Materials and Methods: The study was performed using cell viability assay for mitochondrial dehydrogenase activity in stem cells from human exfoliated deciduous teeth (SHED), after 1, 2, and 3 days of exposure to the biomaterial extracts of varying concentrations. Differences in mean cell viability values were assessed by one-way analysis of variance, followed by Dunnett T3 post hoc test for multiple comparisons (P < 0.05).
Results: The cell viability to Gyp-CHT in low extract concentrations was statistically similar to that of the control and different from that of high extract concentrations. Gyp-5% CHT showed the highest percentage of cell viability with 110.92%, 108.56%, and 109.11%. The cell viability showed a tendency toward increment with low extract concentration and no constant effect of CHT on cell viability toward higher or lower.
Conclusions: Gyp-CHT biomaterial has no cytotoxic effects on the cultured SHED.
Materials and Methods: The prepared root canals of 80 teeth were contaminated with E. faecalis (n = 40) and S. epidermidis (n = 40) for 21 days to create biofilms. The samples in each group were allocated randomly into the following four subgroups (n = 10) according to the decontamination protocol: Group 1: 1% Pediocin, Group 2: 2% CHX, Group 3: Ca(OH)2, and Group 4: saline (negative control). At 5 days, the antimicrobial efficacy of the medicaments against E. faecalis and S. epidermidis was assessed by collecting dentin shavings from the canal walls created using Gates Glidden drill sizes 4 and 5, corresponding to a depth into the root canal walls of 200 μm and 400 μm, respectively. The total number of colony-forming units (CFUs) was counted. The Wilcoxon signed-rank test was used to compare the difference in CFUs between the two depths (P > 0.05).
Results: There was no bacterial growth in samples treated with pediocin, CHX, or Ca(OH)2 at either depth.
Conclusion: In this laboratory experimental model, pediocin exhibited the same antimicrobial properties against E. faecalis and S. epidermidis as CHX and Ca(OH)2.
AIM: The study aimed to evaluate the effect of placement of compactable glass fibers in reinforcing the endodontically treated teeth in a novel conservative manner.
SETTINGS AND DESIGN: Research laboratory, in vitro study.
MATERIALS AND METHODS: Seventy-five extracted maxillary premolars were procured. Fifteen teeth were left untreated (Group A) and the remaining teeth were endodontically treated followed by standardized mesio-occluso-distal preparation and randomly assigned to experimental groups (n = 15) as follows: (B) no restoration, (C) restoration with composite, (D) EverStick® POST followed by composite, and (E) vertical glass fibers within 3 mm of the coronal root canal space and buccopalatal flaring of the coronal fibers followed by composite. After conditioning and thermocycling, specimens were loaded under a universal testing machine to evaluate fracture resistance and fracture pattern of specimens.
STATISTICAL ANALYSIS USED: Obtained scores were statistically analyzed using one-way analysis of variance test for stress analysis, post hoc Tukey's test for intergroup comparison, and Chi-square test for analysis of favorable and unfavorable fracture.
RESULTS: The fracture resistance was highest to lowest as follows: Group A > E > C > D > B (P < 0.001).
CONCLUSION: EverStick®POST used in conservative manner improved fracture strength of teeth significantly.
Materials and Methods: Sixty freshly extracted maxillary incisors teeth collected in saline. Access cavity prepared and canals were made free of bacterial and pulp. The teeth were mounted on the bacteria collecting apparatus. Root canals were contaminated with the Fusobacterium Nucleatum (ATCC25586) and dried at 37°C for 24 h. In Group 1 (Control group): No instrumentation was done and biomechanical preparation done in all other groups with Group 2: Hand K-files, Group 3: Protaper gold, Group 4: K3XF, Group 5: Edge taper platinum, and Group 6: Hyflex CM rotary file systems. Then, the extrude was collected, and it is incubated in Mueller-Hinton agar for 24 h and the number of colony forming units were counted and statistical comparison was done using Kruskal-Wallis test and Mann-Whitney U test.
Results: Hand K-files extruded more bacteria when compared to other four rotary systems, K3XF file system extruded least number of bacteria.
Conclusion: All instrumentation techniques extruded intracanal bacteria apically. However, engine-driven nickel-titanium instruments extruded less bacteria than the manual technique. The K3XF rotary file system comparatively extruded less bacteria than other rotary file systems.
Materials and Methods: Ninety J-shaped canals in resin blocks were filled with 2% Methylene Blue solution and pre-instrumentation images were taken using a Leica microscope at a ×10. They were prepared until size 25 taper 0.04 using (n = 18 per group): T-Flex, HyFlex CM, Vortex Blue, S5, and iRace. After instrumentation, images were captured again, and composite images were made using Adobe Photoshop imaging software. The differences in canal width and canal curvature at each respective landmark were measured and compared. The preparation time and canal abbreviations were also recorded. Statistical analyses were performed using one-way ANOVA and post hoc Tukey HSD tests. The level of statistical significance was set to P = 0.05.
Results: HyFlex CM demonstrated the least difference in canal width after instrumentation, but no significant difference (P > 0.05) as compared to T-Flex and Vortex Blue. The mean canal straightening ranged between 0.91° and 7.65°. T-Flex created the least canal straightening after instrumentation which was significantly less (P < 0.05) than S5, but there was no significant difference (P > 0.05) when compared to HyFlex CM. Instrumentation with the S5 file was significantly faster (P < 0.05), whereas HyFlex CM was the slowest.
Conclusion: T-Flex, HyFlex CM, and Vortex Blue demonstrated better shaping ability, whilst T-Flex and HyFlex CM maintained the original canal curvatures well. S5 tended to straighten the canals and caused the greatest canal transportation, but it required the least amount of time to shape the canal.