- Composition of composite resin
- Restoring Composite Resin
White filling or composite resin is getting more and more popular currently as it produces a nice aesthetic result. Previously silver filling (amalgam) is preferred due to low cost, easy to handle and it has a good mechanical properties (amalgam is strong and durable). However, current composite resin is as strong and durable as amalgam and on top of that, it produce a ‘hard to see restoration’ on the tooth making it a preferred choice for dentist and patient. Anyway, Nobody wants their filling to be seen!!
Composition of composite resin
Composite resins are composed of:
- Bis-GMA monomers or some Bis-GMA analog
- a filler material such as silica and in most current applications,
- a photoinitiator
- Dimethacrylates are also commonly added to achieve certain physical properties such as flowability.
- Further tailoring of physical properties is achieved by formulating unique concentrations of each constituent.Unlike Amalgam which essentially just fills a hole, composite cavity restorations when used with dentin and enamel bonding techniques restore the tooth back to near its original physical integrity.
Dental composite resin
In our clinic, we have multiple shade (or colour) to choose to mimic the original colour of the tooth in the mouth. For every restoration, we use different shade for each ‘layer’ during restoration.
Below are some of the cases done in our clinic.
Restoring Composite Resin
An old amalgam was removed from a upper right molar and the tooth was ready for filling placement
Firstly, the enamel surface of the molar was treated with phosphoric acid 35%
Then, it was followed by the dentine which was located at the center of the tooth
Next, the cavity was cleaned and dried. A thin layer of adhensive solution was applied over the cavity
Light cure unit was used to activated the adhesive which was photo-sensitive
A metal band was used to wrapped around the molar
The metal band was checked to ensure that there was no gap between the tooth and the metal band. This was to prevent the filling material from overflow out from the cavity.
‘Dentine shade’ composite resin was placed at the center of the cavity to cover the darkish stain in the dentine area.
The composite was light-cured to make it harden
Next, ‘enamel shade’ composite was placed over the ‘dentine shade’ composite (layering technique) to get the translucency effect.
‘Enamel shade’ composite was placed at the side-wall of the molar and was cured (with light-cure unit)
The metal band was removed and more composite was placed at the side-wall of the molar so to achieve a nice contour and bulbosity.
This was the result after the composite harden
The composite excess was removed with a rotary white stone
The restoration was checked to look of any interference with the lower teeth during biting and chewing (with a bite registration tape)
And the red markings from bite registration tape was removed
Finally, for aesthetic reason, grooves and fissures was make on the tooth surface
And ‘stain’ composite was placed on the fissure to make it looked like the neighboor teeth
Lastly, light-cure unit used to harden the rest of the composite
The restoration was polished to make is glossy and shining
The Final Result!!
Before and after picture.
Another case: Replacing old silver (amalgam) restorations with composite restorations
This young gentleman came complaining of sensitive to hot and cold at his bottom right molars. On examination, he had a few siler fillings which cracked and had gaps noted at the margin fo the fillings.