Obturation

Question 1

Cold lateral compaction

Answer 1

• master cone to CWL
• check tuck back
• GP should be at CWL and dry canal with paper points
• coat GP cone with sealer
• excess will lead to extrusion
• Super- endo alpha to cut GP
• use Vitrebond to place at orifice

Question 2

Objective of RCT

Answer 2

• provide an environment that allows healing of periradicular tissues so that tooth is retained as a functional unit in the dental arch

Question 3

Working Length

Answer 3

• prep should end at junction of pulpal and periapical tissue
• WL should be as close as CDJ
• usually the narrowest part of the canal, called apical constriction

Question 4

Why fill RCS?

Answer 4

• prevent passage of microorganisms ans fluid along RC and to fill whole canal system
• not only block apical foramen but also the dentinal tubules and accessory canals
• must be carried out after completion of RC prep and when infection is considered to ahve been eliminated and canal can be dried

Question 5

Requirements for materials to fill RCS?

Answer 5

• biocompatible
• dimensionally stable
• able to seal
• unaffected by tissue fluid and insoluble
• non- supportive of bacterial growth
• radiopaque
• removable from canal if re- tx needed

Question 6

Why GP cone needs sealer?

Answer 6

• to fill the voids between the semi solid material and root canal wall

Question 7

GP cone Gutta- Percha

Answer 7

• most common core material
• 20% GP
• 65% ZnO
• 10% Radiopacifiers
• 5% Plasticizers

Question 8

Cold lateral compaction

Answer 8

Pros
- most commonly taught and used
- low cost
- ability to control length of fill

Cons
- voids
- spreader tracts
- incomplete fusion of GP cones
- lack of surface adaptation

Question 9

Warm Vertical Compaction

Answer 9

• achieve 3D obturation
• require continuously tapering funnel and minimal apical diameter
• remove more and more GP
• apical plug of GP and sealer
• place pieces of GP one by one

Question 10

Continuous wave obturation

Answer 10

Question 11

Carrier based obturation

Answer 11

• use hand file as carrier with GP around

Question 12

If tooth is dens in dente?

Answer 12

• fill canal using Bioceramic cements
• MTA - mineral trioxide aggregate
• Biodentine

Question 13

MTA

Answer 13

• harder to remove
• good tissue response

Question 14

Sealer Functions?

Answer 14

• seal space between dentinal wall and core
• fills voids and irregularities in canal, lateral canals ands between GP points used in lateral condensation
• lubricates during obturation

Question 15

Properties of ideal sealer

Answer 15

• exhibits tackiness to provide good adhesion
• establish hermetic seal
• radiopacity
• easily mixed
• no shrinkage on setting
• non- staining
• bacteriostatic/ does not encourage growth
• slow set
• insoluble in tissue fluid
• tissue tolerant
• soluble on re-tx

Question 16

ZnO eugenol based sealer

Answer 16

• antimicrobial
• cytoprotection
• resin acids affect lipids in cell membrane, hence antimicrobial/ cytotoxic
• beneficial with longlasting antimicrobial with cytoprotective effects
• lose volume with time due to dissolution
• breakdown apical seal

Question 17

GI sealer

Answer 17

• dentine bonding properties
• will expand
• minimal antimicrobial activity
• greater solubility
• removal for re- tx is diff

Question 18

Resin sealer, ie: AH plus

Answer 18

• epoxy resin
• paste- paste mixing
• slow setting of 8 hours
• good sealing ability
• good flow
• initial toxicity declining after 24 hours

Question 19

EndoRez as Resin sealer

Answer 19

• UDMA resin based sealer
• hydrophilic
• good penetration to tubules
• biocompatible
• good radioopacity

Question 20

Calcium silicate sealers

Answer 20

• high pH 12.8 during initial 24 hours of setting
• hydrophilic
• enhanced biocompatibility
• does not shrink on setting
• non- resorbable
• excellent sealing ability
• quick set 3-4 hours
• requires moisture
• easy to use
• ie: Bioceramic

Question 21

Assess of obturation

Answer 21

• post-op radiograph
• length
• taper
• density
• GP and sealer removal to facial CEJ in anteriors and canal orifice in posteriors

Question 22

Why tooth should be restored after RCF

Answer 22

• prevent bacterial recontamination of RCS
• prevent fracture of tooth

Question 23

Orifice closure

Answer 23

• finish obturation at orifice/ below orifice level
• ZnO/ Eugenol materials are cytotoxic and form effective antibacterial barrier
• RMGI/ flowable composite

Question 24

CHX

Answer 24

• bisbiguanide
• works on bacterial cell walls causing cell lysis and cell death

Question 25

NaOCl extrusion

Answer 25

• swelling
• brusing/ ecchymosis
• paraesthesia
• haemorrhage
• airway obstruction- submental, submandibular swelling