1. Indications, clinical and laboratory stages of manufacture of pin teeth.

2. ? ? ?

3. How ?
Why ?

4. NON - ODONTOGENIC CYST Misdiagnosis resulted in unnecessary endodontic
treatment of four anterior
teeth.
4/1972

14. The Result
The Concern

15. Considerations for Anterior Teeth
A metal post is not recommended in anterior teeth which do not require complete coverage restorations. This decision primarily focuses on:
[1] the integrity of the remaining tooth structure.
[2] the amount of functional load which to anterior teeth are subjected.
[3] the morphologic development of anterior teeth.

16. Variation in bite force by location

18. The incisal edge of lower anterior teeth
function across the lobes of opposing
upper incisors

20. Comparative resistance to fracture to shear loading

21. Comparison of fracture stress with varying post types

22. Comparative fracture loads with and without posts

23. Comparative fracture loads with and without posts

32. Considerations for posterior teeth
Virtually all posterior teeth which have received endodontic therapy are in turn recommended for a cast restoration coronally. In turn if a coronal buildup is deemed necessary {core} for retention of the cast restoration, then further the decision for the need of a post must be determined. The prevailing considerations for posterior teeth:
[1] greater functional loading of posterior teeth.
[2] morphologic disposition of posterior teeth to splitting.

34. Fusion of buccal and lingual lobes

40. Hazards of treatment
at a S.D.M.

41. Intra-radicular build up without post for molar teeth

47. Design Considerations for Posts

48. Post - endodontic internal build up
Direct restorative
with or without
prefabricated
post in canal
Custom cast post
with core fabricated
either directly or
indirectly or

49. Design considerations for posts
Diameter
retain as much dentin as possible in the roots of all teeth; increasing the diameter of the post has a minimally significant effect on the increase in retention.

50. Effect of Dowel Design and Diameter
On Retention
Zinc Phosphate
8 mm length
Force in Kg

51. Design Considerations for Posts
Taper vs. Parallel
parallel sided design has repeatedly been shown to create significantly less concentration of stress at its tip than a tapered design
parallel sided design has in various reports has been show to provide retention of 1.9 X, 3.3 X, 4.5 X greater than tapered design
in situations where a tapered design is used, it is critical to provide a flat root interface on which the core will seat

52. Force in Kg

53. Design Considerations for Posts
Length
equal to the length of the clinical crown
equal to 3/4 of the root length
equal to 1/2 the length of the canal
equal to 1/2 the length of the root in bone
maintaining 4 mm. of endodontic filling material at the apex of the root

54. Design Considerations for Posts
Length
equal to the length of the clinical crown
maintaining 4 mm. of endodontic filling material at the apex of the root

55. Design Considerations for Posts
Surface Configuration
Fluted or irregular surface configurations because of their increased mechanical retention when cemented within the root are deemed most appropriate.
Adhesively bonded posts are not influenced by
surface configuration.
Active engagement of the root with threaded surface configurations have been shown to be the most retentive but also the most predictive of root fracture; therefore the recommendation for post placement into the root irrespective of surface configuration is a “passive design”.

56. A B C D
Passive
Active

57. Additional design considerations for posts
Resistance form
the irregular shape of a canal particularly with a cast post/ core provides useful circumferential irregularity for an anti- rotational effect; in situations where this is not present and there is minimal remaining coronal dentin, it is advisable to prepare a keyway at the orifice of the canal or include supplemental pins for an anti- rotational effect.

59. Luting Materials for Posts
Zinc phosphate -
{ Fleck’s, Tenacin }
Glass Ionomer -
{ Fuji I, Fuji plus, Ketac-Cem }
Polycarboxylate -
{ Livcarbo, Durelon, Hy-Bond }
Adhesive resin -
{ All- Bond, C& B Metabond,
Variolink II, Panavia }

60. Effect of luting agent on retention

61. Effect of luting agent on retention

62. Manipulation of cement during post placement

63. Manipulation of cement during post placement

65. Additional Design Considerations with Posts
Ferrule effect
The principle of extending the crown margin apical to the ‘tooth stump - core interface’ at least 1.5 mm. to circumferentially encompass the tooth. This reduces the fracture potential of the post within the root when the crown is in function.

