The Effect of Different Surface Treatments on the Micromorphology and the Roughness of Four Dental CAD/CAM Lithium Silicate-Based Glass-Ceramics

Muna Bebsh,Rodrigo França,Asmaa Haimeur

doi:10.3390/ceramics4030034

Abstract

Objective: This study aimed to investigate and compare the effect of various surface treatments on the micromorphology and the roughness of four CAD/CAM lithium silicate-based glass-ceramics (LSGC). Method: Eighty specimens of four LDGC materials (IPS e. max® CAD (Ivoclar-Vivadent, Liechtenstein, Schaan), Vita Suprinity® (Vita Zahnfabrik, Bad Säckingen, Germany), Celtra Duo® (Dentsply, Hanau-Wolfgang, Germany) and n!ce (Straumann, Basel, Switzerland)) were used for this study. All specimens were highly polished with 400, 600, 1200 grit silicon carbide paper and then polished with 3 µm and 1 µm polycrystalline diamond suspension liquid with grinding devices. Each group of ceramic was assigned to one of the following three surface treatments (1) sand-blasting (SB) with 50 µm Al2O3 at 70 psi for 10s, (2) hydrofluoric acid etching (HF) with 5% hydrofluoric acid, according to the manufacturer instructions, (3) and a combination of sand-blasting and hydrofluoric acid (SB + HF). All specimens were cleaned with ethanol for 2 min and placed in an ultrasonic unit with distilled water for 15 min. The microstructure was analyzed by scanning electron microscopy (SEM). The surface roughness and topography were evaluated with atomic force microscopy in tapping mode (AFM). Statistical analysis was done using two-way ANOVA and Tukey tests (α = 5%). Results: All surface treatments had a significant effect on LDGC surface roughness compared to the untreated surface (p < 0.05). The sand-blasting treatment had a significantly higher mean surface roughness value for Vita Suprinity and Celtra Duo compared to other surface treatments (p < 0.05). However, there was no significant difference for surface roughness between sand-blasting and sand-blasting + etching for e.max CAD and n!ce. The hydrofluoric acid produced less surface roughness compared to other surface treatments but was able to change the surface structure. (5) Conclusions: The sand-blasting + etching treatment could be a sufficient method to produce surface roughness for all LSGC types.

Highlights

IntroductionGlass-ceramics, polycrystalline ceramics, and resin-matrix ceramics are the most frequently used materials for prosthodontic restorations [1]
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scanning electron microscopy (SEM) images for hydrofluoric acid etching (HF) specimens had a honeycomb shape for Celta and n!ce (Figure 1(3B,4B)), and a needle shape for e.max CAD (Figure 1(1B)) and Vita Suprinity (Figure 1(2B))

Summary

Introduction

Glass-ceramics, polycrystalline ceramics, and resin-matrix ceramics are the most frequently used materials for prosthodontic restorations [1]. Glass-ceramics are widely used in dentistry as restorative materials for different applications such as crowns, inlays, onlays, and veneers. The success of glass-ceramic dental restorations is in part due to their excellent mechanical and biocompatibility properties [2,3,4]. One of the subcategories of glass-ceramics is synthetic ceramics which include lithium silicate and its derivatives: lithium disilicate, lithium alumina-silicate, and zirconia reinforced lithium silicates. The first generation of LSGC introduced to the dental market was IPS Empress II

Results

Discussion

Conclusion