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
Bacterial infection of tooth pulp can progress into periapical diseases. Root canal treatment has been established as the best treatment. In cases of failure, nonsurgical retreatment of teeth is preferred to surgical procedure and extraction. In this historical cohort study, 104 permanent teeth with apical lesion were treated during 2002-2008. All teeth showed radiographic evidence of periapical lesion varying in size from 1 to >10mm. A total of 55 teeth were treated with initial root canal treatment and 49 teeth required retreatment. Patients were recalled up to 7 years. All radiographs were taken by RSV MAC digital imaging set and long cone technique. The presence/absence of signs and symptoms and periapical index scores [PAI] were used for measuring outcome. Teeth were classified as healed [clinical/radiographic absence of signs and symptoms] or diseased [clinical/radiographic presence of signs and symptoms]. The data were statistically analyzed using student t-test and Pearson chi-square or fisher's exact test. The rate of complete healing for teeth with initial treatment was 89.7%, and for retreatment group was 85.7%; there was no significant difference. Size of lesions did not significantly affect the treatment outcomes. Success of tooth treatment did not reveal significant correlation with gender and number of roots. Orthograde endodontic treatment/retreatment demonstrates favorable outcomes. Thus, nonsurgical endodontic treatment/retreatment should be considered as the first choice in teeth with large periapical lesion
ABSTRACT
Garlic [Allium sativum] extract has an inhibitory effect on various pathogenic bacteria, viruses and fungi. The aim of the present study was to evaluate in vitro inhibitory effect of garlic extract on multi-drug-resistant [MDR] strains of Streptococcus mutans isolated from human carious teeth. Filtered sterilized aqueous extract of garlic was used in the present study. In this in vitro case-control study data was analyzed with Student's t-test [? = 0.05]. From 105 extracted human carious teeth 92 strains of S mutans were isolated. Disk sensitivity tests and broth dilution methods were used to determine antibiotic sensitivity profile and inhibitory activity of garlic extract on S mutans. Among 92 isolates of S mutans, 28 [30.4%] were MDR since they were resistant to four or more antibiotics. The highest and least resistance rates were observed for tetracycline [30.4%] and teichoplanin and vancomycin [0%], respectively; on the other hand, 22.8% and 23.9% of the isolates were resistant to penicillin and amoxicillin, respectively. Chlorhexidine minimum inhibitory concentration [MIC] for MDR and non-MDR S mutans varied from 2 to 16 microg/mL and from 0.25 to 1 microg/mL, respectively [p value < 0.05]. All the isolates, MDR and non-MDR, were sensitive to garlic extract with the MIC ranging from 4 to 32 mg/mL. Considering the data obtained from the present study, mouthwashes or toothpastes containing optimum concentrations of garlic extract can be used for the prevention of dental caries