ABSTRACT
Background: The study aimed to compare the amount of extrusion, the time taken to achieve apical patency and duration for removing filling material during the retreatment of teeth filled with NeoMTA 2® (Avalon Biomed, Houston, TX, USA), a calcium silicate hydraulic cement and AHPlus™ (Denstsply, Konstanz, Germany), a resin-based cement, using continuous rotation and asymmetric reciprocating rotation instruments. Material and Methods: 60 monoradicular human teeth were selected and instrumented with Race #35.06 (FKG Dentaire, La Chaux-de-Fonds, Switzerland). The teeth were randomly assigned to two groups based on the cement used for filling (n = 30 each) AHPlus™ and NeoMTA 2®. Both groups were obturated with gutta-percha, using the lateral condensation technique. During non-surgical retreatments, each group was further divided into two subgroups: D-Race (FKG) and Reciproc (VDW, Munich, Germany) (n = 15 each). The total time to achieve apical patency and complete the retreatment were recorded. Extruded debris were collected and weighted. Student t-tests were employed for mean comparisons to assess significant differences between variables. Results: No statistically significant differences were found in terms of type of cement and apical extrusion. Regarding the rotation system, using the Reciproc system resulted in longer time to achieve patency and retreatment times compared to D-Race system, with statistically significant differences (P< 0.05). Conclusions: All systems used in retreatment led to apical extrusion. Apical patency was achieved in all cases. Key words:D-Race, Reciproc, calcium silicate-based cement, root canal retreatment.
ABSTRACT
Background: The aim of this study was to compare the cytotoxicity of calcium silicate-based endodontic sealer, Bio-C® Sealer, with other calcium silicate-based sealers: BioRoot™ RCS, one silicon-based sealer combined with calcium silicate particles: GuttaFlow® Bioseal, one resin MTA-based root canal sealer: MTA Fillapex®, and an epoxy resin-based sealer: AH Plus®. Material and Methods: NIH 3T3 fibroblasts were cultured and sealers extracts were obtained. Cytotoxicity was evaluated by the MTS assay and the optical densities of the solutions were measured with a microplate reader. This study was designed with one sample for each control group and n=10 for each treatment group of the different sealants. The results were classified according to the degree of cell viability and underwent statistical analysis with the ANOVA test (p<0.05). The samples were examined under an inverted microscope to evaluate the effect of each sealer on fibroblast cell morphology. Results: Cells incubated with GuttaFlow® Bioseal extract showed the highest cell viability without statistically significant differences with the control group. BioRoot™ RCS and Bio-C® Sealer showed moderate (tending to slight) cytotoxicity and both AH Plus® and MTA Fillapex® showed severe cytotoxicity in comparison with the control group (p<0.05). AH Plus® and MTA Fillapex® were not significantly different from one another; nor was BioRoot™ RCS from Bio-C® Sealer. Microscope examination found that fibroblasts in contact with GuttaFlow® Bioseal and Bio-C® Sealer presented the most similar aspects to the control group both in terms of number and shape. Conclusions: Bio-C® Sealer showed moderate (tending to slight) cytotoxicity compared with the control group, GuttaFlow® Bioseal showed no cytotoxicity, BioRoot™ RCS moderate-slight cytotoxicity and AH Plus® and MTA Fillapex® severe cytotoxicity. Key words:Biocompatibility, calcium silicate-based endodontic sealers, cytotoxicity, endodontic sealer.
