RESUMO
AIM: The objective of this in vitro study was to assess the effect of different endodontic instrumentation systems on the amount of apically extruded bacteria. MATERIALS AND METHODS: One hundred and twenty freshly extracted human mandibular premolars with single canal were collected. Endodontic access cavities were prepared and then contaminated with an Enterococcus faecalis suspension (ATCC 29212). After incubation at 37°C for 24 h, the root canals were instrumented with K flare files, F360 Single file system, K3XF files, Heroshaper files, Protaper Next files, and Hyflex EDM Single file system. During instrumentation, apically extruded bacteria were collected in the vials containing 0.9% NaCl. Samples were taken from the vials and incubated in brain-heart infusion agar medium for 24 h. STATISTICAL ANALYSIS: The number of colony-forming units was determined, and data were statistically analyzed using one-way analysis of variance and post hoc Tukey test. CONCLUSIONS: Both rotary and hand instrumentation systems extruded intracanal bacteria through the apical foramen, Group 1 (Hand K Flare files) showed maximum, whereas, Group 5 (Protaper Next) and Group 6 (Hyflex EDM) showed the least extrusion.
RESUMO
BACKGROUND: Root-end resection followed by retrofilling is one of the prime requisites to avoid apical microleakage. AIM: It comparatively evaluated the microleakage after root-end resection by erbium, chromium:yttrium, scandium, gallium, and garnet laser and carbide bur with or without placement of mineral trioxide aggregate (MTA). MATERIALS AND METHODS: In this study, 60 maxillary central incisors were decoronated and biomechanically prepared. Out of 60 samples, 48 were included in the experimental group while the rest 12 were in the control group. The samples in the experimental group were obturated, whereas the samples in the control group were not obturated. The experimental group samples were divided into two: one group resected with the laser and the other half resected with carbide bur. These groups were further subdivided into two - one group retrofilled with MTA and the other half without MTA. The control group had both laser- and carbide bur-resected samples with positive and negative controls. All the samples were dyed, decalcified, and cleared. Digital photograph of each sample was taken, and the area of dye penetration was measured with the help of ImageJ software. STATISTICAL ANALYSIS: Analysis of variance and Tukey's test were done. RESULTS: The highest microleakage was seen in carbide without MTA and the least was seen with laser with MTA. CONCLUSION: Laser-resected MTA-retrofilled samples showed minimum leakage.
