Effect of heating, build platform size, and printing speed on the physicochemical properties of 3D-printed composite resin restorations

• Grant number: 25/04024-9
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: August 04, 2025
• End date: February 03, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Américo Bortolazzo Correr
• Grantee: Ulysses de Toledo Monteiro
• Supervisor: Mateus Garcia Rocha
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
• Institution abroad: University of Florida, Gainesville (UF), United States
• Associated to the scholarship: 24/14671-9 - Effect of heating, build platform size and printing speed on the flexural strength, degree of conversion and accuracy of 3D-printed composite resin crowns, BP.MS

Abstract

The integration of 3D printing in dentistry offers significant advantages, enabling the fabrication of diverse products, including indirect restorations, with reduced time and cost. However, challenges such as increased viscosity in 3D printing resins with fillers impact the accuracy and reliability of printed restorations. Factors such as platform size, heating, and printing speed are critical for optimizing the properties of these materials. This study will evaluate the effect of heating, build platform size, and printing speed on the flexural strength, viscosity, degree of conversion, dimensional accuracy and printing layer thickness of composite resin 3D-printed crowns. To achieve these objectives, the study will be divided into two phases. In Phase 1, a full crown will be digitally designed using the Dental CAD 3.2 software (Exocad, Germany) based on the scan of a prepared molar from a mannequin. The crowns will be 3D printed using a composite resin in an LCD vat photopolymerization printer on two printing platforms (original platform (OP) and reduced platform (RP)) and at three temperatures (25°C, 37°C, and 50°C). The dimensional accuracy of the crowns will be calculated by comparing samples (n=10) with the original digital design. Flexural strength (n=30) will be evaluated according to ISO4049 and data will be analyzed using the Weibull distribution. Viscosity will be assessed using a controlled-stress rheometer and the degree of conversion (n=5) will be assessed using FTIR. In Phase 2, the effect of printing speed on the accuracy of 3D-printed crowns will be investigated. Three printing speeds will be evaluated (n=10): Standard Speed (SS) (crowns printed at 180 mm/m), Fast Speed (FS) (crowns printed at 225 mm/m), and Boost Speed (BS) (crowns printed at 270 mm/m). Printing layer thickness will be measured by optical microscopy. All data will be subjected to the Shapiro-Wilk and Levene tests and analyzed using appropriate statistical methods (¿=0.05). The expected results are to determine optimal parameterizations of heating, platform size, and printing speed to enhance the clinical manufacturing of 3D-printed indirect restorations by maintaining or optimizing their physicochemical properties and reducing time and cost in their fabrication process.