Root canal Obturation

Dr. Gaurav GargDr. Gaurav GargLecturerLecturer

College of Dentistry, ZulfiCollege of Dentistry, Zulfi

Asalaam Alekum

Successful endodontic treatment depends on

•Proper diagnosis

•Favorable prognosis assessment

•Proper disinfection, cleaning, shaping, and

•Obturation of the root canals

WHY TO OBTURATE THE CANAL ???

Readiness of the root canal for filling

o Negative culture

o No excessive exudate from the canal

o Absence of foul odor

o Lack of periapical sensitivity

Requirements for an ideal root filling material (by Grossman,1980)

• Easily introduced in the canal

• Radiopaque

• Dimensionally stable

• Seals the canal laterally and apically, conforming to its

complex internal anatomy

• Impervious to moisture

• Inhibits bacterial growth

• Nonirritating to the periapical tissues

• Sterile or can be easily sterilized

• Does not discolor tooth structure

• Easily removed from the canal if necessary

GUTTA PERCHA :

EVOLUTION INTO

DENTISTRY

“GETAH”- meaning gum

“PERTJA”- name of the tree in

Malay language

First introduced to dentistry as a temporary filling material by Edwin Truman.

CHEMISTRY OF GUTTA-PERCHA

o Trans-isomer of polyisoprene o Harder, more brittle and less elastic than natural rubber

Composition :

18-20% gutta-percha59-76% zinc oxide1-18% radio-opacifiers1-4% plasticizers

Advantages of gutta percha

• Compactibility• Inertness• Dimensional stability• Tissue tolerance• Radiopacity• Becomes plastic when warmed• Known solvents ( Chloroform, Xylene, Eucalyptus oil)• Can be sterilized In 5.25% NaOCl for 1 minute.

Disadvantages

• Lack of rigidity• lack of length control

In 1933, Jasper introduced silver cones. Their rigidity made them easy to place; however, their inability to fill the irregularly shaped root canal system permitted leakage.

Disadvantages:

• Inability to fill the irregularly shaped root canal & hence leakage

• When in contact with tissue fluids or saliva they corrode

• Corrosion products are cytotoxic & produce pathosis or impeded periapical healing.

Silver cones

Root canal sealers

• Zinc oxide containing sealers

• Calcium hydroxide containing sealers

• Glass ionomer containing sealers

• Resin sealers

• Silicone-based sealers

• Urethane methacrylate sealers

I. Solid Core Gutta-Percha with SealantsA. Cold gutta-percha points Lateral compaction

B. Chemically plasticized cold gutta-perchaEssential oils and solventsa. Eucalyptolb. Chloroformc. Halothane

Obturation techniques

C. Canal-warmed gutta-percha1. Vertical compaction/ Schilder’s method 2. System B compaction3. Sectional compaction4. Lateral/vertical compaction - Endotec II5. Thermomechanical compaction• Microseal System/ McSpadden Compactor• Ultrasonic plasticizing

D. Thermoplasticized gutta-percha1. Syringe insertiona. Obturab. Inject-R-Fill, backfill

2. Solid-core carrier insertiona. Thermafil b. Sucessfilc. Simplifil

II. Apical-Third Fil l ing

A. Dentin-chipB. Calcium hydroxide

III. Injection or “Spiral” Fi l l ing

A. CementsB. PastesC. PlasticsD. Calcium phosphate

1. LATERAL COMPACTION OF GUTTA-PERCHA

Objective: fill the canal with gutta-percha points (cones) by compacting them laterally against the sides of the canal walls.

Two main types of spreading instrumentslong handled spreadersfinger spreaders

•Finger spreaders provide: better tactile sensation & less likely to induce fractures

Spreader fit

Fit within 1-2mm of CWL.

If not, more shaping is required because apical size and taper is inadequate.

Excessive force should be avoided—cold gutta-percha is not greatly compressible, and as little as 1.5 kg of pressure are capable of fracturing the root.

Select Master Cone size that corresponds to your MAF size.

