The type of filling materials used are determined by the size of the cavity, the removal of fractures, decay and the old, existing restoration.
The options available for restoring your teeth are as follows:
Composite Resin (Plastic) fillings
White Plastic (composite) fillings – these are successfully placed when less than 40% of your tooth structure has been lost. Research shows that the loss of more than 40% of a tooth results in 90% loss of strength.
Composite fillings are a mixture of glass or quartz filler in a resin medium that produces a tooth-colored filling. Composites are used to restore decayed parts of teeth as well as for small cosmetic improvements of the smile with improved shape & colour. The filling is placed as a soft material and bonded to the tooth structure. It is then hardened using a dental curing light.
Composite fillings last 7-10 years on average but will have a shorter lifespan if the patient clenches or grinds their teeth or when the filling material is not properly supported by the remaining tooth structure(when more than 40% of the tooth has been lost).
Porcelain fillings (Inlays, Onlays & Overlays).
White inlay or onlay fillings made from porcelain, sometimes also referred to as ceramic, are the restoration of choice when 40% to 60% of your tooth structure has been lost. They are much stronger than composite fillings and are made with precision, designed and fabricated by a computer and placed in one visit using CEREC technology.
Porcelain fillings are advised when:
- moderate decay is present;
- there is a need for a long-term, durable restoration that can last up to 30 years or longer;
- there is a desire to limit the amount of healthy tooth structure being removed by adopting a more conservative treatment strategy; and
- a strong and reinforced tooth is desired.
When the porcelain filling material is bonded into the tooth it is called an inlay. With more widespread damage and the new structure covering the entire chewing surface including one or more tooth cusps the porcelain filling is called an onlay or overlay.
Porcelain fillings do not discolour over time as composite fillings.
Porcelain fillings are custom made and do not shrink or change in size during the curing process as composite fillings do, resulting in less post operative sensitivity.
Porcelain full coverage fillings (crowns).
Crowns – these are done when more than 60% of the tooth structure has been damaged. With the severely compromised tooth structure unable to hold a filling the entire tooth needs to be covered and rebuilt to protect it from breaking or fracturing. All the advantages of porcelain fillings apply.
Severely damaged teeth restored with a porcelain crown.
Mercury amalgam is a stable alloy made by combining elemental mercury with silver, tin, copper, and possibly other metallic elements. This is an older filling material that was previously widely used with long term function and poor aesthetics. This type of filling material does not bond to tooth structure and therefore a tooth was more aggressively prepared to place the amalgam filling utilizing only mechanical reinforcement. Over time this results in ditching and fracturing of the tooth away from the amalgam filling resulting is severe tooth damage.
Smaller amalgams can be replaced with composite filling materials. Larger amalgams fillings are replaced with either porcelain fillings (inlays or onlays) or with porcelain crowns.
Porcelain is better than mercury amalgam as it does not contain potentially-toxic mercury and does not expand and contract at a different rate to natural teeth when exposed to varying temperatures.
Porcelain is also better than composite as composite fillings stain and discolour over time. Porcelain is a durable, biologically inert, strong, aesthetic and long lasting restorative material.
The process of creating your porcelain filling means it is custom made to fit your cavity perfectly as well as match the rest of your teeth. Your new porcelain filling is also more durable and stronger than the old metal amalgam fillings. Therefore, although they cost more than mercury amalgam metal or composite fillings, porcelain fillings are a better investment because they will save you money in the long term.
How long does it take?
A composite filling can be placed in a 30 to 45 minutes appointment depending on the size of the restoration.
Porcelain fillings, including crowns, are placed in a 60 -75 minute appointment.