Análise do desgaste produzido por instrumento mecanizado de niti adaptado para uso manual por meio de um cabo adaptadorendodôntico e por limas manuais de aço inoxidável durante o preparo químico-mecânico

Abstract

INTRODUCTION: The conventional technique for preparing root canals, which uses a sequence of stainless steel hand files, presents some disadvantages, such as difficulty in the face of anatomical complexities due to the mechanical limitations inherent to the alloy which hand files are made. Therefore, the use of instruments with superior mechanical properties, manufactured with heat-treated nickel-titanium (NiTi) alloys, allows for a more predictable endodontic preparation. However, for the use of mechanized NiTi instruments, it is necessary to have an endodontic motor for its activation. The recently launched ED File®adapter is an endodontic handle with a “push button” system that allows the adaptation of any mechanized instrument for application as an instrument manual during the preparation of root canals. OBJECTIVES: The objective of this study was to compare, through a qualitative laboratory study, the wear produced by a mechanized NiTi instrument adapted for manual use through the ED File®adapter cable and by manual stainless steel files, during chemical-mechanical preparation of simulated root canals. METHODOLOGY: 10 students were selected, who were not known to have contact with Endodontics. Two artificial teeth, with access surgery previously performed, were given to the students, so that they could prepare the root canals with each of the instruments. For the artificial tooth prepared with stainless steel files, type K files and the conventional instrumentation technique (TCI), “step-back” were used. For preparation with NiTi mechanized instrument adapted with ED File®, ProDesign Logic® instrument # 35. /05 was used and a technique of “Controlled Cutting Force” (FCC), “crown down”. The teeth were radiographed before and before preparation for the qualitative analysis. RESULTS: Radiographic differences were observed regarding the wear produced by the two types of instruments. A higher level of apical transport and loss of working length was observed in the canals prepared with stainless steel hand files. CONCLUSION: The wear promoted with the manual use of a mechanized NiTi instrument reflected many advantages, which strengthens the idea of its incorporation in endodontic treatments as an option to conventional manual preparation with stainless steel files. The ED File® adapter cable adapts to mechanized NiTi instruments for manual root canal preparation.