Influence of soft tissue on density and relative contrast between gutta-percha and dentin images. An in vitro study

The current ANSI/ADA standard for density of gutta-percha (GP) has been found to be insufficient for clinical purposes. Furthermore, it does not take into account the possible influence of soft tissue on the image of GP in the root canal. The present study evaluated the density of GP according to the standard and the influence of soft tissue on the contrast between GP and dentin in vitro. The optical density of all tested GP brands was higher than the recommended standard. Soft tissue significantly influenced the relative contrast between dentin and GP and a decrease of more than 10% was observed when soft-tissue-equivalent phantom was added (p < 0.000). A test simulating a clinical condition is recommended for improving the standard for the density of GP.