obturation

Question 1

Describes the warm vertical (multi-wave) technique. Produces dense, dimensionally stable obturations. Makes an important distinction btwn overfilling (well sealed w/ a surplus of GP) vs overextension (going long w/o an adequate seal). Sees no problem w/ overfilling.

Answer 1

Schilder 1967

Question 2

GP showed an initial acute response which lasted 15 days, and was quickly followed by a fibrous tissue encapsulation. A GP/CaOH formulation showed phagocytic activity. Kloroperka showed a severe inflamm rxn and abscess formation. Study carried out to 64 days [ explains why success rate reduced if over-extension of GP]

Answer 2

Seltzer 1975

Question 3

Silver cones removed from teeth which had been treated 3mo-20yrs prior. The cones were moderately to severely corroded. These corrosion products were highly cytotoxic. Postulated to occur form contact w/ tissue fluids.

Answer 3

Seltzer 1972

Question 4

ZOE sealers shrink upon setting. The faster the setting time, the greater the shrinkage. AH26 has an intial expansion followed by contraction. Therefore, you should maximize the central core material and minimize the amt of sealer used.

Answer 4

Schilder 1971

Question 5

content of ah26

Answer 5

AH26 (NB: AH26 PLUS - see Leyhausen JOE)
Powder:
Silver Powder: 10%
Bismuth Oxide: 60% Hexamethylenentetramine 25% Titanium Oxide 5%
Liquid:
100% Bisphenoldiglycidyl ether

Question 6

content of sealapex

Answer 6

Base:
Ca(OH)2 25% ZnO 6.5%
Catalyst:
Barium sulfate Titanium dioxide 5% Zinc stearate 1%

Question 7

contituent of GP

Answer 7

• 59-75% ZnO - filler; antimicrobial

• 19-22% GP - core material

• 1-17% Heavy metal sulfates – radiopacity (eg., Barium sulfate)

• 1-4% Waxes & resins - make more compactable; resins also antimicrobial
• 0.1-0.3% Pigments 


Question 8

Not all extruded materials were removed from the periradicular tissues. Zinc Oxide eugenol based sealers were removed significantly faster than AH Plus and Epexit
Treatment outcomes is not significantly affected by the type of extruded sealers as long as the root canals were adequately treated
Success rate in overfilled cases are significantly higher in teeth with no lesion in comparison with teeth with apical periodontitis
100% heal rate for overfillings in teeth without AP.

Answer 8

Ricucci 2016

Question 9

Overfilling- histo outcome depends on size of overfill and material
*Zinc ions have been shown to be cytotoxic in numerous studies. Perhaps it is the leaching of Zinc in GP causing reaction.
SMALL GP
• Intense, localised tissue response - accumulation of macrophages and GC:: foreign body reaction
• by 3 mo, fewer host cells compared to 1 mo, blends well with surrounding CT
LARGE GP
• FIbrous tissue encapsulation :: foreign body reaction
• By 1 mo, free of any inflammatory cells
CHLOROFORM GP
• Toxic to tissue
• Remnants of cell -> dead cells noted
• initial toxicity causing cell death, followed by a foreign body reaction.
• Tissue response remain same at 3 mo

Answer 9

Sjogren et al 1995