Predicting Transmitted Light Radiant Exposure of Fiber Dowel Cross Sections from Dowel Diameter and Length

Fiber dowel retention is required for the success of foundation restorations and overlying fixed prostheses. Many factors affect dowel retention, including the depth of cure of the cement used. Lightor dual-cure resin cements are commonly used with fiber dowels. Both cement types require light to initiate polymerization, resulting in varying degrees of conversion, or depth of cure, depending on light intensity and degradation along the length of the root canal system. Reports have shown that some dual-cure cements do not reach adequate degrees of conversion in the absence of light. The use of translucent dowels has been recommended to improve the degree of conversion in dark areas of the root canal that cannot be reached by curing light.

Several studies have examined the effects of light curing on the degree of resin cement conversion. Few reports on light intensity at various locations on different fiber dowels have been published. A few reports have described the effects of light transmission through dowelson resin cement, such as micro-hardness and degree of conversion, rather than reporting on light intensity or radiant exposure of the fiber dowel. Only two studies have examined light transmission through fiber dowels by measuring light counts with a spectrophotometer or luminous intensity with a digital reader. Read more......