2. artificial crowns partial veneer crowns -midterm2

ARTIFICIAL ARTIFICIAL CROWNSCROWNS

PARTIAL VENEER PARTIAL VENEER CROWNSCROWNS

A type of crown that partially covers or veneers the clinical crown

Usually the involved surfaces are the proximal, lingual and incisal/occlusal (anterior and posterior ¾ crown) and some buccal (posterior 7/8 crown and modified ¾ crown) except for laminate veneers wherein the labial, incisal and proximal surfaces are involved

Several types of partial veneers exist:

a.   Posterior teetha.   Posterior teeth

1. Three-quarter crown1. Three-quarter crown

2. Modified three-2. Modified three-quarter crownquarter crown

3. Seven-eights crown3. Seven-eights crown

Several types of partial veneers exist:

b.   Anterior teethb.   Anterior teeth

1. Three-quarter crown

2. Pinledge 3. Laminate veneer

TYPES OFTYPES OF PARTIAL VENEER CROWNS

1. Posterior Teeth PVC

Three-quarter crownSeven-eighth crown

Modified three-quarter crown

Indications:Indications:

a. Sturdy clinical crown of average a. Sturdy clinical crown of average length or longer length or longer

b. Intact buccal surface not in need b. Intact buccal surface not in need of of contour modification and contour modification and well- well- supported by sound supported by sound tooth tooth structure structure

c. No conflict between axial c. No conflict between axial relationship of tooth and relationship of tooth and

proposed path of proposed path of withdrawal of withdrawal of FPD FPD

Contraindications:

a.   Short teetha.   Short teeth

b.   High caries indexb.   High caries index

c.    Extensive destructionc.    Extensive destruction

d.   Poor alignmentd.   Poor alignment

e.    Bulbous teeth e.    Bulbous teeth

f.    Thin teethf.    Thin teeth

Advantages:

a.  Conservative of tooth structurea.  Conservative of tooth structure

b.  Easy access to marginsb.  Easy access to margins

c.  Less gingival involvement than c.  Less gingival involvement than with complete cast crown with complete cast crown

d.  Verification of seating simpled.  Verification of seating simple

e.  Electric vitality test feasiblee.  Electric vitality test feasible

Disadvantages:

a. Slightly less retentive a. Slightly less retentive than complete cast than complete cast crowncrown

b. Limited adjustment of b. Limited adjustment of path of withdrawalpath of withdrawal

c. Some display of metalc. Some display of metal

2. Anterior Teeth PVC a. Three-quarter crown

Indications:Indications:a. Sturdy clinical crown of average a. Sturdy clinical crown of average

length or longerlength or longer

b. Intact labial surface that is not in b. Intact labial surface that is not in need of need of contour contour

modification modification and that is supported and that is supported by sound by sound tooth structuretooth structure

c. No discrepancy between axial c. No discrepancy between axial relationship relationship of tooth of tooth and and proposed path of proposed path of withdrawal of withdrawal of

FPDFPD

Contraindications:a.   Short teetha.   Short teeth

b.   Nonvital teethb.   Nonvital teeth

c.    High caries indexc.    High caries index

d.   Extensive destructiond.   Extensive destruction

e. Poor alignment with path of e. Poor alignment with path of withdrawal of FPDwithdrawal of FPD

f.    Cervical cariesf.    Cervical caries

g.   Bulbous teethg.   Bulbous teeth

h.   Thin teethh.   Thin teeth

Advantages:a.  Conservation of tooth structurea.  Conservation of tooth structure

b.  Easy access to margins for finishing b.  Easy access to margins for finishing (dentist) and cleaning (patient)(dentist) and cleaning (patient)

c.   Less gingival involvement than c.   Less gingival involvement than with complete cast crownwith complete cast crown

d.  Easy escape of cement and good d.  Easy escape of cement and good seatingseating

e.  Easy verification of complete e.  Easy verification of complete seatingseating

f.  Electric vitality test feasiblef.  Electric vitality test feasible

Disadvantages:

a. Slightly less retentive than a. Slightly less retentive than complete complete cast crowncast crown

b. Limited adjustment of path of b. Limited adjustment of path of insertioninsertion

