title: UV-vis spectrophotometric direct transmittance analysis of composite resins.
abstract: OBJECTIVE
  The objective of this experiment was to evaluate the direct transmittance of the micro-hybrid composite resins Charisma F, Solitaire II, Intens and Tetric Ceram, and the nanofilled composite resins Exthet-X and Filtek Supreme in the dentin and translucent shades.
  
  
  METHODS
  Three samples of each composite resin and shade were obtained with dimensions of 12 mm x 12 mm and 1mm thick. After light activation, three measurements for each sample were done with an UV-vis spectrophotometer. The spectra was analyzed by mean values for the percentage of direct transmittance at intervals of 20 nm in the range between 400 and 700 nm (%T) and the percentage of direct transmittance in the wavelengths of 400, 560 and 700 nm (T(d)).
  
  
  RESULTS
  The Student's t-test showed that dentin shade of Charisma F had significant higher %T than the translucent shade. For Solitaire II, Intens, Tetric Ceram and Esthet-X the translucent shade had higher %T than the dentin shade. For Filtek Supreme there was no statistical difference between the dentin and translucent shades. According to analysis of variance (ANOVA) and Tukey multiple-range test Charisma F had the highest %T and T(d) at dentin and translucent shades, except for translucent shade at 700 nm, in which Esthet-X had higher T(d).
  
  
  CONCLUSIONS
  This study indicates that the percentage of direct transmittance is not directly related with the composite resin shade.
authors.affiliation: Dental Materials Laboratory, School of Dentistry, Pontificial Catholic University of Rio Grande do Sul, Brazil.
authors.forename: Alexandre S
authors.initials: AS
authors.lastname: Masotti
authors.forename: Alvaro Barcellos
authors.initials: AB
authors.lastname: Onófrio
authors.forename: Ewerton N
authors.initials: EN
authors.lastname: Conceição
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Spohr
mesh_terms: D000704:Analysis of Variance; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D008027:Light; D008422:Materials Testing; D010316:Particle Size; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins