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: Insolubility is an important criterion for an ideal rootend filling material to both prevent any microleakage between the root canal and the periradicular space and provide sealing ability
Purpose: Many recent studies have shown that mineral trioxide aggregate [MTA] and calcium-enriched mixture [CEM] have acceptable sealing ability. The purpose of this in vitro study was to evaluate the solubility of these root-end filling materials
Materials and Method: Forty stainless steel ring moulds with an internal diameter of 10 +/- 1 mm and a height of 2 +/- 0.1 mm were selected. Samples of MTA and CEM were mixed according to the manufacturer's instructions and inserted into the moulds. The specimens were divided into 4 experimental groups and kept in synthetic tissue fluid [STF] for 2 different time periods [7 and 28 days]. The control group contained 8 empty rings. The moulds' weights were recorded before and after immersion in STF. The changes in the weight of the samples were measured and compared using a two- way ANOVA test at a significance level of 5%. Specimens were evaluated with scanning electron microscopy [SEM] at a magnification of 500×
Results: There was no significant difference in weight changes between MTA and CEM samples [p> 0.05]
Conclusion: MTA and CEM have similar solubility in STF in different time periods
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
The crown-root fracture is a common tooth injury which compromises the biological width and need proper endodontic and prosthodontic treatment to achieve acceptable clinical outcome. This case report describes clinical management of crown-root fracture in maxillary central incisors which was successfully treated by forceps eruption with 180 [degree sign] rotation to restore the biological width. The patient was followed-up for 18 months. Clinical and radiographic evaluation showed acceptable results, the replanted teeth have normal function and no obvious inflammatory root resorption was seen on radiographic examination