FRACTURE RESISTANCE OF VITA SUPRINITY VERSUS IPS E.MAX CAD VONLAYS RESTORING PREMOLARS (IN VITRO STUDY)

Abstract

Statement of problem: Lithium disilicate ceramic (IPS e.max CAD) has been considered one of the strongest glass-ceramics with fracture strength ranging from 300 to 400 MPa which provides higher mechanical properties than other types of glass based ceramic material but still limits its use in thin sections in posterior area. Aim: The aim of the present study was to compare the fracture resistance of lithium disilicate (IPS e.max CAD) vonlays versus VITA suprinity vonlays restoring premolars. Methodology: A natural tooth representing the first maxillary premolar was prepared according to all ceramic restoration preparation guidelines, it was then duplicated into twenty epoxy resin dies, each one was scanned by 3 shape D500 extra oral scanner and then milled by Sirona MCX5 milling machine using IPS e.max and VITA suprinity CAD blocks producing a total of twenty restorations, the samples were divided into two equal groups, group (I) ten vonlay samples fabricated of IPS e.max CAD blocks and group (V) ten vonlays samples fabricated of VITA suprinity CAD/CAM blocks. Load to fracture was tested. Result: Statistically significant difference was found between IPS e.max and VITA suprinity where (p =0.05≤ 0.05). The highest mean value was recorded with VITA suprinity 704.278±139.297N while the lowest mean value was recorded with IPS e.max CAD 582.308±113.443 N.