c. Some display of metalc. Some display of metal

d. Not indicated on nonvital teethd. Not indicated on nonvital teeth

2. Anterior Teeth PVC b. Pinledge

Periodontal problemLingual Preparation

Anterior Splinting

Indications:

a.  Undamaged anterior tth in a.  Undamaged anterior tth in caries-caries- free mouthfree mouth

b.  A high esthetic requirementb.  A high esthetic requirement

c. Where proximal grooves are c. Where proximal grooves are impossible to prepareimpossible to prepare

d. To alter lingual contour of max. d. To alter lingual contour of max. anterior anterior teeth or teeth or

to alter to alter occlusionocclusion

e.   Anterior splintinge.   Anterior splinting

Contraindications:

a.   Large pulpsa.   Large pulps

b.   Thin teethb.   Thin teeth

c.   Nonvital teethc.   Nonvital teeth

d.   Carious involvementd.   Carious involvement

e. Problems with e. Problems with proposed proposed path of path of withdrawalwithdrawal of of FPD FPD

Advantages:

a.   Minimal tooth reductiona.   Minimal tooth reduction

b.   Minimal margin lengthb.   Minimal margin length

c.   Minimum gingival c.   Minimum gingival involvementinvolvement

d.  Optimum access for margin d.  Optimum access for margin finishing and hygiene finishing and hygiene

e.  Adequate retentione.  Adequate retention

f.   Excellent estheticsf.   Excellent esthetics

Disadvantages:

a. Less retentive than a. Less retentive than complete complete coveragecoverage

b.  Alignment can prove b.  Alignment can prove difficultdifficult

c.  Technically demandingc.  Technically demanding

d. Not usable on nonvital d. Not usable on nonvital teethteeth

2. Anterior Teeth PVC2. Anterior Teeth PVC

c. Porcelain c. Porcelain Laminate Laminate

VeneerVeneer

0.3-0.5mm

Proximal contact areas and incisal edge are preserved and the preparation is limited to enamel.

A reduction depth of 0.3- 0.5mm is recommended.

Prepared Teeth for Prepared Teeth for Laminate VeneersLaminate Veneers

Chamfer

Cemented Laminate Cemented Laminate VeneersVeneers

Functionality of bite is critical to comfortable dental rehabilitation.  The mandibular incisors should be in gentle touch with the palatal surfaces of the maxillary incisors, being 1 mm behind and 1 mm below.

  The "S" sound is used to determine the vertical height of dimension.  This helps us to determine the relation of the maxillary and mandibular teeth.

1mm.

1mm.

When porcelain laminate veneers are properly prepared, produced, and finished, an increase of the crevicular fluid decreases the plaque index, and one can see the healthy tissue around the biologically integrated porcelain laminate veneers.

Indications:Indications:

a. Discoloration (e.g. dental fluorosis or mottled

enamel/Tetracycline stain)

b. Correcting  diastema

Diastema closure and lengthening of crown cervicoincisally/widening mesiodistally

c. Fracture involving c. Fracture involving proximoincisal surfaceproximoincisal surface

A B

CD

d.  Masking tooth defects

ex. Peg shaped incisors

e. lengthening of crown cervicoincisally for esthetics

Contraindications:Contraindications:a.  High caries indexb.  Poor plaque controlc.  Extensive existing large

restorations or endodon- tically teeth with little remaining tooth structured.  Tooth wear due to BRUXISMe. Short teeth

f. Teeth with insufficient or inadequate enamel for sufficient retention

(ex. Severe abrasion) g. Patients with oral habits causing

excessive stress on the restoration

(ex. nail biting/pencil biting)

Advantages:Advantages: a. Superior estheticsb. Wear and stain resistantc. Excellent long term

durability – abrasion-resistant/color-stable, excellent resistance to fluid absorption

d. Inherent porcelain strength – exhibits excellent compressive, tensile and shear strength

e. Minimal tooth reduction – 0.3-0.5mm only

f. Soft tissue compatibility – biocompatible w/ soft tissues

Disadvantages:Disadvantages:a.   Increased tooth contour b. Expensivec. Time – multiple visits are requiredd. Fragility – during try-in and

cementatione. Lack of repair ability – difficult, if not

impossible, to repairf. Difficulty in color matchingg. Irreversibility – unlike bleaching,

requires tth reduction although minimal h. Inability to trial cement the

restoration