Light transmission characteristics of dentine and resin composites with different thickness.
J Dent. 2012 Sep 3;
Authors: Nakajima M, Arimoto A, Prasansuttiporn T, Thanatvarakorn O, Foxton RM, Tagami J
Abstract
OBJECTIVE: The purpose of this study was to evaluate the light transmission characteristics of dentine and resin composites with different thickness. METHODS: Disks of bovine dentine and three resin composites (Estelite Σ, Beautifil II and Clearfil Majesty) of OA2 shade were prepared with various thicknesses (0.5, 1.0 and 2.0mm). Using a goniophotometer, the distribution graphs of the light transmission intensity of each specimen were obtained, and diffusion factor (DF) as an indicator for a diffuse transmission property and peak-gain (G0) for a straight-line transmission property were calculated. Their colors were measured on black and white backings using a reflection spectrophotometer to calculate translucency parameter (TP). The data of each value (G0, DF and TP) were analyzed by two-way ANOVA and Dunnett’s T3 for post-hoc test (p=0.05). Regression analyses were used to determine the correlation between G0, DF, TP values and the thickness. RESULTS: Regardless of the thickness, dentine had lower TP values than the resin composites. 0.5 mm-thick specimens of dentine and resin composite produced various G0 and DF values, with dentine exhibiting significantly lower G0 and higher DF than the resin composites (p<0.05), whereas with the 1.0 and 2.0 mm-thick specimens, they were closely aligned. For dentine, G0 and DF increased in inverse proportion to the thickness (G0: R2=0.962, p<0.001; DF: R2=0.891, p<0.001). CONCLUSIONS: Dentine had different light transmission characteristics from resin composite, depending on the thickness. CLINICAL SIGNIFICANCE: : Dentine has different light transmission characteristics (straight-line and diffusion) from resin composite, depending on thickness. Resin composite restoration might be different to accurately reproduce light transmission characteristics of dentine substrate.
[cite source='pubmed']22955005[/cite] – as supplied by publisher]