Influence of irradiant energy on degree of conversion, polymerization rate and shrinkage stress in an experimental resin composite system


Autoria(s): CALHEIROS, Fernanda C.; DARONCH, Marcia; RUEGGEBERG, Frederick A.; BRAGA, Roberto R.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

19/10/2012

19/10/2012

2008

Resumo

Objective. This study evaluated the degree of conversion (DC), maximum rate of cure (R(p)(max)), and polymerization stress (PS) developed by an experimental dental composite subjected to different irradiant energies (3,6,12, 24, or 48J/cm(2)) under constant irradiance (500 mw/cm(2)). Methods. DC and R(p)(max) were monitored for 10 min on the bottom surface of 2-mm thick disks and on 150-mu m thick films (representing the top of the specimen) using ATR-FTIR. PS was monitored for 10 min in 2-mm thick disks bonded to two glass rods (O = 5 mm) attached to a universal testing machine. One-way ANOVA/Tukey tests were used and differences in DC and R(p)(max) between top and bottom surfaces were examined using Student`s t-test. Statistical testing was performed at a pre-set alpha of 0.05. Results. For a given surface, DC showed differences among all groups, except at the top between 24 and 48 J/cm(2). R(p)(max) was similar among all groups at the same surface and statistically higher at the top surface. PS also showed significant differences among all groups. Data for 48 J/cm(2) were not obtained due to specimen failure at the glass/composite interface. Significance. Increases in irradiant exposure led to significant increases in DC and PS, but had no effect on R(p)(max) (c) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

FAPESP[03/13002-0]

FAPESP[04/05975-0]

Identificador

DENTAL MATERIALS, v.24, n.9, p.1164-1168, 2008

0109-5641

http://producao.usp.br/handle/BDPI/25809

10.1016/j.dental.2008.01.006

http://dx.doi.org/10.1016/j.dental.2008.01.006

Idioma(s)

eng

Publicador

ELSEVIER SCI LTD

Relação

Dental Materials

Direitos

restrictedAccess

Copyright ELSEVIER SCI LTD

Palavras-Chave #exposure duration #polymerization #composite #stress #degree of conversion #LIGHT-ACTIVATED COMPOSITES #PRE-HEATED COMPOSITE #DENTAL COMPOSITES #TEMPERATURE RISE #VISIBLE-LIGHT #CONTRACTION STRESS #REACTION-KINETICS #CURE #PHOTOPOLYMERIZATION #HARDNESS #Dentistry, Oral Surgery & Medicine #Materials Science, Biomaterials
Tipo

article

original article

publishedVersion