1. Nickel-titanium instruments (NiTi)
1.1. properties
1.1.1. Shape memory effect (ability to return)
1.1.2. Superelasticity (low modulus of elasticity)
1.1.3. Good biocompatibility
1.1.4. High corrosion resistance
1.2. Type
1.2.1. NiTi File
1.2.1.1. angle between the long-axis and the cutting blade is bigger than in reamers
1.2.1.2. preparation by NiTi file is effective both in rotating motion and in filing motion
1.2.1.3. tip of the instrument is non-cutting which makes the NiTiflex-file well suited for the preparation of curved canals
1.2.1.4. Recommended use
1.2.1.4.1. used both in straight canals as well as in curved canals.
1.2.1.4.2. prepares dentin both in filing motion (up and down) and when rotated.
1.2.1.4.3. curved canals the recommended techniques are
1.3. Comparison
1.3.1. Metal
1.3.1.1. Less flexible
1.3.1.1.1. Straightens and transports canal
1.3.2. Nickel-titanium
1.3.2.1. Excellent flexibility
1.3.2.1.1. Conforms to canal curvature
1.4. NiTi (Nickel titanium) rotary instruments
1.4.1. Function, features and directions for use
1.4.1.1. Used to clean and shape the canals
1.4.1.2. Used with endodontic handpiece and motor
1.4.1.3. flexible and instruments follow the canal outline very well
1.5. Multiple Systems
1.5.1. First-generation Systems
1.5.1.1. have passive cutting radial lands,
1.5.1.2. negative rake angles
1.5.1.3. Require numerous files
1.5.2. Second-generation Systems
1.5.2.1. cutting edges and thus require fewer instruments to prepare a root canal .
1.5.2.2. have a tendency to straighten the canal curvature.
1.5.3. Third-generation Systems
1.5.3.1. using heating and cooling
1.5.3.1.1. reducing cyclic fatigue, and improving safety
1.5.3.2. less breakage of files occurred
1.5.3.3. Ex
1.5.3.3.1. M-wire
1.5.3.3.2. R-phase
1.5.4. Fourth-generation Systems
1.5.4.1. single-filetechnique
1.5.4.2. allows a file to progress more readily, cut efficiently,and remove debris from the canale ffectively
1.5.5. Fifth-generation Systems
1.5.5.1. center of mass or the center of rotation,or both are offset.
1.5.5.2. produce a mechanical wave of motion
1.5.5.3. enhances the removal of debris
2. Modification of Intracanal Instruments:
2.1. three major areas of development of new files
2.1.1. metals
2.1.1.1. Increase the file flexibility
2.1.2. design
2.1.2.1. Increase the file flexibility
2.1.2.2. Increase cutting efficiency
2.1.3. tip
3. Instruments for access cavity preparation
3.1. Burs
3.1.1. Friction grip burs
3.1.1.1. tapered or cylindrical fissure burs
3.1.1.2. used in the initial stages of access
3.1.1.3. For penetrating ceramic or composite materials, diamond-coated burs are needed.
3.1.2. Round burs
3.1.2.1. normal and extra-long
3.1.2.2. used to lift the roof off the pulp chamber and eliminate overhanging dentine.
3.1.2.3. Length
3.1.2.3.1. Short (for anterior)
3.1.2.3.2. Long 28 (for posterior)
3.1.2.3.3. longer and smaller sizes of burs may be used to remove dentine when opening calcified canals.
3.1.3. Safe-ended burs
3.1.3.1. initial access to the pulp space
3.1.3.2. tapered diamond or tungsten-carbide bur (e.g. Endo Z bur
3.1.3.3. non-cutting tip prevents ‘gouging’ of the pulpal floor.
3.1.4. Gates-Glidden burs
3.1.4.1. elliptically (flame) shaped
3.1.4.2. made of stainless steel
3.1.4.3. diameter ranging 0.4–1.4 mm (1-6).
3.1.4.4. bur is operated at low-speed.
3.1.4.5. used to
3.1.4.5.1. open the orifice
3.1.4.5.2. achieve straight-line
3.1.4.5.3. retreatment cases, Gates-Glidden
3.1.4.6. used only in the straight sections of the canal.
3.1.5. Peeso-Reamer Drills
3.1.5.1. parallel cutting sides rather than an elliptical shape.
