COMPOSITE RESTORTIONS by Asma Hayat .pdf

Composite restoration by Dr Asma Hayat

Composites are tooth colored material used to restore carious tooth .
Use in anterior teeth .
Aesthetic tooth color restoration.
Reasonable and easy to use.
Lectures by dr Asma hayat .
Follow for more lectures and updates .

1. COMPOSITE RESTORTIONS
ASMAHAYAT
FINAL YEAR BDS

2. Learning Outcomes
Introduction
Composition
Properties
Indications
Contraindications
Failures

3. Introduction
Silicate cement(1878) self curing acrylic resin(1930) composites(1962)

4. Definition
Compositeisacompound composedofatleasttwo
differentmaterialswithpropertieswhicharesuperioror
intermediatetothoseofindividualcomponent.

5. Composition
Organic matrix or organic phase
Filler or disperse phase
An organo-silaneor coupling agent
Activator-initiator system
Inhibitors
Coloring agents

6. Organic matrix
Resin matrix consist of polymeric mono, di or trimonomerslike
Bis-GMA
UDMA
Combination of Bis-GMA and UDMA
(TEGDMA/MMA/EGDMA), used to reduce viscosity

7. Fillers
Inorganic materials which may be ;
Modified silicate glass(most common)
(silicon dioxide, boron silicates and lithium
aluminum silicates)
Calcium metaphosphate(nowadays)

8. Coupling agents
Organic matrix Silanecoupling agents inorganic fillers

9. Initiator agents
These agents activate the polymerization of composites.

10. Inhibitors
These agents inhabit the free radical generated by spontaneous
polymerization of monomers.
Eg: butylatedhydroxyl toluene(0.01%)
Coloring Agents
Metal oxide such as titanium oxide and aluminum oxides
Ultraviolet absorbers
Commonly used absorber is Benzophenone.

11. Properties
Coefficient of thermal expansion
Water absorption
Wear resistance
Surface texture
Radiopacity
Modulus of elasticity

12. Linear coefficient of thermal expansion
The LCTE is the rate of dimensional change of
material per unit change in temperature .
LCTE ∞ 1/filler content

13. Watersorption
Water sorption is the amount of water that a material
absorbs over time per unit of surface area or volume
Water sorption ∞ 1/filler content

14. Wear resistance
Wear resistance refer to a material’s ability to resist surface loss as a result of
abrasive contact with apposing tooth structure, restorative material etc
Principal modes of wear:
Two body wear
Three body wear
Theories explaining wear:
Micro fracture theory
Hydrolysis theory
Protection theory (micro protection and macro protection)
Chemical degradation theory

15. Polymerization ∞ 1/degradation
Microfilledcomposites show less degradation
Sudden temperature change ∞ degradtion

16. surface texture
Radiopacity
modulus of elasticity
Size and composition of filler particles determines the smoothness of surface
of restoration.
Esthetic restorative materials must be sufficiently radiopaque so that the
radiolucent image of recurentcaries around and the restoration can be
seen easily
Determines material’s rigidity or stiffness .

17. indications
Class 1 and class 2 tooth preparation
Class 3,4,and 5 tooth preparation
Class 6 preparation
Esthetic improvement procedures
Erosion and abrasion defects
Hypo plastic or other defects
Core build
Luting cement

18. Contraindications
Difficult moisture control
Heavy occlusal stresses
Class 5 lesions
Lack of technical skills
Caries on canine
High caries susceptibility and poor oral hygiene
Sub gingival and root caries

19. Failures
Incomplete removal of carious lesion
Incomplete etching or incomplete removal of residual acid from tooth
surface
Excess or deficient application of bonding agent
Lack of moisture control
Contamination of composite with finger/saliva
Improper polymerization method
Incomplete finishing and polishing of composite
Inadequate occlusion of restored teeth

21. Have a safe journey back home
Thank you