Ormocer's

Question 1

Describe features of resin composites.

Answer 1

• Growing number of patients opting for these over dental amalgam
• Permits less invasive treatments
• Susceptible to polymerisation shrinkage
• Potential allergenic effects of BIS GMA & TEGDMA if not bound in a resin matrix
• Bisphenol A oestrogenic effect
• BISGMA cytotoxic in a number of cell cultures

Question 2

what is an Ormocer?

Answer 2

• Organically modified ceramic technology
• Essentially a monomer free matrix consisting of 3-dimensionally cross linked copolymers in which inorganic silanated filler particles :
• Provides abundance of polymerisation opportunities
• As a consequence no residual monomer

Question 3

what are the 3 components of ormocer?

Answer 3

• silicones
• Organic polymers
• Ceramic glasses

Question 4

what do the relative proportions of these structural elements determine?

Answer 4

the materials properties

Question 5

For desired application , what does the manufacturer choose?

Answer 5

• The base materials
• How the inorganic poly condensation reaction is conducted
• The linking reactions which lead to the construction of the organic network

Question 6

what are the physical properties of silicones?

Answer 6

• elasticity
• surface energy
• gas permeability

Question 7

what are the physical properties of organic polymers?

Answer 7

• toughness/ flexibility
• functionalization
• processability

Question 8

what are the physical properties of ceramic glasses?

Answer 8

• hardness
• chemical / thermal stability
• transparency

Question 9

Describe how Ormocers is manufactured.

Answer 9

-Commence with build up of inorganic network:
Controlled hydrolysis and condensation of organically modified Si alkoxides

-Then form organic network:
Application of heat/UV initiate reaction of polymerisation of polymerisable units

-Results in an inorganic-organic copolymer

Question 10

how can you further customise properties of Ormocers?

Answer 10

addition of:
-particles
-fibres
-weaves 
(all of varying composition)

Question 11

How are Ormocers used in dentistry?

Answer 11

• Ormocer based composite restoratives (Admira, Definite)
• Light cured Glass polyalkenoates
• For composite must use dedicated product bonding agent

Question 12

what did the Ormocers dentist composite claim?

Answer 12

• Have less shrinkage on setting

- No residual monomers