Ex. MAF size 30 MC size should also

be size 30.

Master Cone Fit

Check Master Cone (MC) Length

Master Cone Fit

If MC is at FWL, you are ready to obturate.

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Mark the Master Cone to FWL

Place MC in the canal system.

Mark should correspond to reference point.

The Master Cone should seat to final working length.

Obturation length= FWL

Master Cone Fit

The MC should have a definite apical resistance when MC is placed to FWL.

The MC should exhibit “tugback” or resistance to removal.

Master Cone Fit

Mix the Sealer

Mix the Sealer

Mix the Sealer

Mix the Sealer

Sealer Placement

Do this until the canal is obturated to the cervical line.

Take a radiograph at this time and evaluate fill.

This confirms adequacy of the obturation.

Lateral Compaction

Lateral Compaction

If the obturation is satisfactory, the excess gutta percha should be cut to the CEJ level (bucco-lingual).

If obturation is not dense, or if voids are present, remove all the cones and redo the obturation process.

Final Radiograph

Remove the rubber dam clamp and rubber dam material and take the radiograph.

*In a real patient, a temporary restoration is placed before rubber dam is removed.

SUMMARY

Selection of Spreader:

A spreader is selected that matches the taper of the canal and When placed in the canal it should be within 2 mm from the working length.

SUMMARY

Selection of master cone:

Following canal preparation a master cone is selected that has a diameter consistent with the Master Apical File (MAF).

This “master cone” is measured & grasped with a forceps so that the distance from the cone tip to the forceps is equal to the prepared length.

The cone is placed in the canal & if an appropriate size is selected, there will be resistance to displacement or “tug back”.

The master cone placement is confirmed with a radiograph.

SUMMARY

Lateral Condensation:Canal is irrigated and dried with paper points.Sealer is applied to the canal walls and also to the master cone and it is placed in the canal.Now spreader is inserted to make space for accessory cone.After placement the spreader is removed by rotating it back & forth as it is withdrawn.An accessory cone is placed in the space vacated by the spreader.The process is repeated until the spreader no longer penetrate the coronal 2-3 mm of the canal.The excess gutta-percha is removed with heated instrument & the coronal mass is compacted with a plugger.Obturation is checked radiographically.

•“Gold standard”

Advantage :• Excellent length control

Limitations:

However, this technique may not fill canal irregularitiesGutta-percha cones never merge into a homogeneous mass, but they slip and glide and are frozen in a sea of cement

Efficacy of Lateral Compaction

Radiographic evaluation of obturation

Radiolucencies: Voids within the body or at the interface of obturating material and dentin wall represent incomplete obturation.

Density: Material should be of uniform density from coronal to apical aspects. The margins of gutta-percha should be sharp and distinct with no fuzziness, indicating close adaptation.

Length: The material should extend to the preparedlength and be removed apical to the gingival margin(anterior teeth) and orifices (posterior teeth).

Taper: The gutta-percha should reflect the canal shape;that is, it should be tapered from coronal to apical regions.

Restoration: Whether permanent or temporary, the restoration should be contacting enough dentin surface to ensure a coronal seal.

2. VERTICAL COMPACTION OF WARM GUTTA-

PERCHA

• Schilder in 1967.

•Heated gutta-percha has been shown to flow extremely well into all canal irregularities.

•It is particularly useful in situations such as internal resorption, C-shaped canals, and those with fins or webs.

Schilder’s pluggeres (9)Tip diameter: 0.40,0.50,0.60,0.70,0.80,0.90.1.10,1.30,1.50

Spreader- Heat Carrier Pluggers- vertical compaction

Plugger Selection

Coronal third- 5-6mm Middle third- 12-15mm Apical third- 5-6mm

Master Cone Selection

The cone must be slightly shorter than the preparation

Sealer Application

Sealer is mixed and applied in canal with the help of an endodontic file

Master Cone Placement

Master Cone should also be coated with sealer and placed inside the canal at desired length

Vertical Compaction

Coronal Third

Middle third

Apical third

Advantages: filling of canal irregularities and accessory canals.

