3. Post: is a metallic
structure that is placed
within the body of the
root of a tooth that has
had previouse root canal
therapy.
Core: is the part of the
post that shown in the
tooth. It is the part of
that can anchor a cop or
crown.
4. • ET teeth dry out over time and suggested more brittle and
may fracture more easily than non-ET teeth.
• They are like a dead tree branch in comparison to one that
is alive ,so they tend to break a few years down.
• They are likely to shear off because of biting forces. For this
reason, simple fillings do not usually restore them for very
long. These teeth need to have crown placed in order to
protect the investment in the root canal treatment.
5. .Post does not strength the tooth structure.
.Its main function of post is the retention of a core to
support the coronal restoration.
.The evaluation of whether a post is needed is based
on how much natural tooth substance remains.
6. Convenient features :
1.Maximum retention with minimal loss of tooth
structure.
2.Simultaneous transfer of stress by core.
3.Easy removal if failure treatment.
4.Compatibility with crown.
5.It must be with good apical seal and proper canal
obturation.
• Indications for: Molar Premolar Anterior
7. • Many do not require a post because they have
more tooth substance and a larger pulp chamber
to retain a core buildup.
• But it is required when extensive loss of natural
tooth substance.
• It should be placed in the largest and straightest
canal to avoid weakening the root too much
during post space preparation and root
perforation in curved canals.(distal canal for
mandible and palatal canal for maxilla)
8.
9.
10.
11. • Have less tooth substance and smaller pulp
chambers to retain a core buildup than molars.
• Posts are required more often in premolars.
• There are many anatomical characteristics must
be considered carefully during post space
preparation to avoid perforating the root.
12.
13.
14. • Post may be necessary to retain the core so that
these can resist functional forces.
• Few studies have concluded that a post is not
necessary in an ET anterior tooth with minimal
loss of tooth structure.
• Special care must be exercised when placing
posts in mandibular incisors, as they have thin
roots in the mesiodistal dimension.
21. Advantage:
1.Accurately filled the canal regardless the shape.
2.The core is permanently attached to the post unlike
amalgam or composite that breaks away during impression.
3.Good and mechanical properties.
4.We can use indirect technique.
Disadvantage:
1.esthatic;as the metal shows through the newer all-ceramic
restorations.one way to overcome this is to make a PFM post
and core from a metal ceramic alloy.
2.Requires two visits and laboratory fabrication.
22.
23.
24.
25.
26.
27. Advantage:
1.Can be adjusted and inserted in a single visit.
2.Can be used in multi-rooted teeth by using more than one.
3.Tooth conservation.
4.Good adaptation.
5.Few laboratory procedure.
Disadvantage:
1.Low physical and mechanically prosperities (such as:
amalgam corrosion and GICs low strength).
2.Difficult procedures.
3.susceptibility to micro-leakage.
28.
29.
30.
31.
32.
33. • Advantage:
1.Lower elastic modulus and good distribution of
stress.
2.aesthetics.
3.Low installation time.
• Disadvantage:
1.Poor adaptation to channel.