Direct Composites 2

To measure Shrinkage Composite is cured unconstrained

To measure Shrinkage Composite is cured unconstrained

To measure Stress Composite is Always bonded

Silanised Surface

Adhesive

Composite Resin

Tensiometer

Silanised Surface

Adhesive

Composite Resin

Stress

To measure Stress Composite is Always bonded

The resulting force is called Stress!!

Silanised Surface

Adhesive

Composite Resin

Stress

Shrinkage is only one variable which will define Stress

Surface

Composite Resin

If no adhesive is used

And the tooth is restored with resin

and the resin is light-cured

and the resin is light-cured

Then there is shrinkage and gap formation.

Summary: Unconstrained composite shrinks.

If adhesive is used

If adhesive is used

If adhesive is used

and the resin is light-cured

The composite tries to ShrinkThe adhesive tries to hold! Stress builds-up.

Summary: Bonded composite builds-up Stress.

If the stress is too high : Adhesive fracture may occur!In extreme cases even tooth fractures!

To overcome stress build-up:

To overcome stress build-up:Cumbersome Layering Techniques

To overcome stress build-up:Cumbersome Light-Curing Techniques

SDR imparts little stress And the adhesive holds!!

SonicFill

Posterior composites made faster, easier and better

Bulk Filling

Clinical Requirements

1. Adaptation 2. Depth of cure 3. Low shrinkage

PLUS: maintain critical qualities of posterior composite

Using SonicFill

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Sonic energyLow Viscosity

(adapt & fill cavity < 5 seconds)

High Viscosity (Press & Sculpt)

High Viscosity

Soni

c off

Achieving Natural Esthetics

Prep Design Composite Selection Shade Selection Finishing Techniques

Clinicians Ability

0.02

1.0

Managing Light

Scattering relates to particle size.

The smaller the particle, the more scattering occurs.

0.5

0.5

Taking a Shade

Numerical vs. Value

A1 D4

Value

Shade Order by Value

TM

Composite Wear

Composite Wear

Composite Wear

Larger particles in a restorative tend to wear faster. Thus limiting the life of the restoration.

Crack Propagation = Bulk Failure