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Tooth-colored restoration

Tooth-colored restoration

For Class Ⅲ，Ⅳ and Ⅴ，
Esthetic Dentistry

For Class Ⅰand Ⅱ，

What are Tooth-colored materials?
What is their working mechanism?
What are the cavity preparation futures for tooth-colored restoration?

What are steps for tooth-colored

restoration?
What are the advantage & disadvantage
of tooth-colored restoration?


Tooth-Colored Materials
Composite resin

Glass ionomer cement

Compomer

Composite Resin

Traditional composites
Hybird composites
Flowable composites
Condensable composites
Packable
Universal composites

Glass Ionomer

Chemical adhesion to dentin
Release Fluoride

Compomer

Compomer =
Composite
+
Ionomer


Dental Adhesionor Dental Bonding
Adhesion is a process of solid and/or
liquid interaction of one material with
another at a single interface.

Enamel bonding system

Enamel bonding depends on resin tags
becoming interlocked with the surface
irregularities created by etching.

Macrotags: form between enamel rod

peripheries.
Microtags: smaller tags form across
the end of each rod.
Macrotags and microtags are the basis
for micro-mechanical bonding.

Dentin bonding system

The difficulties of dentin bonding:
More water---wet bonding
Lower calcification
Richer organic---collagen network
Smear layer


The bond strength is primarily related
to micro-mechanical bonding to the
intertubular dentin which occures
between tubules along the cut dentin
surface.

Dentin Bonding Agent, DBA

Early DBA were hydrophobic, bonded
directly to the dentin smear layer.
Bond strengths＜6MPa.
Later DBA removed the smear layer but
tended to over-etch dentin.
Bond strengths≈10~12MPa.

DBA were chemically modified to be

more hydrophilic.
Bond Strengths≈18~20MPa.
Careful dentin conditioning,
Coupled with hydrophilic primer,
Bond Strength≈22~35MPa.


The Development of DBA
Enamel etch (1955)
Dentine etch (1960)
Treatment of smear layer (1980)
Wet Bonding technique(1990)

Cavity Preparation

Three designs of cavity preparation:
1.Conventional
2.Beveled conventional
3.Modified

Beveled conventional cavity preparations

are similar to conventional preparation,
in that the outline form has external,
“box-like” walls, but with beveled
enamel margin.





Beveled enamel margin

Beveled conventional cavity designs for

Class Ⅲ, Ⅳ and Ⅴ preparations

The advantages :

The ends of enamel rods are more etched
The increase in etched surface results in
a stronger bond
Increase the retention and reduce marginal
leakage and discoloration.
More esthtically

Modified cavity preparation

Have neither specified cavity wall structure
nor specified pulpal depth, and have enamel
margins.
Conserve more tooth structure.

Modified cavity preparation

Initial Clinical Procedure
Local anesthesia
Preparation of the operating site
Shade selection
Isolation of the operating site
with rubber dam or cotton rolls

Rubber dam

Clinical Procedure
Cavity preparation
Acid etching enamel & conditioning dentin
Matrix application
Application of bonding agent
Insertion of composite
Finishing procedures

Matrix application

Final procedures

Cases

Conservative Operative Dentistry

Minimal intervention dentistry
• is regards as a main stream in caries treatment in the 21st century.

Principles of Minimal Intervention dentistry

• Remineralization of early lesions
• Reduction in cariogenic bacteria, to elminate the risk of further demi-neralization and cavitation
• Repair rather than replacement of defective restorations

Thanks