WHAT IS OBTURATION? According to American Association of Endodontists :

“ Obturation is the method used to fill and seal a cleaned and shaped root canal using a root canal sealer and core filling material.”

PURPOSE OF OBTURATIONTo achieve three dimensional fluid tight

seal of the root canalTo prevent bacterial micro leakageTo achieve total obliteration of root canal

space as to prevent ingress of bacteria and body fluid into the canal as well as there removal if present in canal

To replace the empty root canal space with an inert filling material to prevent recurrent infection

CRITERIA FOR OBTURATIONThe canal should be reasonably dry with no

weeping of fluids in the form of bleeding or serous discharge

When patient is without sensitivity to percussion

Teeth with no periradicular radiolucency

After optimal cleaning and shaping is achieved

Factors influencing the efficacy of primary root canal treatment :

1) ABSENCE of pretreatment periapical lesion.

2) Root canal fillings with NO VOIDS. 3) OBTURATION to within 2.0 mm of

the apex. 4) An ADEQUATE coronal

restoration.

Spreaders :• 2 types of spreaders :

# Hand Spreaders # Finger Spreaders• Finger spreaders provide better tactile sensation &

are less likely to induce fracture in the root when compared with the more traditional hand spreaders.

• Spreaders made from Nickel-Titanium are available and are considered better when compared with Stainless Steel as they provide :

1) FLEXIBILITY 2) STRESS 3) DEEPER PENETRATION

Spreaders

Paper PointsThey are used for drying the canal after irrigation.

TECHNIQUES OF OBTURATION :

1. Cold Lateral Compaction2. Warm Compaction (a) Vertical (b) Lateral 3. Continuous Wave Compaction Technique4. Thermoplasticized gutta-percha injection5. Carrier-based gutta-percha (a) Thermafil thermoplasticized (b) SimpliFill sectional obturation6. McSpadden thermomechanical compaction7. Chemically plasticized gutta-percha 8. Custom cone

COLD LATERAL COMPACTIONProvides for length control during the

compaction.Disadvantage : May not fill the canal

irregularities as well as warm vertical or thermoplasticized techniques.

Is not able to achieve three-dimensional seal.

Clinical considerations :1) Sealer considerations- Sealer application on

the canal walls can also be performed using a lentulo spiral or with the master gutta-percha cone itself.

2) Spreader considerations- Size of the spreader is determined by the

width of the prepared canal and the lateral fit of the primary cone. THE GREATER THE SPACE BETWEEN THE CANAL WALL AND THE BUTT END OF THE GUTTA-PERCHA , THE LARGER (wider) THE SPREADER USED.

The spreader size should reach within 1-2mm of the working length in order to obtain optimal apical compaction.

3) Master cone considerations : - Minimal force should be used on the spreader

during the compaction process in order to avoid root fractures.

- Additional secondary cones are inserted until the spreader cannot be reinserted, an INDICATION THAT THE ROOT CANAL IS FULLY COMPACTED LATERALLY.

4) Several radiographs must be taken while obturation.

Gutta percha

Lentulo spiral

Pretreatment radiograph

Working length radiograph

Coronal access opening

Prepared mesio-buccal canal

Standard master cones with coronal reference marked

Standard master cones fit to length as they exhibit minimal taper and permit deeper penetration of the spreader

Master cone radiograph

Finger spreader in place

Accessory cone placed in the space created by the spreader

Finger spreader placed in preparation, creating space for additional accessory cones.

Additional cones are placed until the spreader does not penetrate pastthe coronal one third of the canal. The cones are then removed at the orifice with heat, and the coronal mass is vertically compacted with aplugger.

Interim radiograph may be exposed to assess the quality of obturation.

Posttreatment radiograph demonstrating adequate length,density, and taper. The gutta-percha is removed to the level of the orifice, and a coronal seal has been established with an adequate provisionalrestoration.

LIMITATIONS :1) The presence of voids in between the

filling as : May not fill the canal irregularities as

well as warm vertical / thermoplastic techniques.

Doesn’t produce a homogenous mass. 2) Warm compaction techniques have a

better ability to seal intracanal defects and lateral canals than cold lateral compaction.

