q5: basics of obturation

endontic success is dependent on…

adequate instrumentation, disinfection, and obturation of the root canal system

objective of obturation

create a watertight seal along the length of the root canal system from the orifice to the apical foramen

obturation prevents leakage of microorganisms and their biproducts into the root canal system from a _________ direction and leakage of periapical tissue fluids into the root canal system from an ______ direction

coronal; apical

t for f: obturation seals within the root canal system any irritants that are NOT fully removed during cleaning and shaping

t

obturation seal allows for _________ and _________ of apical periodontitis

prevention and healing

why obturate (3)

prevention and healing of apical periodontitis

• periapical lesions may heal after root canal debridement without obturation

• if bacteria are eliminated prior to obturation, PA lesions heal regardless of quality of obturation

• if bacteria remain prior to obturation, healing is related to the quality of obturation

t or f: how the root canal system is filled is more important than what is removed

f

obturation depends on… (5)

• pulpal and periapical dx

• radiographic presentation

• signs and symptoms

• degree and difficulty

• pt management issues ‘logistical concerns

in predoc endo clinic, most cases are completed in ___ vist(s)

>1 due to logistical concerns (clinician experience level)

when can you obturate in the case of a vital pulp

can do in 1 visit

when can you obturate is the pulp is swelling and unable to dry

takes 2 visitis

what necrotic diagnoses are included in obturation timing decisions

• Asymptomatic apical periodontitis

• Symptomatic apical periodontitis

• Chronic apical abscess

why might you choose multiple visits instead of single-visit obturation

to allow antimicrobial effect of intracanal medicament.

does multiple-visit treatment improve prognosis compared to single-visit

no evidence of improved prognosis

what features do you want in an obturation material (11)

1. easily manipulated and ample working time

2. dimensionally stable w no skrinkage once inserted

3. seals canal laterally and apically

4. non-irritating to PA tissues

5. impervious to moisture

6. unaffected by tissue fluids- no corrosion or oxidation

7. inhibits bacterial growth

8. radiopaque

9. does not stain tooth

10. sterile or easily sterilizable

11. easily removable from canal, if necessary

when thinking of features that you want in an obturation material, what single material do you think of

no available material that satifies all these criteria

what do we obturate w

• gutta-percha

• sealer

gutta percha is a core material that…

occupies the bulk of the space

sealer must be used w gutta-percha for adequate…

seal

most popular obturation material

gutta percha

composition of commercial gutta percha

• ~20% gutta-percha

• 65% zinc oxide

• 10% radiopacifiers

• 5% plasticizers

gutta percha bond

1,4 trans-polyisoprene (rubber)

2 different forms/phases of gutta percha

• alpha

• beta

beta form/phase of gutta percha

soild, compactable

alpha form/phase of gutta percha

pliable flowable, tacky

how does gutta percha transition between its alpha and beta phase

• alpha: when heated

• beta: when cooled

advantages of gutta percha (5)

• plasticity

• easy of manipulation

• minimal toxicity

• radiopaque

• removable w heat or solvent

disadvantages of gutta percha (2)

• does not bond to dentin

• shrinks on cooling

taper of gutta percha

• .04

• .02

sizing consistency w .04 taper gutta percha

laser cut, so they are consistent tip size

sizing consistency w .02 taper gutta percha

these are hand-rolled so there is some variation within the ISO size

colors of gutta perch match _____

files:

• 15= white

• 20=yellow

• 25=red

• 30=blue

• 35=green

• 40=black

what is gutta-gauge used for

to trim the tip to the ISO size usually for the .02 taper → using a smaller cone size, putting it into the number side and cutting the opposite side w a blade, spoon, etc)

sealer creates _______

seal

sealer serves as a filler between ____________ and ____________

gutta percha and canal irregularities

sealer serves as a _________ in seating gutta-percha during obturation

lubricant

sealer can flow into _________

dentinal tubules

desired properties of sealer (10)

1. biocompatible

2. seals well- hermetic seal

3. adhesive- between it and canal wall

4. radiopaque

5. non-shrinking

6. non-staining

7. set slowly

8. soluble in solvents, but not tissue fluid

9. bacteriostatic/cidal

10. powder particles should be v fine to allow mixing easily w liquid

5 types of sealer

• zinc oxide eugenol (ZOE)

• calcium hydroxide

• glass ionomer

• resin

• bioceramic

what type of sealer will we be using

bioceramic

advantages of lateral condensation (6)

• can be used in wide variety cases

• does NOT require specialized equipment

• track record of clinical success → well-documented efficacy

• safe and simple to learn for novice clinicians- widely taught and used

• less technique sensitive than some techniques

• predictable length control → less likely to overfill

• good length control

disadvantages of lateral condensation

• requires more time than some techniques

• challenging to use in some clinical cases (just like hard cases)

  • does NOT fill canal irregularities, voids, spreader tract

• risk of vertical root fracture → w finger spreader if too much force is applied

used for cold lateral condensation

finger spreader

5-7 condenser/plugger is used to

condense gutta percha after searing

heated plugger is used to

sear GP

ZOE sealer requires mixing ______ and ______

powder and liquid

components that make-up powder in ZOE sealer (5)

