Comparative evaluation of marginal and internal fit of endocrowns with lithium disilicate, biocompatible...

To compare marginal and internal fit of lithium disilicate (LDS), Biocompatible High-Performance Polymer (BIO-HPP), and monolithic zirconia ceramic endocrowns fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) technology.

Thirty human extracted mandibular 1^st molars were selected. Working length was established and biomechanical preparation was carried out to size 25%-4% using NeoEndo rotary files in the crown down technique. Intermittent irrigation was performed after each instrument by 5.25% sodium hypochlorite followed by irrigation with 17% Ethylenediaminetetraacetic acid to remove the smear layer. Final rinse was done with normal saline, and the canals were dried before obturation with a single cone gutta-percha technique and then randomly distributed into three-groups according to type of material used for fabrication. Group 1-LDS, Group 2-BIO-HPP, and Group 3-monolithic zirconia ceramic. Preparation of the samples was done for endocrowns, impression recorded with digital scanner followed by fabrication by CAD/CAM technique. Samples were sectioned in the midsagittal plane and evaluated under a stereomicroscope.

Bio-HPP biomaterial showed the highest marginal gap discrepancy followed by monolithic zirconia ceramic material and then LDS material in the descending order. Internal gap was highest in Monolithic Zirconia Ceramic material followed by Bio-HPP and LDS. LDS material exhibited minimal discrepancies in both the parameters (marginal and internal gap).

Taking into account the limitations of this study, it is evident that the choice of Bio-HPP for endocrowns can be taken up in future after further clinical trials and long-term follow-up studies.