Comparative Evaluation of Efficacy of Four Different Materials in the Repair of Amalgam Restorations: An In Vitro Study.

AIM: This study was aimed to compare the microleakage of amalgam restorations repaired with bonded amalgam, composite resin, ormocer, and glass ionomer restorative material. MATERIALS AND METHODS: Sixty extracted maxillary human premolars were prepared and restored with class I amalgam. A simulated defect was prepared that included the cavosurface margin on restorations, and the premolars were assigned to four treatment groups (n = 15): In group I, premolars were treated by bonded amalgam; in group II, premolars were repaired with composite resin; in group III, premolars were repaired by ormocer; and in group IV, premolars were repaired with glass ionomer restorative material. The teeth were immersed in 50% silver nitrate solution, thermocycled, sectioned longitudinally, and then blindly observed under a stereomicroscope by three trained examiners. Microleakage was evaluated using a 0-4 scale for dye penetration, and data were analyzed by Kruskal-Wallis test and Mann-Whitney U-test. RESULTS: The microleakage values were more in the group repaired with glass ionomer restorative material and the Chi-squared test showed no significant difference in between the groups repaired with bonded amalgam, composite resin, and ormocer, but showed significant difference between the groups repaired with ormocer and glass ionomer restorative materials and between composite resin and glass ionomer restorative materials. CONCLUSION: None of the restorative techniques evaluated were able to completely eliminate marginal microleakage. CLINICAL SIGNIFICANCE: The results seem to be favorable within the limits of the in vitro conditions of the present study; however, the in vivo conditions are the best for clinically relevant findings.

An in vitro study to compare the effectiveness of F-fle with ultrasonically activated K-fle to remove smear layer by using a scanning electron microscope.

AIM: The aim of this study was to compare the effectiveness of the F-fle with an ultrasonically activated #15 K-fle in removing the smear layer after biomechanical instrumentation along with irrigation of Saline, NaOCl and with or without a fush of EDTA. MATERIALS AND METHODS: Sixty decoronated human premolar teeth with a single canal were instrumented with ProTaper using S1, S2 and F1 series to produce the smear layer and randomly divided into two groups. Group A used Ultrasonics and group B used F-fle for activation of irrigants respectively. Each group was further divided in to three subgroups consisting of 10 teeth in each as I, II, III consisting of saline, NaOCl, NaOCl and EDTA as irrigants respectively. SEM micrographs were taken and amount of smear layer removal was analyzed by using Chi-square statistics tests. RESULTS: Most effective smear layer removal was seen only when EDTA was used. There was no statistically signifcant difference between the groups A and B in removal of smear layer. CONCLUSION: There was no increase in smear layer between use of F-fle when compared with the Ultrasonically activated K-fle. CLINICAL SIGNIFCANCE: The F-fle although does not have a superior effcacy than the ultrasonics in removal of smear layer from root canals but when used along with EDTA, can be an effective alternative for the dentists who are unable to bear the initial setup cost of ultrasonics.