Prostho Veneer Restorations and Radicular Retained Restorations

Part 2 (Gingival Retraction, Impression Material, Provisional Restoration): https://knowt.com/flashcards/e0dd88cc-d968-44a3-86ce-2e310e1191fa?fbclid=IwAR2b8T8TFB-k7-Ip7AIzqgQ1PKyq4B8chmouNWp3OUrV-bBCCfTMZ8vfIgc Part 3 (Light, Color): https://knowt.com/flashcards/470c89f8-0fcc-4443-ad14-a070a6d313a3?fbclid=IwAR2KZDw1yV4hfiyQ5W6OBAaI0s2SB0YdIaW9Ej0OedXOrF9O9cnMI1fVAfM Part 4 (Dental Ceramics, Pontic Design): https://knowt.com/flashcards/91c01a3b-06a7-477f-a377-c550a7f9c170?fbclid=IwAR2DPm4lFwr_ywEf3Ca-KZwR6MjA-Q-xPs4P2VDAxZwAs961T4a9m_3xwpM Part 5: https://knowt.com/flashcards/cb8743cf-48ef-421d-b22f-1a1de53cac5e?isNew=true&fbclid=IwAR370ByXuNScWrhYn9J8mqwYyPjphLelFEowu8M-Ttz8DylN4A_MI8a1Z4E

Fixed Prosthodontics Restoration

1. PFM (Porcelain Fused to Metal Crown)

2. All Ceramic Crown (aka Porcelain Crown, Ceramic Crown)

3. Metal Crown (aka Stainless Steel Crown, Shell Crown)

Partial Veneer Restoration

Three-quarter crown

Pin modified three-quarter crown

Seven-eighths crown

Porcelain laminate veneer

Proximal half crown

Intracoronal Restorations

Inlays

Onlays

Radicular Retained Restorations

Dowel Post and Core

Pre-fabricated Post and Core

PFM (Porcelain Fused to Metal Crown)

A type of crown consisting of a complete coverage cast metal crown with layered fused porcelain, offering superior esthetics but requiring substantial tooth structure removal.

Also known as metal ceramic crown.

PFM Indications

• Esthetics

• Porcelain crown contraindicated

• Gingival involvement

PFM Contraindications

Large pulp chamber

Intact buccal wall

Feasible more conservative retainer

PFM Advantage

Superior esthetics

PFM Disadvantages

Removal of substantial amount of tooth structure

Subject to fracture (porcelain brittleness)

Difficulty to obtain accurate occlusion

Difficult shade selection

Inferior esthetics vs porcelain crown

All Ceramic Crown

A crown made entirely of ceramic material, providing excellent esthetics and resembling natural teeth, but being more susceptible to fracture.

Also known as porcelain crown / ceramic crown.

Fabrication Techniques of Porcelain Crown

Platinum Foil Matrix Technique - old technique, adapted to die

Direct Firing - associated with previous tech., die is removed through air abrasion

Lost Wax - most recent technique

C.H. Land

First ceramic crowns and inlays (1886), platinum foil matrix (1887)

Acrylic Resin

Introduced in 1940s, causing ceramic restorations to decline in popularity until disadvantage of resin materials was realized

High Strength Porcelains

Developed due to incidence of fracture in old ceramic restorations.

Two paths:

• Two ceramic materials to fabricate the restoration (high strength, non-esthetic core + low strength, esthetic ceramic)

• Ceramic materials that combine good esthetics with high strength ceramics

• Glass-alumina composite is used instead of feldspar

• Fused aluminum oxide particles are much stronger, acting as a constraint model

High Strength Ceramic Core Indications

High esthetics

Proximal caries

Intact incisal edge

Endodontically treated (w/ post and core)

Favorable distribution of occlusal load

Contraindication of High Strength Ceramic Core

Superior strength is warranted

Significant caries with sufficient coronal tooth structure

Thin teeth faciolingually

Unfavorable distribution of occlusal load

High Strength Ceramic Core Advantages

Esthetics unsurpassed

Good tissue response

Conservative of facial wall

High Strength Ceramic Core Disadvantages

1. Reduced strength (vs PFM)

2. Proper preparation EXTREMELY CRITICAL

3. Among least conservative restoration

4. Brittle

5. Single restoration only

McLean and Hughes

Introduced High Strength Ceramic Core in 1965

Complete Cast Crown

Single tooth or as a retainer

Adequate tooth structure removal to allow restoration to its original contour

Reduction should be sufficient to produce acceptable strength

Complete Cast Crown Advantages

Greater retention and resistance (vs partial veneer crown)

Superior strength

Can modify the axial tooth contour (dealing with malaligned teeth)

Allows modification for proper placement of survey lines, guide planes, and occlusal rests

Easy modification of the occlusion on supraerupted teeth

Complete Cast Crown Disadvantages

Extensive reduction of the occlusal

Common incidence of inflammation of gingiva

Electric vitality test no longer feasible

Objections to display of metal

Complete Cast Crown Indicators

Extensive coronal destruction

Maximum retention and resistance OR high displacement force is anticipated

Support a removable partial denture

Endodontically treated teeth

Complete Cast Crown Contraindications

More conservative restoration

Need for high esthetics

Partial Veneer Crown (POSTERIOR) Indication

Sturdy clinical crown of average length OR longer

Intact buccal surface not in need of contour modification

No conflict between axial relationship of tooth and proposed path of withdrawal

Partial Veneer Crown (POSTERIOR) Contraindications

Short teeth

High caries index

Poor alignment

Bulbous teeth

Thin teeth

Partial Veneer Crown (POSTERIOR) Advantages

Conservative of tooth preparation

Easy access to margins for finishing (dentist), for cleaning (patient)