69. Fracture Comparison of Post Designs with and without Ferrule

77. Customized Cast Post and Core
Direct pattern fabrication
Indirect pattern fabrication

78. Materials/Designs/Shapes
Fiber reinforced
Zirconium
Stainless steel
Titanium
Design
Active
Passive
Hybrid
Shape
Parallel
Tapered
Multi-stage

79. Fiber reinforced Enhanced aesthetics Excellent biocompatibility
No galvanic corrosion signs
Mechanical properties similar to dentin
Easy to use and remove
Firm retention - adhesive bonding
Lower radiopacity than metal post

80. Stainless Steel Good mechanical properties
Problematic esthetics at times
Potential corrosion and embedding of decomposition products
Potential damage to remaining structure
Cemented using zinc phosphate,
glass ionomer, or polycarboxylate cement.

81. Titanium Good mechanical properties Excellent biocompatibility
Questionable aesthetics at times
Potential damage to remaining structure
Cemented with zinc phosphate, glass
ionomer,or polycarboxylate cement

82. Metal v. Fiber Reinforced
Coronal impact is transmitted to remaining tooth
Fiber reinforced
Coronal impact is dispersed through the post alleviating force on remaining tooth
             

83. Active Threads to engage the dentin
Provides the greatest retention method
Risk that engagement may lead to fractures
Material is metal

84. Passive Smaller diameter than drill diameter
No risk of engaging dentinal walls
Slightly more material must be removed than metal post
Adhesive bonding increases retention

85. Hybrid Active at coronal end and passive at apical area
   
     
Active at coronal end and passive at apical area
Used where some mechanical retention is demanded
Material is always metal
Active
Passive

86. Parallel Same width from coronal to apical area
Greater retention /given length
Requires removal of more tooth structure at apical end of post than tapered design

87. Tapered Narrower at apical than coronal area
Designed to adapt to constriction of root dentin
Requires less dentin removal in apical extent

88. Multi Stage Mainly made in metal designs
Larger at coronal area and narrower at apical area
More technique sensitive
Requires multiple drills

89. Fiber Reinforced Posts

94. FRC Postec System

95. Features Benefits Metal-free post with a high degree of translucency
Esthetic properties compatible with all-ceramic restorations
Longitudinal placed glass fibers
Provides light transmittance & translucency
Modulus of elasticity similar to dentin
Minimizes stress concentrations within root structure ?
Passive, tapered design
Provides an excellent fit and saves remaining tooth structure at apical extent ?
Two post sizes with color coded matching reamers
Applied to virtually all teeth except those
with extremely small diameter roots
Adhesively bonded
Excellent retention properties
Integrated system
Coordinated materials for a total adhesive
build-up technique
Retrievable
Possibility for endodontic re-treatment

96. Radiopacity FRC Postec shows reduced radiopacity
Used in conjunction with Variolink II provides additional x-ray identification

97. Comparative X-rays
FRC Postec ParaPost Fiber White FiberKor Luscent Anchor
Ivoclar Vivadent Coltene Whaledent Pentron Dentatus

98. Removal
FRC Postec can be removed with a rotary instrument if retreatment is required

99. Post space preparation
Is it necessary ?
Which canal(s) ?
What size and length ?
What material ?

100. Post Space Preparation
4 mm
Length of
Clinical
Crown

101. Conditioning of the Post Space
Try in the post
Rinse the canal
With NaOCl or
H2O2
Dry canal with
paper points

102. Conditioning of the Post Space
Etch canal and
coronal dentin
with phosphoric acid
Rinse all residue
of etching gel
Dry canal with
paper points
15s

103. Conditioning of the Post Space
Apply dual cure
bonding agent
Remove excess
With paper points
Rinse post with
alcohol and dry
10s

104. Conditioning of the Post
Place the post and fully seat it
Remove excess
Mix Variolink II Base and Catalyst
Coat the cement on FRC Postec

105. Conditioning of the Post
Condition post
surface 60 sec
with silane
Dispense luting
resin
Air dry post
60s

106. Coating and placement of the Post
Mix equal lengths
of base and catalyst
for 20 sec
Coat the post
with resin cement
Passively seat the
post and remove
excess above canal
orifice

107. Direct Core Build-up Build up core with direct composite in increments
Light cure for
60 sec
Prepare tooth
for crown
60s
40s