EFFECT OF TWO DIFFERENT SURFACE TREATMENTS ON MICRO-SHEAR BOND STRENGTH OF CAD/CAM AND HEAT PRESSED GLASS CERAMICS

Abstract

Objective: The aim of this study was to evaluate the micro-shear bond strength between a dual cured resin cement and five different types of ceramics in composition and techniques of construction, using two different surface treatments. Materials & methods: A total of 50 ceramic disks were made and divided into 5 equal groups according to material type IPS Empress CAD, IPS e.max Press, IPS e.max CAD, Vita Suprinity and PM9 (n = 10). Each group was subdivided into 2 subgroups according to surface treatment they will be subjected to (n=5). Subgroup I: Bonding surfaces were etched with 5% HF acid, then coated with Monobond S. Subgroup II: Monobond Etch & Prime was applied on the bonding surfaces. For standardization of bonding surface area, 5 plastic tubings distributed on the bonding surface of each disk were used to place the dual resin cement. The samples were then subjected to micro-shear bond strength. Results: Results showed insignificant difference in micro-shear mean values between the IPS Empress CAD subgroups while significant differences were found between the other subgroups within the same group. Monobond Etch & Prime surface treatment resulted in higher micro-shear bond strength compared with HF surface treated subgroups for all the tested materials except for the PM9 and IPS e.max CAD. Conclusions: It was found that ceramic microstructure as well as the fabrication technique affects the selection surface treatment type. Also, Monobod Etch and Prime as a single step surface treatment produced clinically accepted and comparable results to that of HF treatment.