Sealing ability of two thermoplastic materials after different irrigation protocols

Objectives: The aim was to evaluate the apical and coronal sealing ability of gutta-percha/AH-Plus and resilon/EpiphanySE after five different irrigation protocols. Methods: 200 extracted human single-straight-root-canalled teeth were prepared with MTwo rotary instruments to size 40/04, divided into five groups and irrigated as follows: Group 1 – 5,25% sodium hypochlorite, Group 2 – 20% citric acid, distilled water, Group 3 – 20% citric acid, distilled water, 2% chlorhexidine, Group 4 – BioPure/MTAD (Dentsply), distilled water, Group 5 – BioPure/MTAD, distilled water, 2% chlorhexidine. Each group was divided into two equal subgroups: A and B (n=20). The root canals were filled using vertical condensation technique with gutta-percha/AH-Plus and resilon/EpiphanySE respectively. After incubation, cutting and varnishing, the samples were stored in 2% methylene blue for 7 days. Then the roots were split longitudinally into two halves and the measurement of apical and coronal leakage was carried out with the micrometer and operating microscope OMPI Pico (Zeiss). The data was analyzed with Mann-Whitney U, Kolmogorow-Smirnow and Wald-Wolfowitz tests. Results: The best apical seal was in subgroups 3A, 4A and 5A. The best coronal seal was in subgroup 5A. The worst sealing ability was in subgroups 1B and 4B. Overall gutta-percha/AH-Plus fillings yielded less leakage. Conclusions: 1. The best apical seal was obtained by irrigation with 20% citric acid, water, 2% chlorhexidine and filling with gutta-percha/AH-Plus. 2. The best coronal seal was achieved with the use of BioPure/MTAD, water, 2% chlorhexidine and gutta-percha/AH-Plus. 3. The worst results were gained with 5,25% sodium hypochlorite followed by resilon/EpiphanySE. 4. Overall gutta-percha/AH-Plus exhibited less leakage. 5. The final flush with 2% chlorhexidine improved coronal sealing ability of both materials and apical seal of gutta-percha/AH-Plus (after 20% citric acid) and of resilon/EpiphanySE (after BioPure/MTAD). 6. Chlorhexidine interacted with resilon and lead to discoloration of the teeth.