Jorge N R Martins1,2,3, Emmanuel João Nogueira Leal Silva4,5, Duarte Marques6,7,8,9, Felipe Gonçalves Belladonna5, Marco Simões-Carvalho5, Rui Pereira da Costa6, António Ginjeira6,7, Francisco Manuel Braz Fernandes10, Marco Aurélio Versiani11. 1. Faculdade de Medicina Dentária, Universidade de Lisboa, Cidade Universitária, 1649-003, Lisbon, Portugal. jnr_martins@yahoo.com.br. 2. Grupo de Investigação Em Bioquimica E Biologia Oral, Faculdade de Medicina Dentária, Unidade de Investigação Em Ciências Orais E Biomédicas (UICOB), Universidade de Lisboa, Lisbon, Portugal. jnr_martins@yahoo.com.br. 3. Centro de Estudo de Medicina Dentária Baseada Na Evidência (CEMDBE) - Cochrane Portugal, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal. jnr_martins@yahoo.com.br. 4. Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil. 5. Department of Endodontics, Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil. 6. Faculdade de Medicina Dentária, Universidade de Lisboa, Cidade Universitária, 1649-003, Lisbon, Portugal. 7. Grupo de Investigação Em Bioquimica E Biologia Oral, Faculdade de Medicina Dentária, Unidade de Investigação Em Ciências Orais E Biomédicas (UICOB), Universidade de Lisboa, Lisbon, Portugal. 8. Centro de Estudo de Medicina Dentária Baseada Na Evidência (CEMDBE) - Cochrane Portugal, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal. 9. LIBPhys-FCT UID/FIS/04559/2013, Lisbon, Portugal. 10. CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica, Portugal. 11. Dental Specialty Center, Brazilian Military Police, Belo Horizonte, Minas Gerais, Brazil.
Abstract
OBJECTIVES: To compare the design, metallurgy, mechanical performance, and canal preparation of 5 rotary systems. MATERIAL AND METHODS: A total of 735 25-mm NiTi instruments (sizes 0.17[0.18]/.02v, 0.20/.04v, 0.20/.07v, 0.25/.08v, 0.30/.09v) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-File systems were compared regarding overall geometry and surface finishing (stereomicroscopy and scanning electron microscopy), nickel and titanium ratio (energy-dispersive spectroscopy), phase transformation temperatures (differential scanning calorimetry), mechanical performance (torsional and bending tests), and unprepared canal surface (micro-CT). One-way ANOVA and Mood's median tests were used for statistical comparisons with a significance level set at 5%. RESULTS: Stereomicroscopic analysis showed more spirals and high helical angles in the Premium Taper Gold system. All sets of instruments had symmetrical spirals, no radial lands, no major defects, and an almost equiatomic ratio between nickel and titanium elements, while differences were observed in their tips' geometry and surface finishing. At room temperature (20 °C), DSC test revealed martensitic characteristics for ProTaper Gold and Go-Taper Flex, and mixed austenite plus R-phase for the Premium Taper Gold, while ProTaper Universal and U-Files had full austenitic characteristics. Overall, larger instruments had higher torque resistance and bending load values than smaller ones, while a lack of consistency and mixed values were observed in the angle of rotation. The 0.25/.08v and 0.30/.09v instruments of ProTaper Universal and U-File had the highest maximum torques, the lowest angles of rotation, and the highest bending loads than other tested systems (P < .05). No significant difference was noted regarding the untouched root canal walls after preparation with the tested systems (P > .05). CONCLUSIONS: Although differences observed in the overall geometry and phase transformation temperatures have influenced the results of mechanical tests, unprepared canal surface areas were equivalent among systems. CLINICAL RELEVANCE: Root canal preparation systems with similar geometries might present different mechanical behaviors but equivalent shaping ability.
OBJECTIVES: To compare the design, metallurgy, mechanical performance, and canal preparation of 5 rotary systems. MATERIAL AND METHODS: A total of 735 25-mm NiTi instruments (sizes 0.17[0.18]/.02v, 0.20/.04v, 0.20/.07v, 0.25/.08v, 0.30/.09v) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-File systems were compared regarding overall geometry and surface finishing (stereomicroscopy and scanning electron microscopy), nickel and titanium ratio (energy-dispersive spectroscopy), phase transformation temperatures (differential scanning calorimetry), mechanical performance (torsional and bending tests), and unprepared canal surface (micro-CT). One-way ANOVA and Mood's median tests were used for statistical comparisons with a significance level set at 5%. RESULTS: Stereomicroscopic analysis showed more spirals and high helical angles in the Premium Taper Gold system. All sets of instruments had symmetrical spirals, no radial lands, no major defects, and an almost equiatomic ratio between nickel and titanium elements, while differences were observed in their tips' geometry and surface finishing. At room temperature (20 °C), DSC test revealed martensitic characteristics for ProTaper Gold and Go-Taper Flex, and mixed austenite plus R-phase for the Premium Taper Gold, while ProTaper Universal and U-Files had full austenitic characteristics. Overall, larger instruments had higher torque resistance and bending load values than smaller ones, while a lack of consistency and mixed values were observed in the angle of rotation. The 0.25/.08v and 0.30/.09v instruments of ProTaper Universal and U-File had the highest maximum torques, the lowest angles of rotation, and the highest bending loads than other tested systems (P < .05). No significant difference was noted regarding the untouched root canal walls after preparation with the tested systems (P > .05). CONCLUSIONS: Although differences observed in the overall geometry and phase transformation temperatures have influenced the results of mechanical tests, unprepared canal surface areas were equivalent among systems. CLINICAL RELEVANCE: Root canal preparation systems with similar geometries might present different mechanical behaviors but equivalent shaping ability.
Authors: Emmanuel J N L Silva; Jorge N R Martins; Natasha C Ajuz; Henrique S Antunes; Victor T L Vieira; Francisco M Braz Fernandes; Felipe G Belladonna; Marco A Versiani Journal: Materials (Basel) Date: 2022-07-31 Impact factor: 3.748