Delivery of calcium hydroxide: comparison of four filling techniques.

This study compared the weight and radiographic appearance of Ca(OH)(2) delivered into standardized, minimally and fully prepared canals using (a) an injection system, (b) an endodontic Flex-O file rotated counter-clockwise, (c) a lentulo spiral, and (d) a .04 rotary NiTi file rotated in reverse. Two extracted human second mandibular premolars with single canals were prepared to an MAF #25 or an MAF #40. A weight measurement and radiograph were made for each filling. Three independent examiners evaluated the radiographs. Regardless of technique, only about 45% of the optimal weight of Ca(OH)(2) was delivered into the minimally prepared canal. Radiographically the filling quality was only 1 to 2 (10 scale). In contrast, all delivery techniques delivered near optimal weight of Ca(OH)(2) in the completely prepared canal with a radiographic filling quality of 8.8 to 9.3. The results indicate that complete instrumentation is needed to obtain near optimal delivery of Ca(OH)(2).