Finishing and Polishing Techniques for Monolithic Zirconia Restorations: A Systematic Review of Polishing, Glazing, and Liquid Ceramic Systems

Abstract

Background: Monolithic zirconia restorations require surface finishing following milling or intraoral adjustments to optimize mechanical,
biological, and esthetic performance. Common finishing approaches include mechanical polishing, laboratory glazing, and emerging liquid
ceramic systems such as MiYO, each of which influences surface roughness, wear behavior, and optical properties.
Objective: To systematically evaluate and compare the effects of polishing, glazing, and MiYO/liquid ceramic finishing methods on monolithic
zirconia restorations.
Methods: A systematic search of MEDLINE/PubMed, Scopus, Embase, Web of Science, and Google Scholar was conducted up to November
2025. Studies directly comparing at least two zirconia finishing methods were included. Two independent reviewers performed study selection,
data extraction, and risk of bias assessment using a domain-based approach adapted from the
Cochrane Risk of Bias 2 (RoB 2) framework. Due to heterogeneity in study designs and outcome measures, a qualitative narrative synthesis was
performed.
Results: From 1,742 screened records, 9 in vitro studies met the inclusion criteria. Surface roughness was the most commonly evaluated outcome,
followed by wear behavior, biofilm adhesion, and optical properties. Mechanical polishing consistently produced the lowest surface roughness
and demonstrated stable surface characteristics after simulated wear. Glazed zirconia exhibited superior initial gloss; however, the glaze layer
showed susceptibility to wear, resulting in increased surface roughness and antagonist wear over time. MiYO and related liquid ceramic systems
provided favorable esthetic outcomes and acceptable short-term color stability, although evidence regarding their long-term mechanical
performance remains limited.
Conclusion: Mechanical polishing appears to be the most reliable finishing method for maintaining surface smoothness and reducing antagonist
wear in monolithic zirconia restorations. Glazing and MiYO systems may enhance esthetics but are dependent on the durability of surface
coatings. Further long-term clinical studies are required to validate the performance of these finishing techniques under functional conditions.