Silvia Rojas-Rueda, Franciele Floriani, Fabio Andretti, Hamad Algamaiah, Carlos A Jurado, Mark Adam Antal, Abdulrahman Alshabib
The novel multiacid etchant is highly effective for treating 5Y Zir, creating a favorable microretentive surface for bonding. However, its aggressive action makes it unsuitable for LiDi, where overetching can compromise structural integrity. Selection of etching agents should be material-specific to optimize clinical outcomes while preserving ceramic quality.
BACKGROUND: Establishing a durable bond to high-strength dental ceramics, especially zirconia (Zir), is a clinical challenge. This is due to the material's chemical inertness and its resistance to conventional etching methods. Zir lacks silica, making it unresponsive to traditional hydrofluoric acid (HF) treatments effective for glass ceramics like lithium disilicate (LiDi). This study assesses the efficacy of a novel multiacid etchant in modifying the surface roughness of LiDi and 5 mol% yttria-stabilized Zir (5Y-TZP), comparing its performance against three commercial HF-based etchants.
METHODS: Four etchants were tested: Zircos-E (EDOS [ZiE]), 9.5% porcelain etchant (Bisco [BIS]), 9% porcelain etch (Ultradent [ULT]), and IPS Ceramic Etching Gel (Ivoclar [IPS]). Each was applied for 20 s, 1 min, and 30 min to LiDi (Amber Mill) and 5Y Zir (IPS e.max ZirCAD Prime MT) specimens (n = 10 per group). Surface roughness (Ra) was measured with a profilometer. Data were analyzed using two-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) test (α = 0.05).
RESULTS: On 5Y Zir, Zircos-E produced significantly higher surface roughness than all other etchants, reaching 0.378 µm at 30 min (p < 0.001), indicating a greater ability to modify the Zir surface topography under the conditions evaluated in this study. On LiDi, it also resulted in the highest roughness (0.785 µm) but with signs of excessive etching and surface degradation. In contrast, the HF-based etchants produced more controlled and uniform roughening on LiDi, without overetching.
CONCLUSIONS: The novel multiacid etchant is highly effective for treating 5Y Zir, creating a favorable microretentive surface for bonding. However, its aggressive action makes it unsuitable for LiDi, where overetching can compromise structural integrity. Selection of etching agents should be material-specific to optimize clinical outcomes while preserving ceramic quality.