As time goes by, more people become aware of old silver-mercury fillings known as “amalgam”. Amalgam has been in dentistry for over 80 years. It was a good material because it sat hard in the wet environment of the mouth and lasted a long time. Amalgam is a direct restorative material, meaning that after the tooth preparation is done, the prepared area will get filled with filling material directly.
Composite or commonly known as bonding materials also belong to direct restorative materials. Composite resin filling materials are mostly quartered as fillers. Composites have offered a viable solution to amalgam and casted materials. Composites are tooth colored and mercury free. They are relatively easy to work with and inexpensive with the advantages they have, however, composites are not trouble free. Composites shrink as they harden in place leaving microscopic gaps between the tooth and filling materials. These gaps facilitate future failures of the fillings. Additionally, composites are softer than gold alloys. This means that over time these composite materials could strain as well. One biohazard effect of this dental material is that some composite materials contain Bisphenol A, which has been known to cause cancer.
Contrary to direct restorative materials such as amalgam, there are indirect restorative materials such as gold alloys. Indirect restorative materials are dependent on some type of molding or so-called impression materials. As the science of polymers developed, dentists were able to take a mold of the prepared filling site. The mold then goes to a dental laboratory. There in the lab, the mold gets poured into a cast, which is a replica of the prepared tooth. Through a lengthy and tedious process casted and polished materials (mostly gold alloy) are fabricated and returned to the dental office for installation or cementing. In recent years several different types of porcelain materials can be casted in the laboratories utilizing this same process. Computers are used along with their specialized software to fabricate the necessary components for full or partial crowns. Bridges, dentures and partial dentures additionally are types of indirect restorations as they are fabricated with the usage one of more of these intermittent processes.
As dentistry has always been in search of a “perfect” dental material, research will continue. It is good to mention a dentist is dependent on the strength and properties of a material she or he uses. One of the imperative clinical judgements of a dentist is to choose wisely which material will suit what application are best. In my office, we do not use amalgam or composite materials containing Bisphenol A. We use latest technologies and provide best outcomes for our patients.