Endodontically - Treated Post& Core System IMPT
Endodontically - Treated Post& Core System IMPT
Endodontically - Treated Post& Core System IMPT
Endodontically
Treated Teeth
Post and Core System
Characteristics of endodontically treated teeth
1. Tooth structure loss by:
i. Caries, trauma, erosion, abrasion, attrition.
ii. Previous restorations and recurrent caries under restorations.
iii. Endodontic treatment; due to removal of coronal and intraradicular
Dentine during access and root canal preparation.
2. Micro cracks in remaining tooth structure produced by endodontic
procedures.
3. Weakened collagen intermolecular cross-links of Dentine lower shear
strength.
4. Dehydration; non-vital teeth have less moisture content than vital teeth.
5. Esthetics; biochemically altered Dentine modifies light refraction through the
tooth and modifies its appearance.
I. Direct method
• Material:
A. Wax.
B. Self cure A.R.
C. Plastic ready-made burn out post.
• Steps:
1. Lubrication of root canal (die lubricant).
2. If direct wax pattern:
1) Select a metallic sprue former:
- Fits loosely inside R.C.
- Length > than that of core.
- Serrated using diamond stone or disc (to ensure good retention bet.
wax & sprue).
2) Softening of blue casting wax and insertion into the R.C.
3) Heating of sprue.
4) Wait till hardening of wax.
5) Add for any deficiencies until it’s removed with slight resistance
“snugly fit”.
6) Core can be made of wax, followed by investing and casting.
3. If direct A.R. pattern:
1) Select a plastic dowel:
- Fits loosely inside R.C
- Long.
- Serrated (notched).
2) Mixing of A.R. and insertion into the R.C. before the dough stage.
3) Before complete curing, moisten the dowel with monomer and
insert into R.C.
4) Also before complete curing, move the plastic dowel inward and
outwards to prevent interlocking in any undercuts or roughness.
5) Add any modifications until it’s removed with slight resistance
“snugly fit”.
6) Investing and casting.