3.1.5.2. improving straight-line access
3.1.5.3. not flexible or adaptable
3.1.5.3.1. used with care can perforate canal
3.2. Orifice Opener
3.2.1. opening into the root canal.
3.2.2. Enlarging the root canal orifice is helpful
3.3. Micro-Openers
3.3.1. for locating canal orifices when a dental dam has not been placed.
3.3.2. enhanced visualization of the pulp chamber.
3.4. Ultrasonics
3.4.1. Uses
3.4.1.1. disassemble restorations
3.4.1.2. uncover hidden or calcified canals!
3.4.1.3. remove canal obstructions
3.4.1.4. post/core removal
3.4.2. Fine ultrasonic tips are smaller than conventional round burs
3.4.2.1. abrasive coatings
3.4.3. exploring for canal orifices.
3.5. Barbed broaches
3.5.1. hacking a round, tapered wire with a blade
3.5.2. Function
3.5.2.1. Removal of pulp tissue from wide root canals
3.5.2.2. Cotton wool dressings from the pulp chamber.
3.5.2.3. Removal of pulp requires a broach that will not bind
4. Basic instruments
4.1. front-surfaced mouth mirror
4.1.1. produces an undistorted image for good visibility deep within the pulp chamber..
4.2. The endodontic explorer
4.2.1. double-ended, extra-long, sharp instrument
4.2.2. help in the location of canal entrances and for detecting fractures.
4.3. Amalgam plugger
4.3.1. placement of an inter- appointment restoration.
4.4. surgical haemostat or forceps
4.4.1. used to position X-ray films, for radiography
4.5. Endodontic ruler
4.5.1. measuring of reamer, file and gutta-percha lengths.
4.6. probe
4.6.1. Briault probe
4.6.1.1. initial assessment of the tooth for caries
4.6.2. Periodontal probe
4.6.2.1. localized periodontal condition
4.7. Locking tweezers
4.7.1. handling paper points, gutta-percha points, cotton wool pellets and root canal instruments.
4.8. long spoon excavator
4.8.1. remove pulpal contents and soft caries
5. Hand-Operated Instruments
5.1. Machined
5.1.1. involves machining (grinding)
5.1.2. instrument directly on a lathe
5.1.3. less rotational resistance to breakage than a ground-twisted file of the same size
5.1.4. example
5.1.4.1. Hedström-type file
5.1.4.1.1. more susceptible to separation when locked and twisted.
5.1.4.2. All nickel-titanium instruments
5.1.4.3. Some manufacturers produce K-type files
5.2. Ground-Twisted
5.2.1. wire is ground into tapered geometric blanks
5.2.1.1. square
5.2.1.2. triangular
5.2.1.3. rhomboid
5.2.2. blanks are then twisted counterclockwise to produce helical cutting edges.
5.2.3. Example
5.2.3.1. K-type file
5.2.3.1.1. have more twists per millimeter of length than the corresponding size of K-type reamer.
5.2.3.2. reamers
5.2.3.2.1. are K-type instruments
5.2.3.2.2. used to ream the canals.
5.2.3.2.3. Cut by twisting clockwise then withdrawing
5.2.3.2.4. Rotation action
5.2.3.2.5. Numbers of flutes in reamer are ½-1/mm
5.2.3.2.6. reamer has fewer numbers of flutes than file
5.2.3.2.7. Recommended use
5.2.3.3. Flexoreamer
5.2.3.3.1. tip of the instrument is non-cutting
5.2.3.3.2. triangular steel wire
5.2.3.3.3. Recommended use
5.3. Files
5.3.1. made from stainless steel.
5.3.1.1. K-file
5.3.1.1.1. square or triangular steel wire.
5.3.1.1.2. have 1½ to 2½ cutting blades
5.3.1.1.3. Disadvantage
5.3.1.1.4. Recommended use
5.3.1.2. Flexofile
5.3.1.2.1. rhomboid shaped steel wire.
5.3.1.2.2. tip of the instrument is non-cutting
5.3.1.2.3. suited for the preparation of evenly curved canals without the risk of ledge formation
5.3.1.2.4. Recommended use
5.3.1.3. Hedström file.
5.3.1.3.1. round steel wire by grinding.
5.3.1.3.2. only when instrument is withdrawn because its edges face the handle of the instrument.
5.3.1.3.3. should be used to machine straight canals
5.3.1.3.4. ADV
5.3.1.3.5. DisADV
5.3.1.3.6. Recommended use