The actual working length (AWL) of 56 extracted maxillary incisor teeth were measured with an ERCLMD. All root canals were prepared with the ProTaper system to AWL. Of them, 20 were filled with gutta-percha and a resin-based sealer Itraconazole
(Group A), 20 with gutta-percha and a zinc oxide/eugenol-based sealer (Group
, and 16 roots were used as the control group (Group C). Removal of the root filling and repreparation processes were performed using the ProTaper system. Guttasolv and Resosolv were used as the solvents in Group A and Guttasolv and Endosolv E in Group B. After the removal of the root fillings had been achieved, the same ERCLMD was used to measure the working length (WL). Differences between AWL and WL measurements were analysed by paired t-test, and the accuracy of ERCLMD was assessed using chi-squared tests. There were significant differences between AWL and WL measurements in subgroups A2 (Resosolv group) and B2 (Endosolv E group). In these subgroups, WL was shorter than AWL (P?<?0.05). Also, the accuracy of the Resosolv group was significantly lower than the others (P?<?0.05) at a ��0.5?mm margin of error. Removing root fillings may require use of a solvent. In these cases, ERCLMDs may exhibit a lower accuracy, thus operators must exercise additional care when measuring the working length using ERCLMDs. ""Gandolfi MG, Taddei P, Tinti A, Prati C. Apatite-forming ability (bioactivity) of ProRoot MTA. International Endodontic Journal, 43, 917�C929, 2010. Aim? Apatite-forming ability, considered as an index <a href="http://www.selleckchem.com/products/Verteporfin
(Visudyne).html">check details of bioactivity (bond-to-bone ability), was tested on ProRoot MTA cement after immersion in phosphate-containing solution (DPBS). Methodology? Disk samples were prepared and immersed in DPBS for 10?min, 5?h, 1 and 7?days. The cement surface was studied by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, by micro-Raman spectroscopy and by environmental scanning electron microscope with energy dispersive CYC202 datasheet
X-ray (ESEM-EDX) analyses. The pH of the storage solution was also investigated. Results? Spectroscopic analyses revealed calcium phosphate bands after 5-h immersion in DPBS. After 1?day, an even coating composed of apatite spherulites (0.1�C0.8 micron diameter) was observed by ESEM/EDX. After 7?days, its thickness had increased. Apatite nucleation had already occurred after 5-h immersion. At this time, the presence of portlandite (i.e. Ca(OH)2, calcium hydroxide) on the cement surface was also observed; at longer times, this component was released into the medium, which underwent a remarkable pH increase. Conclusions? The study confirms the ability of ProRoot MTA to form a superficial layer of apatite within hours. The excellent bioactivity of ProRoot MTA might provide a significant clinical advantage over the traditional cements used for root-end or root-perforation repair.