ABSTRACT
Statement of the Problem: Correct proportioning and mixing are essential to ensure cements attain their optimum physical properties
Purpose: The aim of this experimental study was to evaluate the influence of various mixing techniques including manual, mechanical mixing, and ultrasonic vibration on push-out bond strength of calcium enriched mixture [CEM]
Materials and Method: Ninety 2-mm-thick dentin disks were prepared from single-rooted human teeth and filled with CEM mixed with manual, trituration, or ultrasonic methods. Push-out bond strength values of the specimens were measured by a universal testing machine after 3 and 21 days. The samples were then examined under a stereomicroscope at 40× magnification to determine the nature of bond failure. Data were analyzed by Kruskal-Wallis and Mann-Whitney test. [p< 0.05]
Results: The highest [7.59 MPa] and lowest [4.01 MPa] bond strength values were recorded in conventional method [after 21 days] and trituration method [after 3 days], respectively. There was no statistically significant difference between the three techniques in 3 and 21 days
Conclusion: According to the results, various mixing techniques had no effect on the push-out bond strength of CEM cement
ABSTRACT
Statement of the Problem: In clinical situations, Calcium-Enriched Mixture [CEM] comes into direct contact or even mixes with blood during or after placement
Purpose: The aim of this study was to evaluate the effect of blood contamination on the compressive strength of CEM
Materials and Method: Three experimental groups were included in this study. In the first group, CEM was mixed with distilled water and was exposed to normal saline [control group]. In the second group, CEM cement was mixed with distilled water and then was exposed to blood. In the third group, CEM was mixed with and exposed to blood. Nine custom-made two-part split Plexiglas molds with five holes were used to form CEM samples for compressive strength testing [15 samples in each group]. After 7 days of incubation, compressive bond strength testing was performed using a universal testing machine. Data were statistically analyzed using the Mann-Whitney U test with a significance level of p< 0.05
Results: Nine samples from group 3 were fractured during removal from the molds; the other six blocks had some cracks on their surfaces. Therefore, a compressive strength measurement was not obtainable for this group. No statistically significant difference was found between groups 1 and 2 [p> 0.05]
Conclusion: It can be concluded that exposure to blood does not adversely affect the compressive strength of CEM, but incorporation of blood makes the cement very brittle
ABSTRACT
Preparation techniques and instruments produce and push debris out of canals. This can induce inflammation within the periapical area. Therefore, instrumentation that causes less extrusion of debris is more desirable. The purpose of this in vitro study was to evaluate the quantity of debris extruded from the apical foramen during root canal preparation by using one hand and two rotary instrumentation techniques. Three different groups each with 12 mesiobuccal roots of human maxillary first molar were instrumented using either step-back technique with hand instruments, FlexMaster or Mtwo rotary system. Debris extruded from the apical foramen during canal preparation was collected. The mean dry weights of debris were compared using one-way ANOVA. Step-back group had a significantly greater mean weight of debris compared to the other two groups [P<0.05]. Mtwo group had the lowest mean weight of debris, though it was not significantly different from FlexMaster group. According to this study, the engine driven techniques were associated with less apical debris extrusion
ABSTRACT
The purpose of this study was to compare the subcutaneous tissue responses of freshly mixed or set endodontic root canal sealers [i.e. RoekoSeal, AH26, AH Plus] in Wistar Albino rats. Seventy-two male albino rats weighing 200-250g were used. The animals were randomly divided into six groups of 12 rats each. Root canal sealers were implanted in subcutaneous tissue in both freshly mixed and set conditions. The animals were sacrificed after 7, 14, and, 60 days. After histological preparation and Hematoxylin and Eosin [H and E] staining, the specimens were evaluated for capsule thickness, severity and extent of inflammation, and necrosis. Results were statistically analyzed using Multivariate ANOVA test. Differences between set and freshly mixed root canal sealers were significant [P=0.014], but not significant between test materials and controls, except for capsule thickness and extent of inflammation between control and AH26 [P=0.019 and P=0.006 respectively]. The interaction between the type of material and setting condition was significant for capsule thickness and severity of inflammation in AH26 specimens at 14 and 60 day [P=0.001]. Based on the results of this study assessing the biocompatibility, both set and freshly mixed states can be used