European Journal of Prosthodontics and Restorative Dentistry

Is Ammonium Hydrogen Difluoride a Solution for Zirconia Surface Conditioning?

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Cover Date

June 2023

Print ISSN

0965-7452

Electronic ISSN

2396-8893

Vol

31

Issue

2

Abstract

Introduction: This research investigated the topographical features and phase
transformation of high-translucent monolithic zirconia after different surface
conditioning methods. Methods: Zirconia slabs were divided into six groups according
to surface treatment method. Group I: etched with hydrofluoric acid (HF); Group II:
etched with an experimental acid solution (EAS); Group III: melt-etched with ammonium
hydrogen difluoride (AHD); Group IV: air abrasion (AB); Group V: etched with EAS after
air abrasion (AB+EAS); Group VI: melt-etched with AHD after air abrasion (AB+AHD).
Surface topographies of specimens were documented by scanning electron microscopy
(SEM). Tetragonal-to-monoclinic phase transformation was detected by X-ray diffraction
and surface evaluation of zirconia specimens; surface roughness and contact angle
measurements were performed. The data were statistically analyzed by the Kruskal
Wallis test and post hoc tests (P<0.05). Results: The acid-etched zirconia groups (Group
I, II, and III) showed the lowest contact angle and surface roughness values (P<0.05),
while the air abrasion groups (Group IV, V, VI) showed the highest. The SEM images
also supported these results. Conclusion: Within the limitations of this in vitro study,
treating the monolithic zirconia surfaces with EAS or AHD after air abrasion may be
recommended to alter the zirconia surfaces.
Keywords
SEM
XRD
Acids
Zirconium
Hydrofluoric Acid