Root Canal Enlarging Instruments PDF

Root Canal Enlarging Instruments BDS8130 Date : xx / xx / xxxx Aims: The educational aims of this lecture are to detail different instruments available for root canal enlargement. Objectives: On completion of this lecture, the student should have an understanding of how to use different instrume...

Root Canal Enlarging Instruments BDS8130 Date : xx / xx / xxxx Aims: The educational aims of this lecture are to detail different instruments available for root canal enlargement. Objectives: On completion of this lecture, the student should have an understanding of how to use different instruments to enlarge root canals, their indications and advantages and disadvantages of each Pulp Extirpating Instruments Barbed broach (Extirpation = removal of vital pulp) Root Canal Enlarging Instruments Root Canal Enlarging Instruments Root Canal Enlarging Instruments Material Of Construction Technique Of Manufacturing Power Source Diamond Points Stainless steel 1-Material of construction Specially treated Stainless steel Nickel Titanium 2-Power source: Hand driven Engine driven Hand driven (rotary or vibratory) 3-Technique Of Manufacturing: Counter clockwise twisting Incision & elevation Machine grinding R file OR e.g. K File, Reamer OR e.g. H File, NiTi Rotary instruments e.g. R File Root canal Enlarging Instruments can be divided into 3 groups: Group I: Hand operated e.g. broaches, Files, Reamer. Group II: Low speed instruments eg. Gates Glidden drills (GG) & Peeso reamers Group III: Engine driven (similar to hand operated instruments, but the handle is replaced for a latch type) eg. NiTi rotary instruments. Hand Enlarging Instruments (Basic instruments) Reamers Files H-files K- files 1- K-Reamer: 1- Material: Stainless Steel 2-Manufacturing: Counterclockwise twisting 3-Cross Section: Triangle 4-Flutes: Widely separated (0.5-1 flute/mm) 1- K-Reamer: 5- Flexiblility Flexible 6-Cutting efficiency: 7- Helical angle: Low 8-Motion: Reaming motion in apical part insertion,rotation & retraction 20° Helical angle Helical angle: The angle formed between the cutting edge & the long axis of the instrument. Steeper Helical angle Less steep Helical angle 2- K-file: C.S 1- Material: Stainless Steel 2- Manufacturing: Counterclockwise twisting 3-Cross Section: Square 4-Flutes: Close to each other (1.5-2 flutes/mm) 2- K-file: 5- Flexiblility Less Flexible 6-Cutting efficiency: High 7- Helical angle: 40° 8- Motion: Reaming and filing All parts of the canal (Universal File) 1- Material: 2- Manufacturing: 3-Cross Section: 4-Flutes: 5- Flexiblility 6-Cutting efficiency: 7- Helical angle 8-Motion: K- Reamers K-Files Stainless steel Stainless steel Counterclockwise twisting Counterclockwise twisting Triangle Square Widely separated (0.5-1 flute/mm) Close to each other (1.5-2 flutes/mm) Flexible Less flexible Low High 20° 40° Reaming motion in apical part Reaming and filing . All parts of the canal (Universal file) 3- H-File: 1- Material: Stainless Steel 2- Manufacturing: Machine grinding Machine grinding C.S 3-Cross Section: 4-Flutes: Comma shaped Several cones above each other 5- Flexibility: More flexible 6-Cutting efficiency: Most aggressive 7- Helical angle: Close to 90° 7-Motion: Filing motion Coronal 2/3 (No rotation) Helical angle 4-ISO STANDARDIZATION • • • • • • • 1- Length of the instrument. 2- Instrument taper. 3-Numbering of the instrument. 4- Incremental increase in size. 5- Colour coding. 6- Tip angle. 