Influence of manufacturing protocol, polishing, and thermocycling on water contact angle and hardness of zirconia: Comparison of additive and subtractive techniques.
The manufacturing protocol significantly affects the water contact angle and hardness of zirconia, especially before polishing, but differences diminish after polishing.
Where it sits
this study against the rest of the tri-heal max protocol corpusSummary and findings
This in vitro study evaluated the influence of manufacturing protocols on the water contact angle and hardness of zirconia in dental applications. Ninety-six disk-shaped specimens were tested using different additive and subtractive techniques. The results showed that manufacturing protocol significantly affected the outcomes, particularly before polishing.
Abstract
<h4>Statement of problem</h4>The use of additively manufactured zirconia in dental applications is expanding; however, data on how different manufacturing protocols affect its water contact angle and hardness remain limited.<h4>Purpose</h4>The purpose of this in vitro study was to evaluate how the manufacturing protocol, including variations in additive processing and comparison with subtractively manufactured zirconia with different yttria contents, together with polishing and thermocycling, influences the water contact angle and hardness of zirconia.<h4>Material and methods</h4>Ninety-six disk-shaped specimens (Ø10×1.5 mm) were fabricated either additively using a 3-mol% zirconia slurry (INNI Cera; AM) with different firing protocols (combined [1] or separate [2] debinding and sintering cycles) and build orientations (horizontal [AMH], diagonal [AMD], and vertical [AMV]) or subtractively using 3-mol% (IPS e.max ZirCAD LT; SM-LT) or 4-mol% (IPS e.max ZirCAD MT; SM-MT) zirconia (n=12). Water contact angle and Vickers hardness values were measured before polishing, after polishing, and after thermocycling (10 000 cycles, 5 to 55 °C). Data were analyzed using linear mixed-effects models with Bonferroni-adjusted post hoc tests (α=.05).<h4>Results</h4>The interaction between manufacturing protocol and processing stage affected the tested outcomes (P<.001). SM-LT generally exhibited a higher contact angle before polishing (P≤.003), whereas AMH-1 exhibited higher values than AMV-2 after polishing (P=.025). Except for AMD-1 and SM-LT (P>.05), all groups showed their lowest contact angle before polishing (P≤.028). Before polishing, SM-LT and SM-MT mostly exhibited the highest hardness (P≤.032). After thermocycling, SM-LT exhibited higher hardness than AMH-2 (P=.015). AMD and AMV-1 exhibited their lowest hardness before polishing, whereas polishing increased hardness in AMV-2 (P≤.001).<h4>Conclusions</h4>Manufacturing protocol influenced the measured outcomes mainly before polishing. After standardized polishing, differences among subgroups were reduced. AMH-1 and AMH-2 exhibited similar contact angle and hardness values to SM-LT and SM-MT. Polishing generally increased the contact angle and increased the hardness in AMD and AMV specimens, whereas thermocycling did not significantly alter the measured outcomes.
Background
The study addresses the impact of manufacturing techniques on the properties of zirconia, which is widely used in dental prosthetics. Prior research has indicated that the surface characteristics of zirconia can influence its performance in clinical settings. Understanding how different protocols affect these properties is crucial for optimizing dental materials.
Methods
Not reported in abstract.
Results
Not reported in abstract.
Interpretation
Not reported in abstract.
Key findings
- Not reported in abstract.
Limitations
- Not reported in abstract.