Advances in Resin Composites

Flowable Condensable Smart composites Minimal shrink Compomer Geomer Indirect composites Fiber-reinforced

Flowable composites

Regular composites ….. with lower filler contents (≤ 60 wt%)

The material flows readily Higher polymerization shrinkage Lower mechanical properties Higher wear rates

Used only as 1. Cavity liners2. Fissure sealants 3. To restore small class V cavities

Viscosity of flowable composites

REVOLUTION

0500

1000150020002500300035004000

0 0.2 0.4 0.6 0.8 1 1.2

SHEAR RATE [1/s]

AP

PA

RE

NT

VIS

CO

SIT

Y

[Pa.s

]

Material Filler content (mass %)

Henry Schein 41 Starflow 61

Revolution 60 Florestore 50

HENRY SCHEIN FLOWABLE

290

292

294

296

298

300

302

0 0.1 0.2 0.3 0.4 0.5

SHEAR RATE [1/s]

AP

PA

RE

NT

VIS

CO

SIT

Y

[Pa.s

]

Mechanical properties of flowable composites

Filler content (wt %)

5668

53

75 80

flowable hybrid

Wear (m)28 28 2621 22

flowable hybrid

Fracture toughness

1.361.24

2.05 1.90

flowable hybrid

Nano-filled Flowable Composites

Utilizes nano-sized fillers. Still flows readily Excellent aesthetics Low wear Available in capsules

Packable composite

utilizes different filler systems 1. Fibers 2. Trimodal particle distrebution (interlock at the time of packing) 3. Non-slumping fillers 4. Resin impregnated fillers

But, the increased viscosity ↑ incidence of void formation ↓ reduce the adaptability

Usually used in combination with flowable liners

Has the ability to be packed like amalgam Better contact with the adjacent teeth Better occlusal form

Smart Composites

It is a kind of ion-releasing composites

It releases fluoride, hydroxyl and calcium ions, when the pH in areas adjacent to the restoration drops down (e.g. plaque accumulation)

Recent materials are based on alkaline glass fillers. The release of alkaline ions helps in;

1. Inhibiting bacterial growth

2. Buffering the acids produced by bacteria

3. Reduce the incidence of recurrent caries (Reduce the demineralization)

Minimal shrink composites

The development of minimal-shrink composites was based on ….

1. Increasing the filler load Using prepolymerized composite fillers Using nano-sized fillers (Tetric

Evoceram, Ivoclar-Vivadent)

2. Using organic matrices with lower polymerization shrinkage

Spiro-orthocarbonate, can produce composites with no setting contraction,

Oxy bis-methacrylates (bifunctional monomer) shows also a reduced rate of the polymerization contraction

Oxirane and silorane-based monomers (Feltick LS, 3M-ESPE)

Polymerization shrinkage of new minimal-shrink composites

Compomers (Polyacid-modified composites)

To have a kind of modified composite having the main advantages of glass ionomer cement.

Compositional modifications

Certain liquid monomer (HEMA) is modified by polyacrylic acid grafts Filler particles similar to the powder of glass ionomer cement

(calcium- fluoro-alumino-silicate- glass)

Drawbacks: Using bonding systems still mandatory Lower wear resistant < regular composites Insignificant release of fluoride

Flexure strength Taher NM. Comparative study of composite, compomer and ormocer bi-axial flexural strength. Saudi Dent. J. (2002) 14:7-10.

Compomers

To overcome some drawbacks of compomers

The filler particles are a kind of

pre-polymerized glass ionomer

agglomerates

Giomers are fluoride releasing light-cured restoratives. They show a true hybridization of glass ionomers and composites as they have the fluoride release and recharge of glass ionomers and the aesthetics, handling and physical properties of composite resins.

http://www.shofu.com.sg/GiomerList.aspx

RationaleTo get restorations with higher mechanical propertiesTo reduce the subsequent effect of the polymerization shrinkage (i.e. weak bonding, microleakage, improper contact)

Indirect composite restorations

Laboratory Composites

First Generation

Firstly introduced in 1980s as an attempt to decrease the rate of the polymerization shrinkage and Improve the wear resistance of the restoration.

Product commercial nameManufacturer

1. Visio-gem3M-ESPE

2. Denta ColorKulzer

3. ConceptIvoclar-Vivadent

4. IsosetIvoclar-Vivadent

Second Generation

Appeared in 1990s and named ceromers. Most of these materials are light-cured over a cast for 60 seconds and then followed with heat treatment.

Product commercial nameManufacturer

 

1. ArtglassHeraeus-Kulzer

2. BelleGlassKerr

3. TargisIvoclar-Vivadent

4. Simphony3M-ESPE

Fiber-reinforced composites

In many aerospace, automotive, marine, household and recreational industries … etc

Fiber-reinforced Dental Composites

Composites of the 2nd generation reinforced with fiber substructure Good alternative to all and metal-ceramic restorations

- Braid

- Unidirectional- Mesh

- Weave

Dental applications of FRC

1. FRC endodontic post2. Reinforcing denture bases 3. Implant frameworks4. Bases of orthodontic appliances5. Fixed prosthesis 6. Periodontal splints.

Fiber orientation and material’s properties

Different types of fibers

Commercial ProductFiber typeFiber architectureManufacturer

A. Pre-impregnated, dental laboratory products

FiberKor Vectris pontic Vectris frame

&single

GlassGlassGlass

UnidirectionalUnidirectionalMesh

Jeneric/petron Ivoclar-VivadentIvoclar-Vivadent

B. Pre-impregnated, chir-side products:

Splint it Splint it Splint it

GlassGlassPolyethylene

UnidirectionalWeaveWeave

Jeneric/PetronJeneric/PetronJeneric/Petron

C. Impregnation is required, chair-side products

Connect DVA fibers Fiber splint Fiber flex Class span Ribbond

PolyethylenePolyethyleneGlassKevlarGlassPolyethylene

BraidUnidirectionalWeaveUnidirectionalBraidLeno weave

KerrDental VentureInterdental

DistrebutorBioCompGlasspanRibbond

D. Pre-impregnated, prefabricated posts

C-Post FiberKor

CarbonGlass

UnidirectionalUnidirectional

BiscoJeneric/petron

Comparisons are always valuable. Aren't they?