Ca(OH)2 used in endodontics is made with Ca(OH)2 powder, a vehicle and a radiopacifier. Most common radiopacifiers are barium sulfate, bismuth or compounds containing iodine or bromine. While radiopacifiers make the calcium hydroxide more visible radiographically, some radiopacifiers are known to resorb at a slower pace, sometimes making it difficult to see the subtle changes.
While the control of a paste material at the apex of a canal can be very difficult, the resorptive properties of calcium hydroxide make it a very forgiving material. Extrusion of calcium hydroxide past the apex of a tooth is not uncommon. In fact, there are some who would recommend deliberate extrusion in the case of a large, chronic periapical lesion to help in the healing of such a lesion.
Calcium hydroxide (Ultracal - Ultradent - 35% Ca(OH)2
with barium sulfate) was used during treatment of this tooth to control exudate prior to obturation. A significant amount was extruded past the apex in close approximation to the maxillary sinuses during the endodontic treatment.
14 months later, the patient returned for treatment of #14. Our recall radiograph of #15 shows complete resorption of Ca(OH)2. The patient had no complaints and is in full function.
Sources:
Hasan Orucoglu, Funda Kont Cobankara, "Effect of Unintentionally Extruded Calcium Hydroxide Paste Including Barium Sulfate as a Radiopaquing Agent in Treatment of Teeth with Periapical Lesions: Report of a Case", Journal of Endodontics, July 2008 (Vol. 34, Issue 7, Pages 888-891)
