Surface characterization of feldspathic ceramic using ATR FT-IR and ellipsometry after various silanization protocols

Silane coatings are commonly used to improve ceramic bonding in dental restorations. Prior research has shown that silane application can enhance adhesion by forming a chemical bridge between ceramic surfaces and resin cements. However, the effects of post-silane heat treatments and rinsing protocols on silane layer properties remain unclear. This gap motivated further investigation into how different silanization protocols influence surface characteristics of feldspathic ceramics. No prior work had resolved the impact of heat and rinsing on silane film thickness and surface roughness. Established methods like ATR FT-IR and ellipsometry are used to assess surface modifications. The study aimed to explore these effects in a controlled setting. Understanding these variables is essential for optimizing clinical protocols. This paper contributes by systematically analyzing silane layer changes under various conditions.

The aim of this study was to evaluate how different silanization protocols affect the surface properties of feldspathic ceramic. Specifically, the researchers sought to determine the influence of heat treatment and hot water rinsing on silane layer thickness and surface roughness. The motivation for this work stems from the need to improve ceramic bonding in dental applications. By varying silane application conditions, the study aimed to identify optimal protocols for silane layer formation. The researchers also wanted to assess whether heat treatments enhance silane network development. Surface characterization was necessary to understand how these protocols alter ceramic surfaces. This work addresses a specific technical challenge in dental materials science. The findings could inform best practices for ceramic surface preparation.

The study used feldspathic ceramic bars (VM7) prepared to standard dimensions and surface finish. Specimens were divided into nine groups based on silane treatment protocols. All groups received MPS silane application followed by different drying conditions. Some groups were heated at 38°C, 79°C, or 100°C for one minute. Half of each group was rinsed with hot water at 80°C for 15 seconds. ATR FT-IR was used to analyze chemical bond changes. Ellipsometry measured silane film thickness at a fixed wavelength and angle. Surface roughness was assessed using an optical profilometer. Scanning Electron Microscopy provided topographic data. These methods allowed for detailed surface characterization.

ATR FT-IR analysis revealed increased Si-O peak intensities around 940 cm⁻¹, indicating silane layer formation. Ellipsometry showed that heat treatments reduced silane film thickness compared to the 20°C control group (40 nm). The hot water rinsed groups had significantly thinner silane films (9.8–14.4 nm) than their non-rinsed counterparts (30.8–40 nm). Profilometer data indicated smoother surfaces after heat treatments (Ra ≈ 0.10–0.19 μm) compared to the control (Ra ≈ 0.48 μm). SEM images confirmed smoother topography in heat-treated groups. Surface roughness (Rq) also decreased after heat treatment. Hot water rinsing further reduced film thickness without damaging surface smoothness. These findings suggest that heat and rinsing influence silane layer structure and thickness.

The authors concluded that heat treatment after silane application improves silane layer organization. Hot water rinsing removes unreacted silane regions, resulting in thinner films. These findings suggest that controlled heat and rinsing can optimize silane layer properties. The study supports the idea that post-silane treatments influence ceramic surface characteristics. Surface roughness decreased significantly with heat treatment. Ellipsometry confirmed that heat reduces silane film thickness. ATR FT-IR showed chemical changes consistent with silane bonding. SEM imaging supported surface smoothing effects. The results align with the hypothesis that heat and rinsing affect silane layer structure.