Bianchi et al (2002); Bianchi et al (2003); França et al (2004); Cruz et al (2005); Santana et al (2005); Cintra et al (2006); Ulhôa (2006); Ulhôa et al (2006); ; Ulhôa et al (2007); Cruz et al (2008); Bianchi et al (2010), onde foi utilizado o referido método, em função de diferenças das condições e/ou dos materiais envolvidos.…”

“…as partes descritas no texto: 1) suport e do conjunto; 2) peça central do dispositivo-guia; 3) hastes cilíndricas; 4) trave para registro de deslocamento; 5) haste cilíndrica central; 6) local de fixaç ão do disco estático e 7) cânula plástica. Assim, foram desenvolvidos vários trabalhos , como o de Dias (1995); Bianchi et al (1996); Salgado (1996); Salgado, Freitas e Bianchi (1997); Bianchi et al (2000b); Bianchi (2002); Bianchi et al (2002); Bianchi et al (2003); França et al (2004);Cruz et al (2005); Santana et al (2005); Cintra et al (2006); Ulhôa (2006); Ulhôa et al (2006); ; Ulhôa et al (2007); Cruz et al (2008); Bianchi et al (2010), os quais consistiram em artigos publicados em revistas, apresentações em congressos e pesquisas envolvendo Iniciação Científica, Mestrado ou Doutorado.…”