RESTORATIONS IN ENDODONTIC

Epita S. PaneCons Dept FKG USU

Reasons for extraction of Reasons for extraction of endodontically treated teethendodontically treated teeth

Vire, 1991Vire, 1991

Vire, 1991Vire, 1991

Reasons for extraction of Reasons for extraction of endodontically treated teethendodontically treated teeth

Klein et al (1996)

• Evaluated 742 root canal fillings• Success rate of

– Defective coronal restoration + inadequate fillings 46%– Defective restoration + good filling 71%– Good restoration + inadequate fillings 79%– Good restoration + inadequate fillings 79%– Good restoration + good fillings 86%

Quality of coronal seal had as great influence on success as the quality of

root canal treatment

Fracture Risk

• Fracture of endodontically treated teeth are frequently

• Attributed to reduced physical properties of the dentin.

No difference between the strength of dentin of endodontically treated teeth

and that of vital teeth

Cuspal flexureCuspal flexure

Hansen et al (1990)

• The altered mechanical properties of the prepared teeth increase its susceptibility to fracture.

• 20 years observation of amalgam restoration.• Teeth with MOD restoration fractured > than MOD

with intact marginal ridges.with intact marginal ridges.• 30-40% Premolars were still intact at the end of

observation period.• Teeth with smaller restorations had a much higer

survival rate (80%).

No crownNo crownPremolars

Anteriors

MandibularMandibularMaxillaryMaxillary

Effect of coronal coverage on survival rate (1-10 years)

00 2020 4040 6060 8080% Survival% Survival

00 2020 4040 6060 8080 100100% Survival% Survival

CrownCrown

No crownNo crown

100100

Molars

Premolars

Sorensen and Martinoff, 1984Sorensen and Martinoff, 1984

Linn and Messer (1994)

• MOD amalgam restorations reduced the danger of fracture and increased the strength of prepared teeth by 61-82%.

• Cast partial veneer restorastion 125%.• Amalgam restoration that covered the cusps 102-• Amalgam restoration that covered the cusps 102-

175%

Endodontically treated posterior teeth should be restored with at

least a metal casting that ecnampesses the cusps

Panitvisai and Messer (1995)

• Type of access cavity and final restoration influence the risk of fracture.

• An endodontic access preparation further reduces the strength of the crown by half.

Types of restoration

ANTERIOR TEETH• Composite Resin• Glass Ionomer Cement• Crown

Placement of a crown reduced its risk of fracture Placement of a crown reduced its risk of fracture by only 2%.

Types of restoration

POSTERIOR TEETH• Amalgam• Composite Resin

Placement of a NO crown 38-48%• Crown• Crown

With crown, less than 10% for premolars, 5% for molars.

Minimizing cuspal flexureMinimizing cuspal flexureThree restorative designsThree restorative designs

AmalgamAmalgam Amalgam Amalgam overlayoverlay

Cast goldCast goldoverlayoverlay

Posts

Use or not to use ?

Plasmans et al (1988)

• Using 7mm-long post-cores• Fracture resistance: the highest cast post-core

system, followed by prefabricated posts +composite cores = no posts with composite builtup extending 3mm into the canal.builtup extending 3mm into the canal.

deCleen (1992)

• Studies showed that the preparation of post space further weakens the tooth structure, and the placement of the post does not leave the tooth any stronger that it was before the preparation was made

• Post anchored in the root canals have no strengthening effect on the roots and only serve to provide additional retention for the core and artificial crowns.

Types of posts

• Parallel sided > retention than tapered posts.• Parallel sided provide better distribution of force

and lower risk of fracture.• Tapered posts are indicated in mandibular anterior

teeth with small diameters.teeth with small diameters.• Threaded posts provided the best retention, vertival

fracture is greater.

Methods of gutta percha removal

• Mechanical– Hot instruments– Rotary instruments (gates glidden bur, Peeso reamer)

• Chemical– Solvent– Solvent

Length of remaining gutta percha

• Kvist et al 1989: 3mm• Hiltner et al 1992: 4mm

When the length of root canal filling was 5 When the length of root canal filling was 5 mm, the rate of failure with periapical

lesions was less than 10%, but when only 2mm remaining, the rate was almost 30%

Post space preparation

• Using pilot drill of the post system• Final length should be at least as great as the

lenghth of the final crown.• Guidelines:

– It should measure 2/3 of the total canal length.– It should be as long as the future crown length.– It should be as long as the future crown length.– It should equal half of the bone-supported root length.

• Marginal: at least 2mm of root dentin should surround the cast post (Ferrule Effect)

• Create a flat surface around the entrance to the post space

• Monitoring radiograph with post inserted.

Post cementation

• Canal is rinsed with Natrium Hypochlorite and dried with paper point.

• The selected post is coated with cement.• Rotated and screwed into place.

Cementing agent

1. Polycarboxylate cement2. Zinc Phosphate cement3. Glass Ionomer cement4. Composite cement

• Leakage: 4 > 3 > 2 & 1

Core Buildup

• The cavity is etched and bonded• Composite resin core is built up over the fins

radiating from the coronal portion of the posts

Types of core materials

• Composite Resin• Amalgam• Glass Ionomer Cement : Not recommended

Crown preparation

ASIGNMENTS

• Group 1. Read and write about how to prepare a cavity of Anterior tooth for porcelain fused to metal full crown

• Group 2. Read and write about how to prepare a cavity of Posterior teeth for full metal crown

• Group 3. Read and write about causes of tooth • Group 3. Read and write about causes of tooth discoloration.

• Group 4. Read and write about Walking Bleach technique

• Group 5. Read and write about Thermocatalytic bleaching

• Group 6. Read and write about Nightguard vital bleaching

• Group 7. Read and write about Bleaching materials• Group 8. Read and write about Bleaching

mechanismsmechanisms• Group 9. Read and write about Bleaching

complications• Group 10. Temporary restoration in Endodontic

Treatment.

• Dibuat dalam bentuk paper maximum 3 halaman.• Gunakan MS Word, spasi 1,5.• Tuliskan judul paper dan penulis• Gunakan lebih dari 2 references.• References harus dicantumkan• References harus dicantumkan• Dikumpulkan sebelum 2 November 2007