CHAPTER 10: OBTURATION

significance of obturation

sealing the root canal system

entombing residual irritants

preventing periapical pathology

promoting periapical healing

ideal root canal filling

easily retrievable in case retreatment

non-resorbable material that remains stable over time

radiopacity to allow clear assessment on radiographs

complete sealing of the root canal’s apical, lateral, and coronal aspects

non-toxic and biocompatible properties to avoid irritation of periapical tissues

timing of obturation

single-visit obturation

multiple-visit obturation

single-visit obturation

recommended for cases with vital pulps, no signs of infection, and well-dried canals

multiple-visit obturation

a necrotic pulp with infection is present

when there is persistent periapical inflammation

the canal exhibits exudation or is not completely dry

with an intracanal medicament → calcium hydroxide

0.5-1.0mm

the optimal length of obturation, short of the radiographic apex

overfilling (extrusion beyond the apex)

may cause periapical irritation

underfilling (short of the working length)

leaves unsealed spaces that can harbor bacteria

preparation for obturation

before placing the obturation materials, proper cleaning and disinfection are essential

following steps are crucial:

• removal of smear layer

• final irrigation

• drying the canal

removal of smear layer

this layer of dentinal debris and bacteria formed during instrumentation should be eliminated using:

• EDTA

• NaOCl

• citric acid

final irrigation

a combination of NaOCl and EDTA ensures thorough decontamination and allows better adaptation of sealers

drying the canal

paper points are used to eliminate residual moisture before obturation

instruments for obturation

paper points

lentulo spiral

spreaders & pluggers

gutta percha

sealers

[ in order ]

lentulo spiral

usage: clockwise

deliver sealer in the canal

requirements of a good sealers

slow setting time

dimensional stability

solubility, flowability

radiopacity, hermetic seal

retreatment compatibility

non-toxicity and biocompatibility

adhesion to dentin and core material

types of sealers

bioceramic sealers

resin-based sealers

glass ionomer sealers

silicone-based sealers

calcium hyroxide sealers

zinc oxide-eugenol sealers

zinc oxide-eugenol sealers

forms a chelating reaction with dentin, creating a mechanical seal

still widely used but have been largely replaced by more advanced materials

composition of zinc oxide-eugenol sealers

eugenol

zinc oxide

additives for setting control

properties of zinc oxide-eugenol sealers

antimicrobial due to eugenol

long setting time (can take 24+ hrs)

good working time and flow

disadvantages of zinc oxide-eugenol sealers

can shrink over time, leading to leakage

soluble in tissue fluids, reducing long-term stability

eugenol may cause cytotoxic effects on periapical tissues

sample brands of zinc oxide-eugenol sealers

Procosol

Roth’s Sealer

Wach’s sealer

Tubli-Seal EWT

Tubli-Seal (Sybron- Endo)

Pulp Canal Sealer EWT

Pulp Canal Sealer (SybronEndo)

calcium hyroxide sealers

best suited for cases requiring apexification of regenerative endodontics

releases hydroxyl ions promoting antibacterial activity and hard tissue formation

composition of calcium hyroxide sealers

resins, fillers

calcium hydroxide

properties of calcium hyroxide sealers

bactericidal effect due to high pH

stimulates apical barrier formation

disadvantages of calcium hyroxide sealers

weak adhesion to dentin

soluble over time leading to microleakage

sample brands of calcium hyroxide sealers

Apexit

Sealapex

Apexit Plus

CRCS (Calciobiotic Root Canal Sealer)

glass ionomer sealers

forms chemical bonds to dentin improving adhesion

used in cases requiring strong adhesion but less preferred due to difficulty in retreatment

composition of glass ionomer sealers

glass ionomer cement with fluoride release

properties of glass ionomer sealers

high radiopacity

fluoride release may enhance reminiralization

disadvantages of glass ionomer sealers

brittle and difficult to remove in retreatment

can undergo dimensional changes over time

sample brands of glass ionomer sealers

Ketac-Endo

Activ GP

resin-based sealers

adhesive bonding dentin providing excellent sealing ability

AH Plus (epoxy resin) → most commonly used sealers due to its superior sealing properties and low solubility

composition of resin-based sealers

epoxy resin or methacrylate-based formulations

properties of resin-based sealers

high radiopacity

minimal shrinkage

long setting time (8 hrs)