Less gingival involvement than with complete cast crown

Easy escape of cement and good seating

Easy verification of seating simple

Electric vitality test feasible

Partial Veneer Crown (POSTERIOR) Disadvantages

Slightly less retentive than complete cast crown

Limited adjustment of path of withdrawal

Some display of metal

Partial Veneer Crown (ANTERIOR)

Indication

• Same as posterior PVC

Contraindication

• Same as posterior, additional:

  • Nonvital teeth

  • Extensive destruction

  • Cervical caries

Advantages

• Same as posterior

Disadvantages

• Same as posterior, additional:

  • Non-indicated on non-vital teeth

Acid Etching

Retention is accomplished by creation of microporosites in the porcelain and enamel

Treated with 10% acid solution (hydrofluoric acid)

Normally used phosphoric acid

Silane Coupling Agent

Function: alter the surface of a solid, increase the shear strength of porcelain-composite resin bond

Composite Resin Luting Cements

Auto-curing composite resins retain laminate veneers

This kind of luting cement increases working time

Partial Veneer Restoration

Restorations like three-quarter crowns or porcelain laminate veneers that cover only part of the tooth, conserving more tooth structure compared to full crowns.

Porcelain Laminate Veneer Advantages

Excellent esthetics

Excellent long term durability

Inherent porcelain strength

Marginal integrity

Soft tissue compatibility

Minimal tooth reduction

Porcelain Laminate Veneer Disadvantages

Time

Cost

Fragility

Lack of repairability

Difficulty in color matching

Irreversibility

Inability to trial cement the restoration

Porcelain Laminate Veneer Indications

Correcting diastemata

Exception: anything more than 2 mm of diastema causes the PV to be unsupported

Masking discolored or stained teeth

Masking enamel defects

Correcting misaligned or malformed teeth

Porcelain Laminate Veneer Contraindications

Bruxism

Short teeth

Insufficient or inadequate enamel

Large restoration OR endodontically treated teeth

Oral habits causing excessive stress on restoration

Chamfer

Preferred for all gingival finishing lines.

• Impressions are easier to make

• Major disadvantage - visible staining or color changes

Supragingival finishing lines

same advantages as proximal finishing lines

Labial Depth Reduction

0.5-0.7 mm - maxillary teeth

0.3 mm for smaller teeth (mandibular incisors)

Instrument: three-tiered depth cutter;

• To not overproduce and affect the dentinal portion

Inlays

Restorations that fit within the contours of the tooth, used for intracoronal restorations and offering a conservative approach.

Dowel Post and Core

A radicular retained restoration involving a custom or prefabricated post to strengthen endodontically treated teeth before crown placement.

Acrylic Resin Mix

A mixture used to fill and shape around the exposed plastic sprue in dental procedures.

Treatment Planning

Extensive caries or periodontal disease make removal of teeth more sensible than endodontically treating it.

Orthodontic repositioning or root resection may also restore it.

This should be done if its loss will significantly jeopardize the patient’s occlusal function.

Radicular Retained Restoration Considerations

Considerations

Endodontically treated teeth are believed to be weaker than the vital teeth.

Metal post replaces the root canal filling to strengthen it.

Radicular Retained Restoration Disadvantages

• Placing a post needs additional operative procedure

• Preparing the tooth to accommodate the post needs removal of additional tooth structure

• Difficulty of restoration of the tooth later (post may have failed to provide adequate retention)

• Complicates or prevents future endodontic retreatment

Radicular Retained Restoration Considerations (for posterior teeth)

• Endodontically treated posterior teeth are subject to greater loading. 

They are positioned closer to the insertion of the masticatory muscles, combined with morphologic characteristics.

• Complete coverage is recommended with a high risk of fracture.

  • Best protection as the tooth is encircled by the restoration

Principles of Tooth Preparation

Conservation of Tooth Structure

Retention Form

Six Features of a Successful Design Preparation

• Adequate apical seal

• Minimum canal enlargement

• Adequate post length

• Positive horizontal stop

• Vertical wall

• Extension of the final restoration onto the sound tooth structure

Three Stage Operation for a Post and Core Preparation (Direct Method)

Canal preparation

Acrylic Pattern Fabrication

Finish and Cementation of Dowel Core

Radicular Retained Restoration Ispection

Assessment of a tooth for endodontic treatment:

• Good apical seal

• No sensitivity to pressure

• No exudate

• No fistula

• No apical sensitivity

• No active inflammation

Coronal Portion Molding

The process of shaping the labial and lingual parts of a dental structure during the curing of acrylic.

Acrylic Core

The central part shaped according to the outline form of a jacket preparation in dental work.

Smooth Finish

Ensuring the absence of roughness or undercuts on the finished acrylic pattern for dental applications.

Dowel Core Cementation

The process of securing the dowel core in place using a luting agent to fill all voids and prevent inflammation.

Rotary Paste Filler

A tool used to fill canals with cement during the cementation of dowel cores in dental procedures.

Post and Core Insertion

The gentle placement of the post and core to reduce hydrostatic pressure and avoid root fractures.

Groove Placement

Creating a groove along the side post to allow excess cement to escape, especially with parallel side posts.

Dowel Core Location

Specific locations for dowel cores in posterior teeth, such as using the buccal canal for maxillary premolars and the palatal canal for maxillary molars.