A dental filling is also called dental restoration. As it is called, it is a restorative material that artificially restores the function, shape and morphology of any part of the tooth that is missing. Tooth structure is often eroded due to caries that will lead to tooth decay. There are also times that the teeth will break or chip due to external factors like accidents, trauma, and so on.

With our society today, aesthetic qualities play a vital role to every individual. Many surveys showed that the smile and the appearance of the teeth are but two things that people would change in their appearance if they were given the opportunity.

There are a variety of materials being used on dental fillings for teeth restorations. Dental amalgam, composite resins or glass ionomer cement are commonly used materials for direct restorations. These restorative materials can be used indirectly. For example, the porcelain, gold, zirconia or other metals are prepared outside and then attached to the tooth.

Our anterior teeth are the ones immediately visible when we smile. Therefore the choice of a dental filling is largely dependent on its aesthetic value alone. The posterior teeth or the teeth lying at the back of the mouth on the other hand are not immediately visible which lend themselves to a wider choice of dental fillings.

The posterior teeth have several methods of restoration. Each of this method has its advantages and disadvantages, durability, and visual aesthetics. The most common are the amalgam, resin-based composite, porcelain-fused-to metal or PFM, cast gold alloy, and full ceramic ones.

Amalgam fillings

This is any mixture or blending of mercury with another metal or with an alloy. These amalgams are commonly used in dental fillings.

Advantages of amalgam based fillings are:

• they are relatively cheap
• they are durable
• it has been proven to have a longevity of up to 40 years under normal conditions
• it is a simple and easy procedure
• have very good results

Sometimes, there are cases of fracture of the tooth cusp or the amalgam may crack due to caries in the surrounding margins. This will lead to the rest of the tooth to have a dark appearance and the filling will have to be replaced.

Studies and discussions about the use of mercury in dentistry have been unending. The use of mercury has been controversial due to the toxic content of amalgams. Amalgam fillings revealed to have an increase mercury blood levels. Mercury is considered a very potent neurotoxin but mercury fillings are still considered safe by most dentists and are thus being widely used as fillings.

Resin Based composite fillings

There are patients who do not want ant metal fillings especially in areas of the mouth that are visible. In these cases, the filling materials of choice are composites.

Since 1968, resin-based composites for dental fillings have been around. Resin based composites fall into the category of Class II Restoratives. A plastic resin and a filler of finely ground glass-like particles make up a dental composite. These materials are mixed together, blended and matched to the color of the existing tooth.

There has been great improvement in the quality of resin based composite since its introduction in 1968. Dentists have been experimenting with its composition. Dentist will add particle size fillers to arrive at a better substitute. Modern day resin composites have then improved considerably. Well-trained dental technicians can successfully use this filler through careful meticulous handling. This filler can last for at least 10 years.

Problems to watch out for would again be postoperative tooth sensitivity, open contacts, and the awful “white line” that appears at the margins caused by shrinking of the area due to chemical reaction.

Resin base composite is used as an alternative to amalgam. But this type is not greatly successful because of the following:

• inability to withstand excessive wear
• postoperative tooth sensitivity
• pulpal death
• frequent caries
• breakdown of the filling in contact with open areas

Protein-Fused-to-Metal (PFM) Crowns

This is another type of filler. This is used to provide strength to a crown or bridge. This type of restoration is very strong, durable, and resistant to wear, because the combination of porcelain and metal creates a stronger restoration than porcelain being used alone.

For more than 40 years, PFM crowns are used as a means of dental restoration. The advantages of PFM are:

• it is visually appealing
• easy to administer
• has simple cleaning and preparation of the tooth

The disadvantages on the other hand are:

• causes abrasion to the adjoining tooth structure
• become less appealing when the gums start receding

PFMs can last for at least twenty years. But they lose their aesthetic value after about 10 years. In terms of the price value, PFMs are five to six times more costly than the amalgam or composite resins. Even though they are known to be hassle free, they do tend to break or chip away from the metal structure on which it is fused. In addition, the join will be visible after a period of time when the gum recedes, and this does not appear aesthetically desirable.

Cast Gold Alloy Restoration

This is the oldest method of tooth restoration. It has been around for more than 100 years.

Centuries ago, people did not mind showing that bit of gold sparkle in their mouth. But that has changed as more people are reluctant to the idea of gold showing up in their smiles. As a result, cast gold alloy restorations for inlays, overlays, and fillings are losing their status and popularity.

Cast gold alloys have been proven to be the best in terms of durability, non-toxicity and easy applicability. It is considered to be the most advantageous type of filler where the metal will not be visible, such as at the back teeth. Dental practitioners should encourage their patients to go in for cast gold alloy restoration wherever and whenever possible.

The only disadvantages for this type of filler are:

• the metal wearing out
• the tooth fragmenting at the juncture
• repeated attacks of caries

All Ceramic Restorations

Standard full ceramic restorations have been used for posterior teeth as inlays, onlays, crowns, and fixed dentures, but the durability and sturdiness is still questionable.

There have been a number of all-ceramic restorations that have been introduced for years, but so far none has proven to be fault-free. The only exception is the pressed ceramic restoration and some of the computer aided milled ceramic restoration, which uses zircon as its base.

The choice of the material has to depend on the consumer. Every client should have a frank and thorough discussion with their dental practitioner on every aspect of the treatment – the advantages and disadvantages of each type of procedure, what to expect after the procedure, and so on. A client can make an “informed decision” regarding the cost, durability or longevity of the filling and its sustainability to their present state of health.