Translucency, opalescence and light transmission characteristics of light-cured resin composites.
OBJECTIVE
To evaluate the translucency, opalescence and light transmission characteristics of resin composites with different thicknesses.


METHODS
Disks of three resin composites (Estelite∑, Beautifil II, Clearfil Majesty) of A2 shade were prepared in diameter of 10mm with various thicknesses (0.5mm, 1.0mm and 2.0mm). Color was measured according to CIELAB color scale on a reflection spectrophotometer and a color haze meter, and translucency parameter (TP) and opalescence parameter (OP) were calculated. Using the distribution graphs of transmitted light intensity on a goniophotometer, diffusion factor (DF) as an indicator for a diffuse transmission property and peak gain (G0) for a straight-line transmission property were calculated.


RESULTS
The TP and G0 values significantly decreased in the order: 0.5mm>1.0mm>2.0mm thickness (p<0.05). The OP value increased as the thickness of resin composite increased from 1.0mm to 2.0mm (p<0.05), while was similar for the 0.5mm- and 1.0mm-thick groups. The DF value increased from 0.5mm to 1.0mm, but was similar for the 1.0mm- and 2.0mm-thick groups. There was a significant correlation between TP and DF (R(2)=0.96, p<0.001). On the other hand, there was a weak correlation between OP and DF (R(2)=0.21, p<0.005), however within the values of the 0.5mm-thick group, OP was highly correlated with DF (R(2)=0.84, p<0.001).


CONCLUSIONS
At the 0.5mm thickness, the translucency (TP) and opalescence (OP) of resin composites had a significant correlation with a diffuse transmission property (DF). When more than 1.0mm thickness of resin composites, translucency and opalescence were influenced by the thickness, in which translucency significantly decreased and opalescence significantly increased.
Arimoto
Ayako
A
Department of Restorative Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Japan. abookofants@yahoo.co.jp
Nakajima
Masatoshi
M
Hosaka
Keiichi
K
Nishimura
Kozo
K
Ikeda
Masaomi
M
Foxton
Richard M
RM
Tagami
Junji
J
D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects; D003116:Color; D003124:Colorimetry; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D006801:Humans; D008027:Light; D055620:Optical Phenomena; D010783:Photometry; D013053:Spectrophotometry; D013499:Surface Properties
C470433:Beautifil composite resin; D003188:Composite Resins; D003764:Dental Materials; C507124:Estelite sigma; C541508:clearfil majesty; D017438:Bisphenol A-Glycidyl Methacrylate