Filling Ability and Flow of Root Canal Sealers: A Micro-Computed Tomographic Study

Abstract

This study evaluated by micro-computed tomography (μCT) the filling ability in curved root canals, besides the flow of AH Plus (AHP) and Neo MTA Plus (NMTAP) sealers using different methodologies. Mandibular molars mesial roots with two root canals and degree of curvature between 20° and 40° were selected. The specimens were prepared with the ProDesign R system up to size 35.05 and were filled with the sealers by a continuous wave of condensation technique, Thermo Pack II (n=12). The teeth were scanned using μCT after root canal preparation and obturation. The volumetric percentage of filling material and voids were calculated. Flow was evaluated based on ISO 6876/2012 (n=10). Flow and filling were also evaluated in μCT using a glass plate with a central cavity and four grooves from the central cavity (n=6). Flow was linearly calculated into the grooves. The central cavity filling (CCF) and lateral cavity filling (LCF) were calculated in mm³. Data were submitted to non-paired t test with a significance threshold at 5%. The percentage of filling and voids between the root canals filled with AHP or NMTAP was similar (p>0.05). NMTAP presented the lowest flow in conventional test (p<0.05). Using μCT, sealers had similar CCF, LCF and linear flow (p>0.05). In conclusion, NMTAP and AHP had similar filling ability in curved mesial root canals of mandibular molars without presence of isthmus. Although AHP presented better flow than NMTAP using ISO methodology, there was no difference between these materials regarding volumetric filling when evaluated by μCT.

Effect of Additional Apical Preparation on Retreatment of Curved Root Canals Filled with Different Sealers

“…23 Therefore, the apical enlargement allows greater contact of the instrument and dentin walls reducing debris, providing better effect of the irrigating solution 24 and root canal filling. 25 In addition, the decrease of residual filling material was observed after apical enlargement from size 25 to 40, 26 with a success rate of 90.4% after 2 years. 27 Although our study showed a percentage of remaining material less than 20% in the apical third after apical enlargement, the complete removal of filling material was not possible.…”

Effect of Different Irrigation Solutions on the Diffusion of MTA Cement into the Root Canal Dentin

“…Recently, bioceramic-based sealers have emerged containing calcium phosphate, with a crystalline structure and a chemical composition similar to bone and tooth apatite materials. In addition to their excellent sealing capacity and mechanical and physical properties, their biocompatibility prevents rejection by the surrounding tissue [16,19]. A recent systematic review stated that the penetration of bioceramic cement is substantially more significant than that of epoxy resin-based sealers (AH Plus ® , for example), even with activated irrigation methods and chelating agents [20].…”