Comparison of quality, material extrusion and preparation time between a new heat-treated nickel-titanium manual instrument and stainless steel manual instrument and the rotating system

• Grant number: 21/07327-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): January 01, 2022
• Effective date (End): December 31, 2022
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Marco Antonio Hungaro Duarte
• Grantee: Raquel Molina Sanches
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The biomechanical preparation of root canals is the step that seeks to clean and antisepsis the canal system. The advent of nickel-titanium instruments favored a safer preparation and better taper characteristics, and also provided the development of mechanized instruments. However, many professionals and undergraduate courses do not have engines. A new nickel-titanium hand file has been developed and is being marketed and features the possibility of working with it in a full clockwise rotation. The aim of this study will be to compare the quality of the preparation, the material extrusion and the time required during the entire preparation. For this, 60 prototyped mandibular incisors will be used. The teeth will be opened, a Glide Path will be performed with a K10 file and then they will be scanned in a SkyScan 1174 microtomography. The initial volume will be measured and the teeth will be divided into 4 groups of 15 teeth: Group 1: Manual preparation by modified Oregon technique adopting as memory instrument, instrument 40. Group 2: Preparation with Logic 2 system using Progressive technique up to instrument 40/05; Group 3: Preparation with Progressive file up to 40/.05 diameter, Group4: Preparation with SMF up to 40/.04 instrument The teeth will be mounted in an Eppendorf with the cut end and with a filter paper that will be weighed beforehand. The teeth will be instrumented and the time required during the entire preparation of each tooth will be timed. Between one step and another, 5mL of 2.5% sodium hypochlorite will be used. At the end of the preparation, the teeth will be removed from the apparatus, the filter paper will be placed in an oven at 370C, and then weighed again. Teeth will be rescanned. The volume of post preparation, the wall thickness, and the centralization of the preparation will be measured. Data will be compared statistically.(AU)