Abstract

A COMPARISON OF THE EFFECT OF ARTIFICIAL SALIVA WITH DIFFERENT PH VALUES ON SURFACE ROUGHNESS OF VENEERING CERAMIC TO METAL AND ZIRCONIA SUBSTRUCTURE (IN VITRO STUDY)

Inas Mohammed and Dr. Zahraa Nazar Alwahab*

Abstract

Background: Dental ceramics are the restorative material used in dentistry because of their excellent aesthetic and biocompatibility.[1] They have shown the most accurate reproduction of the appearance, color and texture of natural teeth,[2] so they are widely used for both anterior and posterior restoration such as inlays, onlays, veneers, metal- ceramic and all- ceramic restorations. Objective: The purpose of this in vitro study is to compare the effect of artificial saliva with different pH values (3.5, 7.0, and 10.0) on surface roughness of veneering ceramic to metal and zirconia substructure. Materials and methods: Sixty samples rectangular in shape (9mm length X 4mm width X 4mm height) were fabricated from metal and zirconia equally. The veneering ceramic was build up to (3mm height) on metal and zirconia samples. The thirty metal samples were from KERA NH, Ni – Cr alloy then veneered with Vita VMK Master ceramic. The thirty zirconia samples were prepared from pre sintered IPS Emax Zir CAD, then after sintering, they were veneered with IPS Emax Ceram. Each group was divided randomly into three subgroups according to pH values of storage solutions (Neutral 7.0, acid 3.5, and alkaline 10.0). They were stored in incubator for 21 days at 37 C°. Surface roughness (Ra in μm) were recorded in before and after using roughness tester device (profilometer device). Results: The highest mean surface roughness values were for acidic group, followed by alkaline group and then neutral group for both metal and zirconia groups. There was a high statistical significant difference in t – test between metal ceramic and zirconia group after storage. There was a high significant difference within metal ceramic group or zirconia ceramic group before and after storage. Conclusions: Within the limitation of this in vitro study, it can be concluded that, the artificial saliva had significant effect on surface roughness for metal ceramic and zirconia ceramic groups.

Keywords: Metal ceramic, zirconia ceramic, surface roughness.