Microtomographic evaluation of the biomechanical preparation of flattened and curved root canals with heat-treated instruments

• Grant number: 23/04113-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2023
• End date: July 31, 2024
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Jardel Francisco Mazzi Chaves
• Grantee: Julia Godoi Lopes
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The biomechanical preparation of the root canal is one of the most critical and challenging steps in endodontics due to the anatomical complexity of the canals and the anatomical variations found in each tooth. Over the years, various techniques and technologies have been developed to facilitate this step and improve treatment outcomes. However, many of these techniques have limitations in their ability to access the entire length of the root canal, leaving inaccessible areas untreated. With the advancement of technology, rotary and reciprocating instruments were developed to facilitate the preparation of the root canal, allowing greater predictability in the treatment with a significant reduction of errors. Based on this, this study aims to evaluate two-dimensional and three-dimensional changes in the morphological parameters of the root canal after different instrumentation systems, using computed microtomography. For this, 40 mandibular molars will be distributed into four experimental groups (n=10) through stratified sampling according to the instrumentation system used: ProTaper Next System (06/25), ProTaper Ultimate (08/25), 2Shape (08/25) and Reciproc Blue (08/25). The specimens will be scanned in Micro-CT before and after instrumentation, allowing the evaluation of the two-dimensional (area, perimeter, roundness, major and minor diameter) and three-dimensional (volume, surface area, 3D geometry and centering) morphometric parameters of the canals roots. Furthermore, the percentage of prepared and unprepared root canals will be analyzed, as well as the dentin thickness. Additionally, the DataViewer software will allow, through superimposed three-dimensional models, the qualitative evaluation of the formation of the apical stop and the quality of the touched walls of the root canal after the instrumentation in the program CTVol v.2.3.2 (BrukermicroCT).