Comparison of the microhardness and morphology of five different retrograde filling materials in aqueous and dry conditions

Calcium silicate-based cements: composition, properties, and clinical applications

Mineral trioxide aggregate (MTA) is a calcium silicate-based cement (CSC) commonly used in endodontic procedures involving pulpal regeneration and hard tissue repair, such as pulp capping, pulpotomy, apexogenesis, apexification, perforation repair, and root-end filling. Despite the superior laboratory and clinical performance of MTA in comparison with previous endodontic repair cements, such as Ca(OH)₂ , MTA has poor handling properties and a long setting time. New CSC have been commercially launched and marketed to overcome the limitations of MTA. The aim of the present review was to explore the available literature on new CSC products, and to give evidence-based recommendations for the clinical use of these materials. Within the limitations of the available data in the literature regarding the properties and performance of the new CSC, the newer products could be promising alternatives to MTA; however, further research is required to support this assumption.

New methodology to evaluate bond strength of root-end filling materials

This study evaluated the bond strength of root-end filling materials to root-end cavities using a new methodology. Twenty maxillary central incisors were subjected to biomechanical preparation (#80 hand file) and sectioned transversally 2 mm short of the apex and 4 mm coronally to this point. The root cylinders were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. Two groups (n=10) were formed according to the root-end filling material: MTA and Super EBA. A gutta-percha cone (#80) was tug-backed at the limit between the canal and the root-end cavity. The cavity was filled and the gutta-percha cone was removed after complete setting of the sealer. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and run at a crosshead speed of 1.0 mm/min for pushing out the root-end filling material. Data were analyzed by ANOVA (α=5%). Super EBA (6.03±1.31) presented higher bond strength (MPa) than MTA (1.81±0.45) (p>0.05). There was a predominance of cohesive failures for Super EBA and mixed for MTA. The protocol of specimen preparation is effective and introduces a specific methodology for assessing bond strength of root-end filling materials to dentin. Among the materials, Super EBA presented the highest bond strength.

Biological effects and washout resistance of a newly developed fast-setting pozzolan cement

INTRODUCTION

Mineral trioxide aggregate has been widely used as a retrograde filling material. The aim of this study was to evaluate the biological effects of a newly developed fast-setting, mineral trioxide aggregate-derived pozzolan cement (Endocem). Furthermore, we explored whether this cement is resistant to washout in comparison with ProRoot.

METHODS

Biocompatibility was evaluated on the basis of cell morphology and a viability test. The expression of osteogenic genes was evaluated by performing real-time polymerase chain reaction, and calcified nodule formation was assessed by alizarin red S staining. The setting time was measured, and washout testing was performed by placing the material into fetal bovine serum.

RESULTS

The biocompatibility and osteogenicity of Endocem were similar to those of ProRoot. Moreover, Endocem showed a higher resistance to washout than ProRoot did.

CONCLUSIONS

These results suggest that Endocem can be used as an available retrograde filling material because it sets faster and shows similar biological effects when compared with ProRoot.