Indications, clinical and laboratory stages of manufacture of pin teeth.
-
Upload
linda-downs -
Category
Documents
-
view
30 -
download
2
description
Transcript of Indications, clinical and laboratory stages of manufacture of pin teeth.
Indications, clinical and
laboratory stages of
manufacture of pin teeth.
How ?How ?
Why ?Why ?
NON - ODONTOGENICNON - ODONTOGENIC CYSTCYST
Misdiagnosis resultedin unnecessary endodontictreatment of four anteriorteeth.
4/1972
Considerations for Anterior Considerations for Anterior TeethTeeth
A metal post is not recommended in A metal post is not recommended in anterior teeth which do not require anterior teeth which do not require complete coverage restorations. complete coverage restorations. This decision primarily focuses on:This decision primarily focuses on:
[1][1] the integrity of the remaining tooth the integrity of the remaining tooth structure.structure.
[2][2] the amount of functional load which to the amount of functional load which toanterior teeth are subjected.anterior teeth are subjected.
[3][3] the morphologic development of anterior the morphologic development of anterior teeth.teeth.
Variation in bite force by Variation in bite force by locationlocation
The incisal edge of lower anterior teethThe incisal edge of lower anterior teethfunction across the lobes of opposingfunction across the lobes of opposingupper incisorsupper incisors
Comparative resistance to Comparative resistance to fracture to shear loadingfracture to shear loading
Comparison of fracture Comparison of fracture stress with varying post stress with varying post
typestypes
Comparative fracture loads Comparative fracture loads with and without postswith and without posts
Comparative fracture loads Comparative fracture loads with and without postswith and without posts
Considerations for posterior Considerations for posterior teethteeth
Virtually all posterior teeth which have received Virtually all posterior teeth which have received endodontic therapy are in turn recommended endodontic therapy are in turn recommended for a cast restoration coronally. In turn if a for a cast restoration coronally. In turn if a coronal buildup is deemed necessary {core} for coronal buildup is deemed necessary {core} for retention of the cast restoration, then further retention of the cast restoration, then further the decision for the need of a post must be the decision for the need of a post must be determined. The prevailing considerations for determined. The prevailing considerations for posterior teeth: posterior teeth:
[1][1] greater functional loading of posterior greater functional loading of posterior teeth. teeth.
[2][2] morphologic disposition of posterior teeth morphologic disposition of posterior teeth to splitting.to splitting.
Fusion of buccal and lingual lobesFusion of buccal and lingual lobes
Fusion of buccal and lingual lobesFusion of buccal and lingual lobes
Intra-radicular build up Intra-radicular build up without post for molar teethwithout post for molar teeth
Design Considerations for Posts
Post - endodontic internalPost - endodontic internal build upbuild up
Direct restorativeDirect restorativewith with oror without withoutprefabricatedprefabricatedpost in canalpost in canal
Custom cast postCustom cast postwith core fabricatedwith core fabricatedeither directly oreither directly orindirectlyindirectly
Design considerations for Design considerations for postsposts
DiameterDiameter
retain as much dentin as possibleretain as much dentin as possible in the in the roots of all teeth; increasing the diameter roots of all teeth; increasing the diameter of the post has a minimally significant of the post has a minimally significant effect on the increase in retention. effect on the increase in retention.
0 10 20 30 40 50
Tapered 1.6 mm
Tapered 1.8 mm
Parallel 1.6 mm
Parallel 1.8 mm
Force in Kg
Effect of Dowel Design and DiameterOn Retention
Zinc Phosphate8 mm length
Design Considerations for Design Considerations for PostsPosts
Taper vs. ParallelTaper 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
0 5 10 15 20 25 30
Unitek tapered 5 mm
Unitek tapered 8 mm
Whaledent parallel 5 mm
Whaledent parallel 8 mm
Force in Kg
Design Considerations for Design Considerations for PostsPosts
LengthLength
equal to the length of the clinical crownequal to the length of the clinical crown equal to 3/4 of the root lengthequal to 3/4 of the root length equal to 1/2 the length of the canalequal to 1/2 the length of the canal equal to 1/2 the length of the root in equal to 1/2 the length of the root in
bonebone maintaining 4 mm. of endodontic filling maintaining 4 mm. of endodontic filling
material at the apex of the rootmaterial at the apex of the root
Design Considerations for Design Considerations for PostsPosts
LengthLength
equal to the length of the clinical crownequal to the length of the clinical crown
maintaining 4 mm. of endodontic filling maintaining 4 mm. of endodontic filling material at the apex of the rootmaterial at the apex of the root
Design Considerations for Design Considerations for PostsPosts
Surface ConfigurationSurface 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 bysurface 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”.passive design”.
PassivePassive ActiveActive
A B C D
Additional design considerations for posts
Resistance formResistance 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.
Luting Materials for PostsLuting Materials for Posts
• Zinc phosphateZinc phosphate - { Fleck’s, Tenacin }
• Glass IonomerGlass Ionomer - { Fuji I, Fuji plus, Ketac-Cem }
• PolycarboxylatePolycarboxylate - { Livcarbo, Durelon, Hy-Bond }
• Adhesive resinAdhesive resin - { All- Bond, C& B Metabond,
Variolink II, Panavia }
Effect of luting agent on Effect of luting agent on retentionretention
Effect of luting agent on Effect of luting agent on retentionretention
Manipulation of cement Manipulation of cement during post placementduring post placement
Manipulation of cement Manipulation of cement during post placementduring post placement
Additional Design Additional Design Considerations with Posts Considerations with Posts
Ferrule effectFerrule 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.
