Knoop microhardness test on polymers used in the manufacture of surgical guides after the disinfection process

• Grant number: 23/16979-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2024
• End date: February 28, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Guilherme de Siqueira Ferreira Anzaloni Saavedra
• Grantee: Beatriz Cristina de Paulo
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Guided surgery for implant installation consists of virtual planning of the ideal position of the implant in the mouth, planning is carried out using computed tomography associated with intraoral scanners. Using software, it is possible to develop a guide for a more precise and safe installation, when compared to conventional surgery. The surgical guide is obtained through additive manufacturing with liquid resin. During implant installation, the surgical guide comes into contact with the patient's blood and saliva, requiring prior disinfection or sterilization. Previous studies demonstrate that the disinfection and sterilization process can negatively affect the mechanical properties of the polymers used to manufacture the guides. This study aims to analyze the knoop microhardness of samples of the polymer dima® Print Surgical Guide & Tray (Kulzer GmbH, Hanau, Germany) after disinfection methods in different methods. 50 bar-shaped specimens will be designed and printed, which will be oriented diagonally at an angle of 45 degrees in relation to the main axis, on a 3D printer using the DLP method, where they will be separated into 5 groups: C (Control ), AP (Disinfection with 0.2% peracetic acid), CLX (Disinfection with 2% chlorhexidine), EA (Sterilized in autoclave) and AL (Disinfection with 70% alcohol). Three microindentations will be made on the surface of each specimen, where a load of 25g (c) will be used with a residence time of 30s. The microhardness of the surfaces will be measured using a hardness tester model HMV-G21DT (Shimadzu Corporation, Kyoto, Japan).