• ZnO

• staybelite resin

• bismuth subcarbonate

• barium sulphate

• sodium borate, anhydrous

component that makes-up liquid in ZOE sealer

eugenol

setting time for ZOE sealer vs in canal

• 2 hour set time

• within root canal 10-30 min → moisture of dentin

quality of _________ influences the setting of ZOE sealer

ZnO and pH

properties of ZOE sealer (4)

• plasticity

• low setting time

• good sealing potential

• small volumetric change on setting

recommended condensation forces w finger spread in canal

<2.5 lb

loads as small as _____ lbs produced fracture

3.3 lbs

too much force applied w finger spreader, a tooth is likely to undergo

vertical root fractures

advantages of ZOE based sealers

• long history of clinical use and well documented success

• good flow

• antibacterial

disadvantages of ZOE based sealers

• stain (earlier formula)

• shrinkage

• cytotoxicity

• solubility

advantages of resin-based epoxy methacrylate sealer

• good adhesion

• flow

• hydrophillic

disadvantages of resin-based epoxy methacrylate sealer

• polymerization shrinkage

• cytotoxicity

advantages of calcium hydroxide-containing sealers

• antibacterial

• biocompatible

• osteogenic

disadvantages of calcium hydroxide-containing sealers

• high solubility

• poor adhesion and seal

advantages of silicon-based sealers

• dimensionally stable

• slight expansion (.03%)

• moisture-resistant

• low solubility

• thixotropic

• biocompatible

disadvantages of silicon-based sealers

• lack of flow

• shorter working time

• not antibacterial

properties of bioceramic sealers (3)

inorganic, non-metallic, biocompatible

bioceramic sealers are based off _____________ that has shown to be very biocompatible and _______________ manufactured as a single paste system

mineral trioxide silicate (MTA) calcium silicate; calcium silicate based sealer

endosequence of bioceramic sealer contains:

• zirconium oxide

• calcium silicates

• calcium phosphate monobasic

• calcium hydroxide filler

• filler

• thickening agents

key features according to brassler, of bioceramic sealer

• biocompatible and osteogenic

• non-resorbable

• chemical bond of sealer to dentin

• chemical bond of sealer to BC and GP points

• less expensive than carrier technique

• highly antibacterial (+12 pH upon setting)

• can be used as an intra-canal medicament

• highn radiopacity

• hydrophillic

• hydroxyapetite producing

• user friendly

• smaller particle size

• no/zero shrinkage

bioceramic sealer kills ____________ within 2 min of contact

enterococcus faecalis

working time for bioceramic sealer

30 min

setting time for bioceramic sealer

3-4 hrs

particle size of bioceramic sealer

.2-.4 um

bioceramic sealers and MTA are both…

bioceramics → they are similar

_______________ is a refined bioceramic which has a much smaller particle size and a much better viscosity

endosequence BC sealer

endosequence BC sealer is a ___ generation bioceramic

2nd

MTA is a ___ generation

1st

bioceramic sealer is a medical grade bioceramic based off the properties of…

MTA that is Portland cement w the heavy metals removed

setting time of calcium silicate sealers

can depend on water content in the environment but confirmed to be 7 days

bioceramic sealers _________ and ________ allow it to create an interface between the sealer, gutta percha, and dentin

viscosity; small particle size

advantages of bioceramic sealers

• hydrophilic

• good sealing ability

• adequate working time

• dimensionally stable

• bacteriostatis/bactericidal

• biocompatible

_______ (min/max) volume of gutta percha does NOT seal, whereas the _____ (min/max) of sealer seals

max; min

which is showing cold lateral condensation vs warm vertical condensation

• C: cold

• D: warm

advantages of single cone obturation

• time efficient

• no special equipment needed

• good length control

disadvantages of single cone obturation

• considered inappropriate when used w traditional sealers

• more voids and leaking in large/oval canals

advantages of single cone obturation w bioceramic sealer-based obturation

• time efficient

• no special equipment needed

• good length control

• dimensionally stability prevents the formation of voids and gaps after the sealer sets

disadvantages of single cone obturation w bioceramic sealer-based obturation

more voids and leaking in large/oval canals

in the single cone obturation w bioceramic sealer-based obturation technique, gutta percha is used as a delivery tool to help generate….

hydraulic pressure to distribute the sealer (we do NOT do this technique)

9 steps of modified single cone w BC sealer obturation technique

1. MAF radiograph

2. dry canal w paper point

3. select matching WOG GP

4. confirm tug-back

5. master cone RG

6. apply sealer w sterile K file CCW → 1 size smaller than MAF and short of WL

7. “butter” master cone and seat to WL

8. apply accessory cones as needed for large/oval canals → if using .02 taper GP for modified lateral condensation

9. sear GP off within 1 mm facial of CEJ or at orifice in multi rooted teeth

what is an alternative to this step in the modified single cone w BC sealer obturation technique

“apply sealer w sterile K file CCW → 1 size smaller than MAF and short of WL”

coat sterile GP w sealer, place 2 mm short of WL to coat canal walls

what should you use to eliminate the discrepancies between your working length w a file + silicone stop compared to the WL made by grasping either a file or GP cone w cotton pliers

w MAF, move silicone stop away from reference point → grasp the file shaft while touching the reference cusp → remove and measure the length from the file tip to the cotton pliers → use this length to determine whether GP is seated

initial condensation radiograph has what

• master cone GP

• sealer

• accessory if needed