ENDODONTIC INSTRUMENTATION

ENDODONTIC INSTRUMENTATION

Introduction:

To achieve the biological objectives of endodontic therapies, a good knowledge of instrumentation and root canal preparation techniques is essential for optimal practice.

Standardization of endodontic instruments:

• At the instigation of Ingle and Levine, the 1958 International Conference on Endodontics in Philadelphia studied the principle of standardizing root canal instruments.
• 4 criteria were retained:
  •  Identity of diameters and shapes for all instruments
  • The choice of the conical shape for all instruments.
  • Uniform progression of diameters for all instruments
  • Shape permanence regardless of the diameter of the instrument. 
• The conclusions of the Philadelphia conference, defining the rules of endodontic standardization were reported by LAURICHESSE and SANTORO. 
  •  A numbering system for channel instruments and obturation cones using numbers from 06 to 140.
  • The numbers corresponding to the diameters of the instruments and cones expressed in hundredths of a millimeter
  • These diameters are measured at their active ends. The diameter of the tip is called D _1, expressed in 100ths ^of mm it gives the number of the instrument
  • From n°10 to n°60 the increase in diameter is made by 5/100 mm
  • From n°60 to n°140 the increase in diameter is made by 10/100 mm
  • A colour identification code is also used internationally:

Instruments for accessing the pulp chamber and locating canal entrances

• 1-ENDO-Z bur:
•  Tungsten carbide cutter.
• Turbine mounted.
• Intended for opening the pulp chamber on multi-rooted patients without risk of damage to the pulp floor thanks to its blunt tip.
• Features a head length of 9mm. 
• 2 – Zekrya-endo bur (MAILLEFER): This is a long cylindrical-conical bur with a blunt tip. This bur allows cameral opening and trepanation and also allows the removal of possible coronal interferences.
• 3-Endo Access: this is a trepanation bur:             
• Made up of a combination of a ball end mill and a conical end mill, it allows the creation of a conical access 
• Allows rapid penetration to the pulp and also opening and preparation of the pulp chamber

Root canal preparation instruments:

• 1-Description of the endodontic instrument:
• An endodontic instrument consists of three parts:
  • The handle : Made of metal or plastic, allows the instrument to be gripped.
  • The handle must bear the indication of the diameter of the instrument and/or be colored according to the ISO color code.
  • The stem : This is the rough outline of the metal wire from which the working part of the instrument is made.
  • The blade: This is the working part of the instrument located in the extension of the instrument. The length of the instrument is fixed at 16mm whatever the total length of the instrument and its diameter.

ENDODONTIC INSTRUMENTATION

2-Classic canal preparation instruments: manuals

• The channel broach or Reamer (  identification symbol: triangle )
• A-Description: It is a standardized instrument, therefore conical,
•  The spindle is the result of the edge twisting of a triangular stainless steel die.
•  The file pitch is long;
• The pyramid ending the file is triangular and pointed.  
• Dynamic  : The classically assigned action is to bring the instrument into contact with the canal walls, perform a slight direct apical push, apply a quarter turn (90°) clockwise rotation and then pull the pin in the coronal direction.

• – The K type file (KERR) (identification symbol: square)
• A/ Description  : it is a standardized instrument obtained by the twisting on edge of a quadrangular matrix of stainless steel. This significant twisting gives the file tight steps.
• B/ Dynamic  : The K file has a scraping action on the dentinal walls, the best efficiency is found in the longitudinal back and forth movements

This file is operated by 45° clockwise and counterclockwise rotations to advance it into fine canals and in the event of interference.

• -The type H file (HEDSTROM) (identification symbol: a circle)
• A/Description  : This is a standardized instrument machined by micro-grinding from a cylindrical metal matrix. It has a constant pitch wood screw profile, which prevents any rotation in the channel under penalty of blockage and fracture. The angle of attack of the blades relative to the major axis of the instrument is 90°, therefore very acute.
• B/Dynamic  :
• the H file works exclusively by pure traction movements; in parietal support.
• Any rotational movement must be avoided under penalty of fracture
• The H file will only be used after passing a K moon or a broach of the same diameter (the H file was developed to compensate for the restricted widening made by the K file).
• -Probes: non-standardized instruments, 
• round or square section (squaring probe or Miller probe).
•  These are very thin and flexible conical instruments.
• Their role is the catheterization of the canals
• -The nerve puller  : or barbed pin (identification symbol: an eight-pointed star), 
• round section,
•  in drawn and work-hardened stainless steel. 
• The barbs are very sharp and are arranged right up to the tip of the instrument. 
• The nerve puller is not standardized, its blade is cylindrical.
• The main action of the nerve puller is to separate the pulp from the canal wall and remove it by tearing (it is used in clockwise rotation of 180° then traction). 
• The nerve puller is also supposed to remove any septic canal contents and debris generated by the action of the files. 
• 3-Classic canal preparation instruments: mechanized

ENDODONTIC INSTRUMENTATION

 -Drill spindle or TORPAN drill:

• It is a spindle blade equipped with a chuck adaptable to a contra-angle or handpiece. This instrument is standardized.
• The drill pin can, according to some authors, perform the preparation of a canal by eliminating its contents and widening its cervical part. 
• -The Giromatic Reamer:
• It is a nerve puller blade equipped with a mandrel adaptable to a GIROMATIC contra-angle, it is not standardized and has the same defects as the nerve puller, its limited indications.

