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

transcript

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

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

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

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

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

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

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

$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%

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

Length ofClinicalCrown

Conditioning of the Post SpaceConditioning of the Post Space

Try in the post

Rinse the canalWith NaOCl orH2O2

Dry canal withpaper points

Etch canal andcoronal dentinwith phosphoric acid

Rinse all residueof etching gel

Dry canal withpaper points

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

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

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

Documents