Comparative evaluation of microleakage of conventional crowns and endocrowns using confocal laser scanning electron microscope – An in vitro study

Abstract

Background and Aims: The purpose of this study was to compare the microleakage of conventional crowns and endocrowns using confocal laser scanning electron microscope. Materials and Methods: Thirty extracted human permanent mandibular molars were collected and sectioned parallel to the occlusal surface at 2 mm above the CEJ to deroof the pulp chamber. Endodontic treatment was performed. The gutta-percha was removed 1 mm below the orifice of each canal, and flowable resin composite was filled in the canals up to the level of the pulp chamber. Samples were then randomly divided into two groups with 15 teeth each according to the type of post endodontic restoration given – Group 1: conventional crowns and Group 2: endocrowns. In Group (1), teeth were restored with composite cores, wide circumferential deep chamfer margin (0.8 mm) was prepared at the CEJ and 2 mm from the occlusal surface, 1.5 mm were cut from the axial walls. In Group (2), preparation was performed by making a circular butt margin with a central retention cavity with rounded internal line angles. Impressions were made, crowns were fabricated, and cementation was done, followed by thermocycling. The specimens were coated with varnish up to 1 mm from the crown margins, placed in Rhodamine B dye for 60 h, rinsed thoroughly for 30 s, sectioned with hard tissue microtome and examined for microleakage. Statistical Analysis: Statistical analysis was accomplished with the Student t-test, and significance was predetermined at P < 0.05. Results: In this study, endocrowns (6.158) showed significantly low microleakage compared with conventional crowns (14.052). Conclusion: Endocrowns showed significantly lower microleakage.

Keywords

• clsm
• conventional crowns
• dual cure resin
• endocrowns
• hard tissue microtome
• microleakage