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BACKGROUND: Apical leakage assessment is a way to compare the efficiency of a filling material to seal the apical region of the tooth. Many microleakage testing techniques have been introduced through the years, but there has been no agreement as to which technique gives the most accurate results. The aim of this study was to compare the accuracy of fluid filtration and bacterial leakage techniques in the assessment of the apical sealing ability of mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM). MATERIALS AND METHODS: A sample of 34 extracted single-rooted human teeth were selected and prepared. The samples were divided in to 2 experimental groups. The apical 3 mm of each root was resected at 90° to its long axis and root end preparation was done with ultrasonic tips to a depth of 3 mm and filled with MTA and CEM, respectively. Assessment of apical sealing ability was done with fluid filtration technique and bacterial leakage technique along 90 days with Enterococcus faecalis bacteria. Mann-Whitney U-test and Chi-square test were used to analyze the data using SPSS (SPSS Inc., Chicago, IL, USA). P less than 0.05 was considered as significant. RESULTS: There was no significant difference in apical sealing ability between MTA and CEM in bacterial leakage and fluid filtration techniques. Samples which had bacterial leakage showed higher leakage values by fluid filtration technique. CONCLUSION: Both techniques showed same results and there was no significant difference between fluid filtration and bacterial leakage techniques in assessment of apical microleakage.
RESUMO
OBJECTIVE: There is some concern that root resection may alter the seal of the previously set orthograde material. The aim of this study was to evaluate the apical sealing ability of orthograde mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM) plugs after resection of the roots. MATERIALS AND METHODS: The fluid filtration method was carried out on a total of 51 roots in three experimental (n=15) and two control (n=3) groups. The root canals were prepared 3 mm shorter than the working length. In groups A and B, 4 mm of MTA and CEM were placed in an orthograde technique, respectively, and after setting, 3 mm of the root end was resected. In group C, the apical 3 mm of each root was resected, root end preparation was carried out to a depth of 3 mm and filled with MTA. Apical microleakage values of each group were measured. Data was analyzed using Kruskal-Wallis test. RESULTS: Means and standard deviations of apical microleakage in groups A (MTA orthograde), B (CEM orthograde) and C (MTA retrograde) were 2.31×10(-4) (0.32×10(-4)), 3.33×10(-4) (0.29×10(-4)) and 4.42×10(-4) (0.40×10(-4)) µl.min(-1).cmH2o(-1), respectively. The mean values were greater in group C; however, statistical analysis revealed no significant differences between these groups (P>0.05). CONCLUSION: Based on the results of this study, when there is an orthograde access to the root canal and surgery is likely to be necessary in the future, MTA and CEM can be placed in an orthograde technique and it just resects the root during surgery.
RESUMO
INTRODUCTION: The aim of this in vitro study was to determine the sealing ability of orthograde ProRoot mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM) cement as root-end filling materials. MATERIALS AND METHODS: Fifty four extracted single-rooted human teeth were used. The samples were randomly divided into 3 experimental groups. In group A and B, 4 mm of WMTA and CEM cement were placed in an orthograde manner and 3 mm of apices were resected after 24 hours. In group C the apical 3 mm of each root was resected and the root-end prepared with ultrasonic tips to a depth of 3 mm and subsequently, then filled with MTA. The apical sealing ability was performed with bacterial leakage method. Statistical analysis was carried out with Chi-square test. RESULTS: There were no significant differences in the extent of bacterial leakage between the three experimental groups (P>0.05). CONCLUSION: Based on the limitations of this in vitro study, we concluded that MTA and CEM cement can be placed in an orthograde manner when there is a potential need for root-end surgery.
RESUMO
AIM: Cleaning and shaping is one of the most important phases in root canal therapy. Various rotary NiTi systems minimize accidents and facilitate the shaping process. Todays NiTi files are used with air-driven and electric handpieces. This study compared the canal centering after instrumentation using the ProTaper system using Endo IT, electric torque-control motor, and NSK air-driven handpiece. MATERIALS AND METHODS: This ex vivo randomized controlled trial study involved 26 mesial mandibular root canals with 10 to 35° curvature. The roots were randomly divided into 2 groups of 13 canals each. The roots were mounted in an endodontic cube with acrylic resin, sectioned horizontally at 2, 6 and 10 mm from the apex and then reassembled. The canals were instrumented according to the manufacturer's instructions using ProTaper rotary files and electric torque-control motors (group 1) or air-driven handpieces (group 2). Photographs of the cross-sections included shots before and after instrumentation, and image analysis was performed using Photoshop software. The centering ability and canal transportation was also evaluated. Repeated measurement and independent t-test provided statistical analysis of canal transportation. RESULTS: The comparison of the rate of transportation toward internal or external walls between the two groups was not statistically significant (p = 0.62). Comparison of the rate of transportation of sections within one group was not significant (p = 0.28). CONCLUSION: Use of rotary NiTi file with either electric torquecontrol motor or air-driven handpiece had no effect on canal centering. CLINICAL SIGNIFICANCE: NiTi rotary instruments can be used with air-driven motors without any considerable changes in root canal anatomy, however it needs the clinician to be expert.