Disadvantages :-The risk of vertical root fracture

- Less length control than in lateral compaction

-Warm vertical compaction is difficult in curved canals where rigid pluggers are unable to penetrate to the necessary depth, requiring that the canals be enlarged and more tapered in comparison with the lateral condensation technique.

Temperature control •The critical level of root-surface heat required to produce irreversible bone damage is believed to be greater than 10°C

•Use of a flame-heated instrument does not permit temperature control.

•The DownPak Cordless obturation device, the System B, and Touch ’n Heat (SybronEndo) devices, permit temperature control.

Endotec II

It is a battery-powered, heat-controlled spreader/plugger..The quick-change, heated tips are sized equivalent to a No. 30 instrument are autoclavable and can be adjusted to any access angulation.

THERMOMECHANICAL COMPACTION OF GUTTA-

PERCHAIn 1979, McSpadden devised a handpiece-driven (6000-7000 rpm) compactor, which is effectively an inverted Hedstroem file.

The frictional heat from the compactor plasticises the gutta-percha and the blades drive the softened material into theroot canal under pressure.

•The compactor is selected based on the size of the canal preparation and inserted with the hand piece activated alongside the gutta-percha cone 2 to 3 mm from the prepared length.

•The gutta-percha is heated by the friction of the rotating compector, and is compacted apically and laterally as the device is slowly withdrawn from the canal.

Advantages :

simplicity, speed, and the ability to fill canal irregularities.

Disadvantages :

• Extrusion of filling material beyond the apex

• The potential for instrument fracture

• Difficulty in using the technique in curved canals

• Uncontrolled heat generation.

Use of heat and vibration: DownPak

•An alternative to cold lateral compaction with finger spreaders : DownPak Obturation

•The DownPak is cordless and designed with a multifunctional, endodontic heating and vibrating spreader device, and can be used for both warm vertical and lateral condensation techniques.

3. Thermoplastisized Gutta Percha

1. Syringe Insertion- Obtura

2. Solid-core carrier insertion- Thermafil

1. Obtura System

•Consists of a hand-held “gun” with a chamber into which pellets of gutta-percha are loaded, along with silver needles of varying gauges used to deliver the thermoplasticized material to the canal.

•The temperature, and thus the viscosity, of the gutta-percha can be adjusted.

•A wide, well-prepared canal is a prerequisite.

•After drying the canal apply a small amount of sealer.

•The tip of injecting needle should be kept 3-5 mm short of working length and it should be withdrawn outwards coronally while injecting gutta percha.

•The coronal portion of gutta percha should be compacted using a plugger to enhance coronal seal.

Advantages:

Easy and less time consuming 3-D obturation Enhanced apical and coronal seal Useful in C-shaped, irregular and complex root canals

Disadvantage:

Risk of overfilling Not suitable for canals with open apices

Obturators

Thermafil oven

2. Thermafil

Components: a.Thermafi l obturators

a.Size verif iers

a.Thermafi l Oven

Thermafi l Technique:

1.Canal preparation

2.Obturator selection

3.Sealer placement

4.Obturation

Advantages:

Easy to use

Obturation of curved canals

3-D Obturation

Disadvantages:

Not suitable for obturation of teeth with immature apices, Canals with bifurcations or trifurcations in the middle Third

Risk of overfilling

Dentin Chip Apical Fi l l ing

“Biologic seal” rather than a mechanochemical seal. •Stimulate osteo or cementogenesis

•Holland et al., found, however,that dentin chips, if infected, are a serious deterrent to healing (1980)

References

ENDODONTICS: Arnaldo castellucci

PATHWAYS OF THE PULP (6th Edition): Stephen Cohen, Richard C. Burns

PRINCIPLES AND PRACTICE OF ENDODONTICS (3RD EDITION): Walton & Torabinejad

ENDODONTIC THERAPY (6th Edition): Franklin S. Weine

Thank you