In vitro sealing capacity of provisional restoratives used during and after endodontic procedures, prior to the definitive restoration

Abstract

Introduction: The final stage of endodontic treatment usually consists of filling the coronal part of the tooth completely and compactly with materials that have physical-chemical properties, which are capable of securing hermetic sealing and creating a favorable biological environment in order to enable periapical tissue repair. Glass ionomers are permanent restorative materials that could be used to achieve this goal compared to conventional temporary materials. The aim of this investigation was to evaluate the sealing ability of different temporary and permanent restorative materials used for sealing the access cavity during root canal treatment, and to assess the effect of coating varnishes on reducing leakage. Materials & Methods: Intermediate Restorative Material (IRM) and three Glass Ionomer Cements (GIC) were tested. The four materials were allocated to six different groups: A. Chemfil (Dentsply); B. Equia Fil (GC); C. Equia Fil with Equia Coat (GC); D. Riva (SDI); E. Riva with Coat (SDI); and F. IRM (Dentsply) as a positive control. Standardized Class I cavities simulating access cavities were prepared in 60 intact freshly extracted human Premolar and Molar teeth. Prepared teeth were randomly allocated to the predetermined groups and filled with the corresponding restorative systems. Then they were thermo-cycled (500 cycles, 5 degrees C-55 degrees C) and subsequently immersed in 2% methylene blue solution (pH = 7.4). Subsequently, the teeth were sectioned in sagittal plane and the depth of dye penetration was examined. The sectioned specimens were viewed and photographed using a stereomicroscope (x10). The following scoring system was used to determine the level of dye penetration: 0 - No dye penetration. 1 - Dye penetration limited to DEJ. 2 - Dye penetration up to half of the cavity preparation. 3 - Dye penetration deeper than level 2. Results: Analysis of the data using the Chi-square test identified the control group (IRM) as exhibiting significantly more leakage than all glass ionomer groups with 80% of its specimens exhibiting microleakage with a score of "3" for (a dye penetration deeper than half of the cavity preparation). All glass ionomer cements (GIC) groups demonstrated superior sealing ability (P[more than]0.005) compared to the (IRM) control group with leakage scores not exceeding "2" for (half of the depth of the cavity preparation). There was no significant difference between the three formulations of (GIC) studied. The application of a varnish coat increased the sealing ability with 40% of the coated (GIC) specimens scored exhibiting a score "0" for (no dye penetration) (P[less than]0.005). Conclusions: The following can be concluded from this study: - Glass ionomer cements exhibited a better seal than the ZOE (IRM) control. - No significant difference was found between the sealing ability of the different glass ionomer formulations. - The coronal seal was significantly improved when a varnish coat was added to glass ionomer restorations.