Anatomic Endodontic Technology: Listen to the needs of the tooth

Anatomic Endodontic Technology (AET) is a minimally invasive endodontic preparation system. The evolution of reciprocating AET has advanced the effi ciency and predictability of the enlargement of root canal system. This new advancement utilizes stainless steel shaping fi les to anatomically instrument the coronal and middle third of the tooth, followed by nickel titanium fi les to instrument the critical zone towards the apex. It eliminates or minimizes the degree and types of procedural errors that occur during shaping. Review Article Anatomic Endodontic Technology: Listen to the needs of the tooth E Soujanya*, Chandrakanth Majeti Associate Professor, Department of Conservative Dentistry and Endodontics, University of KNR UHS, Army College of Dental Sciences, India Received: 25 May, 2020 Accepted: 03 June, 2020 Published: 04 June, 2020 *Corresponding author: Dr. E Soujanya, Associate Professor, Department of Conservative Dentistry and Endodontics, University of KNR UHS, Army College of Dental Sciences, India, Tel: +91 9581878168; E-mail:


Introduction
The main objective of root canal therapy is thorough cleaning and shaping of all pulp spaces and its complete obturation with an inert fi lling material. Although successful endodontic therapy depends on many factors, one of the most important steps in any root canal treatment is canal preparation. Root preparation includes mechanical debridement, total elimination of remaining pulp tissue, microorganisms from the root canal system, creation of space for delivery of medicaments, and the creation of optimal canal geometries for adequate obturation [1]. The aim of root canal preparation is to achieve a progressive and uniform conical shape within the canal. However, this may not always be possible in canals that do not have a circular morphology. Latrou (1980) classifi ed root canals based on their crosssectional shape as: laminar or tubular. Laminar canals can be further divided into semi lunar, fi gure of 8 and straight, while tubular canals may be circular, triangular or oval. Variation in canal cross sectional shape & the presence of anatomic irregularities together with canal curvature lead to procedural errors such as ledge, zip, elbow formation, canal transportation and perforation. [2][3][4][5][6].
This anatomical reality demonstrates the need for a reciprocating system that address each canal according to its unique anatomy. Recently, an innovative concept of mechanical root canal preparation, AET, Anatomic Endodontic Technology has been introduced.

Basic concepts of the aet technique
The AET instruments, consistent with the crown-down technique permits a perimetric or circumferential preparation of the coronal and middle canal thirds. The dentin is selectively removed and weakening of the walls of the canal or perforation in those areas where they are thinner is avoided [7][8][9]].

Description of system
The AET technique is composed of shaping fi les, apical fi les and Endo eze handpiece.

Endo-Eze hand piece
The Endo-Eze handpiece is a dedicated handpiece for the Shaping fi les with a 30 º right 30º left reciprocating action. It is possible to vary the insertion depth of the instrument within the head of the handpiece, via a push button collett. Minimal (only 30º) reciprocating motion facilitates rapid, complete, uniform instrumentation of all the walls in an irregularly shaped canal. It has "milling" action rather than the "drilling" action of traditional rotary systems [10] (Figure 3).

Operative procedure
Coronal Phase: In this phase, access opening is done and canal orifi ces are identifi ed. Round and tapered diamond are used to prepare the access cavity; Non end-cutting bur is used to remove the roof of the chamber without damaging the pulpal fl oor and Safe-point diamond bur is used to refi ne the walls without dentine interferences.

Coronal-middle Phase:
In this phase, middle third of canal is prepared along with refi nement of coronal third of root canal. For this , 4 Shaping fi les S1,Sc,S2,S3 and Endo Eze hand piece is used.

Methodology:
Tooth length is determined on diagnostic radiograph; 3mm is subtracted from the obtained measurement. Ex: tooth length in the x-ray = 21 mm -3 mm = 18 mm. Shaping 1 (yellow) oscillating instrument is used to shape the canal to previously determined length, and then Shaping 2 (blue), Shaping 3 (green) is used. The Shaping 1 (yellow) oscillating instrument is inserted manually into the root canal to determine the working length (WL) then it is attached to the handpiece for the shaping of the canal till working length.

Apical phase
Safe NiTi hand instruments are used to achieve the goal of preserving apical curvature and respecting anatomy. Apical Working Length (AWL) is determined by subtracting 0.5 mm from the electronically determined canal length. In most canals, having completed preparation with Shaping fi les, the size 25 hand apical NiTi used in manual rotary motion will easily reach the AWL. If this is not possible, use stainless steel apical fi les with diameters ranging from size 08 up to size 20 and with ¼ turn and withdrawal movements until reaching the AWL with the size 25 Apical NiTi. Continue with the Apical NiTi (size 30, 35, 40, etc.) until reaching the fi nal Diameter of Apical Preparation (DAP); Ethylenediamine tetracetic acid (EDTA) and sodium hypochlorite (NaOCl) should be used as irrigants after each instrumentation.

Conclusion
Anatomic Endodontic Technology is an innovative concept of mechanical root canal preparation. It is an oscillating (reciprocating) instrumentation system, which uses fl exible stainless steel instruments driven by the 4:1 reduction Endo-Eze AET contra-angle handpiece. It offers simplicity, reliability and profi tability and promotes better results with fewer risks regardless of anatomical variations of tooth system.