Page 7 - SPEMD_62-1

Revista Portuguesa de Estomatologia,
Medicina Dentária e Cirurgia Maxilofacial

rev port estomatol med dent cir maxilofac. 2021;62(1):1-8

Original Research

Comparison of geometric design, metallurgical
features and mechanical behavior of ProTaper Gold SX

and two replica-like instruments

d,e
Jorge N.R. Martins a,b,c , Emmanuel J.N.L. Silva , Duarte Marques c,f,g ,
f,i
f,h
Sofia Arantes-Oliveira , João Caramês , Marco Aurélio Versiani j
a Department of Endodontics, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisboa, Portugal
b Unidade de Investigação em Ciências Orais e Biomédicas (UICOB), Faculdade de Medicina Dentária, Universidade de Lisboa, Portugal
c Centro de Estudo de Medicina Dentária Baseada na Evidência (CEMDBE), Faculdade de Medicina Dentária, Universidade de Lisboa, Portugal
d Department of Endodontics, School of Dentistry, Grande Rio University (UNIGRANRIO), Rio de Janeiro, Rio de Janeiro, Brazil
e Department of Endodontics, Fluminense Federal University, Niteroi, Rio de Janeiro, Brazil
f LIBPhys-FCT UID/FIS/04559/2013, Lisboa, Portugal
g Prosthodontics Postgraduation Department, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisboa, Portugal
h Faculdade de Medicina Dentária, Universidade de Lisboa, Lisboa, Portugal
i Department of Oral Implantology, Faculdade de Medicina Dentária, Universidade de Lisboa, Lisboa, Portugal
j Dental Specialty Center, Brazilian Military Police, Minas Gerais, Brazil

a r t i c l e i n f o a b s t r a c t

Article history: Objectives: To assess the characteristics, performance, and safety of ProTaper Gold SX (PTG
Received 10 September 2020 SX) replica-like instruments.
Accepted 1 December 2020 Methods: A multimethod research involving the assessment of geometric design (macro and
Available online 22 January 2021 through scanning electron microscope), Ti/Ni proportions (energy-dispersive X-ray spectros-
copy), phase transformation temperatures (differential scanning calorimetry), torsional re-
Keywords: sistance, and flexibility was conducted to compare two SX replica-like instruments (Premi-
Differential scanning calorimetry um Taper Gold and Go-Taper Flex) with the original PTG SX. Results were compared using
Energy dispersive x-ray spectroscopy one-way ANOVA with post hoc Tukey or Kruskal-Wallis tests according to gaussian or
Mechanical stress non-gaussian distribution (Shapiro-Wilk test). The significance level was set at 0.05.
Nickel-titanium alloy Results: The three SX instruments have nine cutting blades with helix angles of approxi-
Torsional force mately 21º, symmetrical blade geometry without radial lands, a convex triangular cross-sec-
tion design, and near equiatomic Ti/Ni atomic proportions. Design differences were ob-
served at the tip geometry and surface finishing, which was smoother in the Premium
Taper Gold and irregular in the Go-Taper Flex. Distinct R-phase start (Rs) and finish (Rf)
phase transformation temperatures were noted between PTG (Rs ~48ºC and Rf ~30ºC),
Go-Taper Flex (Rs ~43ºC and Rf ~25ºC), and Premium Taper Gold (Rs ~30ºC and Rf ~15ºC). In
the mechanical tests, Go-Taper Flex presented lower maximum torque (mean 0.5 N.cm)
and higher bending resistance (mean 582.2 gf) (less flexibility) than PTG (means 0.8 N.cm

* Corresponding author.
E-mail address: jnr_martins@yahoo.com.br (Jorge N.R. Martins).
http://doi.org/10.24873/j.rpemd.2021.01.817
1646-2890/© 2021 Sociedade Portuguesa de Estomatologia e Medicina Dentária. Published by SPEMD.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).