In these years, different kind of rotary instruments were created for root canal shaping. The aim of using these instruments was to create a correct tapered shaped canal in order to respect the original canal anatomy and avoid canal transportation, ledge formation and perforations. Rotary instruments can be of different wire: Nichel Titanium, M-Wire, Gold-wire.
Which is the best between these?
The study published in the Journal of Endodontics by Van Der Vyver et al tried to answer this question. In fact, the aim of this study was to was to evaluate the root canal shaping effect of instruments manufactured from nickel titanium, M-Wire, and Gold wire with different glide path preparation techniques
MATERIALS AND METHODS
135 mesiobuccal canals of extracted human maxillary molars were randomly divided into 3 equal groups (N = 45) for glide path preparation with K-files (KF) (Dentsply Sirona, Ballaigues, Switzerland), One G (OG) files (Micro-Mega, Besanc ̧on, France), and ProGlider (PG) files (Dentsply Sirona). Specimens of each glide path group were further divided equally into 3 groups for instrumentation with ProTaper Next (PTN, Dentsply Sirona), One Shape (OS, Micro-Mega), and WaveOne Gold (WOG, Dentsply Sirona) systems (n = 15). Micro–computed tomographic imaging was used to scan teeth before instrumentation and after shaping to compare centering ratio and canal transportation values at the apical, midroot, and coronal levels and the overall changes in canal volume. Data sets were statistically analyzed (analysis of variance and Kruskal-Wallis H tests).
Apical canal transportation was recorded, in particular, in the groups with the combination of K-file plus One Shape (K+OS) and K-file plus Protaper Next (K+PTN) (P = .003).
Mid-root canal transportation was recorded in groups with the combination of: K-file plus Protaper Next (K+PTN), K-file plus One Shape (K+OS), and One G plus One Shape (OG+OS) (P = .0003).
Coronal canal transportation was recorded in groups with the combination of: k-file plus protaper next (K+PTN) and k-file plus One Shape (K+OS) (P = .011). The lowest canal volume changing was recorded in the group with the combination of Proglider and WaveOne Gold (PG+WOG); the highest in the groups with Protaper Next (PTN).
Proglider with the WaveOne Gold can guarantee the best preservation of root canal structure and volume during the shaping. This isn’t the same when we use K-file with nickel titanium instruments or M-wire instruments, which remove more dentin from the canal walls.