In vitro study of Coronal Leakage of Four Temporary Filling Materials Immersed in Alcoholic Methylene Blue Dye

Abstract Introduction: Temporary restorative materials are placed in access cavity to provide the coronal seal of the root canal during multi-visits RCT. This in vitro study was designed to evaluate the coronal microleakage of four different temporary restorative materials commonly used in endodontics in Myanmar, viz., MD.Temp, Orafil, Caviton, Zinc oxide eugenol. Materials and Methods : Forty-four extracted human premolars were selected, and access cavity was prepared. Pulp chambers were filled with wet cotton pellets leaving approximately 4 mm coronally. Forty teeth were randomly divided into four experimental groups equally. The remaining four teeth were equally divided into two control groups. Access cavities in each group were filled with one of the above tested materials, and immediately put into the water. Tooth surfaces except occlusal surface were then coated with nail varnish. Equal parts of 2% methylene blue and methylated alcohol were mixed to prepare a dye solution. Samples were immersed in dye for 10 days at 32 ± 2°C. Teeth were rinsed, dried, and sectioned mesiodistally and evaluated under a stereomicroscope at a magnification of 15X for linear dye penetration along cavity walls. Data were analyzed using KruskalWallis and Tukey HSD tests. Results : The lowest microleakage value was observed in MD.Temp and Orafil, and the highest in Zinc oxide eugenol (ZOE). Caviton was not statistically different from Orafil and ZOE, but significantly higher in microleakage than MD.Temp. Clinical Significance : ZOE which is dissolvable in alcohol was the least effective material for preventing microleakage, while MD.Temp and Orafil provided the best sealing in content of alcohol in this study

The Effect of Adhesive Resin Coating on Microleakage of Class II Composite Inlay Cemented with Self-Adhesive Resin Cement

ABSTRACT Objective: The objective of this in vitro investigation was to evaluate the effect of adhesive resin coating with a self-etch dentin bonding agent and etch and rinse dentin bonding agent and without coating on microleakage of class II indirect composite inlay cemented with self-adhesive resin cement on enamel and dentin interfaces after thermocycling. Methods: Thirty-six upper permanent premolars extracted for orthodontic needs were selected for this study and randomly allocated to three experimental groups (n=12). These samples of teeth were prepared in a standardized manner under jig assembled on a milling machine. After preparation, group I: no surface treated with dentin bonding agent; group II: prepared surface treated with a self-etch dentin bonding agent and group III: prepared surface treated with etch and rinse dentin bonding agent. And then, impression taking with rubber base impression materials and indirect composite inlays were fabricated and cemented with self-adhesive resin cement. Restored teeth were artificially aged with a thermocycling machine (5±2oC and 55±2oC, 1000 cycles with 30 sec dwell time). After thermocycling, the samples were immersed in 2% methylene blue dye solution for 24 hours. Then, teeth samples were sectioned mesiodistally with Isomet linear precision saw. The most linear penetration of the dye was observed under a stereomicroscope at 40x magnification. All the samples were scored and statistically analyzed with Kruskal-Wallis nonparametric test (p<0.05) followed by Mann-Whitney U-test for multiple comparisons. Results: In group I, no treatment of the prepared surface with dentin bonding agent immediately after preparation and before impression taking (Control group), the mean score was 3.17. In group II, prepared surface coated with self-etch dentin bonding agent immediately after preparation and before impression taking, the mean score was 2.17. In group III, prepared surface coated with total-etch dentin bonding agent immediately after preparation and before impression taking, the mean score was 2.67. According to statistical analysis, there was a significant difference (p<0.05) between all groups in microleakage values by using Kruskal-Wallis non-parametric test. And there is no significant difference between Group I Vs III and Group II Vs III. Conclusion: 1. Microleakage of class II composite inlay cemented with selfadhesive resin cement significantly decreased by using adhesive resin coating with a self-etch dentin bonding agent on the prepared surface before impression taking. 2. There is highly significantly lower leakage at the occlusal margin versus the dentin margin of all tested groups in inter-group comparison