Fracture Comparison of Post Fracture Comparison of Post Designs with and without Designs with and without
FerruleFerrule
Customized Cast Post and CoreCustomized Cast Post and Core
Direct pattern fabrication
Indirect pattern fabrication
Materials/Designs/Shapes
MaterialFiber
reinforcedZirconium
Stainless steelTitanium
Design
ActivePassiveHybrid
ShapeShape
ParallelTapered
Multi-stage
Fiber reinforced
Enhanced aestheticsExcellent biocompatibilityNo galvanic corrosion signsMechanical properties similar to dentinEasy to use and remove Firm retention - adhesive bonding Lower radiopacity than metal post
Stainless Steel
Good mechanical properties Problematic esthetics at timesPotential corrosion and embedding of decomposition productsPotential damage to remaining structure Cemented using zinc phosphate,glass ionomer, or polycarboxylate cement.
Titanium
Good mechanical propertiesExcellent biocompatibility Questionable aesthetics at timesPotential damage to remaining structureCemented with zinc phosphate, glassionomer,or polycarboxylate cement
Metal v. Fiber Reinforced
MetalMetalCoronal impact is transmitted to remaining tooth
Fiber reinforcedFiber reinforcedCoronal impact is dispersed through the post alleviating force on remaining tooth
Active
Threads to engage the dentinProvides the greatest retention methodRisk that engagement may lead to fracturesMaterial is metal
Passive
Smaller diameter than drill diameterNo risk of engaging dentinal wallsSlightly more material must be removed than metal postAdhesive bonding increases retention
Hybrid
Active at coronal end and passive at apical areaUsed where some mechanical retention is demandedMaterial is always metal
Active
Passive
Parallel
Same width from coronal to apical areaGreater retention /given lengthRequires removal of more tooth structure at apical end of post than tapered design
Tapered
Narrower at apical than coronal areaDesigned to adapt to constriction of root dentinRequires less dentin removal in apical extent
Multi Stage
Mainly made in metal designsLarger at coronal area and narrower at apical areaMore technique sensitive Requires multiple drills
D e s i g n
P o s t M a t e r i a l
A c t i v e P a s s i v e H y b r i d S h a p e
F i b e r r e i n f o r c e d
P a r a P o s t F i b e r W h i t e – C o l t e n e W h a l e d e n t
C o r e P o s t – D e n M a t
F i b r e K o r P o s t - P e n t r o n
P a r a l l e l
F R C P o s t e c - I v o c l a r
D T L i g h t P o s t - B i s c o
L u s c e n t A n c h o r s - D e n t a t u s
A e s t h e t i c P l u s - B i s c o
T a p e r e d
M u l i t S t a g e
Fiber Reinforced PostsFiber Reinforced Posts
$16,009,238
$17,630,111$18,021,250
$19,167,932 $19,373,966
$0
$2,000,000
$4,000,000
$6,000,000
$8,000,000
$10,000,000
$12,000,000
$14,000,000
$16,000,000
$18,000,000
$20,000,000
1997 1998 1999 2000 2001
Total Retail Market Value- Posts1997-2001
Posts-Introductory KitsBrand Market Share
YTD 2001
Para Post Fiber White17%
Flexi Post11%
Para Post Plus11%
Para Post XT9%
Others8%
Luscent7%
Para Post XP7%
Para Post XH7%
Intergrapost5%
Private Label5%
Dentatus Post4%
C-I2%
Kurer Ready Core2%
Kurer Universal Anchor2%
Flexi Flange3%
Post Refills-Brand Market Share2001 YTD
Flexi Post27%
Para Post18%
Para Post Plus17%
Para Post XT8%
Dentatus Post8%
Integra Post5%
Para Post XP5%
Para Post XH5%
Flexi Flange4%
Para Post Fiber White3%
FRC Postec System
Features BenefitsMetal-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 thosewith extremely small diameter roots
Adhesively bonded Excellent retention properties
Integrated system Coordinated materials for a total adhesivebuild-up technique
Retrievable Possibility for endodontic re-treatment
RadiopacityRadiopacity
FRC Postec shows reduced radiopacity
Used in conjunction with Variolink II provides additional x-ray identification
Comparative X-raysComparative X-rays
FRC Postec ParaPost Fiber White FiberKor Luscent AnchorIvoclar Vivadent Coltene Whaledent Pentron Dentatus
RemovalRemoval
FRC Postec can be removed with a rotary instrument if retreatment is required
Post space preparationPost space preparationIs it necessary ?Which canal(s) ?
What size and length ?What material ?
Post Space PreparationPost Space Preparation
4 mm
Length ofClinicalCrown
Conditioning of the Post SpaceConditioning of the Post Space
Try in the post
Rinse the canalWith NaOCl orH2O2
Dry canal withpaper points
Conditioning of the Post SpaceConditioning of the Post Space
15s
Etch canal andcoronal dentinwith phosphoric acid
Rinse all residueof etching gel
Dry canal withpaper points
Conditioning of the Post SpaceConditioning of the Post Space
10s
Apply dual curebonding agent
Remove excessWith paper points
Rinse post withalcohol and dry
Conditioning of the PostConditioning of the Post
Coat the cement on FRC Postec
Mix Variolink II Base and Catalyst
Place the post and fully seat it Remove excess
Conditioning of the PostConditioning of the Post
60s
Condition post surface 60 sec with silane Air dry post
Dispense lutingresin
Coating and placement of the Coating and placement of the PostPost
Mix equal lengthsof base and catalystfor 20 sec
Coat the postwith resin cement
Passively seat thepost and removeexcess above canalorifice
Direct Core Build-upDirect Core Build-up
40s60s
Light cure for60 sec
Build up core withdirect composite inincrements
Prepare toothfor crown