Rotary System Rotary System for Endodontic for Endodontic

TreatmentTreatment

Ishik UniversityFacultu of Denistry

Endodontic department

Rizgar Saeed Hangaw Tariq

Rotary system• nickle-titaninm rotary files substantially

simplify root canal preparation,particularly in curved and restricted canals

Nickel Titanium 55% nickel & 45% titanium

Advantages• Shape memory• Super elasticity• Low modulus of elasticity• Corrosion resistant• Softer• Good resiliency• Biocompatibility.

Disadvantages

• Poor cutting efficiency.• Do not show signs of fatigue before they fracture.• Poor resistance to fracture as compared to stainless steel.

Guidelines• Frequently clean & inspect files• Use only in well irrigated canals• Never force instruments• Don’t Start and Stop• Prepare with hand files up to size #20 prior to

rotary use• Determine exact working length• Recommended speed is 150 to 350 rpm

Conclusions :Under the conditions of this ex vivo study all Ni–Ti systems

maintained the canal curvature, were associated with few instrument fractures and were more rapid than a standardized manual technique. ProTaper instruments created more regular canal diameters.

Understanding torque and cyclic fatigue• The most common factors that can result in file separation are excessive

force (torque) and the build-up of cyclic fatigue (metal fatigue). Torque is a result of a twisting motion, similar to twisting a pencil in opposite directions. We actually can see excessive torque as an unwinding of a rotary file. Naturally, when we see this, we immediately discard the instrument. Cyclic fatigue, on the other hand, cannot be seen. It is, in fact, insidious. It is a result of a repetitive bending motion, similar to bending a clothes hanger. Cyclic fatigue accumulates to a point where the next bend will separate the instrument. The only way to monitor cyclic fatigue is to discard an instrument after it has been used in a troublesome canal or tooth.

• It has been our experience that rotary files that separate in the apical 1 to 3 mm are usually the result of excessive torque. Files that separate higher up on the shank, such as 5 to 6 mm are the result of cyclic fatigue. Additionally, those separations that are immediate or involve large sizes such as a # 35 / .06 taper file are generally a result of accumulated cyclic fatigue.

Many Rotary systems are Available in the market

• 1- System GT( Buchanan, Tulsa Dental• 2-Protaper (Dent)• 3-Profile (Dentsply)• 4-Ra Ce (Schotlander)• 5-K3 (Sybron Keer

Protaper File• It was introduced by D Cliff Ruddle, Dr Johan West, Ben John and Dr Pierre.• Protaper means progressively taper. •NiTi

Tapering

• The progressively tapered design improves flexibility, Cutting efficiency and the safety of these files .

• Change percentage of taper over the length of cutting blades (unique feature ).

Tip

•modified guiding tip.• rounded, non-cutting, and parabolicshaped tip.Better follow the canal. loose debris into the intrablade flutes.

• Variable tip diameters of ProTaper file allows it to have specific cutting action in defines area of canal without stressing instrument in other sections.

helical angle

Changing helical angle over its cutting blades which reduces the instrument from screwing into the canal and allows better removal of debris.

Active MotionIt acts in active motion.increases its efficiency.Reduces torsional strain.

Length of file handleReduced from 15 to 12.5 mm

Allows better access in posterior areas.K-file

Benefits of design:• Increased flexibility• Each instrument produces its own 'crown down effect' as larger tapers make way for smaller tapers.• Protaper files engage a smaller area of dentine reducing torsional loads and file fatigue

Crown down technique

• Corono-apical technique• Introduced recently andgaining popularity.• Starts with largestinstruments.• Shapes coronal 1/3rd initially.• Commonly uses rotary files.

Protaper FilesProtaper FilesThe ProTaper system consists of just three

shaping and five finishing files

Protaper Configuration

• Three Shaping files----------SX,S1,&S2• Three finishing files---------F1,F2, F3+• Accessory finishing files F4&F5

All files available in 21mm , 25 mm and 31 mm lengths.

Cross-Section

• Convex triangular.• Decreases friction between blades of file and canal wall.• Increasing its cutting efficiency.

S-1 and S-2 FilesShaping Files-1 is designed to prepare the coronal 1/3 of the canal, whereas.Shaping file S-2 enlarges and prepares the middle third in addition to the coronal critical coronal region of the apical third

Canal Preparation1. Fill the pulp chamber with either Glyde or Sodium

Hypochlorite(NaOCL) for all initial negotiation procedures.

2. Fined out the canal orifices then insert hand file NO.10 and 15 using a reciprocating back and forth motion. Work those instruments passively and progressively until they are loose

Small files confirm the presence or absence of straight line access and reveal information regarding the diameter and anatomy of a canal

3-Re- Irrigate, Recapitulate with hand file K103- Using S1to remove the crown ledge in brushing motion for better straight line access. Complete finishing the coronal area this accomplished when a Light resistance is encountered

• 4- Re irrigate, recapitulate using file K10 to negotiate the rest of the canal and establish patency then use hand file K15 to confirm working length and verify a glide path

• 5-Use S1 to full length it will go easily once it reaches withdraw it . We should never force any rotary instrument

• Shaping file S-2 is now used to full working length. Once it reaches remove ,Irrigate, reciprocate and re irrigate

• Now The Coronal and 2/3 of root canal are prepared

Finishing Stage• With the canal flooded with irrigant,work F-

1(yeallow20) to full working length in one or two canals.

• If the F-1 ceases to advance deeper into the canal , remove the file .clear its blades ,then continue with its use until until it reaches the full length .

• Irrigate ,reciprocate ,re- irrigate

Finishing files.• They are F-1, F-2 and F-3+ Accessory

files F-4,F-5 have been designed to plane away the variations in canal diameter in the apical one-third.

• F-1,F-2,F-3 have tip diameters (Do)of ISO sizes 20,25, and 30, respectively.

• Following the use of F1, if the #20 K-file is loose at length, then gauge the size of the foramen with a 25/ 02 tapered K-file. If the #25 file is snug at length, then the canal is fully shaped and ready to fill.

• file is loose at length, then use an alternative NiTi rotary files or manual files to finish the apical extent of these larger, easier and more straightforward canals. ProTaper shapes are easy to fill utilizing a ProTaper matching gutta percha master cone in conjunction with a warm vertical condensation technique.

Accessory Files • F-4, F-5 Files are added under the name

Protaper universal these files have tip diameters (D(هof ISO sizes 40and 50 tapers

Thanks