WARM COMPACTION METHOD

A) WARM VERTICAL COMPACTION :By Schilder It is a method of three-dimensional

filling the radicular space Preparation requirement : Preparing the

canal with a continuously tapering funnel and keeping the apical foramen as small as possible.

Instrument requirements : Variety of pluggers and heat source.

Using heated pluggers, one applies pressure in a vertical direction to the heat-softened gutta-percha and thereby causes it to flow and to fill the entire lumen of the canal.

Schilder’s objectives :A continuous tapering funnel should be present

from the root canal orifice to the root apex.The root canal should be prepared so that it

flows with the shape of the original canal.The shape of the apical foramen should not be

changed or moved.The apical foramen should be kept as small as

is practical so that excess gutta-percha will not be forced through it during vertical compaction.

Indications :As an alternative to the cold lateral

compaction technique.When the fitting of a conventional

master cone to the apical portion of the canal is impossible, as when there is a ledge formation, perforation, or unusual canal curvatures, internal resorptions, or large lateral canals.

Techniques :A primary nonstandardized or greater taper

gutta-percha cone corresponding to the last instrument used is fitted in the canal in the usual manner.

The canal wall is coated with a thin layer of root canal sealer.

The primary gutta-percha cone or master cone is inserted upto the working length.

The coronal end of the cone is cut off with a heated instrument.

A “heat carrier” such as root canal plugger, is heated to redness and is immediately forced into the coronal third of the gutta-percha. (An alternative is to employ electric heat carriers like Touch n Heat or System B as they permit temperature control of the heat carrier instrument.

The coronal gutta-percha is seared off be by the plugger as it is removed from the canal.

A vertical condenser or plugger of suitable size is inserted, and the vertical pressure is applied to the heated gutta-percha to force the plasticized material apically.

This alternative application of heat carrier and condenser is repeated until the plasticized gutta-percha seals the larger accessory canals and fills the lumen of the canal in three dimensions up to the apical foramen.

The remaining portion of the canal is plugged with warm sections of additional pieces of gutta-percha.

Advantages :Excellent seal of the canal apically and

laterally.Obturation of the larger lateral and

accessory canals.

Disadvantages :The amount of time it takes.The risk of vertical root fracture

resulting from undue force.Periodic overfilling with gutta-percha or

sealer that cannot be retrieved from the periradicular tissues.

B) WARM LATERAL COMPACTION :This provides length control during obturation.Placement of master cone and lateral

compaction using heat carriers such as Endotec II tips and EndoTwinn tips.

The device is placed beside the master cone and activated followed by placement of an unheated spreader in the space previously occupied by the heat carrier.

Accessory cones are then placed and the process repeated until the canal is filled.

CONTINUOUS WAVE COMPACTION TECHNIQUE:

This is a variation of the warm vertical compaction technique introduced by Buchanan.

Employs the use of gutta-percha cones and pluggers that mimic the tapered preparation, thereby permitting the application of greater hydraulic force during warm compaction.

It uses Nickel-Titanium systems to prepare the canal.

Pluggers are selected in consistence with the size of the shaping instruments used.

Tapered pluggers #.06 , #.08 , #.10 , #.12 with a tip diameter similar to the tapered gutta-percha points, respectively, are employed.

This procedure is carried out with a heat carrier system (System B, SybronEndo)

Buchanan System B pluggers

THERMOPLASTICISED GUTTA-PERCHA INJECTION TECHNIQUESPRINCIPLE:- This technique comprises a

pressure apparatus consisting a electrically heated syringe barrel and a selection of needles ranging from 18-25gauge size.

The plunger is designed to prevent the backflow of the Gutta percha.

The degree of heat is regulated to provide proper extrusion of the gutta percha according to the size of the needle.

TECHNIQUEEXAMPLE:- OBTURA III(OBTURA SPARTAN)A suitable gauge needle is selected to be

positioned at 3-5mm short of working length.

TEMPERATURE:- 200o C. In the injection method, the canal

preparation is restricted apically with flaring of the body of the canal toward the access opening.

LIMITATIONLack of precision.Creation of voids in the final set filling.

CARRIER BASED GUTTA PERCHA TECHNIQUESThermafil Thermoplasticised Technique It is a carrier based gutta percha obturation

system comprising a plastic core carrier coated with alpha phase gutta percha.