7- Tolerance (quality control). Cross section Shaft Working Part Handle Rubber stopper 1-Length of the Instrument : Working part D16 16 mm 25 mm (21, 31mm) Handle D0 D0 21 mm 31 mm 25mm 2- Instrument Taper: Is usually expressed as the amount the file diameter increases each millimeter along its working surface from the tip toward the file handle. The file diameter increases at standard rate of 0.02mm diameter/mm. Taper 2% (0.02 mm/mm Diameter at 16 mm Tip Diameter (mm) D16 more than D0 by 0.32mm D16 – D0 Length of working part 0.32 = 16mm = 0.02 mm/ mm length 3-Numbering of the instrument: Number (Size) Tip Diameter (mm) Colour code Shaft Working part 4-Colour Coding: Size 15 20 25 30 35 40 Color White Yellow Red Blue Green Black Size Color Whit e Yellow Red Blue Green Black The colors of the handles of instruments were standardized for easy manipulation to be as follow: 6 8 Gray. Pink. 15 45 90 White 20 50 100 Yellow 25 55 110 Red 30 60 120 Blue 35 70 130 40 80 140 Green Black 10 purple. 5-Incremental increase in size: 21 Instruments There’s 50 microns ( 0.05 mm ) increase in size from one instrument to the next one There is 100 microns ( 0.1 mm ) increase in size from one instrument to the next one. There is 20 microns ( 0.02 mm ) increase in size from one instrument to the next one 6 8 10 6- Tip Angle: The angle formed between the instrument tip and the long axis of the instrument shaft is standardized to be 75 degree + or - 15 degree . Tip Angle Tip angle 75 degrees ± 15 7-Tolerance (quality control): • ± 0.02mm (instrument) • ± 0.04 mm (gutta-percha) Force Force Zipping Strip perforation Restoring Forces with inflexible & large files Group 1- Hand Enlarging Instruments (Hybrid instruments) Why inventing Hybrid Instruments: Curved canals preparation: Oval C.S 1- Flexible instrument. 2-Incresed cutting efficiency. 3-Increased debris loading.` 4- Decrease procedural mishaps. Apical stop Round C.S Hybrid or modified instruments: I- Geometric dimensions & designs 1- Cross.Section. 2- Depth or angle of the cutting edges of the flutes 3- Tip design 4- Taper II- Method of construction III- Material of construction IV- Developing apical preparation instruments V- Using constant % change in dimensions at D0 rather than the linear dimensional change VI- Developing intermediate sized instruments I- Geometric dimensions & designs: Increased flexibility 1-Cross Section K- file Diamond C.S. (K flex) *K Flex file Triangular (FlexO file) Increase Flexibility Increase Cutting Efficiency. 1-Cross Section *S file *Unifile H- file *Helifile *Triocut Increase strength & cutting efficiency I- Geometric dimensions & designs: 2- Depth & angle of the blade Safety Hedstrom (smooth non cutting side) Non-cutting side avoid strip perforation I- Geometric dimensions & designs: 3- Tip Design: Flex-R file A milled K-type file with non-cutting tip. Increased flexibility & C. E. I- Geometric dimensions & designs: 4- Taper: 2%, 4%, 6%, 8% & 10% .02 .04 .06 Increased taper allowed for flaring of the coronal portion before apical preparation Crown-Down Technique: Cervical triangle Control over the apical curve II- Method of construction: Milled instrument is more flexible than twisted one of the same size and shape 1- Twisting : K file, K Reamer, K flex file, Flex-O-file & Twisted file (NiTi) 2- Machine grinding: H file, Safety H, Flex R, all NiTi files except Twisted file. III- Material of construction: 1- Specially treated Stainless steel 2- Ni Ti alloy(Superelastic) -Negotiation -curved canals Avoidance of instrument separation: Separation of hand instruments could be prevented by regularly inspecting the St St file for 1. Unwinding of the flutes 2. Roll-up of the flutes 3. Tip distortion 4. Corrosion Aims: The educational aims of this lecture are to detail different instruments available for root canal enlargement. Objectives: On completion of this lecture, the student should have an understanding of how to use different instruments to enlarge root canals, their indications and advantages and disadvantages of each Reading material: -The dental reference manual, Geraldine M. Weinstein, springer 2017 (Chapter 12) -Essential skills for dentists, Peter A.Mossey et al, Oxford, 2006 (Chapter 2.6) -Endodontics, Kishor Gulabivala and Yuan-Ling NG, Mosby Elsevier 2014 -Harty`s endodontics in clinical practice, Bun San Chong, Elsevier 2017 -Clinical endodontics, Lief Tronstad, Thieme 2009 (main reference) Thank you Date : xx / xx / xxxx