Curing-light attenuation in filled-resin restorative materials
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Date
2006
Authors
Journal Title
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Publisher
Dental Materials
Abstract
To characterize the attenuation of the curing light in filled resin restorative materials (FRRMs) to aid understanding of curing depth.
One hundred and eighty materials of various shades from several manufacturers were tested in various ways. One set (66 materials) was used to determine the applicability of Lambert's Law using a quartz-tungsten-halogen curing light (Optilux 400, Demetron Research) by measuring the transmitted light with a dental radiometer (Cure Rite, EFOS) for successive thicknesses of ground 10mm diameter specimens from 3 to 0.5mm in 0.5mm steps. A second set (17 materials) were similarly tested with separate specimens from 1 to 5mm in thickness using a transmission densitometer (DT1405, RY Parry) fitted with a curing-light dichroic filter. For a third (overlapping) set (165 materials), the 1mm pure (reflectance-free) optical density (D1 value) was determined from two specimens, ∼1 and ∼2mm thick using the densitometer as above. From D1 the critical thickness (xCRIT), identified as depth of cure (DoC) for an excess surface exposure factor of 2, was calculated.
Lambert's Law was found to hold with no evidence of appreciable differential absorption effects. Attenuation coefficient and D1 were significantly correlated (P<1×10−13). D1 varied between about 0.23 and 0.72, for corresponding xCRIT values of 1.3 and 0.4mm. There was no correlation between D1 and reflectance (P>0.09), and no systematic effect due to shade letter, but a highly significant (P<7.5×10−8), but weak (−0.066mm/unit), correlation between shade number and D1.
Description
Keywords
Light attenuation, Resin composite restorative materials, Irradiance
Citation
Musanje, L., & Darvell, B. W. (2006). Curing-light attenuation in filled-resin restorative materials. Dental Materials, 22(9), 804-817.https://doi.org/10.1016/j.dental.2005.11.009