It is available in ISO standardised sizes as well as variable tapered sizes suitable for canals prepared with nickel-titanium tapered instruments.

Used in conjunction with a heating device known as THERMAPREP PLUS OVEN

SIMPLIFIL SECTIONAL OBTURATION TECHNIQUE

It is a carrier based sectional gutta percha obturation system used in conjunction with the light speed rotary instruments.

The Simplifil carrier has an apical 5mm plug of gutta percha which performs cold sectional obturation of the root canal.

The carrier size is chosen according to the diameter of the master apical file(MAF).

After drying the canal and applying the sealant , the carrier is applied up to the working length.

The handle of the carrier is rotated quickly in the counter clockwise direction three to four times to disengage the apical plug of gutta percha from the carrier.

The remaining coronal space can be filled with lateral compaction or thermoplasticised gutta percha methods .

McSPADDEN THERMOMECHANICAL COMPACTION METHODThis method used heat to decrease the gutta

percha viscosity and increase its plasticity.The heat is created by rotating a compacting

instrument in a slow speed contra angle handpiece at 8000-10,000 RPM alongside gutta percha cones inside the root canal.

The compactor whose spiraled 900 flutes are similar to the flutes on HEDSTROEM FILE , but in reverse , forces the softened gutta-percha apically and laterally.

As the comparator blade breaks easily if it binds , this method should be used to fill straight canals only.

Step back method is used to enlarge the canals.

Gutta percha cones are inserted in the prepared canal short of the root apex and a comparator blade selected according to the width and length of the prepared canal , is inserted between the gutta percha and the canal wall.

With a stop on the comparator blade , the rotating tip of the blade is guided to within 1.5mm of the root apex.

Restriction of the blade within the canal prevents the forcing of thermoplasticized gutta percha through the root apex.

The plastic gutta percha moves laterally and apically because the reversed flutes on the compactor blade push the softened gutta percha forward and sideways even when one is withdrawing the rotating blade from the canal.

ADVANTAGESEase of selection and insertion of gutta

percha cones.Economy of time.Rapid filling of canals apically and laterally ,

including irregular spaces within the canal if one uses a sealer.

DISADVANTAGEInability to use the technique in narrow

canals.Frequent breakage of compactor blades.Frequent overfilling of the canals.Shrinkage of the cooled , set filling.

CHEMICALLY PLASTICIZED GUTTA PERCHA TECHNIQUE(EUCAPERCHA , CHLOROPERCHA)Gutta percha can be plasticized by

chemical solution such as chloroform , eucalyptol or xylol.

The advantage is it can be used in unusually curved canals.

The disadvantage of using a chemical solvent filling material is its inability to control overfilling with resultant periapical tissue reaction and shrinkage of the filling after setting , resulting in a poor apical and lateral seal.

CUSTOM CONE TECHNIQUECustom cone technique is a chair side

procedure employed for customizing the gutta percha in wide angles where traditional master cone cannot be adapted.

The clinician has to customize a gutta percha point to achieve a tug back.

TECHNIQUE:-Soften an appropriate sized gutta percha with one

or more accessory cones with the help of heat and heat and roll together between two glass slabs. A spatula may also be used as an alternative. A single master cone of incresed diameter is created which is then sized within the canal.

Soften the tip of the master cone with chloroform , eucalyptol or halothane for few seconds and gently place it to the working length with a locking plier. On removal , the softened gutta percha carries the impression of the canal and this process is repeated till a snug fit is achieved. Ensure that the gutta percha remains semirigid during this process.

References :Cohen’s Pathways of the Pulp 10th editionGrossman’s Endodontic Practice13th edition

1) In Obtura III , the gauge needle is selected to be positioned at?1-2 mm short of working length2-3 mm short of working length3-5 mm short of working length0.5-1 mm short of working length

2) The spreader should reach within how much of the working length?

1-2 mm of working length2-3 mm of working length3-5 mm of working length0.5-1 mm of working length

3) In SimpliFill Sectional Obturation, a heating device is used in conjunction with the obturators. TrueFalse

4)Which phase of gutta-percha is most commonly available commercially?Alpha phaseBeta phaseGamma phaseBoth Alpha & Beta

5)

Hand spreaderPluggerFinger spreaderLentulo spiral