Effects of different films (SiOx, SiOxCyHz, and SiOx-SiOxCyHz) applied by plasma-enhanced chemical vapor deposition on the optical and structural characteristics of resin matrix ceramics under different aging conditions

• Grant number: 25/05480-8
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2025
• End date: August 31, 2027
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Aldiéris Alves Pesqueira
• Grantee: Victor Alves Nascimento
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Resin matrix ceramics for CAD/CAM have surface treatment through mechanical polishing with silicone tips to ensure a smooth and polished surface, preventing issues such as microorganism adhesion, cavities, wear on the antagonist tooth, color changes, and inadequate light reflection. An innovative and promising alternative for surface treatment of dental materials is plasma-enhanced chemical vapor deposition (PECVD). The development of more efficient films, with higher corrosion resistance and stability, is an important step to improve the durability and performance of dental ceramics. The application of bilayer systems, such as silica and organosilicon, offers a promising solution for surface protection and enhancement of barrier properties, allowing more effective control over chromatic stability and wear resistance. This study aims to evaluate two resin matrix ceramics: a nanoceramic resin (Cerasmart - GC) and a zirconia and silica ceramic in an interpenetrating resin matrix (SHOFU HC - Shofu Dental), after surface treatments consisting of mechanical polishing (using the Ceramisté polishing kit - Shofu), followed by film deposition via PECVD (a layer of silica (SiOx) or an organosilicon layer (SiOxCyHz), or a bilayer system combining silica and organosilicon layers (SiOx/SiOxCyHz)), and to investigate the effectiveness of this treatment on the structural and optical properties of resin matrix ceramics subjected to different in vitro aging conditions. The study is divided into two main areas of analysis: 1) Physicochemical characterization of resin matrix ceramics after surface treatments through the quantification of layer thickness (EC), molecular structure analysis (EMC), scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS); and 2) Evaluation of the structural and optical characteristics of these ceramics and their surface treatments subjected to different in vitro aging procedures, including thermocycling combined with immersion in a dye solution (TC + I), erosive challenge with HCl combined with immersion in a dye solution (DE + I), or simulated brushing combined with immersion in a dye solution (ES + I). Structural analyses will be performed by evaluating surface roughness (Ra), microhardness (VHN), and surface free energy (ELS). Optical characteristics will be assessed through color change (¿E00), translucency (TP), and contrast (CR). Analysis times will be at two levels: T1 - after 24 hours of storage in distilled water (control), and T2 - after in vitro aging procedures (TC+I, DE+I, or ES+I). In statistical analysis, in vitro aging procedures (TC+I, DE+I, or ES+I) will be compared independently, i.e., not against each other. The data obtained in each analysis will undergo normality testing and subsequently be subjected to the most appropriate statistical test, with a significance level of 5%. (AU)