RESUMO
Introduction: Irregularities and defects on NiTi endodontic instruments originating from the manufacturing process can lead to the structural collapse and fracture of these instruments during treatment. To assess the cause of instrument wear and fracture, as well as increasing fracture incidence, destructive and non-destructive methods have been used for the analysis of surfaces and internal structures of new and used NiTi instruments. The aim of this systematic review was to undertake a detailed analysis of the methods used to evaluate the surface and internal microstructure of endodontic instruments. Methods and Materials: The scientific literature was comprehensively and systematically searched in the MEDLINE (PubMed), Web of Science, Cochrane Library, Scopus, and LILACS/BBO databases for studies published up to June 9, 2019. The eligibility criteria was based on the PICO (Patient, Intervention, Comparison, and Outcome) strategy with the question "What is the best method for structural analysis of endodontic files?" Two aspects were considered for inclusion in this study: (i) endodontic instruments and (ii) methods for structural analysis of NiTi instruments. . The systematic review was performed according to the PRISMA statement. Results: Based on the inclusion criteria, 94 articles were selected. The results showed that although specific methods have been used for qualitative and/or quantitative structural analysis of NiTi instruments, no study addressed both the surface and internal structure of the instruments at the same time. According to this review, the need to compare the methodologies used in the selected articles has been identified; however, each type of method used has its own limitation on the analysis of both the surface and the internal structure of the instruments. Conclusions: The comparison between the different types of methodologies used in the studies revealed the reliability and the limitations of the methods employed for structural analysis of endodontic instruments; thus assisting us in determining their validity.
RESUMO
The aim of this study was to undertake a qualitative and quantitative assessment of nanoscale alterations and wear on the surfaces of nickel-titanium (NiTi) endodontic instruments, before and after use, through a high-resolution, noncontact, three-dimensional optical profiler, and to verify the accuracy of the evaluation method. Cutting blade surfaces of two different brands of NiTi endodontic instruments, Reciproc R25 (n = 5) and WaveOne Primary (n = 5), were examined and compared before and after two uses in simulated root canals made in clear resin blocks. The analyses were performed on three-dimensional images which were obtained from surface areas measuring 211 × 211 µm, located 3 mm from their tips. The quantitative evaluation of the samples was conducted before and after the first and second usage, by the recordings of three amplitude parameters. The data were subjected to statistical analysis at a 5% level of significance. The results revealed statistically significant increases in the surface wear of both instruments groups after the second use. The presence of irregularities was found on the surface topography of all the instruments, before and after use. Regardless of the evaluation stage, most of the defects were observed in the WaveOne instruments. The three-dimensional technique was suitable and effective for the accurate investigation of the same surfaces of the instruments in different periods of time.
Assuntos
Endodontia/instrumentação , Níquel/química , Preparo de Canal Radicular/instrumentação , Titânio/química , Desenho de Equipamento , Humanos , Imageamento Tridimensional/métodos , Interferometria/métodos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Propriedades de Superfície , Fatores de TempoRESUMO
Abstract The aim of this study was to undertake a qualitative and quantitative assessment of nanoscale alterations and wear on the surfaces of nickel-titanium (NiTi) endodontic instruments, before and after use, through a high-resolution, noncontact, three-dimensional optical profiler, and to verify the accuracy of the evaluation method. Cutting blade surfaces of two different brands of NiTi endodontic instruments, Reciproc R25 (n = 5) and WaveOne Primary (n = 5), were examined and compared before and after two uses in simulated root canals made in clear resin blocks. The analyses were performed on three-dimensional images which were obtained from surface areas measuring 211 × 211 µm, located 3 mm from their tips. The quantitative evaluation of the samples was conducted before and after the first and second usage, by the recordings of three amplitude parameters. The data were subjected to statistical analysis at a 5% level of significance. The results revealed statistically significant increases in the surface wear of both instruments groups after the second use. The presence of irregularities was found on the surface topography of all the instruments, before and after use. Regardless of the evaluation stage, most of the defects were observed in the WaveOne instruments. The three-dimensional technique was suitable and effective for the accurate investigation of the same surfaces of the instruments in different periods of time.