• The Girofile  : or mechanized scraper:
• It is an H file blade equipped with a mandrel for exclusive use against Giromatic angle. It is a standardized instrument;
• -Gates-Glidden drill: Drill with non-working tip, having (03) blades on a short active part of 2.5 to 4.5 mm in length, used on Contra-angle in pure rotation. 
• They are particularly indicated in canal preparation. They also allow the action of round burs to be reached in the cervical third of the canal.
• -LARGO or PEESO drill or widening drill: These are drills whose active part is cylindrical and whose profile is the same as that of Gates-Glidden, but its working part is longer equipped with a blunt tip. This type of drill is useful for clearing the canal orifices in the case of calcified canals.
• -The Beutelrock drill:
• This instrument is available in very fine diameters, it is very flexible. It is an instrument often beneficial in cases of delicate treatment revisions. It is formidable because its tip is very active and engages blindly in the canal walls.
• -LN bur (Maillerfer): It is equipped with a very thin and long neck and a very small caliber round active end. This 28mm long bur allows visual control in the search for a calcified canal orifice. It thus allows the creation of the canal trepanation cavity.

• There are other root canal preparation instruments which are: 
• The K FLEXO-FILE , The Flexo-Reamer, The K-Flex: (D-file), The Sensor file , The MME or (ME in the USA) (Micro-Mega Widener) and the MMC , The Burns Unifile , ‘Hélifile, The Heliapical  , The RISPI , The Dynatrak , The HELIGIRO-Triple Edge: or “Trio cut” 

3-Nickel titanium (NI-TI) instrumentation:

Instrumental profile:

• 1-Instruments with constant taper
  • i-Classification according to blade design
    • -Passive instruments:
• The presence of a radiating flat on passive instruments avoids self-tapping and screwing into the canal.

Ex: profile system

• -Active instruments: 

Their blades are sharp unlike passive instruments which perform surfacing. These cutting instruments have a disadvantage which is the screwing effect which can be avoided by varying the pitch of the turns.

EX: CMA system

2-Variable Taper Instruments

• As opposed to regular taper, where an instrument has a constant and regular increase in diameter, in the concept of variable taper, the taper of the instrument varies across the active blade of the same instrument. 
• So it can be 2% over 1 or 2 mm, then 4% over the following mm, then 7% over a few mm, etc.
• Ex: protaper system 

• -Root obturation instruments:
• 1- Manual instruments
  • A- The crushers:

  1 – Spreaders  : With pointed end => side spreaders.

•  They are intended to condense cold gutta-percha laterally
• These instruments are not standardized and exist in two types of presentation: handle spreaders and finger spreaders. These instruments are conical and thin to be able to descend deep into the canals
• 2- Pluggers  : Flat end => vertical pluggers.

• Are intended to condense gutta-percha vertically softened by the application of heat. These instruments are not standardized. They are equipped with a long handle called “endodontic pluggers”, or short handle called finger pluggers depending on the manufacturer.
• 2- Mechanized or rotating instruments:
• A-Pasta wads:
• These are instruments used to fill the canal with a filling paste . 
• 1- LENTULO pastry filler: pas filer
• Rotating instrument, not standardized, developed by H. Lentulo in 1928. The manufacturing principle results from the twisting of a fine metal wire resulting in regular, flexible and fine “Archimedes screw” turns used in a clockwise direction only on a low-speed contra-angle (3000 to 10000 rpm).
• Available in four diameters; extra fine, fine, medium, coarse and in three lengths; 17mm, 21mm, 25mm.
• 2-The Mac-Spadden compactor
• Standardized metallic rotary instrument, used on a conventional contra-angle intended to obturate root canals by thermomechanical condensation of gutta.
• These are profile instruments resembling an inverted H file mounted on a contra-angle with a blue ring “speed 8000 rpm” allows the gutta to be softened by heating, then pushed back in the apical direction.
• MAC SPADDEN offers a Nickel-Titanium compactor allowing thermomechanical condensation of curved channels.
• 3- Heaters:
• These are spreader-type instruments with handles intended to be heated to soften the gutta. There are instruments whose metal alloy and manufacturing principle are specially designed to slow down heat loss during clinical handling.
• Electric heaters are the most accurate in terms of instrument temperature.
• This is the “Touch’N Heat” system, consisting of a handpiece on which a smooth heater can be displayed, connected to an electric heat source. 
• Gutta-percha guns:
• obtura: It is a syringe that delivers thermoplastic gutta-percha at high temperature, which can be used in clinical situations such as the ascending wave during vertical compaction of hot gutta, indicated for obturation of internal resorptions, immature teeth after apexification.

ENDODONTIC INSTRUMENTATION

• Conclusion:
• To ensure the best possible result, endodontic instruments must be used strictly and they must be integrated into an adequate method.

ENDODONTIC INSTRUMENTATION

  Wisdom teeth can be painful if they are misplaced.
Composite fillings are aesthetic and durable.
Bleeding gums can be a sign of gingivitis.
Orthodontic treatments correct misaligned teeth.
Dental implants provide a permanent solution for missing teeth.
Scaling removes tartar and prevents gum disease.
Good dental hygiene starts with brushing twice a day.
 

ENDODONTIC INSTRUMENTATION