Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2018-03-06, 08:52:14 | version 1.38.0
| industry report Mastering flare preparations with One Flare Description of a new thermally treated instrument that simplifies access to the apex Dr Franck Diemer, France; Dr Jean-Philippe Mallet, France; Haifa Ben-Rejeb, Tunisia & Dr Walid Nehme, Lebanon For more than 20 years, the use of nickel-titanium (NiTi) in endodontics has allowed the speed, quality and repro- ducibility of root canal therapy to be improved. Over the same period, the geometry of the relevant instruments has evolved significantly too. In 2008, the appearance of the asymmetrical cross section with Revo-S1 (MICRO-MEGA) allowed for fewer restrictions2 and the cleaning capacity of endodontic instruments to be improved. MICRO-MEGA’s mastering of NiTi machining and changes in cross sec- tion and surface treatments (electropolishing and thermal treatment) have created a new instrument dedicated to enlarging root canal entrances. The corono-radicular junction sometimes produces a particular form of mineralisation that partially obstructs root canal entrances. To give an example, sometimes this trian- gular mineralisation, at the level of the root canal entrances to the molars, is located opposite the furcation (Fig. 1). In order to prevent it from limiting the use of files and to op- timise initial preparation for endodontic treatment, it must be removed (Fig. 2). Generic instruments such as Gates– Glidden or Largo drills have been used for this purpose, but they present a risk of effecting major changes to the root canal anatomy, particularly in the case of the endodontic treatment of multirooted teeth.3 This challenge was the rea- son for the development of specific instruments such as ENDOFLARE (MICRO-MEGA) and ProTaper Universal SX (DENTSPLY, now Dentsply Sirona). A new generation of these files, whose design has benefited from advanced technologies related to asymmetry, cross section and thermal treatment, is now available in the form of MICRO- MEGA’s One Flare. At only 17 mm, One Flare is relatively short in order to be able to work at the root canal entrance at the corono-ra- dicular junction. It features a triple-helix cross section, which has been found to be one of the sturdiest among those that are currently used in clinical practice. Like the one of Revo-S or One Shape (MICRO-MEGA), this cross section is asymmetrical, but with a progression from the tip to the shaft for optimised flexibility. One Flare has a constant cone taper of 9 % and a tip diameter of 0.25 mm. This tip gives the file extraordinary strength while remain- ing sufficiently thin to be able to easily penetrate after a scouting file. The sharpened section of the instrument (13 mm) is made from NiTi wire with a diameter of 1 mm. The ac- tive section therefore varies from 0.25 to 1 mm, from the tip to the shaft, while the interval and angle of the helix increase. It also undergoes electropolishing treatment to remove machining burrs and give it a smooth surface and straight cutting edges without any snags, as well as thermal treatment to increase its flexibility and resis- tance to fracture (Figs. 3a & b). This treatment proves particularly significant when enlarging the entrance to a second mesiobuccal canal in the maxillary molar, for example. The great flexibility also makes it possible to enter ex- tremely curved canals or ones with extreme changes of direction, all without any risk of fracturing the tip or of creating blockages or stops. The geometry of and treat- ments used in the production of One Flare allow it to be used with a motor, with or without torque control, and continuous rotation of between 250 and 400 rpm, without pressure or with very low apical pressure. After the initial scouting and securing using a hand file with a tip diameter of 0.1 mm or a continuous-rotation NiTi instrument such as One G (MICRO-MEGA), One Flare prepares the area of the corono-radicular junction. The instrument uses a conventional wave movement in three successive phases, from the crown to the tip, centred in the canal and allowing it to progress by a few millimetres. After treatment, the file is withdrawn from the canal and 18 roots 1 2018