Porosity distribution in root canals filled with gutta percha and calcium silicate cement

Gutta percha is commonly used in conjunction with a sealer to produce a fluid-tight seal within the root canal fillings. One of the most commonly used filling methods is lateral compaction of gutta percha coupled with a sealer such as calcium silicate cement. However, this technique may result in voids and worse, the filling procedures may damage the root.

We compared the volume of the voids associated with two root canal filling methods, namely lateral compaction and single cone. Micro-computed tomography was used to assess the porosity associated with each method in vitro. An automated, observer-independent analysis protocol was used to quantify the unfilled regions and the porosity located in the sealer surrounding the gutta percha.

Significantly less porosity was observed in root canals filled with the single cone technique (0.445% versus 3.095%, p<0.001). Porosity near the crown of the tooth was reduced 6 fold, whereas in the mid root region porosity was reduced to less than 10% of values found in the lateral compaction filled teeth.

Our findings suggest that changing the method used to place the endodontic biomaterials improves the quality and homogeneity of root canal fillings.