Reflectance, direct transmittance and fluorescence of resin composite systems

Objectives:The objective of this study was to verify the percentage of reflectance (R) and direct transmittance (Td), and intensity of fluorescence of 3 resin composite systems, Filtek Supreme XT - 3M ESPE (SU), 4 Seasons – Ivoclar Vivadent (4S) and Durafill VS - Kulzer (DU), in colors indicated to reproduce enamel (E), incisal (IN) and dentin (D).

Methods:Human enamel and dentin discs were obtained from 5 extracted molars and used as control groups. Five specimens were prepared for each group using standardized metallic matrices (20 x 38 x 0.37 ± 0.01mm) with a round perforation of 8mm. For quantitative analysis of obtained data, mean values were calculated between wave lengths of 340 and 800nm (visible light) was determined using a specific software. For fluorescence test, a spectrofluorimeter with 390nm incidence was employed.

Results:Data were submitted to statistical analysis using one-way ANOVA (material) and Tukey's test to verify differences among groups (a = 0.05). Regarding reflectance, all composites for E obtained lower values when compared to enamel. For Td, only DU for E presented statistically similar results to enamel. All materials for dentin obtained lower reflectance values than dentin, whereas in Td only 4S presented statistically higher values than the other composites. SU for IN presented the highest values in Td and lowest in R. Among composites for E evaluated, Su was the only material that showed statistically similar F values to enamel. No analyzed composite for dentin presented similar F values to dentin. SU obtained the lowest values, followed by DU and 4S with the highest values. SU for IN presented no fluorescence peaks.

Conclusions:The reflectance and direct transmittance of composite resins are strongly influenced by the inorganic composition especially by the form and amount of the particles. The fluorescence ranged intensity by the brand of the composite resin.