disadvantages of resin-based sealers

difficult to remove in retreatment

requires complete canal dryness for bonding

some formulations contain cytotoxic components

sample brands of resin-based sealers

AH-26

AH Plus

EndoREZ

Diaket

Epiphany

RealSeal

silicone-based sealers

expansion upon setting ensuring a tight seal

guttaflow combines gutta-percha particles within the sealer making it an easy-to-use material

composition of silicone-based sealers

silicone-based materials with gutta-percha particles (in guttaflow)

properties of silicone-based sealers

biocompatible and tissue-friendly

dimensional stability → does not shrink

disadvantages of silicone-based sealers

weaker adhesion to dentin

expensive compared to other sealers

sample brands of silicone-based sealers

RoekoSeal

GuttaFlow

bioceramic sealers

forms hydroxyapatite upon setting, chemically bonding to dentin

becoming the gold standard due to their superior sealing ability, biocompatibility, and dimensional stability

composition of bioceramic sealers

zirconium oxide

calcium silicates

calcium phosphate

properties of bioceramic sealers

excellent biocompatibility and bioactivity

strong antimicrobial properties due to high pH

hydrophilic, works well in moist environment

disadvantages of bioceramic sealers

long setting time (12-24hrs)

expensive compared to traditional sealers

sample brands of bioceramic sealers

zirconium oxide

calcium silicates

calcium phosphate

methods to introduce sealers into the canal

coating the master cone

using lentulo spirals

applying with files and reamers

utilizing ultrasonic devices

core filling material

must be stable and provide a three-dimensional seal

3 common core materials

resilon

silver cones

gutta-percha

gutta-percha

the gold standard in root canal obturation

available in standardized and non-standardized cones

composition:

• 20% gutta-percha

• 65% zinc oxide

• 10% radiopacifiers

• 5% plasticizers

used as matrix

gutta percha

used as filler

zinc oxide

used as plasticity

waxes or resins

used as radiopacitiy

metal sulfates (barium, strontium)

resilon

bonds chemically to resin-based sealers

a synthetic polymer-based alternative to gutta-percha

shows promise but has lower long-term clinical success compared to GP

methods of obturation

lateral compaction

warm vertical compaction

continuous wave compaction

thermoplastic injection techniques

carrier-based gutta-percha

thermo-mechanical compaction

cold lateral compaction

most commonly taught technique

uses a master gutta-percha cone and additional accessory cones compacted laterally using a spreader and sealer

advantages of cold lateral compaction

simple, cost-effective, and provides good control

disadvantages of cold lateral compaction

may leave voids and does not adapt well to irregular canal anatomy.

warm vertical compaction

involves softening gutta-percha using heat and compacting it vertically with a plugger

advantages of warm vertical compaction

provides better adaptation to canal walls and irregularities

disadvantages of warm vertical compaction

more technique sensitive and requires specialized equipment

continuous wave compaction

a variation of warm vertical compaction using a heated plugger to down-pack gutta-percha in one continuous motion

advantages of continuous wave compaction

more efficient than traditional warm vertical compaction

disadvantages of continuous wave compaction

requires a learning curve and specialized instruments

thermoplastic injection techniques

uses injected thermoplasticized gutta-percha via a delivery system (ex: Obtura III, Calamus)

advantages of thermoplastic injection techniques

provides a homogeneous fill and excellent adaptability to canal irregularities

disadvantages of thermoplastic injection techniques

expensive and may lead to overfilling if not controlled properly

carrier-based gutta-percha

uses a central plastic or cross-linked gutta-percha carrier coated with flowable gutta-percha

advantages of carrier-based gutta-percha

quick and easy placement, good adaptation

disadvantages of carrier-based gutta-percha

difficult to retreat if necessary

thermo-mechanical compaction

uses a rotating compactor (ex: McSpadden Compactor) to generate frictional heat, softening and compacting gutta-percha

advantages of thermo-mechanical compaction

efficient and quick technique

disadvantages of thermo-mechanical compaction

risk of apical extrusion

coronal orifice sealing

cavit or resin-modified GIC → commonly used temporary restorations for this purpose (placed before permanent restoration (composite, crown)

after obturation, sealing the coronal access is vital to prevent reinfection (immediate coronal seal is critical to prevent microleakage)

radiographic evaluation of a well-obturated canal

appear homogeneous, radiopaque, extend to the proper working length

common errors of obturation

underfilling → incomplete obturation

voids → inadequate compaction or sealer placement

overfilling → apical extrusion of gutta-percha or sealer

special considerations when obturating

retreatment cases

root resorption cases

immature teeth with open apices (apexification & regenerative endodontics)