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: A maxillary first premolar typodont tooth was prepared to receive lithium disilicate onlay. Mesio-occluso-distal cavity was prepared with palatal cusp reduction and collar preparation. In the proximal box, gingival seat was placed 1 mm coronal to the cementoenamel junction and mesiodistal width of the seat was kept to 1 mm. Thirty stone models were prepared from thirty rubber base impressions and divided into two groups, based on the technique of fabrication of onlays: (1) Group CL (CAD/CAM lithium disilicate) and (2) Group PL (Pressable lithium disilicate). Fifteen onlays per each group were fabricated by following the manufacturer instructions. Marginal fit of all the samples were analyzed by using stereomicroscope with Image Analysis software. Statistical analysis was done by t-test.
Results: Statistical significant difference was found between both the groups. The lowest marginal discrepancy (41.46 μm) was measured for Group CL (CAD/CAM lithium disilicate) specimens, and the highest (55.95 μm) discrepancy was observed on the Group PL (Pressable lithium disilicate) specimens.
Conclusion: Although there was a statistically significant difference between the two groups, marginal gap of both the groups were in clinically acceptable levels.
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.
AIM: The present work aims to gain knowledge about dentists' opinions and experiences on assessing the risk factor related to the development of root caries and to help identify any overlooked factors that may contribute to less efficacious clinical outcomes.
METHODOLOGY: A questionnaire related to root surface caries was distributed among practicing dentists in nine different countries, namely the United Kingdom, Libya, Jordan, Saudi Arabia, Egypt, Brazil, India, Malaysia, and Iraq. Questionnaire responses were analyzed, and the results were compared among the groups.
RESULTS: Dentists around the world ranked the oral hygiene status of patients as the most important factor in the development of root surface caries. Patients with poor oral hygiene, active periodontal disease, reduced salivary flow, and gingival recession are perceived to have a higher risk of developing new root surface caries. There is a greater focus on prevention in the UK and greater levels of untreated dental disease in other countries, especially those recovering from civil wars.
CONCLUSION: This work identified some overlooked factors that may have contributed to the less efficacious clinical outcomes reported in the literature. It is hoped that this deep dive into risk factors coupled with the findings presented in Part I of this study will be used as a basis for a more comprehensive investigation into the management of patients with root surface caries.
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.
Materials and Methods: Twenty-five enamel slabs were divided into three treatment groups: light-activated bleaching, laser-activated bleaching, and control. The baseline data were recorded for enamel microhardness (Vickers microhardness [VMH]) and surface roughness (Roughness average, Ra). The specimens were cured for 10 min upon hydrogen peroxide application for the light-activated bleaching group and activated with a laser source, 8 cycles, 10 s per cycle for the laser-activated group. The changes in VMH and Ra at days 1, 7, and 28 were evaluated. Kruskal-Wallis, Friedman, Wilcoxon, and Mann-Whitney tests were used to analyze both VMH and Ra between the treatment groups at different time intervals.
Results: There were a significant reduction in VMH values and significant differences between days 1, 7, and 28 against the baseline in the light-activated bleaching group (P = 0.001). The Ra values revealed significant differences in both light- (P = 0.001) and laser-activated (P = 0.033) groups.
Conclusion: Light activation of a bleaching agent caused a reduction in enamel microhardness and an increase in surface roughness when compared to laser activation.