IMPACT OF DIFFERENT EROSIVE MEDIA ON SURFACE ROUGHNESS AND BOND STRENGTH OF REPAIRED LITHIUM DISILICATE CERAMIC USING TWO REPAIR SYSTEMS: AN IN VITRO STUDY.

Abstract

Objectives: This study aims to evaluate the impact of various erosive media on the surface roughness and bond strength of repaired lithium disilicate ceramic using two repair systems.Materials and Methods: Sixty-four discs of lithium disilicate (Amber Press) ceramic were prepared and divided into two main groups, each group was repaired using intra oral repair systems (Nanoksa Lab and Bisico Multi Repair). After that each main group was divided into four subgroups according to erosive media applied (Saliva, HCl, Red-Bull®, Coca-Cola®). The surface roughness (Ra) was measured before and after exposure to the erosive media using Mitutoyo profilometer, then shear bond strength (SBS) test was evaluated (MPa) using a universal testing machine Instron. Data were statistically analyzed using ANOVA and Tukey's post hoc test.Results: The surface roughness was significantly different between different subgroups, where a high degree of Ra was recorded in the Coca-Cola® subgroups for both repair systems, while the saliva subgroups showed the lowest degree of surface roughness. The shear bond strength for "Nanoksa" was consistently higher across all erosive media compared to "Bisico." The mean shear bond strength for "Nanoksa" ranges from (3.559- 4.49 MPa), while for "Bisico," it ranges from (0.495- 2.322MPa).Conclusions: This study found that the surface roughness and bond strength of repaired lithium disilicate ceramic are significantly influenced by the erosive media. The success of the repair is also greatly influenced by the system of repair that is selected.KEYWORDS: Surface roughness, Bond strength, Lithium disilicate ceramic, Erosive media, Repair systems.